Early Cretaceous gold–silver mineralization in the Sylvester allochthon, near Cassiar, north central British Columbia

1986 ◽  
Vol 23 (9) ◽  
pp. 1455-1458 ◽  
Author(s):  
Dale A. Sketchley ◽  
A. J. Sinclair ◽  
C. I. Godwin
Keyword(s):  
British Columbia ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Related Event ◽  
North Central ◽  
Quartz Veins ◽  
Early Tertiary ◽  
Gold Silver ◽  
Silver Mineralization

K–Ar dates on sericite from several gold–silver bearing white quartz veins in the Cassiar area indicate that mineralization occurred in the Early Cretaceous at about 130 Ma. Thus, these veins predate the mid-Cretaceous Cassiar batholith and Late Cretaceous and early Tertiary plutons in the immediate area. The Early Cretaceous date probably represents either a thermal precursor to emplacement of the Cassiar batholith or a structurally related event associated with allochthonous emplacement of the Sylvester Group. Either of these events may have caused circulation of the meteoric fluids responsible for the veins.

Cretaceous sedimentation and tectonics, Tyaughton–Methow Basin, southwestern British Columbia

1985 ◽  
Vol 22 (2) ◽  
pp. 154-174 ◽  
Author(s):  
Karen L. Kleinspehn
Keyword(s):  
British Columbia ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Strike Slip ◽  
Dispersal Patterns ◽  
Western Margin ◽  
Early Tertiary ◽  
Active Intermediate ◽  
Major Strike ◽  
Fault Displacement

The Mesozoic Tyaughton–Methow Basin straddles the Fraser–Yalakom–Pasayten – Straight Creek (FYPSC) strike-slip fault zone between six tectono-stratigraphic terranes in southwestern British Columbia. Data from Hauterivian–Cenomanian basin fill provide constraints for reconstruction of fault displacement and paleogeography.The Early Cretaceous eastern margin of the basin was a region of uplifted Jurassic plutons and active intermediate volcanism. Detritus shed southwestward from that margin was deposited as the marine Jackass Mountain Group. Albian inner to mid-fan facies of the Jackass Mountain Group can be correlated across the Yalakom Fault, suggesting 150 ± 25 km of post- Albian dextral offset. Deposits of the Jackass Mountain Group overlap the major strike- slip zone (FYPSC). If that zone represents the eastern boundary of the tectono-stratigraphic terrane, Wrangellia, then accretion of Wrangellia to terranes to the east occurred before late Early Cretaceous time.The western margin of the basin first became prominent with Cenomanian uplift of the Coast Mountain suprastructure. Uplift is recorded by dispersal patterns of the volcaniclastic Kingsvale Group southwest of the Yalakom Fault.Reversing 110 km of Late Cretaceous – early Tertiary dextral motion on the Fraser – Straight Creek Fault followed by 150 km of Cenomanian – Turonian motion on the Yalakom – Ross Lake Fault restores the basin to a reasonable depositional configuration.

Late Cretaceous and early Tertiary plutonism and deformation in the Skagit Gneiss Complex, North Cascade Range, Washington and British Columbia

1991 ◽  
Vol 103 (10) ◽  
pp. 1297-1307 ◽  
Author(s):  
RALPH A. HAUGERUD ◽  
PETER VAN DER HEYDEN ◽  
ROWLAND W. TABOR ◽  
JOHN S. STACEY ◽  
ROBERT E. ZARTMAN
Keyword(s):  
British Columbia ◽  
Late Cretaceous ◽  
Cascade Range ◽  
Gneiss Complex ◽  
Early Tertiary

Early to middle Cretaceous paleogeography of north-central British Columbia: stratigraphy and basin analysis of the Skeena Group

1997 ◽  
Vol 34 (12) ◽  
pp. 1644-1669 ◽  
Author(s):  
Kari N. Bassett ◽  
Karen L. Kleinspehn
Keyword(s):  
British Columbia ◽  
Early Cretaceous ◽  
Tidal Basin ◽  
Second Phase ◽  
Western Basin ◽  
North Central ◽  
Devil’S Claw ◽  
Oblique Convergence ◽  
Basin Margin ◽  
Basin Fill

