Radiolarian ages from the Cache Creek and Bridge River complexes and from chert pebbles in Cretaceous conglomerates, southwestern British Columbia

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Radiolarian ages from the Cache Creek and Bridge River complexes and from chert pebbles in Cretaceous

conglomerates, southwestern British Columbia

F. Cordey

To cite this version:

F. Cordey. Radiolarian ages from the Cache Creek and Bridge River complexes and from chert pebbles

in Cretaceous conglomerates, southwestern British Columbia. Current Research, Part E/Recherches

En Cours, Partie E, Geological Survey of Canada, 1986. �hal-03274268�

- 72 -

Radiolarian ages from the Cache Creek and B tJge River complexes and from chert pebbles in C taceous

conglomerates, southwes r Britis olumbia

Cordilleran

Cordey, F., Radiolarian ages from the Cache Creek and Bridge River complexes and from chert pebbles in Cretaceous conglomerates, southwestern British Columbia; in Current Research, Part A, Geological Survey of Canada, Paper 86-1A, p. 595-602, 1986. -

Abstract

Radiolarians from four localities in the Cache Creek Complex and from twelve localities in the Bridge River Complex range in age respectively, from Early Permian to Late Triassic and from Middle Triassic to Early Jurassic. Radiolarian chert pebbles from Cretaceous conglomerates in the region show the same Permian to Jurassic range.

Resume

L'age des radiolaires provenant de quatre emplacements dans Ie complexe de Cache Creek et de douze emplacements dans Ie complexe de Bridge River varie respecti vement du Permien ancien au Trias recent et du Trias moyen au Jurassique ancien. L'age des radiolarites provenant de conglomerats cretaces dans la region varie egalement du Permien au Jurassique.

1 Universite Pierre et Marie Curie, Laboratoire de Stratigraphie, 4, Place Jussieu, 75230 Paris Cedex, France

Introduction

The Cache Creek and Bridge River complexes in south- western British Columbia comprise disrupted radiolarian chert, argillite, mafic volcanic and ultramafic rock and locally extensive bodies of carbonate. These rocks are inferred (e.g., Monger and Price, 1979) to be lower Mesozoic accretionary complexes of oceanic provenance. Prior to 1971 the only diagnostic fossils that had been reported were Permian fusulinids from the Cache Creek Complex. In 1971, Cameron and Monger extracted Middle Triassic conodonts f:om carbonates in the Bridge River Complex, 'which at that time was called Fergusson Group. In 1977, .radiolarian cherts collected by Monger (personal communication) from the Bridge River Comple.x were sent to D.L. Jones of the United States Geological Survey, who suggested in a written communication with E.A. Pessagno, University of Texas that the radiolaria range from Late Triassic to Early

Jur~ssic.

Later.' D.L. Jones (oral communication, 1981) collected Permian and Triassic radiolaria from the Cache Creek

Comple~, .and Orchard (1981, 1984-, and personal communicatIOn) extracted Pennsylvanian Permian and Tr!ass!c conodonts from the Cache Creek

C~mplex,

^{and Late}

TriaSSIC conodonts from the Bridge River Complex.

{\),

~

E2i:9

*

chert-pebble conglomerate, sandstone, shale; ? denotes lithologically sirellar but undat~d strata (Monger, 1985) . 1I0ZAM£EX : chert, argillite, limestone, and metamorphosed equivalents.

BRIDGE RIVER: chert, argil l i te, basalt and metamorphosed equivalents.

CACHE CREEK

western facies : argillitet chert.

central facies : Marble Canyon Formation carbonate, argillite, volcanics.

eastern facies ! melange with chert, carbonate, basal t in a chert/argillite mat~ixi basalt, ultrareafic rock.

radiolarian locality in this paper. road

The present study, funded by Centre National de la Reche:che Scientifique-ASP 950078 (Paris), and supported in the. field by the Geological Survey of Canada under Project 800029, was undertaken in part to determine the upper age limits of these accretionary complexes, because

co~od~nts are ~~t known in rocks younger than Upper TriassIc. In additIOn, radioloarian-chert clasts in known and possible mid-Cretaceous chert-pebble conglomerates were sampled in order to clarify the provenances of the conglomerates. The study is not complete; this paper reports the results of field work during 1984-.

Method

Radiolarians were identified first with a hand lens in the fie!d prior

!O

^sampli~g. In the laboratory, the samples were dissolved In very dllute hydrofluoric acid (l to 2%) for one week, using the extraction technique of Dumitrica (1970) and Pessagno and Newport (1972), as slightly modified by De w.ever (1982). :he chert pebbles from conglomerates were first cleaned with concentrated hydrofluoric acid to avoid risk of contamination (Seiders and Blome, 1984-), and this was followed by separate etching of each pebble in dilute acid.

