Review of Late Jurassic-early Miocene sedimentation and plate

Document technical information

Format pdf
Size 3.8 MB
First found May 22, 2018

Document content analysis

Category Also themed
Language
English
Type
not defined
Concepts
no text concepts found

Persons

Tommy Hilfiger
Tommy Hilfiger

wikipedia, lookup

Organizations

Places

Transcript

Chin. J. Geochem. (2015) 34(2):123–142
DOI 10.1007/s11631-015-0042-x
ORIGINAL ARTICLE
Review of Late Jurassic-early Miocene sedimentation
and plate-tectonic evolution of northern California: illuminating
example of an accretionary margin
W. G. Ernst
Received: 21 January 2015 / Revised: 23 January 2015 / Accepted: 23 January 2015 / Published online: 7 February 2015
Ó Science Press, Institute of Geochemistry, CAS and Springer-Verlag Berlin Heidelberg 2015
Abstract Production of voluminous igneous arc rocks,
high-pressure/low-temperature (HP/LT) metamafic rocks,
westward relative migration of the Klamath Mountains
province, and U–Pb ages of deposition, sediment sources,
and spatial locations of Jurassic and younger, detrital zirconbearing clastic rocks constrain geologic development of the
northern California continental edge as follows: (1) At
*175 Ma, transpressive plate underflow began to generate
an Andean-type Klamath-Sierran arc along the margin. (2)
Oceanic crustal rocks were metamorphosed under HP/LT
conditions in an inboard, east-inclined subduction zone from
*170-155 Ma. Except for the Red Ant blueschists, such
lithologies remained stored at depth; most HP/LT mafic
tectonic blocks returned surfaceward only during mid- and
Late Cretaceous time, chiefly entrained in circulating,
buoyant Franciscan mud-matrix mélange. (3) By *165 Ma
and continuing to *150-140 Ma, erosion supplied volcanogenic debris to proximal Mariposa-Galice ± Myrtle
overlap strata. (4) At *140, immediately prior to the onset
of paired Franciscan and Great Valley Group (GVG) ?
Hornbrook deposition, the Klamath salient was deformed
and displaced *100–150 km westward relative to the
Sierran arc, stranding pre-existing oceanic crust on the south
as the Coast Range Ophiolite (CRO). (5) After the end-ofJurassic seaward step-out of the Farallon-North American
convergent plate junction, terrigineous debris began to be
deposited in the outboard Franciscan trench and intervening
Great Valley forearc. (6) Voluminous sedimentation and
accretion of Franciscan Eastern ? Central belts and GVG
detritus took place during paroxysmal igneous activity and
W. G. Ernst (&)
Department of Geological & Environmental Sciences, Stanford
University, Stanford, CA 94305-2115, USA
e-mail: [email protected]
rapid, nearly orthogonal plate convergence at *125-80 Ma.
(7) Sierran arc volcanism-plutonism ceased by *80 Ma in
northern California, signaling a transition to shallow, nearly
subhorizontal eastward plate underflow attending Laramide
orogeny far to the east. (8) Presently exposed Paleogenelower Miocene Franciscan Coastal Belt sedimentary strata
were deposited in a tectonic realm unaffected by HP/LT
subduction. (9) Grenville-age detrital zircons are absent
from the post-120 Ma Franciscan section. (10) Judging from
petrofacies and zircon U–Pb data, the Franciscan Eastern
Belt contains debris derived principally from the Sierra
Nevada and Klamath ranges; detritus from the Idaho Batholith as well as Sierra Nevada Batholith may be present in
some Central Belt sandstones, whereas clasts from the Idaho
Batholith, Challis volcanics, and Cascade Range appear in
progressively younger Paleogene-lower Miocene Coastal
Belt sediments. (11) Gradual NW dextral offset of the
Franciscan trench deposits of as much as *1,600 km may
have occurred relative to the native GVG forearc and basement terranes of the American Southwest.
Keyword Post-Paleozoic subduction Franciscan-Great
Valley strata California crustal evolution JurassicMiocene accretion
1 Geologic introduction
This review summarizes some recent studies of clastic strata
exposed in the Sierran Foothills, the eastern and western
edges of the Klamath Mountains, and main units comprising
the Sacramen to Valley ? outboard California Coast Ranges—rocks deposited during a period typified by mainly
transpressive to convergent plate motions. The times of
sedimentation, provenance of these strata, and their post-
123
124
Chin. J. Geochem. (2015) 34(2):123–142
magmagenic depths followed by subsequent ascent and
emplacement of primary calcalkaline igneous rocks (i.e.,
continental growth). Crustal construction also involved the
generation of secondary products of clastic sedimentation
and HP/LT metamorphism, both of which provide additional
information regarding the regional plate-tectonic history.
Figure 1 presents the broad geologic framework of the region, including most of California. Figure 2 is a more
depositional recrystallization P–T histories provide insights
regarding the Late Jurassic through early Miocene petrotectonic evolution of northern California. This review is
aimed particularly at Asian Earth scientists unfamiliar with
northern California, because the area constitutes a relatively
clear example of a 175-20 Ma convergent to transpressive
plate margin that hosted a substantial infusion of new sialic
crust, chiefly through subduction-induced partial melting at
122°W
125-80 Ma granitic rocks
v
v
bduction zo
v
120°W
42°N
e
ad
sc
Ca Arc
v
Hornbrook Fm
124°W
42°N
Cascade su
v
Myrtle Fm
v
v
ne
MF
Jurassic metased. + metavolc.
rocks (incl. Mariposa-Galice)
(?)
Paleozoic-Triassic metased.
and metavolcanic rocks
lex
n
ca
cis
mp
t
as
Co ges
n
Ra
Co
an
Fr
OF-SS
175-140 Ma granitic rocks
Modoc
Plateau
Klamaths
SB
Paleozoic and Mesozoic
serpentinized ultramafic rocks
CF-EC
Foo
ls B
thil
39°N
elt
t Vall
Grea
F
SA
End of CretaceousMiocene Coastal Belt
da
va
Ne
Mainly Cretaceous Great
Valley Group (Lower K tan)
rra
roup
Sie
ey G
Cenozoic sedimentary
and volcanic rocks
Paleozoic intrusive rocks
lith
tho
Ba
N?
Upper Cretaceous
Franciscan Central Belt
F
SG
Lower to Upper Cretaceous
Franciscan Eastern Belt
n
ia
lin
Sa
Bl
k
oc
N
F
SA
W
E
S
0
100
200 km
34°N
117°W
Fig. 1 General geologic map of most of California, depicting the 175-140 Ma Klamath-Sierranand 125-80 Ma Sierran volcanic-plutonic arcs,
Great Valley Group forearc strata, and Franciscan trench belts, simplified from the U. S. Geological Survey and California Division of Mines and
Geology (1966) geologic map, terrane map of Silberling et al. (1987), the Klamath Sierran map of Irwin (2003), land coastal maps of Dickinson
et al. (2005). Shasta Bally pluton = SB. The South Fork and Coast Range faults juxtapose rocks of the Franciscan Complex against those of the
Klamath province and the GVG respectively (e.g., Blake et al. 1999). Labeled fault zones: Oak Flat-Sulphur Spring = OF-SS; Cold Fork-Elder
Creek = CF-EC; on-land and offshore segments of the Nacimiento, = N and N? San Gregorio-Hosgri = SGF; Mendocino = MF; San
Andreas = SAF
123
Chin. J. Geochem. (2015) 34(2):123–142
125
43°N
H
Klamath Mountains units
M
Western Klamaths incl. Galice Fm
W
Condrey Mountain terrane
E
Rattlesnake Creek terrane
S
Western Hayfork terrane
Eastern Hayfork terrane
Hayfork terrane undivided
North Fork terrane
Stuart Fork terrane
Central Metamorphic terrane
GVG
41°N
E. Klamath terrane undivided
ly n
ain ca
M cis x
an ple
Fr om
C
0
20
40
60
80
100 Km
OF-SS
Red Ant
blueschists
Younger overlap strata (Klamaths)
M = Myrtle Formation
H = Hornbrook Formation
GVG = Great Valley Group
39°N
Sierran Foothills units
Upper Jurassic incl. Mariposa Fm
Slate Creek complex
rd
oa
utb lex
do p
an Com
ata n
str ca
G ncis
GV Fra
Jura-Triassic arc belt
Calaveras complex
Feather River terrane
Northern Sierra terrane
37°N
124°W
122°W
120°W
Fig. 2 Simplified lithostratigraphic terranemap of the Klamath Mountains and the western Sierran Foothills ignoring plutons, after Irwin (1981,
2003), Sharp (1988), Edelman and Sharp (1989), Ernst (1998), and Snow and Scherer (2006). The Galice and Mariposa formations are of Late
Jurassic age. Klamath-margin locations of the northernmost Great Valley Group, Myrtle (M), and Hornbrook (H) formations are indicated. The
Myrtle is of latest Jurassic-earliest Cretaceous age, whereas the GVG and Hornbrook are chiefly of mid- and Late Cretaceous age. Also shown is
the Oak Flat-Sulphur Spring sinistral fault zone (OF-SS), but not the slightly younger Cold Fork-Elder Creek fault zone of Fig. 1. The
Klamaths were displaced oceanward *100–150 km relative to the northern extension of the Jurassic Sierran arc but separation across the OF-SS
is only *80–100 km because of viscous drag induced curvature ofthe imbricate salient
detailed view of the study area, and the disposition of
Klamath, Sierran Foothills, Sacramento Valley, and northern Coast Range clastic sedimentary units treated in this
paper.
1.1 Jurassic crustal growth
The late Paleozoic-early Mesozoic development of northern
California was typified by chiefly margin parallel slip,
123
126
episodic suturing of far-traveled ophiolitic complexes, and
deposition of superjacent chert-argillite deep-marine
sedimentary units (Saleeby 1981, 1982, 1983; Ernst et al.
2008). Scattered sialic igneous activity characterized the Late
Triassic margin of California, but most lithologic sections of
late Paleozoic-early Mesozoic age are oceanic in their genesis.
However, a major Andean-type arc began to form in the Sierra
Nevada and Klamath Mountains by *175 Ma attending the
transpressive eastward underflow of oceanic lithosphere
(Dunne et al. 1998; Irwin 2003; Dickinson 2008). This volcanic-plutonic arc shed clastic detritus into the ophiolitic
realm of the Jura-Triassic arc belt ? Early and Middle
Jurassic Eastern Hayfork ? North Fork terranes, and the
earliest Late Jurassic continental margin Mariposa ? Galice
formations of the Klamath and Sierran ranges, respectively
(Miller and Saleeby 1995; Scherer et al. 2006). The Sierran
Jura-Triassic arc belt and Klamath chert-argillite-rich North
Fork and Eastern Hayfork units were laid down at *175165 Ma (Snow and Ernst 2008; Scherer and Ernst 2008),
whereas the near-shore Mariposa-Galice formations began
accumulating by *165-160 Ma (Ernst et al. 2009a).
Transpressive plate convergence also generated HP/LT
basaltic eclogites and garnet-glaucophane schists along the
Middle and Late Jurassic convergent plate junction
at *170-155 Ma (Cloos 1986; Wakabayashi 1990; Tsujimori et al. 2006; Ukar et al. 2012).However, except for
the *174 Ma Red Ant blueschists (Hacker and Goodge
1990; Hacker 1994), such HP/LT metamafic rocks remained
at depth, and fragments apparently returned surfaceward
only during mid- and Late Cretaceous time as tectonic ± olistostromal blocks were sheared and gravity-fed into
low-density Franciscan mud-matrix mélange. These
relatively high-grade metamafic blocks formed much earlier
during construction of the emergent arc. They were not intensely overprinted by low-grade metamorphic phases, so
evidently were stored at rather shallow upper mantle depths
as indicated by the common spatial association of HP/LT
blocks with serpentinized peridotites—never with deepseated xenoliths of continental crust. The arc-derived Mariposa-Galice volcanogenic strata predate formation of the
Great Valley Group forearc and subparallel Franciscan
trench depositional realms (Ernst 2011).Similar to the disaggregated fragments of transported oceanic lithosphere and
capping deep-sea chert, the relatively old HP/LT tectonic
blocks (e.g., Anczkiewicz et al. 2004) represent exotic additions to the Franciscan trench.
