About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 64 (1980)

Issue: 5. (May)

First Page: 754

Last Page: 755

Title: Evolution of Brooks Range Thrust Belt and Arctic Slope, Alaska: ABSTRACT

Author(s): Charles G. Mull

Article Type: Meeting abstract

Abstract:

Rotation of a small continental lithospheric plate in Early Cretaceous time formed the southern part of the Canada basin of the Arctic Ocean and an Atlantic-style extensional plate margin underlying the continental shelf north of Alaska. Simultaneously a compressional margin formed to the south, causing over 500 km of crustal shortening and large-scale obduction of ophiolitic rocks over the leading edge of the Arctic alaska plate. An asymmetric foredeep north of the thrust belt is filled with Neocomian to Albian lithic flysch derived from the imbricated sedimentary and mafic-ultramafic igneous terranes. Middle and Late Cretaceous isostatic rebound of the depressed sialic crust resulted in several kilometers of vertical uplift in the southern Brooks

End_Page 754------------------------------

Range and extensive refolding and refaulting of the allochthons throughout the range. At the mountain front, autochthonous Triassic and older sedimentary rocks are at depths of over 8 km except in the northeast, where they are exposed by erosion of a regional Late Cretaceous and Tertiary vertical uplift centered in the Romanzof Mountains. North of the range an Albian and Late Cretaceous molassoid wedge derived from the south and west is deformed by decollement that dies out northward; the zone of detachment is incompetent Albian shale.

Oil and gas potential is greatest to the north, where Cretaceous sedimentary rocks truncate and prograde over the rifted plate margin. At Prudhoe Bay, northward onlapping Carboniferous to Jurassic platform sedimentary rocks are truncated by organic-rich Cretaceous shale beds, which are the hydrocarbon source and part of the trap. Southward the basin is dominantly a gas-prone stratigraphic trap province; however, potential reservoirs are limited. In the Brooks Range, reservoir potential exists in only a few areas of Carboniferous carbonate rocks that have extreme structural complexity.

End_of_Article - Last_Page 755------------

Copyright 1997 American Association of Petroleum Geologists