~SPENCES

) BR~DGE

I

. / )

'" LYTTON

N

t

C-3'

I b

^KM

Figure 72.1. Lithological units and radiolarian localities, southwestern British Columbia.

122°30' 122°15'

,

122°45'

I

"

1I1 ,

^{" 0} • ^{KM 5 I 19 B09}

--" _-

B12

B04

Figure 72.2. Radiolarian localities, Bridqe River Complex, British COlumbia.

Table 72.1. Bridge River complex localities (see also Fig. 72.2)

Locality Longitude/Latitude BOI 122° 15'20"; 50⁰ 46'00"

B02 122⁰14'13";50⁰45'21"

B03 122⁰14'00";50⁰45'06"

B04 122⁰14'10";50⁰45'28"

B06 122⁰45'00";50⁰53'55"

B07 122⁰32'00";50⁰51 '50"

B09 122⁰24'50";50⁰49'29"

BIO 122⁰23'26"; 50⁰ 48'19"

BII 122⁰23' 13";50⁰48' 16"

BI2 122⁰17'16";50⁰46'02"

B13 122⁰17'08"; 50⁰ 46'00"

BI5 122⁰04'05";50⁰48'47"

Grid reference Bridge River 92J/ 16 52540 Bridge River 92J/ 16539228 Bridge River 92J/16 541223 Bridge River 92J/16 536230 Bralorne 92J/15 176384 Bralorne 92J/15 324346 Bridge River 92J/ 16 413303 Bridge River 92J/16 429282 Bridge River 923/16 432281 Bridge River 92J/16 502241 Bridge River 92J/16 504240 Bridge River 92J/ 16 657292

Location

(kilometres by road gi ven)

On road between Seton and Carpenter Lakes, 3.45 km from Mission Pass.

1.35 km north of Mission Pass.

0.50 km north of Mission Pass.

1.75 km north of Mission Pass.

10 km east of Gold Bridge (bridge), on north side of Carpenter Lake.

28 km from Gold Bridge, north side of Carpenter Lake.

39 km from Gold Bridge, 0.6 km east of Bighorn Creek, north side Carpenter Lake.

42 km from Gold Bridge, west of Fall Creek, north side Carpenter Lake.

43 km from Gold Bridge, east of Fall Creek, north side Carpenter Lake.

52 km from Gold Bridge, 0.7 km east of Viera Creek, north side Carpenter Lake.

0.9 km east of Viera Creek, north side of Carpenter Lake.

North side Bridge River Valley, 27 km from the Carpenter Lake dam toward Lillooet.

'""

Table 72.2. Cache Creek Complex localities (see also Fig. 72.3)

Locality Longitude/Latitude C02 121 °27'44";50°41'13"

C03 121 ° 19'39";50°48'27"

C05 121 °26'15";50° 53'10"

C08 121 °36'51";50°47'05"

Grid reference Ashcroft 921/ II 086159 Cache Creek 921/14 179295 Cache Creek 921/14 099381 Pavilion E 921/13 977284

Location

(kilometres by road gi ven) 2.2 km south of fire lookout on Cornwall Hills.

West side of settlement of Cache Creek.

On the Highway 12, 3.0 km west of Highway 97.

300 m north of Highway 12, 20.1 km west of Highway 97.

Table 72.3. Chert-pebble conglomerate localities (see Figures 72.1, 72.3) Locality Longi tude/Lati tude

C07 121 °32'05";50° 51'10"

POI 120 042'47"j50° 10'00"

LOI 120° 36'42";50°00'32"

L02 120° 36'57"j50000'08"

ADI 120°46'25";49° 54'30"

o

5 10

.... --~K""'M---....I'

C05-

,

o

0.5

L--....J

KM "

! '

121"30'

Grid reference

Location

(kilometres by road given) Pavilion E 931/ 13 032342

Merritt 921/2 634595 Merritt 921/2 711422 Merritt 921/2 709415

On Highway 12, 11.2 km from Cariboo Highway 97.

5 km northeast of Merritt.

0.2 km west from Highway 5 (elevation 3500 ftl.

0.6 km west of Highway 5 (elevation 4000 ftl.