1.2 Formation of the Klamath Mountains salient
Paleozoic, fault-bounded Klamath Mountain units on the east
are structurally high in the accretionary stack, whereas the
formational ages of successively added lower allochthons
123
Chin. J. Geochem. (2015) 34(2):123–142
Fig. 3 Palinspastically restored Sierra Nevada-Klamath volcanic- c
plutonic arc prior to hypothesized differentialslip, including 20°
clockwise rotation of the Klamath salient back to a contiguous
Jurassic arc configuration. Underflow of a segmented Farallon plate
beneath the North American margin at *140-136 Ma was proposed
(Ernst 2012) to account for the present outboard location of the
Klamath Mountains relative to both the Sierra Nevada on the SE and
the Blue Mountains on the NE (Snoke and Barnes 2006, Fig. 1). The
Cretaceous batholith belt trends NNW compared to the NW-trending
Jurassic Andean arc
decrease progressively toward the west (Irwin 1972, 1994).
The tectonized, imbricate collage of west-vergent lithostratigraphic terranes consists of basal ophiolitic units, chiefly
overlain by cherts and fine-grained terrigenous strata (e.g.,
Frost et al. 2006), all invaded by Jurassic calc-alkaline arc
plutons. The accreted terrane assembly of the Klamath
Mountains has long been correlated with the northern Sierran
Foothills based on similar rock types, structures, ages of the
rock packages, the progressive oceanward assembly of successively younger geologic units, and their times of deformation (Davis 1969; Davis et al. 1980; Wright and Fahan
1988; Wright and Wyld 1994; Irwin 2003). However, the
accreted Sierran Foothill terranes stand nearly vertically,
whereas the Klamath thrust sheets root gently to the east.
Figure 1 shows that the Klamath Mountains concave-tothe-east contractional assembly now lies well outboard of
the trend of the Sierra Nevada Range. This salient appears
to be situated *100–150 km west of the formerly contiguous Sierran segment of the curvilinear arc. North of the
Klamath promontory, a major eastward jog toward apparently correlative lithologic units in the Blue Mountains
(LaMaskin 2011; LaMaskin et al. 2011; Schwartz et al.
2011) suggests the possibility of a greater oceanward offset
of the Klamath Mountains relative to the late Mesozoic
accretionary continental margin of eastern Oregon (Snoke
and Barnes 2006). The manner in which this tectonic offset
of the Klamath Mountains collage was accomplished remains obscure. However that may be, Fig. 3 provides a
geologic restoration of what probably was an original, preCretaceous, continuous arc in northern California.
At the end-of-Jurassic time, the Klamath accretionary
terrane assembly was deformed and displaced *100–150 km
westward relative to the Andean arc, gradually removing the
accretionary stack of Klamath allochthons from a site over the
deep-seated magmagenic zone stoking the Sierra Nevada igneous belt (Ernst 2012). Abundant granitic plutons intruded
the Klamath Mountains during 170-140 Ma (Hacker et al.
1995; Irwin and Wooden 1999; Irwin 2003; Snoke and Barnes 2006), with emplacement ages generally younging eastward. This igneous activity in the Klamaths ceased at the
beginning of Cretaceous time. The youngest such body is the
apparently *136 Ma Shasta Bally pluton (Lanphere et al.
1968; Lanphere and Jones 1978; Irwin and Wooden 1999).
However, this date may represent the time of cooling and
Chin. J. Geochem. (2015) 34(2):123–142
127
Cenozoic sedimentary
and volcanic rocks
125-80 Ma granitic rocks
175-140 Ma granitic rocks
Jurassic metased. + metavolc.
rocks (incl. Mariposa-Galice)
Paleozoic-Triassic metased.
and metavolcanic rocks
Paleozoic and Mesozoic
serpentinized ultramafic rocks
Paleozoic plutonic rocks
E
W
S
0
100
200 km
123
128
annealing of the pluton rather than the time of its emplacement. Geologic mapping by Blake et al. (1999) documented
Hauterivian GVG strata resting with angular unconformity on
exhumed, eroded Shasta Bally rocks, supporting a
Valanginian or older age for the intrusive (SB locates the
plutonon Fig. 1). Thus, prior to offset of the Klamath
Mountains, a continuous Klamath-Sierra Nevada volcanicplutonic arc was sited above the mantle hearth supplying melt
to the crustal superstructure (Fig. 3).
The hypothesized westward step-out of the convergent plate
junction at *140 Mare positioned the trench directly offshore
from the Klamath orogen. To the south, the new suture trapped
pre-existing, far-traveled oceanic crust-capped lithosphere on
the landward side as the *175-165 Ma Coast Range
Ophiolite ± overlying tuffaceous and distal oceanic strata
(Shervais et al. 2005; Hopson et al. 2008). Slab rollback involving coeval suprasubduction-zone generation of the CRO
would have produced an ophiolitic basement younger than the
rifted apron of terrigenous sediments. Because this mafic crust
is actually *25 Myr older than the basal GVG sediments (e.g.,
Stern 2004; Stern et al. 2012; Shervais and Choi 2012), the
postulated plate-junction step-out stranding pre-existing
oceanic lithosphere appears to more fully accounts for the
geologic relationships than would a gradual slab rollback.
Chin. J. Geochem. (2015) 34(2):123–142
1.4 Paleogene-early Miocene crustal growth
Strongly deformed, weakly metamorphosed Paleogenelower Miocene Franciscan Coastal Belt rocks (McLaughlin
et al. 2000; Dumitru et al. 2013), still sourced in part from
the now-inactive Sierranarc, contain significant amounts of
quartzofeldspathic debris derived from yet more northerly
arc terranes (Dumitru et al. 2013, in press). These Coastal
Belt strata exhibit the effects exclusively low-pressure recrystallization (Bachman 1978; Underwood et al. 1987;
Terabayashi and Maruyama 1998; Ernst and McLaughlin
2012). Reflecting near-surface accretionary offloading,
such units apparently were never deeply subducted.
Although important members of the Franciscan lithotectonic assemblage, the low-P transformation of Coastal Belt
strata stand in marked contrast to much of the rest of the
Franciscan Complex. Underplating of younger sections
beneath older slabs of the Franciscan undoubtedly aided
the buoyant ascent and erosional decapitation of the latter,
so the farthest inboard sections have been exhumed to the
greatest extent. It is thus possible that HP/LT tracts of the
Coastal Belt currently are stored deep within the imbricate
accretionary prism.
1.3 Cretaceous crustal growth
2 Late Jurassic time
At *140 Ma, volcanic-plutonic detritus from the KlamathSierran arc started to accumulate on mafic basement within
the Great Valley depositional basin, whereas clastic debris
carried past the forearc came to rest on the descending Farallon oceanic plate as the outboard Franciscan deep-sea
trench fill. Because the lowermost Cretaceous, relatively
continuous GVG strata were laid down on the stable North
American plate, protected from both surface erosion and
subcrustal tectonic removal, inauguration of this forearc
proximal-to-distal terrigineous sedimentation also signaled
the onset of coeval deposition in the yet more distal, coeval
Franciscan Complex, *25–30 Myr after Middle Jurassic
initiation of the Andean arc (Dumitru et al. 2010; Ernst
2011). Voluminous sedimentation and accretion of Franciscan and GVG rocks took place during the 125-80 Ma
flare-up of the Sierran arc (Surpless et al. 2006; Snow et al.
2010; Dumitru et al. 2010; Sharman et al. in press). The
youngest Sierran granites are *80 Ma, reflecting Late
Cretaceous quenching of the magmagenic zone beneath
northern California. The end of continental margin arc activity generally has been ascribed to a lessening of the subduction dip and relatively shallow, subhorizontal oceanic
plate underflow attending Laramide orogeny well to the east
(Coney and Reynolds 1977; Dickinson and Snyder 1978;
Bird 1988).
123
2.1 Mariposa Formation clastic sedimentation
Snow and Ernst (2008) analyzed zircons from five volcanogenic metaturbidite layers from the upper part of the
Mariposa Formation of the western Sierran Foothills using SIMS methods. Mesozoic U–Pb age populations are
dominated by zircons exhibiting a broad unimodal distribution from *175-155 Ma. The aggregate zircon U–Pb
ages for these metasandstones suggest that the zircons
were derived mainly from the Jurassic Klamath-Sierran
orogenic belt, especially the mid-Paleozoic to mid-Mesozoic terrane collage, and the spatially associated
younger Andean-type arc volcanic rocks ? granitoids.
This interpretation is compatible with Mariposa paleocurrent data indicating an overall southerly transport
direction (Bogen 1985). Accumulation began at *165160 Ma and continued until at least 150 Ma (Ernst et al.
2009a). Indistinct age culminations at 1,000–1,200,
1,600–1,800, and C2,500 Ma (Snow and Ernst 2008)
suggest minor derivation of the studied Oxfordian and
younger Mariposa sandstones from Grenville, MazatzalYavapai and older SW North American cratonal rocks,
and/or younger, multicycle clastic strata sourced from
these basement terranes.
Chin. J. Geochem. (2015) 34(2):123–142
2.2 Galice Formation clastic sedimentation
The turbiditic Galice Formation is the NW continuation of
Mariposa-type volcanogenic lithologies in the western
Klamath Mountains (Gray 2006; MacDonald et al. 2006).
Miller and Saleeby (1995) reported a 153 Ma depositional
age for the upper Galice, but sedimentation may have begun during or before earliest Oxfordian time based on
biostratigraphic data summarized by Saleeby and Harper
(1993). This is supported by the local interdigitation of
Galice metaturbidites with pillow lavas of the subjacent
164-162 Ma Josephine ophiolite (Harper 2006; MacDonald
et al. 2006). Like the Mariposa Formation, the provenance
of Galice sandstones evidently was a combination of both
ancient SW North American basement rocks and mid-Paleozoic to mid-Mesozoic oceanic ophiolite ? chert-argillite complexes, and the younger, nearly coeval Andean arc
(Snoke 1977; Frost et al. 2006).
2.3 Myrtle Formation clastic sedimentation
Scattered erosional remnants of uppermost Jurassic to early
Lower Cretaceous Myrtle detrital strata rest on the Galice
Formation in SW Oregon (Imlay et al. 1959; Dickinson
2008, Fig. 3a). By analogy with the underlying Galice,
Myrtle detritus plausibly was derived from both the landward Klamath-Sierran arc ± minor old SW North American continental basement sources.
3 Earliest Cretaceous time
3.1 Pacificward relative displacement of the Klamath
Mountains salient
Figure 4a shows that the Klamath Mountains stack of allochthons currently is located well outboard of the trend of
the Sierra Nevada Range of northern California, as well as
the Blue Mountains of SE Oregon. Palinspastic reconstruction combined with clockwise rotation of 20° of the
Klamath salient as shown in Fig. 4b, would restore the
complex to the end-of-Jurassic, presumably curvilinear
Andean margin. Such a back-rotation also would help
minimize the seemingly larger offset separating the Klamaths from the Blue Mountains. However, this simplified
restoration does not address the arcuate bulge (i.e., eastward concavity) which likely reflects *50–100 km of
additional strain induced by differential slip of the Klamath
Mountains salient relative to the adjacent segments of the
once-continuous volcanic-plutonic arc.
Just how relative displacement of the Klamath
tectonostratigraphic belts took place remains obscure, but
constraints provided by the sedimentary section suggest a
129
mainly earliest Cretaceous (*140-136 Ma) westward offset and minor counterclockwise rotation of the salient
relative to the Sierran Foothills (Ernst 2012). Upper
Jurassic Galice-Mariposa, and uppermost Jurassic-lowermost Cretaceous Myrtle strata rest unconformably on the
western flanks of the Klamath Mountains and Sierran
Foothills segments of the emergent Andean arc whereas, as
pointed out below, post-140 Ma Great Valley ? Hornbrook clastic units lie outboard of the Sierran arc but inboard of the Klamath salient. Whether the Klamath
Mountains moved westward, or the Sierra Nevada ? Blue
Mountains moved eastward, or both tracts were displaced,
is unclear. Here, only the differential slip and its timing are
considered.
Geologic relationships among units of the Klamath
Mountains province, the Franciscan Complex, and the
GVG in the vicinity of the Yolla Bolly triple junction
(Jones and Irwin 1971; Sliter et al. 1984; Blake et al.
