Title | Upper Paleozoic to lower Mesozoic strata and their conodonts, western Coast Plutonic Complex, British Columbia |
Author | Woodsworth, G J; Orchard, M J |
Source | Canadian Journal of Earth Sciences vol. 22, 1985 p. 1329-1344, https://doi.org/10.1139/e85-137 (Open Access) |
Year | 1985 |
Alt Series | Earth Sciences Sector, Contribution Series 2005821 |
Publisher | Canadian Science Publishing |
Document | serial |
Lang. | English |
Media | paper; on-line; digital |
File format | pdf |
Province | British Columbia |
NTS | 103J/07; 103J/10 |
Area | Moffat Islands; Randall Island; Dunira Island; Ducie Island |
Lat/Long WENS | -130.8000 -130.7167 54.5333 54.4167 |
Subjects | paleontology; stratigraphy; structural geology; economic geology; microfossils; conodonts; biostratigraphy; stratigraphic analyses; stratigraphic correlations; systematic paleontology; fossil
descriptions; taxonomy; fossil distribution; relative ages; structural analyses; tectonic history; metamorphism; deformation; metamorphic rocks; greenschist facies; sedimentary rocks; limestones; siltstones; dolomites; clastics; phyllites; rhyolites;
volcanism; mafic volcanic rocks; igneous rocks; flysch; mineral deposits; mineral potential; veins; sulphide deposits; copper; zinc; galena; sphalerite; chalcopyrite; volcanogenic deposits; base metals; precious metals; Coast Plutonic Complex; Dunira
Formation; Randall Formation; Alexander Terrane; Gravina-Nutzotin belt; Phanerozoic; Mesozoic; Cretaceous; Jurassic; Triassic; Paleozoic; Carboniferous |
Illustrations | sketch maps; stratigraphic columns; photographs; tables; photomicrographs; stratigraphic charts |
Abstract | Six lithologic units, including two newly named formations, were mapped on Randall, Dunira, and nearby islands. The islands are characterized by greenschist-facies metamorphism and westerly directed
thrusting. The oldest unit is a Late Mississippian, massive limestone on Ducie Island. The Dunira Formation, composed of thin-bedded limestone and siltstone, is Early and Middle Pennsylvanian in age. It is unconformably overlain by limestone and
dolomite of the Upper Triassic Randall Formation. The Randall Formation grades upwards into a green phyllitic unit of Late Triassic(?) age. Rhyolitic and more mafic volcanic rocks may represent a bimodal volcanic suite of Early Jurassic age, based on
a U-Pb date of 188 Ma on zircons. These five units correlate with rocks in the Alexander Terrane in southeastern Alaska. The sixth and presumed youngest unit consists of flysch-like sedimentary rocks of probable Middle Jurassic to Early Cretaceous
age that may correlate with rocks of the Gravina-Nutzotin belt. The three older units yielded 15 conodont genera from 29 localities. The 13 Paleozoic genera are described and illustrated. |
GEOSCAN ID | 222004 |
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