Aspen Grove 92H/ 15 598305 9.75 km east of Kingsvalej

N

t

1.5 km south of Vogt Creek Road

In general, the radiolarians recovered from chert pebbles were found to be better preserved than those from the Cache Creek and Bridge River complexes. The recovery rate, namely, number of determinable radiolarians extracted/number of samples collected with visible radiolarians, ranged from 0 to 45% (average 20%) for cherts within the complexes, to 12 to 70% (average 50%) from chert pebbles in conglomerates.

Bridge River Complex

The Bridge River Complex, located west of Lillooet in the eastern margin of the Coast Plutonic Complex, is a Middle Triassic to Lower Jurassic melange comprising tectonically disrupted chert, argillite, basalt, alpine-type ultramafic rock and minor carbonate (Potter, 1983). Its probable south-southeasterly continuation, across the Fraser River Fault System, is the Hozameen Group (Fig. 72.1), which contains Permian to Lower, and possibly Middle Jurassic strata (R.A. Haugerud,

!!l

Monger and McMillan, 1984).

Radiolarian chert samples were collected along the road on the north side of Carpenter Lake, which lies 20 km west of the town of Lillooet (Fig. 72.2 and Table 72.ll.

There, ribbon chert probably forms more than half of the total outcrop, and consists of beds I to 10 cm thick that are commonly broken and highly disrupted; because of this it is not possible to measure sections.

Figure 72.3. Radiolarian localities near Cache Creek, British Columbia.

Twelve ribbon chert outcrops provided radiolarians that were sufficiently well-preserved to permit the determinations given in Table 72.4. Seven locations are new (BOI, 02, 03, 04, 06, 07, 09), and the remainder coincide with localities collected by Potter (I983). Ages range from Middle Triassic (BI5) to Lower Jurassic (B07), with most in the Upper Triassic (Table 72.4). Ages generally become younger westward, with the exception of B06.

Table 72.4. Radiolarian associations and age of specimens from Bridge River Complex

801-10 Bridge River Group age: Late Triassic (late Carnian to Norian)

Capnuchosphaera sp . . . ..... . . Late Triassic (late Carnian to early middle Norian) Kahlerosphaera(?) sp . . . ........ . . Late Triassic

Poulpus phasmatodes De Wever ......... Carnian-Norian

Sarla sp. cf S. natividadensis Pessagno ..... . . Late Triassic (early Carnian to late Norian) stYlQsphaera(?I spinulosa (Nakaseko & Nishimura) .•... ?Late Triassic

Stylosphaera(?) compacta (Nakaseko & Nishimura) ... ?Late Triassic Tetraporobrachia sp . . . ..... . . known in late Carnian

B02-01 Bridge River Group age: Late Triassic

Capnodoce sp. cf ~ venusta Pessagno . . . Late Triassic (late Carnian to early middle Norian) Capnodoce sarisa De Wever ............. . . Late Triassic

Gorgansium spo . 0 • • • • • • • • • • ••• • • ••• • • • •••• ••• •• • • • • • • • • • • • • • Late Triassic to Late Jurassic

Sarla sp . .. 0 •••• • • • • •• • • •• ••• • ••• • • • • • • • • • • • • • • • • • • • • • • • • • • Late Triassic (early. Carnian to late Norian)

B03-0 1 Bridge Ri ver Group age: Triassic

Emiluvia(?) sp. cf E. (?) cochleata Nakaseko & Nishimura •... ?Anisian to early Ladinian?

Staurocontium sp. c~ minoense Nakaseko & Nishimura ... ?Late Triassic Stylosphaera (?) hellcata (Nakaseko & Nishimura) .••.•••.•.•. ?La te Triassic Stylosphaera sp. cf S. (?) spinulosa (Nakaseko & Nishimura) . ?Late Triassic

BO~ -03 Bridge River Group age: Late Triassic-Jurassic

Gorgansium sPo 0 0 • • • • • • • • • • • • • • • • •• • •• • • • • • • • • • • 0 • • • • 0 • • • • • • Late Triassic to Late Jurassic

Kozurastrum sp . . . 0 • • • • • • • • • • • • Triassic-Early Jurassic (middle Jurassic?)

B06-02 Bridge River Group age: probably Late Triassic

Sarla spo Late TriassiC (early Carnian to late Norian)

B07-01 Bridge River Group age: Early Jurassic

canoptum anulatum Pessagno & POisson ...•••.••..••••••••. Early JurassiC (L. Pliens.) to Mid.Jurassic(Bajocian) Canutus spo . . . ... . . .... Early Jurassic (Sinemur. to Toarc./L.Pliensbachlan)

~diuD1(?) sp. C in HO 1982 .•...•.••••••.••••••••.•... early Early Jurassic?