The Lower–middle Cretaceous Skeena Group records the Early Cretaceous evolution of the southern margin of the Jura-Cretaceous Bowser basin in north-central British Columbia. We formalize Skeena Group nomenclature and present interpretations of three distinct paleogeographic and tectonic phases. During the first phase (Neocomian–Aptian), Skeena deposition was limited to a restricted tidal basin represented by Laventie Formation black-shale deposits, surrounded by coal-swamp deltas of the lower Bulkley Canyon Formation. The lower Skeena Group, correlated to the McEvoy Formation (Bowser Lake Group) in the northern basin, represents final filling of the Bowser foredeep produced by Jurassic accretion of the Intermontane Superterrane to North America. In the second phase (early Albian – Early Cenomanian), marine deposition transgressed eastward and southward accompanied by intrabasinal Rocky Ridge volcanism shedding volcanic detritus into the Kitsuns Creek Member of the Bulkley Canyon Formation. The Rocky Ridge Formation does not correlate northward to other Bowser basin fill but represents intrabasinal volcanism in a transtensional setting along the Omineca continental arc. During the final phase (early–middle Cenomanian), red-bed chert-pebble fluvial deposits of the Rocher Deboule Formation prograded westward, shifting the shoreline to tide-dominated deltas on the far western basin margin. The Rocher Deboule Formation correlates to the Devil's Claw Formation (Bowser Lake Group), the lower member of the Tango Creek Formation (Sustut Group), and, tentatively, to the lower conglomeratic Kasalka Group, all attributed to transpressional Omineca uplift and cannibalization of older Bowser basin fill. Thus the southern basin margin evolved from an Early Cretaceous flexural foredeep to a middle Cretaceous arc setting dominated by oblique convergence, first transtensional then transpressional.

Spatially overlapping episodes of deformation, metamorphism, and magmatism in the southern Omineca Belt, southeastern British Columbia

2018 ◽  
Vol 55 (1) ◽  
pp. 84-110 ◽  
Author(s):  
Ewan Russell Webster ◽  
David R.M. Pattison
Keyword(s):  
British Columbia ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Middle Jurassic ◽  
Canadian Cordillera ◽  
Spatial Relationships ◽  
Metamorphic Belt ◽  
Facies Metamorphism ◽  
Contact Aureoles ◽  
Greenschist Facies Metamorphism

The southeastern Omineca Belt of the Canadian Cordillera preserves a record of overlapping Barrovian and Buchan metamorphism spanning 180–50 Ma. This paper documents the timing, character, and spatial relationships that define separate domains of Middle Jurassic, Early Cretaceous, and Late Cretaceous deformation and metamorphism, and the nature of the geological interfaces that exist between them. A domain of Early Jurassic deformation (D1) and regional greenschist-facies metamorphism (M1) is cross-cut by Middle Jurassic (174–161 Ma) intrusions. Associated contact aureoles are divided into lower pressure (cordierite-dominated; ∼2.5–3.3 kbar; 1 kbar = 100 MPa) and higher pressure (staurolite-bearing; 3.5–4.2 kbar) subtypes; contact metamorphic kyanite occurs rarely in some staurolite-bearing aureoles. Jurassic structures are progressively overprinted northwards by Early Cretaceous deformation and metamorphism (D2M2), manifested in a tightening of Jurassic structures, development of more pervasive ductile fabrics, and Barrovian metamorphism. The D2M2 domain is the southerly continuation of the 600 km long Selkirk–Monashee–Cariboo metamorphic belt. Mid-Cretaceous intrusions (118–90 Ma) were emplaced throughout the D2M2 domain, the earliest of which contain D2 fabrics, but cut M2 isograds. The D2M2 domain makes a continuous, southeasterly transition into a domain of Late Cretaceous regional Barrovian metamorphism and deformation (D3M3; 94–76 Ma). The interface between these two domains is obscured by the coaxial nature of the deformation and the apparent continuity of the metamorphic zones, resulting in a complex and cryptic interface. Similarities between the D3M3 domain and the Selkirk Crest of Idaho and Washington suggest that this domain is the northerly continuation of the northward-plunging Priest River Complex.

Paleomagnetism of the Late Cretaceous-Early Tertiary north-central Montana Alkalic Province

1983 ◽  
Vol 88 (B12) ◽  
pp. 10593-10609 ◽  
Author(s):  
J. F. Diehl ◽  
M. E. Beck ◽  
S. Beske-Diehl ◽  
D. Jacobson ◽  
B. C. Hearn
Keyword(s):  
Late Cretaceous ◽  
North Central ◽  
Early Tertiary ◽  
Central Montana

Review of radiometric data from the Yukon Crystalline Terrane, Alaska and Yukon Territory

1985 ◽  
Vol 22 (4) ◽  
pp. 525-537 ◽  
Author(s):  
Frederic H. Wilson ◽  
James G. Smith ◽  
Nora Shew
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Yukon Territory ◽  
Early Jurassic ◽  
Metamorphic Event ◽  
East Central ◽  
Early Tertiary ◽  
Radiometric Data

The results of more than 20 years of geochronological studies in the Yukon Crystalline Terrane in east-central Alaska and the western Yukon Territory suggest at least six igneous and thermal (metamorphic?) events. Plutonism during Mississippian, Early Jurassic, mid-Cretaceous, Late Cretaceous, and early Tertiary times is indicated. Evidence also indicates that Mississippian, Early Jurassic, late Early Cretaceous, and late Cretaceous thermal (metamorphic?) events have affected parts of the terrane. The western part of the terrane was affected by a significant regional metamorphic event in late Early Cretaceous time, followed by a terrane-wide mid-Cretaceous plutonic event. The pattern of K–Ar ages allows division of the terrane into domains, bounded by northeast-trending lineaments.

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