1999) include several important fault systems. In addition
to the major terrane bounding, NW-trending South Fork
and Coast Range faults, Blake et al. (1999) mapped numerous transverse breaks transecting GVG stratigraphic
units in this area. Significant faults include, from north to
south, the Oak Flat, Sulphur Spring, Cold Fork, and Elder
Creek structures. The Oak Flat-Sulphur Spring fault zone
strikes ENE and is properly oriented to accommodate the
conjectured earliest Cretaceous sinistral slip in northern
California, although the offset is only *80–100 km. To
the south, Wright and Wyld (2007) interpreted the NWtrending Cold Fork-Elder Creek fault zone as an important discontinuity defining several hundred kms of dextral
slip. Judging by geologic field relations documented by
Blake et al. (1999), the Cold Fork-Elder Creek fault zone
and subparallel structures truncate the Oak Flat-Sulphur
Spring faults. Thus, oceanward relative displacement of
the Klamath Mountains salient along the Oak Flat-Sulphur Spring fault zone apparently was mainly completed
in Valanginian-Hauterivian time, prior to the right-lateral
motion described by Wright and Wyld—which therefore
represents Barremian and younger offset. Thicknesses of
the Lower Cretaceous GVG units in the Yolla Bolly triple
junction area monotonically increase northward, so these
breaks underwent at least some slip to as late
as *125 Ma (Constenius et al. 2000; Wright and Wyld
2007).
Perhaps due to the complex sequence of strike-slip and
subduction-exhumation compound motions that occurred
in the vicinity of the Yolla Bolly triple junction, the published aeromagnetic anomaly map of this area (Roberts and
Jachens 1999, Fig. 2) fails to show clear paleomagnetic
evidence supporting a major discontinuity that could be
linked to a postulated deep-seated sinistral offset along the
Oak Flat-Sulphur Spring zone.
123
130
Chin. J. Geochem. (2015) 34(2):123–142
125°W
125°W
120°W
Canad
a
(a) post-136 Ma:
120°W
Canad
a
(b) pre-140 Ma:
45°N
45°N
Washin
g
Blue
Mountains
(thick oceanic
plate)
Washin
g
ton
Blue
Mountains
Orego
n
ton
Orego
n
45°N
45°N
(thin
oceanic
plate)
Klamath
Mountains
40°N
backa
sprea rc
ding?
Idaho
40°N
(future path
of thin,
warm
oceanic
plate)
Idaho
Klamath
Mountains
40°N
40°N
CRO
(thick oceanic
plate)
va
da
lifo
a
a
rni
rni
lifo
da
Ca
Sierra
Nevada
Range
35°N
Ne
va
Ca
Sierra
Nevada
Range
Ne
35°N
35°N
35°N
0
80
0
160 km
80
160 km
Arizona
Arizona
Mexico
Mexico
120°W
115°W
120°W
115°W
Fig. 4 Diagrammatic sketch of the hypothesized underflow at *140-136 Ma of a segmented Farallon plate beneath the North American margin (Ernst
2012). a At the beginning of Cretaceous time, a thin, warm slab of oceanic lithosphere slidbeneath the Klamath Mountains, largely decoupled from the
overlying section of gently east-dipping CCW-rotating crustal allochthons. Thicker, older Farallon plate segments on both north and south were strongly
coupled to the continental margin, resulting in contraction and deformation of the accreted collages into relatively steeply dipping sections. Arrows show
direction of relative crustal slip ± possible backarc extension. Bounding transforms of the Farallon oceanic lithosphere have subparallel, ENE trends
constrained by fault offsets in the pre-existing curvilinear arc. b Inferred palinspastically restored original Sierran-Klamath-Blue Mountains arc prior to
the end-of-Jurassic offset, including 20° clockwise rotation of the Klamath salient (such CW rotation reduces the apparent offset between the Klamaths
and the Blue Mountains). No attempt has been made to undo the accumulated strain caused by frictional drag during the postulated slip that produced the
westward arcuate bulge of the salient
3.2 Hypothesized Klamath salient displacement
mechanism
The Early Cretaceous Farallon lithospheric plate evidently
approached the western edge of California in a largely
convergent but dextral transpressive fashion (Engebretson
et al. 1984; May and Butler 1986; Schettino and Scotese
2005; Sager 2007; Doubrovine and Tarduno 2008). It appears to have fragmented into several smaller east-dipping
plate segments (Wang et al. 2013). Plate-tectonic models
accounting for the structure and offset of the Klamath
123
Mountains relative to the Andean arc require impingence
of far-traveled oceanic plate transporting, for example:
(a) a mantle plume; (b) a spreading ridge; (c) a thermal
high generating backarc extension; (d) a microcontinent or
island arc; or (e) an oceanic plateau. After consideration
and rejection of this diverse set of geologic models, Ernst
(2012) instead proposed a different scenario: (f) two subparallel transform faults bounding a thin, relatively warm
oceanic slab.
Shown schematically in Fig. 4, this model postulates the
underflow of a relatively young slab of the Farallon plate
Chin. J. Geochem. (2015) 34(2):123–142
beneath the Klamath Mountains beginning at *140 Ma.
The warm, plastically deformable platelet, bordered on
both north and south across hypothesized ENE-trending
transform faults by old, cold, much thicker, stiffer oceanic
lithosphere, would have been largely decoupled from the
Klamath stack of gently east-rooting crustal allochthons.
Collision of thick oceanic lithosphere on both north and
south could have been responsible for contraction and
eastward displacement of the North American continental
marginal relative to the Klamath Mountains, which would
thus assume its salient configuration. Moreover, shortening
in the Sierran arc might have caused rotation of the Foothills terrane collage to the present stack of near-vertical
imbricate sheets. Whatever the origin of outboard relative
displacement of the Klamath Mountains at *140-136 Ma
relative to the Sierra Nevada Range and the Blue Mountains, it seems likely that segmented eastward underflow
responsible for the architecture that developed in the crust
of northern California was sited in the end-of-Jurassic to
earliest Cretaceous upper mantle lithosphere and subjacent,
flowing asthenosphere.
4 Early Cretaceous-Miocene
4.1 Great Valley Group clastic sedimentation
West of the Cretaceous Sierran arc, the slightly to somewhat younger Great Valley Group clastic strata exhibit a
largely Sierran-Klamath provenance based on sedimentary
petrofacies analysis (Ingersoll 1978, 1979, 1983; Linn et al.
1992). The well-developed GVG forearc, laid down on the
Coast Range Ophiolite and the inboard edge of the Klamath province, began receiving detritus by Valanginian
time. Except for far-traveled basal sandstones that contain
distinctive CRO debris ± a cap of very-fine-grained deepsea turbidites of Tithonian age, the younger quartzofeldspathic section was derived chiefly from the Middle Jurassic
to Late Cretaceous igneous arc. Abundant volcanic clasts
typify many of the lower GVG beds, whereas in general,
Upper Cretaceous strata are richer in plutonic quartz and
alkali feldspars (Dickinson and Rich 1972; Dickinson et al.
1982; Surpless in press). The largest volume of Great
Valley sedimentary strata formed during Late Cretaceous
time, especially in the San Joaquin section (Mansfield
1979; Moxon 1990). GVG sandstones include widespread
but small numbers of zircon grains, typified by igneous U–
Pb ages mostly in the *175-140 and 120-60 Ma ranges
(DeGraaff-Surpless et al. 2002; Surpless et al. 2006;
Wright and Wyld 2007; Sharman et al. in press). Minor
concentrations of Early Cretaceous magmatic zircons in the
basal clastic sediments suggest that shallow intrusives and
the more voluminous Jurassic extrusive arc units in the
131
Sierra Nevada-Klamath belt supplied debris to the initial
forearc. Great Valley Group deposition evidently began
at *140 Ma, with detritus largely derived from the inboard igneous arc. Because the Sierran magmatism died
by *80 Ma, some of the youngest GVG igneous zircons
probably had a more northerly source.
A few pre-Mesozoic, multicycle grains were reported from
basal GVG sandstones by DeGraaff-Surpless et al. (2002) and
Wright and Wyld (2007). These zircon ages provide Precambrian peaks at 1,000–1,200, 1,400, 1,800–2,000, and
2,600 Ma, suggesting that minor ultimate sources including
the Grenville, Mazatzal-Yavapai, and Wyoming or Superior
provinces.
4.2 Hornbrook Formation clastic sedimentation
The mid- and Upper Cretaceous Hornbrook Formation,
correlative with the far more voluminous Great Valley
Group, rests with angular unconformity on the landward
margin of the Klamath Mountains near the CaliforniaOregon border (Sliter et al. 1984; Nilsen 1993; Surpless
and Beverly 2013). Like the GVG strata of northern
California, the Albian and younger Hornbrook Formation
rests on the eastern edge of the province, so clearly accumulated after seaward relative displacement of the Klamath
promontory. Detrital zircon U–Pb spectra indicate that
clastic materials were supplied chiefly by the nearby
Sierran and Klamath volcanic-plutonic arcs ± possible
igneous sources in the Pacific Northwest, with only minor
contributions from recycled debris originally sourced in
Grenville, Proterozoic and latest Archean basement
(Surpless and Beverley 2013).
4.3 Franciscan Complex clastic sedimentation
Three major, fault-bounded tectonic belts of the Franciscan
Complex, consisting dominantly of clastic sedimentary
strata, crop out in northern California—the Eastern, Central
mélange, and Coastal belts (Bailey et al. 1964; Blake et al.
1988; Jayko et al. 1989; McLaughlin et al. 1994, 2000).
The Eastern Belt comprises two principal lithotectonic
units, the Pickett Peak and structurally lower Yolla Bolly
terranes, whereas the Coastal Belt contains three major
entities, the inboard, structurally higher Yager, medial
Coastal, and outboard, structurally lower King Range terranes (Blake et al. 1988). Although tectonic and olistostromal mélanges characterize the Central Belt, mélanges
also are present in all three Franciscan belts (Cowan 1978;
Raymond 1984, in press; Aalto 2014). Rocks of these three
accretionary belt assemblies apparently were deposited on
far-traveled oceanic crust as it neared the continental
margin (Ernst 1965, 2011). Petrofacies analyses of graywacke-shale and rare conglomeratic units of the Central
123
132
and Eastern belts indicate derivation chiefly from the
northern Californian Andean arc (Dickinson et al. 1982;
Seiders 1983), similar to clastic strata of the directly inboard GVG. Terranes of the Coastal Belt contain similarly
sourced debris but also include clasts derived in part from
the Pacific Northwest (see below).
Most detrital zircons separated from Eastern Belt
sandstones possess Jurassic igneous SIMS U–Pb ages
of *180-160 Ma (Dumitru et al. 2010), but a fewigneous
zircon grains occupy the *120-80 Ma age range (Joesten
et al. 2004; Tripathy et al. 2005; Unruh et al. 2007). The
oldest Franciscan clastic unit is the Skaggs Spring Schist
(Wakabayashi and Dumitru 2007; Snow et al. 2010), so
deposition of the Franciscan apparently began
at *140 Ma. Prior to recent work, Late Jurassic-Early
Cretaceous age assignments for the Eastern and Central
belt strat a relied on the presence of the bivalve, Buchia,
but these occurrences probably reflect redeposited macrofossils, as documented by Dumitru (2012). The source of
such transported specimensmight have included Upper
Jurassic proximal facies rocks of the Mariposa-Galice
overlap sequence. In any case, most of the Eastern Belt
Yolla Bolly quartzofeldspathic units accumulated during
the mid- and Late Cretaceous (120-80 Ma; Ernst et al.
2009b; Dumitru et al. 2010), and were exhumed and exposed shortly thereafter (Mitchell et al. 2010). Sited in
progressively more seaward positions, the Central and
Coastal belts, for which zircon U–Pb age data have now
become available (Dumitru et al. 2013, in press), have Late
Cretaceous (*90-60 Ma) and Tertiary (65-20 Ma) maximum depositional ages, respectively. The presence of
young igneous zircons in clastic rocks of the Coastal Belt
indicate progressive sedimentary supply to the Yager,
Coastal, and King Range terranes of detrital zircons
derived from the Idaho Batholith, Challis volcanic pile, and
Cascade arc.
In addition to post-Paleozoic arc sources, analyzed zircons from Franciscan rocks exhibit small Precambrian age
peaks as follows. Pickett Peak terrane: 1,000, 1,400-1,600,
1,800, and 2,200 Ma (Dumitru et al. 2010). Yolla Bolly
terrane: Pacheco Pass (Ernst et al. 2009b) 1,350, 1,800,
2,600–2,900 Ma; San Francisco Bay area (Snow et al.
2010) 1,500–1,700, 2,000, 2,500 Ma; NW Coast Ranges
(Dumitru et al. in press) 1,300–1,400, 1,800, [ 2,500 Ma.