Hsgiastrum sp . . . ............ . . ... Early Sinemurian to Early Cretaceous Hsuum sp . . . ⁰ • • • • • • • • • • • • • • • • • • • • • 0 early Pliensbachian to late Valanginian

~rium spo . . . Early JuraSSic (Late Pliensbachian) to m. Jurassic Parahsuum(?) sp. C in YAO 1982 .••••••.••••••••...•••..•.... early Early Jurassic?

Stichocapsa sp.A in YAO 1982 . . . early Early Jurassic?

Trillus elkhornensis Pessagno & Blome . . . Pliensbachian to Bajocian

809-01 Bridge River Group age: Late Triassic

Canoptum triassicum Yao . . . ^{0 • • • • • • •} late Norian and Rhaetian Capnodoce sp . . . . 0 • • • • • • 0 •• 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 0 Late Triassic

Pentaspongodiscus(?) sp. . .. 0 • • • • • • • • • • • • • • • • • • • • • 0 • • • 0 • 0 • • 0 Late Anisian to Carnian

Sarla sp . . . 0 • • o. 0 • •• • 0 • • • • • • • • 0 • • • • • • • • • • • • • • • • • • 0 • • • • • 0 • • • Late Triassic (early Carnian to late Norian)

810-02 Bridge River Group age: Late Triassic

Canoptum spo . . . 0 • • • • • • • • • Late Triassic (Carnian) to Middle JUrassic Pantanellium spo . 0 . 0 0 • • • •• ••• • • • • • • • • • • • • • • • • 0 • • • • • • • • • • • • • Late Triassic (early Carnian) to Early Cretaceous Sarla sp ....•••••.•...••..••...•.••••••...•• Late Triassic (early Carnian) to late Norian)

B11-0~ Bridge River Group age: Late Triassic

Capnuchosphaera triassica De Wever . . . 0 0 • • Late Triassic Kahlerosphaera parvispinosa Kozur & Mostler .0 ..•... early Carnian Praeorbiculiformella spo ... 0 • • • • • • • • • • • • • 0 • • • • • • • • • • • • • • • • • Triassic

Pseudoheliodiscus spo .. . . 0 • • • 0 • • • • • • Triassic-early Jurassic Spongostylus spo . . . 0 • • • • • • • • 0 • • • • • • • • • • • • • • early Carnian

Stylosphaera(?) spinulosa (Nakaseko & Nishimura) ••••.•••••• ?Late Triassic

Tetraspongodiscus sp . . . 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 0 . ?Ladinian-early Carnian insofar as known

B12-02 Bridge River Group age: Late Triassic (Carnian to Middle Norian)

Capnodoce baldiensis Blome •..•••••.•••••...•...•...•• Late Triassic (l.Carnian?-e.to l.Middle Norian) Capnuchosphaera deweveri Kozur & Mostler . . . 0 . 0 .. 0 Late Triassic (Carnian to late Middle Norian) Renzium sp . . . .. . . .......... . . Late Triassic (l.Carnian?-e.to 1. Middle Norian)

~campe nova Yao . . . 0 •• • • •• • •• •• • ••• • Carnian to Norian

B13-01 Bridge River Group age: Late Triassic

Canoptum rhaeticum Kozur & Mostler . . . 0 • • • • • • • • • • • • • Late Triassic (Norian-Rhaetian) Capnodoce sp . . . 0 0 • • • 0 • ••• Late Triassic

Kozurastrum spo . . . 0 • • • • •• • • • TriaSSic-Early Jurassic (MiddleJurassic?) Pantanellium sp . .... . . 0 • • • • • • • • • • • • • • • • • • • • • • •• • 0 • • Late Triassic to early Cretaceous

Sarla prietoensis Pessagno . . . Late Triassic (late Middle to early middle Norian)

815-02 Bridge River Group age: Middle Triassic

Table 72.5. Cache Creek Complex - Radiolarian associations and age of specimens

C02-08 Cache Creek Group (central belt) age: Middle-Late Triassic (Middle Anisian(?) to Norian) Eptingium sp. cf h manfred! Dumitrica . . . Middle Anisian(?) to Norian

Staurosphaera(?) sp. B in Yao 1982 . . . ?Ladlnian, so far as known Stylosphaera(?) spinulosa (Nakaseko & Nishimura) . . . ?Late Triassic

Triassocampe _sp . . . Middle Triassic (Ladin. to Late Triassic (Norian)

