Upper Cretaceous and Lower Jurassic Strata in Shallow Cores on the Chukchi Shelf, Arctic Alaska
Links
- Document: Report (3.9 MB pdf)
- Larger Work: This publication is Chapter C of Studies by the U.S. Geological Survey in Alaska, Volume 15
- Figures:
- Figure 4 - High Resolution (170 MB pdf) Graphic section and composite photograph of U.S. Geological Survey vibracore C62, Chukchi Shelf, Alaska
- Figure 6 - High Resolution (170 MB pdf) Graphic section and composite photograph of U.S. Geological Survey vibracore C67, Chukchi Shelf, Alaska
- Figure 8 - High Resolution (390 MB pdf) Graphic section and composite photograph of U.S. Geological Survey vibracore C65, Chukchi Shelf, Alaska
- Figure 11 - High Resolution (431 MB pdf) Graphic section and composite photograph of U.S. Geological Survey vibracore C53, Chukchi Shelf, Alaska
- Figure 13 - High Resolution (23 MB pdf) Composite photograph of U.S. Geological Survey cores from the Chukchi Shelf, Alaska, showing examples of damage induced by rotary coring
- Figure 16A - High Resolution (468 MB pdf) Composite photographs of U.S. Geological Survey rotary core C3, Chukchi Shelf, Alaska
- Figure 16B - High Resolution (456 MB pdf) Composite photographs of U.S. Geological Survey rotary core C3, Chukchi Shelf, Alaska
- Figure 16C - High Resolution (476 MB pdf) Composite photographs of U.S. Geological Survey rotary core C3, Chukchi Shelf, Alaska
- Figure 16D - High Resolution (486 MB pdf) Composite photographs of U.S. Geological Survey rotary core C3, Chukchi Shelf, Alaska
- Figure 20 - High Resolution (342 MB pdf) Photographs of U.S. Geological Survey rotary core C7, Chukchi Shelf, Alaska
- Download citation as: RIS | Dublin Core
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
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Upper Cretaceous and Lower Jurassic strata in shallow cores on the Chukchi Shelf, Arctic Alaska |
| 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 |
| Google Analytic Metrics | Metrics page |