Supplemental Material: Ulungarat Basin: Record of a major Middle Devonian to Mississippian syn-rift to post-rift tectonic transition, eastern Brooks Range, Arctic Alaska

10.1130/geos.s.14781495.v1 ◽

2021 ◽

Author(s):

A.V. Anderson ◽

K.E. Meisling

Keyword(s):

Middle Devonian ◽

Depositional Environments ◽

Reference List ◽

Brooks Range ◽

Tectonic Transition ◽

Arctic Alaska ◽

Age Constraints

<div>Describes the organization, sedimentology, and depositional environments of the Ulungarat Basin succession including description of type sections of the Ulungarat and Mangaqtaaq formations. Table S1 documents published fossil and radiometric age constraints used to construct the mid-Paleozoic tectonostratigraphic chart (Fig. 12), including basis for age assignment and list of source references. A reference list of all sources cited in Table S1 is included.<br></div>

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Supplemental Material: Ulungarat Basin: Record of a major Middle Devonian to Mississippian syn-rift to post-rift tectonic transition, eastern Brooks Range, Arctic Alaska

10.1130/geos.s.14781495.v3 ◽

2021 ◽

Author(s):

A.V. Anderson ◽

K.E. Meisling

Keyword(s):

Middle Devonian ◽

Depositional Environments ◽

Reference List ◽

Brooks Range ◽

Tectonic Transition ◽

Arctic Alaska ◽

Age Constraints

<div>Describes the organization, sedimentology, and depositional environments of the Ulungarat Basin succession including description of type sections of the Ulungarat and Mangaqtaaq formations. Table S1 documents published fossil and radiometric age constraints used to construct the mid-Paleozoic tectonostratigraphic chart (Fig. 12), including basis for age assignment and list of source references. A reference list of all sources cited in Table S1 is included.<br></div>

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Supplemental Material: Ulungarat Basin: Record of a major Middle Devonian to Mississippian syn-rift to post-rift tectonic transition, eastern Brooks Range, Arctic Alaska

10.1130/geos.s.14781495.v2 ◽

2021 ◽

Author(s):

A.V. Anderson ◽

K.E. Meisling

Keyword(s):

Middle Devonian ◽

Depositional Environments ◽

Reference List ◽

Brooks Range ◽

Tectonic Transition ◽

Arctic Alaska ◽

Age Constraints

<div>Describes the organization, sedimentology, and depositional environments of the Ulungarat Basin succession including description of type sections of the Ulungarat and Mangaqtaaq formations. Table S1 documents published fossil and radiometric age constraints used to construct the mid-Paleozoic tectonostratigraphic chart (Fig. 12), including basis for age assignment and list of source references. A reference list of all sources cited in Table S1 is included.<br></div>

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A new species of Droharhynchia (Brachiopoda) from the lower Middle Devonian (Eifelian) of west-central Alaska

Journal of Paleontology ◽

10.1017/s0022336000034223 ◽

1994 ◽

Vol 68 (6) ◽

pp. 1235-1240 ◽

Cited By ~ 1

Author(s):

Mary E. Baxter ◽

Robert B. Blodgett

Keyword(s):

New Species ◽

Middle Devonian ◽

The Arctic ◽

Geographic Proximity ◽

Brooks Range ◽

West Central ◽

Arctic Alaska ◽

Northern Alaska ◽

A New Species

A new species of the genus Droharhynchia Sartenaer is established from lower Eifelian strata of west-central Alaska and the northwestern Brooks Range of Alaska. Droharhynchia rzhonsnitskayae n. sp. occurs in the Cheeneetnuk Limestone of the McGrath A-5 quadrangle, west-central Alaska, and the Baird Group of the Howard Pass B-5 quadrangle, northwestern Alaska. These occurrences extend the lower biostratigraphic range of both the genus and the subfamily Hadrorhynchiinae into the Eifelian. They also suggest close geographic proximity of the Farewell terrane of southwestern and west-central Alaska and the Arctic Alaska superterrane of northern Alaska during Devonian time.

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Ulungarat Basin: Record of a major Middle Devonian to Mississippian syn-rift to post-rift tectonic transition, eastern Brooks Range, Arctic Alaska

Geosphere ◽

10.1130/ges02272.1 ◽

2021 ◽

Author(s):

Arlene V. Anderson ◽

Kristian E. Meisling

Keyword(s):

Middle Devonian ◽

Passive Margin ◽

Rift Basin ◽

Early Devonian ◽

Marine Strata ◽

The North ◽

Tectonic Transition ◽

Arctic Alaska ◽

Tectonic Settings ◽

Rifted Margin

The Ulungarat Basin of Arctic Alaska is a unique exposed stratigraphic record of the mid-Paleozoic transition from the Romanzof orogeny to post-orogenic rifting and Ellesmerian passive margin subsidence. The Ulungarat Basin succession is composed of both syn-rift and post-rift deposits recording this mid-Paleozoic transition. The syn-rift deposits unconformably overlie highly deformed Romanzof orogenic basement on the mid-Paleozoic regional angular unconformity and are unconformably overlain by post-rift Endicott Group deposits of the Ellesmerian passive margin. Shallow marine strata of Eifelian age at the base of the Ulungarat Formation record onset of rifting and limit age of the Romanzof orogeny to late Early Devonian. Abrupt thickness and facies changes within the Ulungarat Formation and disconformably overlying syn-rift Mangaqtaaq Formation suggest active normal faulting during deposition. The Mangaqtaaq Formation records lacustrine deposition in a restricted down-faulted structural low. The unconformity between syn-rift deposits and overlying post-rift Endicott Group is interpreted to be the result of sediment bypass during deposition of the outboard allochthonous Endicott Group. Within Ulungarat Basin, transgressive post-rift Lower Mississippian Kekiktuk Conglomerate and Kayak Shale (Endicott Group) are older and thicker than equivalents to the north. North of Ulungarat Basin, deformed pre-Middle Devonian rocks were exposed to erosion at the mid-Paleozoic regional unconformity for ~50 m.y., supplying sediments to the rift basin and broader Arctic Alaska rifted margin beyond. Although Middle Devonian to Lower Mississippian chert- and quartz-pebble conglomerates and sandstones across Arctic Alaska share a common provenance from the eroding ancestral Romanzof highlands, they were deposited in different tectonic settings.

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