C02-14 Cache Creek Group (central belt) age: Middle-Late Triassic (Middle Anisian(?)-Norian) Stylosphaera(?) japonica (Nakaseko & Nishimura) . . . ?Ladinlan-Norian

Baumgartneria retrospina Dumitrlca . . . Late Anisian to Carnian, insofar as known Eptingium manfred! Dumitrica . . . Middle Anisian(?) to Norian

C03-05 Cache Creek Group (eastern belt, matrix) age: Late Triassic (late Carnian to middle Norian) Capnodoce kochi Blome . . . Late Triassic (l.Carn.(?); e.to l.Middle Norian) Capnodoce sarisa De Wever . . . Late Triassic

Capnodoce sp. cf ~ fragilis Blome . . . Late Triassic (l.Carn.(?); e.to l.Middle Norian) Capnodoce sp. cf ~ media Blome . . . Late Triassic (l.Carn.(?); e.to l.Middle Norian) Capnuchosphaera sp . . . Late Triassic (late Carnian to late Middle Norian) Paleosaturnalis sp . . . Late Triassic

Renziurn sp . . . Late Triassic (l.Carn.(?); e.to l.Middle Norian)

C03-09 Cache Creek Group (eastern belt, matrix) age: Middle-Late Triassic (Ladinian to Norian) Stylosphaera(?) spinulosa (Nakaseko & Nishimura) ••...•.•... ?Late Triassic

Triassocampe sp . . . Middle Triassic (Ladin.) to Late Triassic (Norian) Welirella sp . . . Middle-Late Triassic

C03-13 Cache Creek Group (eastern belt, matrix) age: probably Middle Triassic (late Anisian to Ladinian?) Gomberellus sp . . . ?Ladinian

Oertlispongus sp . . . Late Anisian to Ladinian, insofar as known Paroertlispongus sp . . . Late Anisian to Ladinian, insofar as known Paurinella sp . . . Late Anisian to early Carnian, insofar as known Tetraspongodiscus sp . . . Late Anisian to Carnian

C03-20 Cache Creek Group (eastern belt, matrix) age: Middle Triassic-Late Triassic (Mid.Anis.(?) to Norian) Eptingiurn sp. cf h manfredi Dumitrica . . . Middle Anisian(?) to Norian

Gomberell us sp. . . . ?Ladinian

Plafkeriurn longidentatum Kozur & Mostler . . . ?Late Anisian-Ladinian insofar as known Stylosphaera(?) japonica (Nakaseko & Nishimura) . . . ?Ladinian-Norian

C03-23 Cache Creek Group (eastern belt, matrix) age: Middle-Late Triassic Stylosphaera(?) spinulosa (Nakaseko & Nishimura) . . . ?Late Triassic

Eptingium sp. cf h manfredi Dumitrica . . . Middle Anisian (?) to Norian Triassocampe sp . .I.:.. deweveri Kozur & Mostler . . . ?Ladinian

C03-26 Cache Creek Group (eastern belt, matrix) age: Late Triassic (late Carnian to Middle Norian) Canesium sp . . . Late Triassic (l.Carn.(?); e.to 1.Middle Norian)

~e fragilis Blome . . . Late Triassic (l.Carn.(?); e.to l.Middle Norian) Capnodoce sarisa De Wever . . . Late Triassic

Capnodoce sp. cf ~ malaca Blome . . . Late Triassic (l.Carn.(?); e.to l.Middle Norian) C<;lpnodoce sp. cf ~ primaria Pessagno . . . Late Triassic (1. Carnian to 1. Middle Norian) Triassocampe sp . . . Middle Triassic (Ladinian) to Late Triassic (Norian) Xipha sp . . . Late Triassic (l.Carn. (?); e. to l.Middle Norian)

C05-01 Cache Creek Group (central belt) age: probably Early Permian Pseudoalbaillella scalprata Holdsworth & Jones . . . 0 Early Permian Pseudoalbaillella sp. cf .E:!.:. longuscornis Ishiga & Imoto ... Early Permian

C08-01 Cache Creek Group (central belt) age: Middle-Late Triassic (Middle Anisian(?) to Norian) Stylosphaera( ?) sp. cf ~ spinulosa (Nakaseko Nishimura) . ?Late Triassic

Eptingium sp. cf h manfredi Dumitrica . . . Middle Anisian (?) to Norian

Triassocampe spo . . . 0 • • • • • • • 0 . 0 . 0 . 0 • • • • 0 • • • • • • 0 • • • 0 • • • 0 Middle Triassic (Ladinian) to Late Triassic (Norian)

