skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Sedimentation and diagenesis at a Late Cambrian biomere extinction horizon

Abstract

The base of the Eurekia apopsis Subzone of the Saukia Zone, slightly below the present Cambrian-Ordovician boundary, has been interpreted as a biomere extinction crisis for trilobites and conodonts. This boundary can be recognized to within two centimeters in platform carbonates in Utah, Nevada, Texas, and Oklahoma. Regional stratigraphy in West Utah reveals that this extinction horizon occurs within a shoaling upward sequence in which sedimentation was predominantly episodic. Shallow subtidal sedimentation, producing bioturbated mixed-skeletal wackestones and graded intraclastic grainsupportstones (tempestites), shifted to peritidal sedimentation through the boundary interval and for the duration of the E. apopsis Subzone. Associated lithofacies include sponge-dominated thrombolite mounds with tidal channels, sublittoral stromatolite reefs, and a restricted marine lagoon. The base of the E. apopsis Subzone in West Utah is a sharp contact but is interpreted as neither a disconformity nor a surface of subaerial exposure. In Texas, this boundary is a planar disconformity between biosparites. The bed underlying this surface displays features that reflect wholesale aragonite dissolution followed by two stages of inferred meteroic phreatic cementation. The surface is well washed and provided a clean substrate for epitaxial cementation across the boundary. The overlying basal strata of the E. apopsis Subzone are cementedmore » with marine phreatic non-ferroan calcite and contain faunas that are strikingly dissimilar to those below.« less

Authors:
; ;
Publication Date:
Research Org.:
Univ. of Wisconsin, Madison (USA)
OSTI Identifier:
6598007
Report Number(s):
CONF-8510489-
Journal ID: CODEN: GAAPB
Resource Type:
Conference
Journal Name:
Geol. Soc. Am., Abstr. Programs; (United States)
Additional Journal Information:
Journal Volume: 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; CARBONATE ROCKS; DIAGENESIS; PALEONTOLOGY; PETROLOGY; STRATIGRAPHY; NEVADA; OKLAHOMA; TEXAS; UTAH; BIOLOGICAL EXTINCTION; CAMBRIAN PERIOD; GEOLOGIC HISTORY; LITHOLOGY; SEDIMENTATION; FEDERAL REGION IX; FEDERAL REGION VI; FEDERAL REGION VIII; GEOLOGIC AGES; GEOLOGY; NORTH AMERICA; PALEOZOIC ERA; ROCKS; SEDIMENTARY ROCKS; USA; 580100* - Geology & Hydrology- (-1989); 580300 - Mineralogy, Petrology, & Rock Mechanics- (-1989)

Citation Formats

Grimm, K A, Miller, J F, and Taylor, J F. Sedimentation and diagenesis at a Late Cambrian biomere extinction horizon. United States: N. p., 1985. Web.
Grimm, K A, Miller, J F, & Taylor, J F. Sedimentation and diagenesis at a Late Cambrian biomere extinction horizon. United States.
Grimm, K A, Miller, J F, and Taylor, J F. 1985. "Sedimentation and diagenesis at a Late Cambrian biomere extinction horizon". United States.
@article{osti_6598007,
title = {Sedimentation and diagenesis at a Late Cambrian biomere extinction horizon},
author = {Grimm, K A and Miller, J F and Taylor, J F},
abstractNote = {The base of the Eurekia apopsis Subzone of the Saukia Zone, slightly below the present Cambrian-Ordovician boundary, has been interpreted as a biomere extinction crisis for trilobites and conodonts. This boundary can be recognized to within two centimeters in platform carbonates in Utah, Nevada, Texas, and Oklahoma. Regional stratigraphy in West Utah reveals that this extinction horizon occurs within a shoaling upward sequence in which sedimentation was predominantly episodic. Shallow subtidal sedimentation, producing bioturbated mixed-skeletal wackestones and graded intraclastic grainsupportstones (tempestites), shifted to peritidal sedimentation through the boundary interval and for the duration of the E. apopsis Subzone. Associated lithofacies include sponge-dominated thrombolite mounds with tidal channels, sublittoral stromatolite reefs, and a restricted marine lagoon. The base of the E. apopsis Subzone in West Utah is a sharp contact but is interpreted as neither a disconformity nor a surface of subaerial exposure. In Texas, this boundary is a planar disconformity between biosparites. The bed underlying this surface displays features that reflect wholesale aragonite dissolution followed by two stages of inferred meteroic phreatic cementation. The surface is well washed and provided a clean substrate for epitaxial cementation across the boundary. The overlying basal strata of the E. apopsis Subzone are cemented with marine phreatic non-ferroan calcite and contain faunas that are strikingly dissimilar to those below.},
doi = {},
url = {https://www.osti.gov/biblio/6598007}, journal = {Geol. Soc. Am., Abstr. Programs; (United States)},
number = ,
volume = 17,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1985},
month = {Tue Jan 01 00:00:00 EST 1985}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: