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

Conference · Tue Jan 01 00:00:00 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-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

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