COB-09 Cache Creek Group (central belt) age: Triassic

Stylosphaera(?) compacta (Nakaseko & Nishimura) . . . ?Late Triassic Stylosphaera(?) japonica (Nakaseko & Nishimura) . . . ?Ladinian-Norian Triassocampe sp. cf ~ deweveri (Nakaseko & Nishimura) ... 0. ?Ladinian

Table 72.6. Chert-pebble conglomerates - Radiolarian associations and ages for specimens

C07-1~ pebble from Cretaceous conglomerate, Highway 12 age: La te Permian Fol11cuculus scholasticus Ormiston & Babcock . . . Late Permian Follicuculus ventricosus Ormiston & Babcock . . . Late Permian

P01-22 pebble from conglomerate near Merritt age: Middle-Late Triassic Stylosphaera(?) sp. of ~ spinulosa (Nakaseko Nishimura). ?Late Triassic Tetraporobrachia sp . . . early Carnian Triassocampe(?) sp. of !:. deweveri (Nakaseko & Nishimura) .. ?Ladinlan Triassocampe(?) sp. G in YAO 1982 . . . ?Ladinian

P01-~2 pebble from conglomerate near Merritt age: Early Jurassic

Emiluvia ap . . . . Early Jurassic-Early Cretaceous Hallum sp ••••••••.••...•...•...•...••...

~suum simplum Yao . . . .

Early Jurassic (e.Pliens.) to e.Cret.(Valongnian) early Early Jurassic?

Praeconocaryomma sp. cf f.:. ^{immodica Pessagno} & Poisson .... 0

PraeconocaryoDlilla spo cf !:.:. media Pessagno & Poisson

Ear ly Jurassic (Sinemurian-P liensbachian) Early Jurassic (?Pliensbachian?)

L01-01 pebble from conglomerate near Courtney Lake age: probably Late Permian Follicuculus sp. cf F. scholasticus Ormiston & Babcock Late Permian

Nazarovella sp . . . ::- ... 0 0 0 • • • 0 . 0 0 . 0 • • 0 • • • 0 • • • 0 • • • • • • • • • • • • Late Permian Pseudoalbaillella sp . . . 0 . 0 0 0 0 • • • • • • • • • • • • • • • • • Carboniferous-Permian

Quingueremis spo 0 . 0 0 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • ••• • • • • • • • • Late Carboniferous to Late Permian

L02-0 1 pebble from conglomerate near Courtney Lake age: Early Permian Pseudoalbaillella lomentaria Ishiga & Imoto . . . Early Permian Pseudoalbaillella sp. cf Ps. u-forma Holdsworth & Jones .... ?Early Permian

Quinqueremis sp . . . :::-.~ . . . Late Carboniferous to Late Permian

L02-0~ pebble from conglomerate near Courtney Lake age: Late Triassic (Norian)

Canesium sp . . . 0 • • • • • • • • • • • • • • • • • • • • 0 0 0 0 0 • • 0 . 0 0 . 0 0 • • • • • • • Late Triassic Cl.Carn? ; e.to l.Middle Norian)

~e antiqua Blome .... 0 • • • • 0 0 0 0 0 0 0 0 . 0 . 0 0 0 . 0 0 • • • • • • • • • • Late Triassic Capnuchosphaera sp . . 0 • • • • • • • • • • • • 0 . 0 0 . 0 . 0 • • 0 • • • 0 . 0 • • 0 • • • • • • Late Triassic Corum spo 0 0 . 0 • • • • • • • • • • • • • • • • • • • • • • • • • ••• • • • • • •••• •• • • • • • • • Late Triassic

(l.Carn.?; e.to l.middle Norian) (l.Carn. ?; e. to l.Middle Norian) Poulpus pansus De Wever .... . . . Late Triassic

Poulpus piabyx De Wever . . . . Late Triassic (Norian)

Guasipetasus sp . . . 0 • • 0 0 • • • • 0 . 0 • • • • • • • • • Late Triassic (l.Carn. ? e. to l.Middle Norian) Renzium adversum Blome . . . 0 • • • • 0 0 • 0 • • • 0 • 0 • • • • • • • • Late Triassic (l. Carn.? e. to l.Middle Norian) Sarla sp--:-crs:-del.icata Blome . . . .

spongosaturnaUs----sp:-cr~ elegans Kozur & Mostler . . . .