Except for a few Grenvillian zircons in analyzed Eastern
Belt Skaggs Spring-Pickett Peak metasandstones, these age
data suggest ultimate derivation of the more voluminous
Yolla Bolly strata in part from the Mazatzal-Yavapai and
Wyoming or Superior basement provinces. Central Belt
strata include zircon ages of 1,300–1,400, 1,600–1,750 Ma,
indicating minor Mazatzal-Yavapai Middle Proterozoic
sources, but lacking Late Archean provenance; Coastal
Belt zircons yield Precambrian ages peaking at
123
Chin. J. Geochem. (2015) 34(2):123–142
1300-1400 Ma, suggesting an orogenic granite sources
from the Mazatzal-Yavapai realm. Thus, except for
the *140 Ma Skaggs Spring and slightly younger Pickett
Peak metagraywackes, Franciscan clastic rocks lackzircon
grains of Grenvillian affinity.
5 HP/LT recrystallization of the Franciscan Complex
Franciscan Eastern and Central belt sandstones display
pervasive effects of HP/LT subduction-zone metamorphism, as widely documented in the Cretaceous Franciscan
sections of northern California (Cloos 1982, 1986; Blake
et al. 1988; Jayko and Blake 1989; Jayko et al. 1989;
Wakabayashi and Dumitru 2007). In contrast, presently
exposed clastic units of the chiefly Tertiary Coastal Belt
only show the effects of feeble, low-T, low-P recrystallization (Bachman 1978; Underwood et al. 1987; Blake
et al. 1988; Dumitru 1989; Tagami and Dumitru 1996;
Ernst and McLaughlin 2012). Deeply buried Lower Cretaceous strata of the Great Valley Group and the moderately recrystallized volcanogenic Mariposa-Galice units
exhibit neoblastic mineral parageneses similar to those
typifying Franciscan Coastal Belt rocks (Dickinson and
Rich 1972; Gray 2006; Snow and Scherer 2006). However,
the Mariposa-Galice units show strong grain flattening and
platy metamorphic cleavage, unlike weakly metamorphosed strata of the Coastal Belt.
Prograde phase relations and schematic physical conditions for Franciscan Eastern, Central, and Coastal belt
rocks, and essentially also for the GVG, Mariposa and
Galice formations, are illustrated in Fig. 5. The
metasedimentary rocks of the Franciscan Eastern coherent
and Central mélange belts display prograde HP/LT
geothermal gradient paths of 100–300 °C 5–8 kbar as
typically followed by units subjected to subduction-zone
P–T conditions, whereas in contrast, other sandstone sections summarized in this review simply appear to show the
effects of diagenesis common in rocks involved in low-P
burial. Because subduction-zone refrigeration continued
during the episodic return toward the surface of Eastern
and Central belt Franciscan sections, their retrograde (i.e.,
decompression) P–T trajectories more-or-less followed
their prograde paths in reverse, but at slightly lower pressures for a given T.
In addition to the in situ post-Jurassic, dominantly
metasedimentary Franciscan section, lenses of much higher
grade eclogite and garnet glaucophane schist are present as
rare, but mineralogically spectacular phase assemblages.
These high-grade blocks of mid- to Late Jurassic metamorphic age are relatively well studied (Coleman and
Lanphere 1971; Wakabayashi 1992; Anczkiewicz et al.
2004; Wakabayashi and Dumitru 2007; Ukar et al. 2012).
Chin. J. Geochem. (2015) 34(2):123–142
133
12
High-grade
blocks
10
tz
Q
b
Jd LA
Ar c
C
Pressuere in kbar
+
t
el
8
B
rn
te
s
Ea
6
elt
lB
tra
n
Ce
4
Pum
te
He
al
ast
Co
t
e
B l
0
0
so
ai
W
te
ki
ra
i
nd
a
ul
2
te
ni
w
La
Preh
m
u
La
An + Qtz
200
400
Temperature in °C
600
Fig. 5 Phase diagram for northern California Franciscan metagraywacke compositions, partly after Terabayashi and Maruyama (1998,
Fig. 7). Pfluid is assumed equal to lithostatic pressure. Stability fields for
heulandite, laumontite (Laum), lawsonite and wairakite are from Liou
(1971), the calcite-aragonite (Cc-Ar) transition is from Carlson (1983)
and the low albite-jadeite ? quartz phase boundary (LAb-Jd ? Qtz) is
from Newton and Smith (1967). Also shown are the Frey et al. (1991)
computed P–T stability fields for prehnite (Preh) and pumpellyite
(Pum) in metabasaltic rocks (Liou et al. 1983). An = anorthite.
Prograde metamorphic P–T paths for the Franciscan belts are from
Ernst (1993) and Ernst and McLaughlin (2012), extended to include P–
T conditions attending recrystallization of the high-grade metabasaltic
blocks. Retrograde P–T paths are not shown. Deeply buried GVG strata
and weakly transformed Mariposa-Galice units have new phase
assemblages comparable to those of the Franciscan Coastal Belt
Initially solidified as Farallon oceanic crust far from the
North American margin, these rocks recrystallized in a
relatively young, warm oceanic-continental convergence
zone along an unrefrigerated, relatively warm mantle
hanging wall, as reflected by HP/LT mineral parageneses
indicating counterclockwise decompression P–T-time trajectories (Cloos 1982, 1986; Wakabayashi 1990, 1999;
Saha et al. 2005; Page et al. 2007; Ukar and Cloos 2014).
Most high-grade tectonic blocks were transformed
at *10–12 kbar, and *400–600 °C (Fig. 5), but some
evidently formed at even higher P–T ranges (e.g., Krogh
et al. 1994; Tsujimori et al. 2006).
In contrast to their relatively well-understood petrogenesis, field occurrences of these high-grade metamafic
blocks are problematic, reflecting an obscure geologic
context. Most such coarse-grained, penetratively deformed
rocks rest on the Earth’s surface with no apparent genetic
relationship to the regionally extensive, distinctly lower
metamorphic grade Franciscan lithologies. In some cases,
the bedrock consist of serpentinite, more commonly of
mud-matrix mélange, or a mixture of pelitic and serpentinitic matrix materials. How the high-grade metamafic
blocks and spatially associated Franciscan, chiefly
metasedimentary section were exhumed is a matter yet
debated (e.g., Ernst 1971; Platt 1986, 1993; Ring and
Brandon 2008). Some HP metabasalts exhibit nearly
complete rinds of actinolite ± chlorite ± talc that are
slightly younger than the high-grade blocks (Moore 1984;
Catlos and Sorensen 2003; Ukar 2012; Ukar et al. 2012). In
the rare cases where Jurassic metamafic blocks are clearly
enveloped in surrounding fine-grained mud-matrix or serpentinite bodies, the latter are substantially younger (e.g.,
mid- to Late Cretaceous). Detailed histories of the exotic
HP/LT blocks provide additional constraints on the Jurassic-Cretaceous convergent margin evolution of northern
California and development of the accretionary Franciscan
Complex during a period typified by oblique-to-orthogonal
plate convergence (Ernst 2011).
6 Clastic strata of northern California: ages
and provenance
A relatively continuous record of mid-Jurassic through
early Miocene sedimentation is preserved in the sandstones
cropping out in northern California. Approximate maximum depositional age spans of these units, largely constrained by detrital zircon U–Pb data, are: North
Fork ? Eastern Hayfork, 175-165 Ma; Mariposa ? Galice, 165-150 Ma; Myrtle, 150-140 Ma; Great Valley
Group ± Hornbrook, 140-60 Ma; Franciscan Eastern
Belt, *140-80 Ma; Central Belt mélange, *90-60 Ma;
Coastal Belt, 65-20 Ma. Except for GVG and Hornbrook
strata situated directly inboard from the Klamath Mountains salient, maximum depositional ages of these
tectonostratigraphic units systematically decrease seaward.
Detrital zircons separated from the studied rocks were
sourced dominantly from pre-existing igneous rocks, chiefly
Mesozoic granitoids and their comagmatic volcanic
equivalents. Generalized temporal relationships between
these primary igneous sources and derived sedimentary
products considered here are shown on Fig. 6. Precambrian
zircon grains are rare, but of those present, most are well
rounded, and undoubtedly underwent multiple cycles of
erosion, transportation, and deposition. Prior to deposition in
their present host rock, most probably last resided in Paleozoic clastic strata derived from the Precambrian basement. Interpreted ultimate source terranes for the described
detrital units, illustrated in the map of Fig. 7, are as follows:
Mariposa-Galice ± Myrtle = Sierran-Klamath arc, Grenville, Mazatzal-Yavapai, and older SW North American
cratons; basal Great Valley Group and Franciscan Skaggs
Spring Schist-Pickett Peak terrane = Sierran-Klamath arc,
123
134
Chin. J. Geochem. (2015) 34(2):123–142
35-0
Cascade arc rocks
c
athi
s
ldsp e rock
e
f
o
c
z
r
t
u
r
qua ous so
igne
Challis volcanic rocks
Idaho Batholith rocks
51-43
98-53
125-80
Cretaceous Sierran arc rocks
175-140
Jurassic Klamath + Sierran arc rocks
~175-161
Coast Range Ophiolite
(CRO)
65-20
Cenozoic GVG + Franciscan Coastal Belt
?
120-60
Main GVG + Yolla Bolly + Central Belt
~140-120
165-150
ived
Mariposa + Galice formations
its
y un
Basal GVG + Skaggs Spring-Pickett Pk
der
tar
men
i
sed
175-165
North Fork + Eastern Hayfork terranes
175
150
125
100
75
50
25
0
Age in Ma
Hearn
>2.50 Ga
Trans-Huds
on
1.80-1.90
Ga
Fig. 6 Schematic diagram of mid-Mesozoic and younger California-Pacific Northwest igneous arcs inferred to have provided much of the
quartzofeldspathic debris to the sandstones treated here. Ages of volcanic-plutonic generation, the CRO, and largely arc-derived clastic
sedimentary strata are summarized from Irwin (2003), Shervais et al. (2005), Wakabayashi and Dumitru (2007), Hopson et al. (2008), Scherer
and Ernst (2008), Snow and Ernst (2008), Snow et al. (2010), Ernst et al. (2009a, b, 2010), and Dumitru et al. (2010, 2013, in press). Zircon U–Pb
age data are not available for the uppermost Jurassic to lowermost Cretaceous Myrtle clastic strata, but on this diagram it would lie
stratigraphically above the Mariposa-Galice formations, and below-to-coincident with the basal GVG
Superior >2.50 Ga
40°N
~35 Ma
a
0G
-1.8
a
1.70 1.70 G
1.62
Grenville
1.03-1.19 Ga
A
0. ppa
36 la
-0 ch
.7 ian
6
G
a
m
An
tle
~70 Ma
r>
0.
37
i
G
0. og
a
27 e
o
-0 c
.6 lin
4 e
G
a
Wyoming
~100 Ma
can
ncis
Fra plex
Com
Yavapai
l
Mazatza
W
E
S
0
Ouachita
YucatanCampeche
0.40-0.58 Ga
1000 km
Suwanee
0.54-0.68 Ga
Ancestral Rockies
1.40-1.48 Ga granitoids
1.34-1.40 Ga granitoids
20°N
Oaxaca
1.00-1.25 Ga
120°W
Cordilleran
terranes and
arcs <0.20 Ga
East
Mexico arc
0.23-0.29 Ga
80°W
Fig. 7 Basement map of some North American geologic provinces and their ages of formation, after Dickinson and Gehrels (2009, Fig. 1) and
Gehrels et al. (2011, Fig. 7). Heavy black arrows show inferred westward transport directions of erosional debris shed from Cordilleran volcanicplutonic arcs during the *140-25 Ma accumulation of the Franciscan Complex. Detrital zircon ages suggest possible NW drift of the trench fill
as sedimentation-accretion continued and new volcanic-plutonic arcs lit up on the north. A progressive increase over time in the arrival of
detritus from younger NW igneous arcs could equally well explain the changing source patterns recorded in native (i.e., non-drifting) Franciscan
terranes
123
Chin. J. Geochem. (2015) 34(2):123–142
Grenville, Mazatzal-Yavapai, and late Archean basement;
main GVG ± Hornbrook = Sierran-Klamath arc, Idaho
Batholith, minor Grenvillian, Mazatzal-Yavapai, and Wyoming or Superior cratonal sources; Franciscan Yolla Bolly
terrane = Sierran-Klamath arc, Mazatzal-Yavapai and
Wyoming or Superior basement; Franciscan Central Belt
mélange = Sierran arc ± Idaho Batholith, MazatzalYavapai basement; Franciscan Coastal Belt = Sierran arc,
Idaho Batholith, Challis-Cascade volcanic units.
