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Stratigraphic, structural, and tectonic setting of an Upper Devonian-Mississippian volcanic-sedimentary sequence and association base metal deposits in the Pelly Mountains, southeastern Yukon Territory

The central Pelly Mountains in southeastern Yukon Territory consist of imbricate thrust sheets, which have undergone syn- and post-thrusting deformation and metamorphism. The local geology is further complicated by intrusion of Upper Cretaceous batholiths, and by strike-slip faulting related to the Tintina Fault, a major northwest-trending transcurrent fault of uppermost Cretaceous or early Tertiary age. This faulting disrupts
the northeast edge of the study area.
Upper Devonian and Mississippian strata are present in at least two of the thrust sheets, but the Mississippian volcanic rocks occur in only one of them. The volcanic rocks consist of volcaniclastic material with minor interbedded flows, and were deposited in a submarine
environment. Several coeval and cogenetic syenite and trachyte domes and small stocks are the remains of vent areas. Although the volcanic
rocks are all highly altered and show evidence of widespread chemical mobility, trace element data indicate that the rocks are meta-luminous trachytes, most closely resembling peralkaline volcanics generated in extensional environments. This suggestion of a predominantly extensional tectonic setting in mid-Mississippian time in the Pelly Mountains is consistent with recent tectonic syntheses for the area.
Stratabound and stratiform massive base metal sulphide deposits that occur within the Mississippian volcanic sequence are similar in

many respects to the Kuroko-type volcanogenic massive sulphide deposits of Japan. The Pelly Mountains deposits, however, are among the first known occurrences in the world of Kuroko-type mineralization in a rift environment. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Identiferoai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/22257
Date January 1979
CreatorsMortensen, James Kenneth
Source SetsUniversity of British Columbia
LanguageEnglish
Detected LanguageEnglish
TypeText, Thesis/Dissertation
RightsFor non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

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