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Upper Cretaceous and Lower Jurassic strata in shallow cores on the Chukchi Shelf, Arctic Alaska: Chapter C in Studies by the U.S. Geological Survey in Alaska, vol. 15

Professional Paper 1814-C

By:
ORCID iD , ORCID iD , and ORCID iD
https://doi.org/10.3133/pp1814C

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Abstract

Shallow cores collected in the 1980s on the Chukchi Shelf of western Arctic Alaska sampled pre-Cenozoic strata whose presence, age, and character are poorly known across the region. Five cores from the Herald Arch foreland contain Cenomanian to Coniacian strata, as documented by biostratigraphy, geochronology, and thermochronology. Shallow seismic reflection data collected during the 1970s and 1980s show that these Upper Cretaceous strata are truncated near the seafloor by subtle angular unconformities, including the Paleogene mid-Brookian unconformity in one core and the Pliocene-Pleistocene unconformity in four cores. Sedimentary structures and lithofacies suggest that Upper Cretaceous strata were deposited in a low accommodation setting that ranged from low-lying coastal plain (nonmarine) to muddy, shallow-marine environments near shore. These observations, together with sparse evidence from the adjacent western North Slope, suggest that Upper Cretaceous strata likely were deposited across all of Arctic Alaska.

A sixth core from the Herald Arch contains lower Toarcian marine strata, indicated by biostratigraphy, truncated by a Neogene or younger unconformity. These Lower Jurassic strata evidently were deposited south of the arch, buried structurally to high levels of thermal maturity during the Early Cretaceous, and uplifted on the Herald thrust-fault system during the mid to Late Cretaceous. These interpretations are based on regional stratigraphy and apatite fission-track data reported in a complementary report and are corroborated by the presence of recycled palynomorphs of Early Jurassic age and high thermal maturity found in Upper Cretaceous strata in two of the foreland cores. This dataset provides evidence that uplift and exhumation of the Herald thrust belt provided sediment to the foreland during the Late Cretaceous.

Suggested Citation

Houseknecht, D.W., Craddock, W.H., and Lease, R.O., 2016, Upper Cretaceous and Lower Jurassic strata in shallow cores on the Chukchi Shelf, Arctic Alaska, in Dumoulin, J.A., ed., Studies by the U.S. Geological Survey in Alaska, vol. 15: U.S. Geological Survey Professional Paper 1814–C, 37 p., http://dx.doi.org/10.3133/pp1814C.

ISSN: 2330-7102 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Geologic Setting
  • Previous Work
  • Methods
  • Core Descriptions and Data
  • Discussion
  • Conclusions
  • References Cited

Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Upper Cretaceous and Lower Jurassic strata in shallow cores on the Chukchi Shelf, Arctic Alaska: Chapter C in Studies by the U.S. Geological Survey in Alaska, vol. 15
Series title:
Professional Paper
Series number:
1814
Chapter:
C
DOI:
10.3133/pp1814C
Year Published:
2016
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Eastern Energy Resources Science Center
Description:
Report: v, 37 p.; 10 Figures
Larger Work Type:
Report
Larger Work Subtype:
USGS Numbered Series
Larger Work Title:
Studies by the U.S. Geological Survey in Alaska, vol. 15 (Professional Paper 1814)
Country:
Russia, United States
Online Only (Y/N):
Y
Additional Online Files (Y/N):
Y