7 Mid-Jurassic-early Tertiary evolution of northern
California
The new detrital zircon U–Pb data summarized here support previous radiometric, geologic, structural, and paleontologic studies on a broad range of post-Paleozoic
sandstones, further documenting the crustal growth of
northern California. Middle and Upper Jurassic clastic
strata draped over the western flanks of the Klamath ? Sierra Nevada orogenic belts, the Cretaceous GVG lying
along the westernmost margin of the Sierra Nevada but
along the eastern edge of the Klamath Mountains, and the
yet farther outboard Tertiary sedimentary sections all attest
to a gradual seaward growth of the continent. The Mariposa-Galice ± Myrtle formations define the Pacific margin
of sialic crust at 165-150 Ma to possibly as young
as *140 Ma. In northernmost California, Hauterivian
Great Valley Group and Albian Hornbrook strata lying
inboard from the Klamath Mountains document the time of
essential completion of oceanward relative displacement of
the salient. To the south, the suture between the basal GVG
forearc and the Franciscan trench complex defines the
position of the convergent plate junction after *140 Ma.
Varying degrees of convergence regionally lasted into the
Miocene. As known from prior work (e.g., Bailey et al.
1964), sedimentary ages of the Franciscan imbricate
tectonostratigraphic terranes decrease toward the Pacific
Ocean. Maximum times of deposition and nearly coeval
tectonic accretion range from Early to Late Cretaceous for
the east-rooting Pickett Peak and tectonically underlying,
younger Yolla Bolly terrane metagraywackes of the Eastern Belt, through overlapping latest Cretaceous deposition
and recrystallization for Central Belt metasandstones interstratified with mud-matrix mélanges, to Paleogene-early
Miocene for structurally lower Coastal Belt sandstones.
Jurassic volcanic-plutonic ? Cretaceous Sierran Batholith, Late Cretaceous-Paleocene Idaho Batholith, early
Eocene Challis volcanics, and Oligo-Miocene Cascade arcs
supplied most of the igneous zircons to the clastic strata
described here. Although the Middle and Upper Jurassic
proximal sequences contain substantial contributions
derived from Grenvillian source terranes, 1,000–1,200 Ma
135
zircons appear to be rare in most GVG strata (Surpless in
press), and are absent from all but the oldest Franciscan
metasedimentary units—i.e., the Skaggs Spring-Pickett
Peak terrane. Cretaceous emergence of the growing Sierranvolcanic-plutonic arc may have blocked the outboard
regional supply of recycled Grenvillian materials from the
continental interior. Overthe course of time, the Franciscan
Complex clearly began receiving greater proportions of
young igneous arc detritus from more northerly sources.
GVG sandstone petrofacies analyses show an analogous
south-to-north trend from basement uplift—[ dissected
arc—[ transitional arc—[ undissected arc (Ingersoll
2012). Older Franciscan bedrock sources on the SE included the Mazatzal-Yavapai 1,400 Ma anorogenic granites and 1,700–1,800 Ma basement terranes. Grenville and
Appalachian igneous zircons are missing from the Franciscan section deposited after *120 Ma, suggesting the
possibility of as much as 1,600 km for progressive, postdepositional NW offset of the trench deposits relative to the
Great Valley Group forearc and craton of the SW conterminous U. S. and NE Mexico. Figure 7 shows the hypothetical extent of dextral offset of the Franciscan Complex
attending its post-120 Ma accumulation (see also Jayko
and Blake 1993).
Other explanations instead may account for the absence
of Grenville zircons in Franciscan mid-Cretaceous to lower
Miocene clastic sediments. These include: (1) non-erosion
of Grenvillian rocks due to cover and/or low elevation; (2)
intervening topographic divides diverting the transport of
detritus away from the Pacific margin; (3) channeling of
arc debris by a few river systems that fluctuated in flow
direction over time; (4) sample bias and/or SIMS analytical
error. Provenance studies described here for northern
California indicate coeval deposition and possible later
NW translation of the Franciscan section; *1,600 km is
merely a reasonable value for the conjectured offset. Alternatively, a systematic NW increase in the supply of
detritus from progressively younger volcanic-plutonic arcs
might have been solely responsible for the changing source
patterns recorded in these tectonostratigraphic terranes as
igneous belts to the south died whereas others to the north
became active.
8 Mid-Jurassic to Miocene northern California
geohistory
Before Middle Jurassic time, chiefly ophiolite ? chertargillite terranes arrived at, and were stranded along the
continental margin, reflecting dominantly transform ± transpressive plate motions during the mid-Paleozoic to Early Jurassic assembly of northern California
(Saleeby 1981, 1982, 1983; Silberling et al. 1987; Ernst
123
136
(a) ~165 Ma:
Mariposa-Galice fms
Andean arc
converging CRO
N. Amer
plate
ra
llo
n
pl
asthenosphere
H
m igh
et -g
ab ra
as de
al
t
at
e
mantle
wedge
UHP?
(b) ~150 Ma:
converging CRO
Mariposa-Galice
± Myrtle fms
Andean arc
N. Amer
plate
H
m igh
et -g
ab ra
as de
al
t
Fa
ra
llo
pl
asthenosphere
n
at
e
123
have been a crustal response in the Klamaths to the arrival and
underflow of a segmented Farallon plate. Most of the differential slip occurred prior to Early Cretaceous deposition of the
GVG-Hornbrook strata along the landward SE ? NE edges
of the Klamath Mountains, respectively (Figs. 1, 2). Modest
additional sinistral displacement evidently continued across
the Oak Flat-Sulphur Spring fault zone during Early Cretaceous time (Ernst 2012). Schematic relationships among the
Jurassic volcanic-plutonic Andean arc rocks, and depositional
histories of the Mariposa-Galice ± Myrtle sediments are
diagrammed in the cross-sections of Fig. 8, reflecting the
tectonic configuration of northern California prior to the
postulated end-of-Jurassic oceanward step-out of the Farallon
lithospheric plate. After this *140 Ma step-out, spatial relationships involving the Cretaceous Sierran Batholith, Great
Valley-Hornbrook, and Franciscan clastic strata are depicted
in the cross-sections of Fig. 9.
Late Jurassic sequestration of HP/LT metamafic schists
at moderate depths along the mantle wedge and later tectonic transference of exotic blocks and lenses into buoyant
mélanges ascending along the subduction channel (Cloos
1982, 1986; Cloos and Shreve 1988) of the progressively
less steeply east-dipping oceanic plate well after
the *140 Ma step out are also illustrated schematically.
Fa
et al. 2008). This older oceanic terrane collage was capped
by mid-Jurassic and younger sedimentary and volcanic
rocks derived from an emergent igneous arc constructed
along the continental edge. Middle and Late Jurassic Andean volcanism-plutonism in the Klamath ? Sierra Nevada ranges (Dunne et al. 1998; Irwin 2003; Dickinson
2008) reflects an important component of eastward subduction of the Farallon oceanic plate commencing no later
than *175 Ma, and continuing until *140 Ma. Underflow also resulted in the generation and storage at depth of
HP/LT metamafic rocks, now present as tectonic ± olistostromal blocks in mélanges chiefly of the Franciscan
Central Belt (Cloos 1982, 1986; Wakabayashi et al. 2010).
Middle and Late Jurassic oceanic plate motion probably
involved oblique convergence rather than nearly orthogonal subduction (Ernst et al. 2008), because if a major
forearc basin and trench had formed during this stage,
evidence of this subparallel couplet has since disappeared
completely. Alternatively, a substantial component of
transform slip or subcrustal erosion (Wright and Wyld
2007; Scholl and von Huene 2007; Stern and Scholl 2010;
Dumitru et al. 2010) might removed all but the farthest
inboard Mariposa-Galice ± Myrtle overlap strata.
In the Franciscan Complex, the famous 170-155 Ma highgrade metabasaltic eclogites and garnet-blueschists formed
during early stages of the underflow that generated the
emergent mid- and Late Jurassic Klamath-Sierran arc as well
as the derivative Mariposa-Galice proximal sedimentary
aprons. The HP/LT mafic tectonic blocksevidently were
sequestered at moderate depths, predating onset of the
lengthy period of subduction that produced the paired GVG
and Franciscan sedimentary belts. In general, intrusion
of *170 Ma granitoid bodies in the western Klamath
Mountains and progressive geographic restriction of
younger plutons to the more easterly Klamath lithotectonic
belts (Hacker et al. 1995; Irwin and Wooden 1999; Irwin
2003) suggest that seaward migration of the salient might
have started earlier, perhaps at *155-140 Ma, as the crustal
assembly of ophiolitic terranes and superjacent clastic ? volcanogenic rocks gradually began to migrate off the
deep-seated magmagenic zone along or directly above the
descending paleo-Pacific plate. This west-directed oblique
offset of the imbricated Klamath belts apparently occurred
during a relatively brief period characterized by widespread
left-lateral slip along the western margin North America
(Saleeby 1992; Saleeby et al. 1992).
Attending Late Jurassic termination of Mariposa-Galice ± Myrtle sedimentation, the Klamath promontory rotated *20° counterclockwise and moved outboard *100–
150 km (? arcuate deformation of 50–100 km) relative to the
formerly contiguous Sierran arc (e.g., Coleman et al. 1988;
Constenius et al. 2000; Ernst 2012). The manner in which the
tectonic offset was accomplished remains unclear, but may
Chin. J. Geochem. (2015) 34(2):123–142
mantle
wedge
UHP?
Fig. 8 a Diagrammatic depths of recrystallization, and b later, ascent
and modest-depth storage of high-grade metabasaltic rocks of the
descending Farallon plate. Relationships exaggerated for clarity are
shown before stranding of pre-existing oceanic lithosphere as the
Coast Range Ophiolite inboard from the ~140 Ma plate junction. The
mechanism allowing the sequestered HP metabasaltic material to
ascend along the plate junction (arrows) may have involved
transportation as blocks in buoyant serpentinite
Chin. J. Geochem. (2015) 34(2):123–142
(a) ~90 Ma:
137
Galice
GVG-Hornbrook
Klamath salient
Far
asthenosphere
Hig
me h-gra
tab de
asa
lt
allo
np
mantle
wedge
late
Eastern Franciscan
Central Franciscan
High-grade blocks
(b) ~90 Ma:
GVG
Sierran flare-up
CR
asthenosphere
Far
Mariposa
O
allo
N. Amer
plate
Hig
me h - g r a
tab d e
asa
lt
np
late
mantle
wedge
Fig. 9 Schematic introduction of high-grade metamorphosed oceanic
crustal blocks into the Franciscan Complex outboard from a the
Klamath Mountains and b the central Sierra Nevada Range. Sustained
underflow of progressively younger, warmer Farallon lithosphere
resulted in a gradually decreasing lithospheric plate dip. Two-way
flow within the subduction zone is indicated. Note insertion of HP
tectonic blocks into the voluminous, low-density, Upper Cretaceous
Franciscan circulating mud matrix and net upward transport.
Although the thickness of the circulating mélange zone in the Central
Belt is exaggerated for clarity, it probably consisted of a progressively seaward-younging series of much thinner subduction channels,
judging from mapped tectonic imbrications. Also sketched are
olistostromal blocks probably carried surfaceward by serpentinite
diapirs (not shown), and introduced into the Franciscan section
through erosion, transportation, and sedimentary deposition
Insertion of the high-grade tectonic blocks involved a
process whereby traction of circulating subduction-zone,
low-density mélange against an overlying stable lithospheric plate induced shearing and plucking of HP/LT
tectonic blocks and lenses previously stored along the
mantle hanging wall into a Cloos-type subduction channel.
How these Jurassic HP/LT units previously had ascended
to shallower storage depths remains unclear, but metasomatic actinolitic rinds on many tectonic blocks suggest
their early-stage inclusion in buoyant serpentinites. Prior to
the *125 Ma onset of nearly orthogonal, rapid subduction
and return flow of large volumes of Central Belt mudmatrix mélange, plate-margin shearing apparently was insufficient to cause the tractive insertion of dense metamafic
blocks into the subduction channel.
During mid-Paleozoic to mid-Jurassic time, predominantly margin-parallel differential slip involved the
episodic docking of ophiolitic complexes along the
continental edge. In contrast, Andean-type arc magmatism
(Barth et al. 2013) was vigorous over the period *175140 Ma, and became paroxysmal during mid- and Late
Cretaceous time (*125-80 Ma) during the change from a
southward to a northward tangential component of drift of
the Pacific-Farallon plate junction (Engebretson et al. 1984;
May and Butler 1986; Schettino and Scotese 2005; Sager
2007; Doubrovine and Tarduno 2008). U–Pb ages of detrital zircons document the presence of relatively small
volumes of Lower Cretaceous clastic strata, and in general,
much larger masses of Upper Cretaceous sediments in the
Franciscan Complex. Based on these relationships, Dumitru et al. (2010) proposed that, reflecting the change in
relative plate motions, coastal California transitioned from
a non-accretionary to an accretionary margin at *123 Ma.
