Structural geology and tectonic evolution of the central Brooks Range, Alaska

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6198551

Hickman, R G

The Brooks Range is the northwestern extension of the late Mesozoic-early Tertiary Cordilleran thrust-fold belt. From north to south the central Brooks Range can be divided into 7 Zones: (1) large detachment folds in Cretaceous strata, (2) imbricately faulted mid-Cretaceous strata, (3) imbricately faulted Lower Cretaceous-Mississippian strata, (4) south-dipping sheets of Upper Devonian and younger strata, (5) para-autochthonous pre-Upper Devonian and younger strata, (6) para-autochthonous Devonian and older schists, (7) allochthonous ultramafic and basaltic rocks. Minimum shortening across the range is about 660 km. In the Late Triassic, a shoreline lay near the present Arctic coast and a broad, southward-deepening shelf extended to a continental margin south of the present Brooks Range. In the Jurassic, southward subduction of this margin beneath an island arc resulted in obduction of oceanic crust onto the margin and initiation of northward thrusting of the continental margin rocks. Lithospheric loading of these nappes resulted in development of a series of foredeeps to the north. These basins were filled with submarine fan deposits derived from the uplifted nappes. In the mid-Early Cretaceous, imbricate thrusting produced a series of far-travelled allochthons and dismembered the early foredeep deposits. Concurrently, a new foredeep developed to the north, while uplift continued to the south. The new basin was largely filled during the Albian by flysch- and later by mollase-type sediments.

• Research Organization: Union Oil Science and Technical Division, Brea, CA (USA)
• OSTI ID: 6198551
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
ALASKA
BASALT
CENOZOIC ERA
CONTINENTAL MARGIN
CRETACEOUS PERIOD
FEDERAL REGION X
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
IGNEOUS ROCKS
MESOZOIC ERA
METAMORPHIC ROCKS
MOUNTAINS
NORTH AMERICA
ORIGIN
OROGENESIS
PLATE TECTONICS
ROCKS
SCHISTS
SEDIMENTARY BASINS
SEDIMENTS
SUBDUCTION ZONES
TECTONICS
TERTIARY PERIOD
USA
VOLCANIC ROCKS