(l. Carn.? e. to l.Middle Norian) Late Triassic

Late Triassic Triassocampe nova Yao ... 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Carnian-Norian

A01-02 pebble from conglomerate near Vogt Creek age: Middle-La te TriassiC Pterospongus (?) sp. . . . Ladinian-Carnian

A01-08 pebble from conglomerate near Vogt Creek age: Early Permian Albaillella sp . . . Carboniferous-Permian

Latentifistula crux Nazarov & Ormiston . . . Early Permian (Asselian insofar as known) Latentifistula ~ . . . 0 • • 0 . 0 0 . 0 . 0 . 0 0 • • • 0 • • • • • Early Carboniferous to Early Permian Octatormentum sp. cf 00 cornelli Nazarov & Ormiston . . . .. Early Permian

Guadriremis sp . . . -::.~. 0 . 0 0 • • 0 • • • • • • • • • • • • • • • • • • • • Late Carboniferous to Late Permian

AOl-21 pebble from conglomerate near Vogt Creek age: Early Permian

Pseudoalbaillella longuscornis Ishiga & Imoto ... 0 • • • • • • • Early Permian (Wolfcampian insofar as known) Pseudoalbaillella scalprata Holdsworth & Jones . . . O. Early Permian

Pseudotormentu3 kamigoriensi3 De Wever & Caridroit . . . Late Permian insofar as known Quingueremis sp . . . ....... . . ...... . . 0 0 0 0 Late Carboniferous to Late Permian

AO 1 -28 pebble from conglomera te near Vogt Creek age: Early Jurassic Dictyomitrella sp. cf sp. C in YAO 1982 ••••..•...•. early Early Jurassic?

Hsuum sp . . . early Pliensbachian to late Valanginian Pantanellium sp. cf P. tanuense Pessagno & Blome ••.•... Rhaetian(?)-Hettangian

Pantanellium sp . . . . -::o~

...

⁰ • • • • • 0 • • • • • • • • • • • Late Triassic (early Carnian) to Early Cretaceous Parahsuum simplum Yao . 0 0 0 • • • • • • ••• • • • • • • • • 0 • • • • • • • • • • • • • • • • early Early Jurassic?

Parahsuum(?) sp. C in YAO 1982 . . . early Early Jurassic?

Praeconocaryornma immodica Pessagno & Poisson . . . Early Jurassic to early Tithon.-!ate Kimmer.

AOl-31 pebble from conglomerate near Vogt Creek age: Late Triassic

Capnodoce 3p . . . Late Triassic (late Carnian to late Middle Norian) Capnuchosphaera schenki Blome ...... . . La te Triassic (la te Carnian to late Middle Norian) Capnuchosphaera theloides De Wever . . . 0 0 • • 0 • • • • • • • Late Triassic

Sarla sp . . . 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 0 • • • • Late Triassic (early Carnian to late Norian)

Cache Creek Complex

All radiolarians are from the central and eastern belt of the Cache Creek Complex (Monger and McMillan, 1984). The central belt comprises mid- to Late Permian and Triassic carbonates of the Marble Canyon Formation and minor thin-bedded chert, tuff and chert of Triassic age. The eastern belt is melange containing blocks of Pennsylvanian and Early Permian limestone along with chert, basalt, ultramafic and acidic volcanic blocks, in a chert and argillite matrix of Late Permian to Late Triassic age (Orchard, 1984).

The central belt contains two new radiolarian localities (Fig. 72.3). The first, C08, is located near the road through Marble Canyon, and consists of a cliff of red ribbon chert and carbonates. Two red chert samples, one in place (C08-09), the other in the talus (C08-0t) provided poorly preserved radiolarians respectively of Triassic and Middle to Late Triassic age. The second locality, C02, is situated on the Cornwall Hill road. The outcrop consists of alternating, thinly bedded, cherty carbonate and grey to white ribbon chert that contains clearly visible radiolarians, many of which are joined together, particularly at the tops and bottoms of chert beds. The radiolarians extracted were of Middle or Late Triassic age (C02-08) and of Late Ladinian to Early Carnian age (C02-14). The latter were associated with the conodont Gondolella inclinata Kovacs (determination by B. Vrielynck) which is Upper Ladinian to Lower Carnian. In the same general area, Orchard (J 984; localities 2 I and 22) obtained Early (?) Norian and Smithian ages.

Radiolarians were extracted from the matrix rocks at two main locaties in the eastern melange belt. Locality C03 consists of a 500 m long road cut in chert, cherty argillite and argillite with a variety of blocks on the west side of the settlement of Cache Creek (Fig. 72.3). Six stratigraphic levels were dated there (Table 72.5), ranging from Middle to Upper Triassic. Radiolarians from locality C05, (GSC locality C-087650, collected originally by K.R. Shannon, in Monger and McMillan, 1984) were recollected, and include Lower Permian forms.