Although plausible, nearly head-on convergence also
would result in larger tracts of lithosphere descending
through the magmagenic zone—and increasing generation
of arc magmas—hence rapid, nearly orthogonal mid- and
Late Cretaceous plate convergence might equally well have
been responsible for the *125-80 Ma flair-up in igneous
arc activity and consequent production of voluminous
Upper Cretaceous GVG and Franciscan clastic units (Blake
et al. 1988; Ernst et al. 2008; Cloos and Ukar 2010).
The Middle to Late Jurassic Andean ? Cretaceous
Sierran arc, and Paleocene-Miocene Idaho Batholith,
Challis complex, and Cascade volcanic rocks supplied
most of the igneous zircons to the Franciscan clastic strata
discussed in this paper. Although Middle and Upper
Jurassic continental margin proximal sequences contain
substantial contributions derived from Grenvillian source
terranes, 1,000–1,200 Ma zircons appear to be sparse in
Cretaceous GVG strata, and are absent from all but the
oldest Franciscan trench units. With the passage of time,
the Franciscan Complex began receiving greater proportions of younger arc detritus from more northerly source
areas. This change in provenance raises the possibility, but
does not require up to *1,600 km of post-120 Ma northwesterly transport of the Franciscan trench complex during
deposition, relative to the Great Valley Group forearc and
tracts of the SW North American basement terranes.
9 A final word
Like many other parts of the world, northern California has
received the detailed investigative attention of geologists,
geochemists and geophysicists for more than a century.
Accordingly, much of the geologic-geophysical framework
and geochemical-petrotectonic development of the crust
briefly sketched in this summary has been well understood
for decades. However, the advent of TIMS and SIMS microanalyses of individual detrital zircon grains and their
123
138
aggregate populations has made possible a relatively independent way to study the diverse igneous, metamorphic
and sedimentary lithologic assemblages. Integrated with
spatial knowledge of the region, these data provide new
constraints on the geohistory (i.e., plate tectonic development). This review of independent age and provenance
constraints reflected in the zircon U–Pb data represents just
one example of how the study of new geochemical systems
can increase our understanding of a critical portion of the
Earth—in this example, the post-Triassic convergent plate
margin of northern California. The attempt has been to
elucidate a few principles involving accretionary crustal
growth for Asian Earth scientists unfamiliar with California, because every area is different. However, although the
geologic histories of east Asia and NW California contrast
markedly, the governing principles are likely the same.
Acknowledgments Stanford University supports my field and
analytical studies of Californian lithotectonic belts. The National
Science Foundation provided additional aid through grant NSF EAR
0948676 to Marty Grove. Various workers carried out the detrital
zircons U–Pb age determinations on which this summary in based,
chiefly employing the SHRIMP-RG at the Stanford-USGS MicroAnalysis Center and the LA-ICPMS at the University of Arizona
LaserChron Center. Many of of these works are already published, but
as noted in the text, some of the zircon U–Pb data are still in press.
References
Aalto KR (2014) Examples of Franciscan complex mélanges in the
northernmost California Coast Ranges, a retrospective. Int Geol
Rev 56:555–570
Anczkiewicz B, Platt JP, Thirlwall MF, Wakabayashi J (2004)
Franciscan subduction off to a slow start: evidence from highprecision Lu-Hf garnet ages on high grade-blocks. Earth Planet
Sci Lett 225:147–161
Bachman SB (1978) Cretaceous and early tertiary subduction
complex, Mendocino Coast, northern California. In: Howell
DG, McDougall KA (eds) Mesozoic paleogeography of the
Western United States: Pacific Section, Society of Economic
Paleontologists and Mineralogists, Pacific Coast Paleogeographic symposium no. 2, pp 419–430
Bailey EH, Irwin WP, Jones DL (1964) Franciscan and related rocks
and their significance in the geology of western California:
California division of mines and geology. Bulletin 183:177p
Barth AP, Wooden JL, Jacobson CE, Economos RC (2013) Detrital
zircon as a proxy for tracking the magmatic arc system: the
California arc example. Geology 41:223–226
Bird P (1988) Formation of the Rocky Mountains, western United
States: a continuum computer model. Science 239:1501–1507
Blake MC Jr, Jayko AS, McLaughlin RJ (1988) Metamorphic and
tectonic evolution of the Franciscan Complex, northern California. In: Ernst WG (ed) Metamorphism and crustal evolution of
the Western United States. Prentice-Hall, Englewood Cliffs,
pp 1035–1060
Blake MC, Jr, Harwood DS, Helley EJ, Irwin WP, Jayko AS, Jones
DL (1999) Geologic map of the Red Bluff 300 9 600 Quadrangle, California: USGS Map I-2542, scale 1:100,000, and
accompanying pamphlet
123
Chin. J. Geochem. (2015) 34(2):123–142
Bogen NL (1985) Stratigraphic and sedimentologic evidence of a
submarine island-arc volcano in the lower Mesozoic Peñon
Blanco and Jasper Point Formations, Mariposa County, California, Geological Society of America Bulletin, Vol 96,
pp 1322–1331
Carlson WD (1983) The polymorphs of CaCO3 and the aragonitecalcite transformation. In: Reeder RJ (ed) Carbonates: mineralogy and chemistry: reviews in mineralogy, vol 11, pp 191–225
Catlos EJ, Sorensen SS (2003) Phengite-based chronology of K- and
Ba-rich fluid flow in two paleosubduction zones. Science
299:92–95
Cloos M (1982) Flow melanges: numerical modeling and geologic
constraints on their origin in the Franciscan subduction complex,
California. Geol Soc Am Bull 93:330–344
Cloos M (1986) Blueschists in the Franciscan Complex of California:
petrotectonic constraints on uplift mechanisms. Geol Soc Am
Mem 164:77–93
Cloos M, Shreve RL (1988) Subduction-channel model of prism
accretion, mélange formation, sediment subduction, and subduction erosion at convergent plate margins. 1. Background and
description. Pure Appl Geophys 128:455–500
Cloos M, Ukar E (2010) Subduction initiation along the California
plate margin: timing and thermal evolution of the Franciscan
Complex: geological Society of America, Abstracts with
Programs, vol 42, No. 5, pp 576–577
Coleman RG, Lanphere MA (1971) Distribution and age of highgrade blueschists, eclogites, and amphibolites from Oregon and
California. Geol Soc Am Bull 82:2397–2412
Coleman RG, Mortimer N, Donato MM, Manning CE, Hill LB (1988)
Tectonic and regional metamorphic framework of the Klamath
Mountains and adjacent Coast Ranges, California and Oregon.
In: Ernst WG (ed) Metamorphism and crustal evolution of the
Western United States. Prentice-Hall, Englewood Cliffs,
pp 1061–1097
Coney PJ, Reynolds S (1977) Cordilleran Benioff zones. Nature
270:403–406
Constenius KN, Johnson RA, Dickinson WR, Williams TA (2000)
Tectonic evolution of the Jurassic-Cretaceous Great Valley
forearc, California: implications for the Franciscan thrust-wedge
hypothesis. Geol Soc Am Bull 112:1703–1723
Cowan DS (1978) Origin of blueschist-bearing chaotic rocks in the
Franciscan Complex, San Simeon, California. Geol Soc Am Bull
89:1415–1423
Davis GA (1969) Tectonic correlations Klamath Mountains and
western Sierra Nevada, California. Geol Soc Am Bull
80:1095–1108
Davis GA, Ando CJ, Cashman PH, Goullaud L (1980) Geologic cross
section of the central Klamath Mountains, California: summary.
Geol Soc Am Bull 91:139–142
DeGraaff-Surpless K, Graham SA, Wooden JL, McWilliams MO
(2002) Detrital zircon provenance analysis of the Great Valley
Group, California: evolution of an arc-forearc system. Geol Soc
Am Bull 114:1564–1580
Dickinson WR (2008) Accretionary Mesozoic-Cenozoic expansion of
the Cordilleran continental margin in California and adjacent
Oregon. Geosphere 4:329–353
Dickinson WR, Gehrels GE (2009) U-Pb ages of detrital zircons in
Jurassic eolian and associated sandstones of the Colorado
Plateau: evidence for transcontinental dispersal and intraregional
recycling of sediment. Geol Soc Am Bull 121:408–433
Dickinson WR, Rich EI (1972) Petrologic intervals and petrofacies in
the Great Valley Sequence, Sacramento Valley, California. Geol
Soc Am Bull 83:3007–3024
Dickinson WR, Snyder WS (1978) Plate tectonics of the Laramide
orogeny. In: Matthews V III (ed) Laramide folding associated
with basement block faulting in the Western United States.
Chin. J. Geochem. (2015) 34(2):123–142
Geological Society of America Memoir 151, Boulder,
pp 355–366
Dickinson WR, Ingersoll RV, Cowan DS, Helmold KP, Suczek CA
(1982) Provenance of Franciscan graywackes in coastal California. Geol Soc Am Bull 93:95–107
Dickinson WR, Ducea M, Rosenberg LI, Greene HG, Graham SA,
Clark JC, Weber GE, Kidder S, Ernst WG, Brabb EE (2005) Net
dextral slip, Neogene San Gregorio-Hosgri fault zone, coastal
California: geologic evidence and tectonic implications, Geological Society of America Special Paper 391
Doubrovine PV, Tarduno JA (2008) A revised kinematic model for
the relative motion between Pacific oceanic plates and North
America since teh Late Cretaceous. J Geophys Res 113:B1201.
doi:10.1029/2008JB005585
Dumitru TA (1989) Constraints on uplift in the Franciscan subduction
complex from apatite fission track analysis. Tectonics 8:197–220
Dumitru TA (2012) New, much younger ages for the Yolla Bolly
terrane and a revised timeline for accretion in the Franciscan
subduction complex, California. Trans Am Geophys Union, Vol
93, No. 52, Fall Meeting Supplement, Abstract T11A-2543
Dumitru TA, Wright JE, Wakabayashi J, Wooden JL (2010) Early
Cretaceouss (ca. 123 Ma) transition from nonaccretionary
behavior to strongly accretionary behavior within the Franciscan
subduction complex. Tectonics 29(TC5001):2010. doi:10.1029/
2009TC002542
Dumitru TA, Ernst WG, Wright JE, Wooden JL, Wells RE, Farmer
LP, Kent AJR, Graham SA (2013) Eocene extension in Idaho
generated massive sediment floods into Franciscan trench and
into Tyee, Great Valley, and Green River basins. Geology
41:187–190
Dumitru TA, Ernst WG, Hourigan JK, McLaughlin RJ in press
Detrital zircon U-Pb reconnaissance of the Franciscan accretionary complex in northwestern California. Int Geol Rev
Dunne GC, Garvey TP, Osborne M, Schneidereit D, Fritsche AE,
Walker JD (1998) Geology of the Inyo Mountains volcanic
complex: implications for Jurassic paleogeography of the Sierran
magmatic arc in eastern California. Geol Soc Am Bull
110:1376–1397
Edelman SH, Sharp WD (1989) Terranes, early faults, and pre-Late
Jurassic amalgamation of the western Sierra Nevada metamorphic belt, California. Geol Soc Am Bull 101:1420–1433
Engebretson DC, Cox A, Gordon RG (1984) Relative motions
between oceanic plates of the Pacific basin. J Geophys Res
89:10291–10310
Ernst WG (1965) Mineral parageneses in Franciscan metamorphic
rocks, Panoche Pass, California. Geol Soc Am Bull 76:879–914
Ernst WG (1971) Tectonic contact between the Franciscan melange
and the Great Valley Sequence, crustal expression of a Late
Mesozoic Benioff zone. J Geophys Res 75:886–901
Ernst WG (1993) Metamorphism of Franciscan tectonostratigraphic
assemblage, Pacheco Pass area, east-central Diablo Range,
California Coast Ranges. Geol Soc Am Bull 105:618–636
Ernst WG (1998) Geology of the Sawyers Bar area, Klamath
Mountains, northern California: California Division of Mines
and Geology, Map Sheet 47, scale 1:48,000, accompanying text
59p
Ernst WG (2011) Accretion of the Franciscan complex attending JuraCretaceous geotectonic development of northern and central
California. Geol Soc Am Bull 123:1667–1678
Ernst WG (2010) Late Mesozoic subduction-induced gold deposits
along the eastern Asian and northern Californian margins:
efficacy of oceanic versus continental lithospheric underflow.
