Clastic sedimentary rocks of the Nanaimo Group on Saltspring Island, British Columbia are Late Cretaceous in age, overlie a deformed and intruded Paleozoic basement complex, and consist of
eight formations. These eight formations, from oldest to youngest, are the Comox, Haslam, Extension-Protection, Cedar District, De Courcy, Northumberland, Geoffrey, and Spray...
The western part of the Late Cretaceous Nanaimo Basin
is exposed on Vancouver Island at Nanaimo, British Columbia.
The five lowest members of the Nanaimo Group are present
and represent a complete sedimentary cycle. The two lowest
formations, the Comox and Haslam, represent the marine part
of the cycle. The...
Regionally preserved in a structural basin, rocks of
the Cretaceous Nanaimo Group nonconformably overlie metavolcanic
and metasedimentary rocks of the Permian and older
Sicker Group.
Cretaceous rocks of the thesis area occur in three
formations, the Comox, Extension-Protection, and Cedar Dist;
and, during two cycles, were deposited in environments which,...
An ancient delta complex is partly recorded by the upper seven
formations of the Cretaceous Nanaimo Group exposed on Mayne and
Samuel Islands of southwestern British Columbia. Features especially
suggestive of deltaic sedimentation here are: upward-coarsening
marine to fluvial sequences, cyclic repetition of facies, subaqueous
slumping, fluvial-marine interfingering, facies changes,...
During the Late Mississippian-Early Pennsylvanian (latest
Chesterian-early Morrowan), a thick sequence of shallow -water
carbonate-clastic sediments, equivalent to the "Amsden" and lower
Quadrant Formations, was deposited in the Snowcrest trough on the
western margin of the northern Rocky Mountain Cordilleran platform
in southwestern Montana. Today this late Chesterian sequence is...
The Middle and West Forks of Little Sheep Creek in the southern Tendoy Range have incised valleys across Cenozoic structural features exposing strata that range in age from the Mississippian to the Neoene. Paleozoic strata are 1,349 m thick and belong to the Mission Canyon Limestone, the Big Snowy, Amsden,...
The Garnet Range-Bearmouth area of western Montana was the
depositional site for basinal, platform slope, shelf, and
peritidal Mississippian carbonate rocks. The following
stratigraphic units, listed in ascending order, are recognized:
the Paine Limestone, Middle Canyon Formation, Mission Canyon
Limestone, and McKenzie Canyon Limestone of the Tendoy Group; the
Kibbey...
The bedrock of Thetis, Kuper, and seven adjacent islands and
islets of British Columbia's Gulf Islands consists of four Late Cretaceous
(Campanian) formations of the Nanaimo Group. The four, from
oldest to youngest, are the Cedar District, De Courcy, Northumberland,
and Geoffrey Formations.
The formations vary greatly in thickness but...
Pre-Tertiary metamorphic rocks, Jurassic granitic intrusions,
and Eocene basalts are exposed along the North Fork of the John Day
River at its confluence with Granite Creek. Geochemical and textural
evidence suggest greenschist-metamorphosed, strongly sheared,
volcanogenic rocks originated in an island-arc environment. These
greenstones were apparently intruded during the Late Permian...