Chert-pebble conglomerates

Small, isolated outcrops of chert-pebble conglomerate, sandstone and argillite are scattered across parts of Ashcroft (921) and Hope (92H) map areas (Fig. 72.ll. In places, these strata are known to be of mid- to Late Cretaceous age (Monger and McMillan, 1984) but elsewhere are undated, and are correlated solely on the basis of lithological similarity.

Radiolarians in the chert pebbles had not been studied previously, but four collections were made in an attempt to obtain some idea of the provenances of the conglomerates (Tables 72.3, 72.6).

Exposed at one locality is the mid- to Late Cretaceous conglomerate that lies within the central belt of the Cache Creek Complex. The chert pebbles within it are slightly metamorphosed, and only one, Late Permian age (C07-14) was obtained (Table 72.6).

Chert pebbles were examined from three, undated conglomerates near the town of Merritt. Pebbles northeast of Merritt (Locality POI) ranged from Late Permian to Early Jurassic. Outcrops near Courtney Lake (Localities LO I, L02) yielded Early Permian to Late Triassic fossils. Chert pebbles from conglomerate near Vogt Creek (Locality AOl) ranged from Early Permian to Early Jurassic with some adjacent pebbles yielding very different ages.

Conclusion

At present, radiolarian faunas in the lithological packages containing abundant chert (Cache Creek and Bridge River complexes, Hozameen Group) are too poorly known to

make any precise correlations; the presence of Jurassic pebbles in the conglomerates near Merritt favours their derivation from the Hozameen Group or Bridge River Complex, rather than the Cache Creek Complex.

Acknow ledgments

I would like to thank B. Forman and M.J. Orchard for their help in the field, P. De Wever and M.J. Orchard for critical reading of the manuscript, and J. W .H. Monger for help in corrections and translation.

Selected bibliography

Cameron, B.E.B. and Monger, J.W.H.

197 I: Middle Triassic conodonts from the Fergusson Group, northeastern Pemberton map-area, British Columbia; in Report of Activities, Part B, Geological Survey of Canada, Paper ?I-IB, p. 94-96.

De Wever, P.

1982: Radiolaires du Trias et du Lias de la Tethys (Systematique, Stratigraphie); Societe Geologique du Nord, Lille, Publication No.7, 599 p.

Dumitrica, P.

1970: Cryptocephalic and cryptothoracic Nassellaria in some Mesozoic deposits of Romania; Revue Roumaine de Geologie, Geophysique et Geographie, Serie de Geologie, Bucharist, v. 14, p.45-124.

Monger, J.W.H. and McMillan, W.J.

1984: Bedrock geology of Ashcroft (920 map area;

Geological Survey of Canada, Open File 980.

Monger, J.W.H. and Price, R.A.

1979: Geodynamic evolution of the Canadian Cordillera - progress and problems; Canadian Journal of Earth Sciences, v. 16, p. 770-791.

Orchard, M.J.

1981: Triassic conodonts in the Cache Creek Group, Marble Canyon, southern British Columbia; in Current Research, Part A, Geological Survey

Of

Canada, Paper 81-lA, p. 357-359.

1984: Pennsylvanian, Permian and. Triassic conodonts from the Cache Creek Group, southern British Columbia; in Current Research, Part B, Geological SUrvey of Canada, Paper 84-lB, p. 197-206.

Pessagno, E.A., Jr. and Newport, R.L.

1972: A technique for extracting Radiolaria from Radiolarian chert; Micropaleontology, v. 18/2, p. 231-234.

Potter, C.J.

1983: Geology of the Bridge River Complex, southern Shulaps Range, British Columbia: a record of convergent tectonics; unpublished Ph.D thesis, Uni versi ty of Washington, 192 p.

Seiders, V.M. and Blome, C.D.

1984: Clast compositions of Upper Mesozoic conglom- erates of the California Coast Ranges and their tectonic significance; ~ Franciscan Geology of Northern California, ed. M.C. Blake, Jr.; Pacific Section Society of Economic Paleontologists and Mineralogists, v. 43, p. 135-148.

Yao,A.

1982: Middle Triassic to Early Jurassic radiolarians from the Inuyama area, Central Japan; Journal of Geosciences, Osaka City University, Osaka, v. 25, no. 4, p. 55-70.