Island Arc 19:213–229
Ernst WG (2012) Earliest Cretaceous Pacificward offset of the
Klamath Mountains salient, NW California-SW Oregon. Lithosphere 5:151–159
139
Ernst WG, McLaughlin RJ 2012 Mineral parageneses, regional
architecture,
and tectonic
evolution of
Franciscan
metagraywackes, Cape Mendocino-Garberville-Covelo 300 9
600 quadrangles, northwest California. Tectonics, 31:TC1001.
doi:10.1029/2011TC002987
Ernst WG, Snow CA, Scherer HH (2008) Contrasting early and late
Mesozoic petrotectonic evolution of northern California. Geol
Soc Am Bull 120:179–194
Ernst WG, Saleeby JB, Snow CA (2009a) Guadalupe plutonMariposa Formation age relationships in the southern Sierran
Foothills: onset of Mesozoic subduction in northern California?
J Geophys Res 114:B11204. doi:10.1029/2009JB006607
Ernst WG, Martens U, Valencia V (2009b) U-Pb ages of detrital
zircons in Pacheco Pass metagraywackes: Sierran-Klamath
source of mid- and Late Cretaceous Franciscan deposition and
underplating.
Tectonics
28:TC6011.
doi:10.1029/
2008TC002352
Frey M, de Capitani C, Liou JG (1991) A new petrogenetic grid for
low-grade metabasalts. J Metamorph Geol 9:497–509
Frost CD, Barnes CG, Snoke AW (2006) Nd and Sr isotopic data from
argillaceous rocks of the Galice Formation and Rattlesnake
Creek terrane, Klamath Mountains: evidence for the input of
Precambrian sources. In: Snoke AW, Barnes CG (eds)
Geological studies in the Klamath Mountains province, California and Oregon, Geological Society of America Special Paper,
Vol 410
Gehrels GE, Blakey R, Karlstrom KE, Timmons JM, Dickenson WR,
Pecha M (2011) Detrital zircon U-Pb geochronology of
Paleozoic strata in the Grand Canyon, Arizona. Lithosphere
3:183–200
Gray GG (2006) Structural and tectonic evolution of the western
Jurassic belt along the Klamath River corridor, Klamath
Mountains, California. In: Snoke AW, Barnes CG (eds)
Geological studies in the Klamath Mountains province, California and Oregon: a volume in honor of William P. Irwin,
Geological Society of America Special Paper 410, pp 141–151
Hacker BR (1994) Evolution of the northern Sierra Nevada
metamorphic belt: petrological, structural, and Ar/Ar constraints.
Geol Soc Am Bull 105:637–656
Hacker BR and Goodge JW (1990) Comparison of early Mesozoic
high-pressure rocks in the Klamath Mountains and the Sierra
Nevada. In: Paleozoic and early Mesozoic paleogeographic
relations; Sierra Nevada, Klamath Mountains, and related
terranes, Geological Society of America Special Paper 225,
pp 277–295
Hacker BR, Donato MM, Barnes CG, McWilliams MO, Ernst WG
(1995) Timescales of orogeny: Jurassic construction of the
Klamath Mountains. Tectonics 14:667–703
Harper GD (2006) Structure of syn-Nevadan dikes and their
relationship to deformation of the Galice Formation, western
Klamath terrane, northwestern California. In: Snoke AW, Barnes
CG (eds) Geological studies in the Klamath Mountains province,
California and Oregon: a volume in honor of William P. Irwin,
Geological Society of America Special Paper 410, pp 121–140,
Boulder
Hopson CA, Mattinson JM, Pessagno EA, Jr, Luyendyk BP (2008)
California Coast Range Ophiolite: composite Middle and Late
Jurassic oceanic lithosphere. In: Wright JE Shervais JW (eds)
Arcs, ophiolites, and batholiths: a tribute to Cliff Hopson,
Geological Society of America Special Paper 438, pp 1–101
Imlay RW, Dole HM, Peck DL, Wells FG (1959) Relations of certain
Upper Jurassic and Lower Cretaceous formations in southwestern Oregon. Am Assoc Pet Geol Bull 43:2770–2785
Ingersoll RV (1978) Petrofacies and petrologic evolution of the Late
Cretaceous forearc basin, northern and central California. Geol
Soc Am Bull 86:335–352
123
140
Ingersoll RV (1979) Evolution of the Late Cretaceous forearc basin,
northern and central California: Geological Society of America
Bulletin, Vo. 90, part I, pp 813–826
Ingersoll RV (1983) Petrofacies and provenance of late Mesozoic
forearc basin, northern and central California. Am Assoc Pet
Geol Bull 67:1125–1142
Ingersoll RV (2012) Composition of modern sand and Cretaceous
sandstone derived from the Sierra Nevada, California, USA, with
implications for Cenozoic and Mesozoic uplift and dissection.
Sedim Geol 280:195–207
Irwin WP (1972) Terranes of the Western Paleozoic and Triassic
Belt in the southern Klamath Mountains, California, U.
S. Geological Survey Professional Paper, 800-C:C103–C111
Irwin WP (1981) Tectonic accretion of the Klamath Mountains. In:
Ernst WG (ed) The geotectonic development of California.
Prentice-Hall, Englewood cliffs, pp 29–49
Irwin WP (1994) Geologic Map of the Klamath Mountains, California
and Oregon, U. S. Geological Survey, Miscellaneous Investigations Series Map I-2148, scale 1:500,000
Irwin WP (2003) Correlation of the Klamath Mountains and the
Sierra Nevada: Sheet 1—map showing accreted terranes and
plutons of the Klamath Mountains and Sierra Nevada, scale
1:1,000,000; Sheet 2—successive accretionary episodes of the
Klamath Mountains and northern part of the Sierra Nevada, U.
S. Geological Survey Open file Report 01-490, 2 sheets
Irwin WP, Wooden JL (1999) Plutons and accretionary episodes of
the Klamath Mountains, California and Oregon, U. S. Geological
Survey Open File Report 99-0374
Jayko AS, Blake MC Jr (1989) Deformation of the Eastern Franciscan
Belt, northern California. J Struct Geol 11:375–390
Jayko AS, Blake MC, Jr, McLaughlin RJ, Ohlin HN, Ellen SD,
Kelsey H (1989) Reconnaissance geologic map of the Covelo
30- by 60-minute quadrangle, northern California: scale
1:100,000, U. S. Geological Survey Miscellaneous Field Studies
Map, MF-2001
Jayko AS, Blake MC, Jr (1993) Northward displacement of forearc
slivers in the Coast Ranges of California and southwest Oregon
during the late Mesozoic and early Cenozoic. In: Dunn G,
McDougall K (eds) Mesozoic paleogeography of the Western
United States-II, Pacific Section SEPM, Book 71, pp 19–36
Joesten R, Wooden JL, Silver LT, Ernst WG, McWilliams MO (2004)
Depositional age and provenance of jadeite-grade metagraywacke from the Franciscan accretionary prism, Diablo Range,
central California—SHRIMP Pb-isotope dating of detrital
zircon. Geological Society of America, Abstracts with Programs,
36(5):120
Jones DL, Irwin WP (1971) Structural implications of an offset Early
Cretaceous shoreline in northern California. Geol Soc Am Bull
82:815–822
Krogh EJ, Oh CW, Liou JG (1994) Polyphase and anticlockwise P-T
evolution for Franciscan eclogites and blueschists from Jenner,
California, USA. J Metamorph Geol 12:121–134
LaMaskin TA (2011) Detrital zircon facies of Cordilleran terranes in
western North America. GSA Tod 22(3):4–11
LaMaskin TA, Vervoort JD, Dorsey RJ, Wright JE (2011) Early
Mesozoic paleogeography and tectonic evolution of the western
United States: Insights from detrital zircon U-Pb geochronology,
Blue Mountains Province, northeastern Oregon. Geol Soc Am
Bull 123:1939–1965
Lanphere MA, Jones DL (1978) Cretaceous time scale from North
America. In: Cohee GV, Glaessner MF, Hedberg HD (eds)
Contributions to the geologic time scale, American Association
of Petroleum Geologists, Studies in Geology, No. 6, pp 259–268
Lanphere MA, Irwin WP, Hotz PE (1968) Isotopic age of the Nevadan
orogeny and older plutonic and metamorphic events in the
Klamath Mountains, California. Geol Soc Am Bull 79:1027–1052
123
Chin. J. Geochem. (2015) 34(2):123–142
Linn AM, DePaolo DJ, Ingersoll RV (1992) Nd-Sr isotopic,
geochemical, and petrographic stratigraphy and paleotectonic
analysis: mesozoic Great Valley forearc sedimentary rocks of
California. Geol Soc Am Bull 104:1264–1279
Liou J (1971) P-T stabilities of laumontite, wairakite, lawsonite, and
related minerals in the system CaAl2Si2O8-SiO2-H2O. J Petrol
12:370–411
Liou JG, Kim HS, Maruyama S (1983) Prehnite-epidote equilibria
and their petrologic applications. J Petrol 24:321–342
MacDonald JH, Jr, Harper GD, Zhu B (2006) Petrology, geochemistry, and provenance of the Galice Formation, Klamath
Mountains, Oregon and California. In: Snoke AW, Barnes CG
(eds) Geological studies in the Klamath Mountains province,
California and Oregon: a volume in honor of William P. Irwin.
Geological Society of America Special Paper 410, Boulder,
pp 77–101
Mansfield CF (1979) Upper Mesozoic subsea fan deposits in the
southern Diablo Range, California: record of the Sierra Nevada
magmatic arc, Geological Society of America Bulletin, Vol 90,
part I, pp 1025–1046
May SR, Butler RF (1986) North American Jurassic apparent polar
wander; implications for plate motion, paleogeography and
Cordilleran tectonics. J Geophys Res 91:11519–11544
McLaughlin RJ, Sliter WV, Frederiksen NO, Harbert WP, McCulloch
DS (1994) Plate motions recorded in tectonostratigraphic
terranes of the Franciscan Complex and evolution of the
Mendocino triple junction, northwestern California. US Geol
Surv Bull 1997:60p
McLaughlin RJ, Ellen SD, Blake MC, Jr, Jayko AS, Irwin WP, Aalto
KR, Carver GA, Clarke SH, Jr, Barnes JB, Cecil JD, Cyr KA
(2000) Geology of the Cape Mendocino, Eureka, Garberville,
and southwestern part of the Hayfork 30 9 60 minute
quadrangles and adjacent offshore area, including a digital
database, U. S. Geological survey, Miscellaneous field studies
Map MF-2336, scale 1:137,000
Miller MM, Saleeby JB (1995) U-Pb geochronology of detrital zircon
from Upper Jurassic synorogenic turbidites, Galice Formation,
and related rocks, western Klamath Mountains: Correlation and
Klamath Mountains prove. J Geophys Res 100:18045–18058
Mitchell C, Graham SA, Suek DH (2010) Subduction complex uplift
and exhumation and its influence on Maastrichtian forearc
stratigraphy in the Great Valley Basin, northern San Joaquin
Valley, California. Geol Soc Am Bull 122:2063–2078
Moore DE (1984) Metamorphic history of a high-grade blueschist
exotic block from the Franciscan Complex, California. J Petrol
25:126–150
Moxon IW (1990) Stratigraphic and structural architecture of the San
Joaquin-Sacramento Basin, Ph.D. thesis, Stanford University,
Stanford
Newton RC, Smith JV (1967) Investigations concerning the breakdown of albite at depth in the earth. J Geol 75:268–286
Nilsen TH (1993) Stratigraphy of the Cretaceous Hornbrook Formation, southern Oregon and northern California, U. S. Geological
survey professional paper 1521
Page FZ, Armstrong LS, Essene EJ, Mukasa SB (2007) Prograde and
retrograde history of the Junction School eclogite, California,
and an evaluation of garnet-phengite-clinopyroxene thermobarometry. Contrib Miner Petrol 153:533–555
Platt JP (1986) Dynamics of orogenic wedges and the uplift of
high-pressure metamorphic rocks. Geol Soc Am Bull
97:1037–1053
Platt JP (1993) Exhumation of high-pressure metamorphic rocks: a
review of concepts and processes. Terra Nova 5:119–133
Raymond LA (1984) Classification of melanges. In: Raymond LA
(ed) Melanges: their nature, origins, and significance, Geological
Society of America Special Paper 198, pp 7–20
Chin. J. Geochem. (2015) 34(2):123–142
Raymond LA in press Designating tectonostratigraphic terranes versus
mapping rock units in subduction complexes: perspectives from
the Franciscan Complex of California, USA. Int Geol Rev
Ring U, Brandon MT (2008) Exhumation settings, Part I: relatively
simple cases. Int Geol Rev 50:97–120
Roberts CW, Jachens RC (1999) Preliminary aeromagnetic anomaly
map of California, U. S. Geological Survey, Open File Report
99-440
Sager WW (2007) Divergence between paleomagnetic and hotspotmodel-predicted polar wander for the Pacific plate with implications for hotspot fixity. In: Foulger GR, Jurdy JM (eds) Plates,
plumes, and planetary processes, Geological Society of America,
Special Paper 430, Boulder, pp 335–357
Saha A, Basu AR, Wakabayashi J, Wortman GL (2005) Geochemical
evidence for a subducted infant arc in Franciscan high-grade
metamorphic tectonic blocks. Geol Soc Am Bull 117:1318–1335
Saleeby JB (1981) Ocean floor accretion and volcano-plutonic arc
evolution of the Mesozoic Sierra Nevada, California. In: Ernst
WG (ed) The geotectonic development of California. PrenticeHall, Englewood Cliff, pp 132–181
Saleeby JB (1982) Polygenetic ophiolite belt of the California Sierra
Nevada: geochronological and tectonostratigraphic development. J Geophys Res 87:1803–1824
Saleeby JB (1983) Accretionary tectonics of the North American
Cordillera. Annu Rev Earth Planet Sci 15:45–73
Saleeby JB (1992) Petrotectonic and paleogeographic settings of U.
S. Cordilleran ophiolites. In: Burchfiel BC, Lipman PW, Zoback
ML (eds) The Cordilleran Orogen: Conterminous U.S, Geological Society of America, The Geology of North America, Vol
G-3
Saleeby JB, Harper GD (1993) Tectonic relations between the Galice
Formation and the Condrey Mountain Schist, Klamath Mountains, northern California. In: Dunne GC, McDougall KA (eds)
Mesozoic paleogeography of the Western United States II,
Society of Economic Paleontologists and Mineralogists Pacific
Section, Vol 71, Los Angeles, pp 61–80
Saleeby JB, Busby-Spera C, Oldow JS, Dunne GC, Wright JE, Cowan
DS, Walker NW, Allmendinger RW (1992) Early Mesozoic
tectonic evolution of the western U.S. Cordillera. In: Burchfiel
BC, Lipman PW, Zoback ML (eds) The Cordilleran Orogen:
Conterminous U.S., Geological Society of America, The
Geology of North America, Vol G-3, pp 107–168
Scherer HH, Ernst WG (2008) North Fork terrane, Klamath Mountains, California: geologic, geochemical, and geochronologic
evidence for an early Mesozoic forearc. In: Wright JE, Shervais
JW (eds) Arcs, ophiolites, and batholiths: a tribute to Cliff
Hopson, Geological Society of America Special Paper No. 438,
pp 289–309
Scherer HH, Snow CA, Ernst WG (2006) Geologic-petrochemical
comparison of early Mesozoic oceanic terranes: Western
Paleozoic and Triassic Belt, Klamath Mountains, and JuraTriassic arc, Sierran Foothills. In: Snoke AW, Barnes CG (eds)
Geological studies in the Klamath Mountains province, California and Oregon, Geological Society of America Special Paper
410, pp 377–392
Schettino A, Scotese CR (2005) Apparent polar wander paths for the
major continents (200 Ma to present): a paleomagnetic reference
frame for global plate tectonic reconstructions. Geophys J Int
163:727–759. doi:10.1111/j.1365-246X.2005.02638.x
Scholl DW, von Huene R (2007) Crustal recycling at modern
subduction zones applied to the past: Issues of growth and
preservation of continental basement crust, mantle geochemistry,
and supercontinent reconstruction. In: Hatcher RD, Jr, Carlson
MP, McBride JH, Martı́nez Catalán JR (eds) 4-D framework of
continental crust, Geological Society of America Memoir 200,
pp 159–179
141
Schwartz JJ, Snoke AW, Cordey F, Johnson K, Frost CD, Barnes CG,
LaMaskin TA, Wooden JL (2011) Late Jurassic magmatism,
metamorphism, and deformation in the Blue Mountains
Province, northeast Oregon. Geol Soc Am Bull 123:2083–2111
Seiders VM (1983) Correlation and provenance of upper Mesozoic
chert-rich conglomerate of California. Geol Soc Am Bull
94:875–888
Sharman GR, Graham SA, Grove M, Kimbrough DL, Wright JE in
press Detrital zircon provenance of the Late Cretaceous-Eocene
California forearc: influence of Laramide low-angle subduction
on sediment dispersal and paleogeography. Geol Soc Am Bull
Sharp WD (1988) Pre-Cretaceous crustal evolution of the Sierra
Nevada region: p. In: Ernst WG (ed) Metamorphism and crustal
evolution of the western United States. Prentice-Hall, Englewood Cliffs, pp 824–864
Shervais JW, Choi SH (2012) Subduction initiation along transform
faults: the proto-Franciscan subduction zone. Lithosphere
4:484–496
Shervais JW, Murchey BL, Kimbrough DL, Renne PR, Hanan B
(2005) Radioisotopic and biostratigraphic age relations in the
Coast Range Ophiolite, northern California: implications for the
tectonic evolution of the Western Cordillera. Geol Soc Am Bull
117:633–653
Silberling NJ, Jones DL, Blake MC, Jr, Howell DG (1987)
Lithostratigraphic terrane map of the western conterminous
United States, Miscellaneous Field Studies Map MF 1874-C,
scale 1:2,500,000
Sliter WV, Jones DL, Throckmorton CK (1984) Age and correlation
of the Cretaceous Hornbrook Formation. In: Nilsen TH (ed)
Geology of the Upper Cretaceous Hornbrook formation, Oregon
and California: Society of Economic Paleontologists and Mineralogists, Pacific Section, Los Angles, pp 89–98
Snoke AW (1977) A thrust plate of ophiolitic rocks in the Preston
Peak area, Klamath Mountains, California. Geol Soc Am Bull
88:1641–1659
Snoke AW, Barnes CG (2006) The development of tectonic concept
for the Klamath Mountains province, California and Oregon. In:
Barnes CG, Snoke AW (eds) Geological studies in the Klamath
Mountains province, California and Oregon: a volume in honor
of William P. Irwin, Geological Society of America Special
Paper, 410: 1–29
Snow CA, Ernst WG (2008) Detrital zircon constraints on sediment
distribution and provenance of the Mariposa Formation, central
Sierra Nevada Foothills, California. In: Wright JE, Shervais JW
(eds) Arcs, ophiolites, and batholiths: a tribute to Cliff Hopson,
Geological Society of America Special Paper No. 438, pp. 311–330
Snow CA, Scherer HH (2006) Terranes of the western Sierra Nevada
Foothills metamorphic belt, California: a critical review. Int
Geol Rev 48:46–62
Snow CA, Wakabayashi J, Ernst WG, Wooden JL (2010) SHRIMPbased depositional ages of Franciscan metagraywackes, westcentral California. Geol Soc Am Bull 122:282–291
Stern RJ (2004) Subduction initiation: spontaneous and induced.
Earth Planet Sci Lett 226:275–292
Stern RJ, Scholl DW (2010) Yin and Yang of continental crust
creation and destruction by plate tectonic processes. Int Geol
Rev 52:1–31
Stern RJ, Reagan M, Ishizuka O, Ohara Y, Whattam S (2012) To
understand subduction initiation, study forearc crust: to understand forearc crust, study ophiolites. Lithosphere 4:469–483
Surpless KD in press Geochemistry of the Great Valley Group: an
integrated provenance record. Int Geol Rev 56
Surpless KD, Beverly EJ (2013) Understanding a critical basinal link
in Cretaceous Cordilleran paleogeography: detailed provenance
of the Hornbrook Formation, Oregon and California. Geol Soc
Am Bull 125:709–727
123
142
Surpless KD, Graham SA, Covault JA, Wooden JL (2006) Does the
Great Valley Group contain Jurassic strata? Reevaluation of the
age and early evolution of a classic forearc basin. Geology
34:21–24
Tagami T, Dumitru TA (1996) Provenance and thermal history of the
Franciscan accretionary complex; constraints from zircon fission
track thermochronology. J Geophys Res 101(B5):11353–11364
Terabayashi M, Maruyama S (1998) Large pressure gap between the
Coastal and Central belts, northern and central California.
Tectonophysics 285:87–101
Tripathy A, Housh TB, Morisani AM, Cloos M (2005) Detrital zircon
geochronology of coherent jadeitic pyroxene-bearing rocks of
the Franciscan Complex, Pacheco Pass, California: implications
for unroofing: Geological Society of America, Abstracts with
Programs 37(7):18
Tsujimori T, Matsumoto K, Wakabayashi J, Liou JG (2006)
Franciscan eclogite revisited: Reevaluation of P-T evolution of
tectonic blocks from Tiburon Peninsula, California, USA.
Mineral Petrol 88:243–267
Ukar E (2012) Tectonic significance of low-temperature blueschist
blocks in the Franciscan mélange at San Simeon, California.
Tectonophysics 568–569:154–169
Ukar E, Cloos M (2014) Low-temperature blueschist-facies mafic
blocks in the Franciscan mélange, San Simeon, California: field
relations, petrology, and counterclockwise P-T paths. Geol Soc
Am Bull 126:831–856
Ukar E, Cloos M, Vasconcelos P (2012) First 40Ar-39Ar ages from
low-T Mafic Blueschist blocks in a Franciscan mélange near San
Simeon: implications for initiation of subduction. J Geol
120:543–556
Underwood MB, Blake MC, Jr, Howell GD (1987) Thermal maturity
of tectonostratigraphic terranes within the Franciscan Complex,
California. In: Leitch EC, Scheibner E (eds) Terrane accretion
and orogenic belts: geodynamics series, Vol 19, American
Geophysical Union, pp 307–321
Unruh JR, Dumitru TA, Sawyer TL (2007) Coupling of early tertiary
extension in the Great Valley forearc basin with blueschist
exhumation in the underlying Franciscan accretionary wedge at
Mount Diablo, California. Geol Soc Am Bull 119:1347–1367
U.S. Geological Survey and California Division of Mines and
Geology (1966) Geologic Map of California: U. S. Geological
123
Chin. J. Geochem. (2015) 34(2):123–142
Survey, Miscellaneous Geologic Investigations Map I-512, scale
1:2,500,000
Wakabayashi J (1990) Counterclockwise P-T-t paths from amphibolites, Franciscan Complex, California: relics from the early
stages of subduction zone metamorphism. J Geol 98:657–680
Wakabayashi J (1992) Nappes, tectonics of oblique plate convergence, and metamorphic evolution related to 140 million years
of continuous subduction, Franciscan Complex, California.
J Geol 100:19–40
Wakabayashi J (1999) Subduction and the rock record: Concepts
developed in the Franciscan Complex, California. In: Sloan D,
Moores EM, Stout D (eds) Classic cordilleran concepts: a view
from California, Geological Society of America, Special Paper,
Vol 338, pp 123–133
Wakabayashi J, Dumitru TA (2007) 40Ar/39Ar ages from coherent,
high-pressure metamorphic rocks of the Franciscan Complex,
California: revisiting the timing of metamorphism of the world’s
type subduction complex. Int Geol Rev 49:873–906
Wakabayashi J, Ghatak A, Basu AR (2010) Suprasubduction-zone
ophiolite generation, emplacement, and initiation of subduction:
a perspective from geochemistry, metamorphism, geochronology, and regional geology. Geol Soc Am Bull 122:1548–1568
Wang Y, Forsyth DW, Rau CJ, Carriero N, Schmandt B, Gaherty J,
Savage B (2013) Fossil slabs attached to unsubducted fragments
of the Farallon plate. Proc Natl Acad Sci 110:5342–5346. doi:10.
1073/pnas.1214880110
Wright JE, Fahan MR (1988) An expanded view of Jurassic
orogenesis in the western United States Cordillera: middle
Jurassic (pre-Nevadan) regional metamorphism and thrust faulting within an active arc environment, Klamath Mountains,
California. Geol Soc Am Bull 100:859–876
Wright JE, Wyld SJ (1994) The Rattlesnake Creek Terrane, Klamath
Mountains, California; an early Mesozoic volcanic arc and its
basement of tectonically disrupted oceanic crust. Geol Soc Am
Bull 106:1033–1056
Wright JE, Wyld SJ (2007) Alternative tectonic model for Late
Jurassic through Early Cretaceous evolution of the Great Valley
Group, California. In: Cloos M, Carlson WD, Gilbert MC, Liou
JG, Sorensen SS (eds) Convergent Margin Tectonics and
Associated Regions, Geological Society of America Special
Paper 419, pp 81–95

Similar documents

×

Report this document