Paleocurrents and Depositional Environments of the Dakota Group (Cretaceous), San Miguel County, New Mexico

Persistent Link:
http://hdl.handle.net/10150/244084
Title:
Paleocurrents and Depositional Environments of the Dakota Group (Cretaceous), San Miguel County, New Mexico
Author:
Bejnar, Craig Russel
Issue Date:
1975
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the Antevs Library, Department of Geosciences, and the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author or the department.
Collection Information:
This item is part of the Geosciences Theses collection. It was digitized from a physical copy provided by the Antevs Library, Department of Geosciences, University of Arizona. For more information about items in this collection, please email the Antevs Library, antevs@geo.arizona.edu.
Abstract:
The Dakota Group surrounding Las Vegas, New Mexico, consists of three units: 1) a basal, predominately trough cross-stratified, conglomeratic sandstone, 2) middle intercalated, thin-bedded sandstone and carbonaceous shale, and 3) upper, predominately tabular-planar cross-stratified, sandstone containing trace fossils. These units represent, respectively, 1) a fluvial piedmont plain, 2) fluvial coastal plain, and 3) a beach, littoral, and shallow marine complex. The cross-stratification in the lower sandstone unit indicates an easterly paleoslope. The cross-stratification in the upper sandstone unit has a bimodal distribution almost at right angles to the paleoslope, suggesting deposition by longshore currents. The standard deviation of the cross-stratification in the lower sandstone unit of 78° is typical of fluvial deposits. The standard deviation in the upper sandstone unit of 97° indicates a marine origin.
Type:
text; Thesis-Reproduction (electronic)
Keywords:
algae; bedding plane irregularities; biostratigraphy; clastic rocks; Cretaceous; cross-stratification; Dakota Formation; depositional environment; environment; environmental analysis; indicators; lithostratigraphy; marine; Mesozoic; microfossils; Mora County New Mexico; nannofossils; nearshore; New Mexico; northeast; paleocurrents; palynomorphs; planar bedding structures; Plantae; provenance; ripple marks; San Miguel County New Mexico; sandstone; sedimentary petrology; sedimentary rocks; sedimentary structures; sedimentation; shale; shallow; stratigraphy; streams; terrigenous; thallophytes; United States; Geology -- New Mexico -- San Manuel County
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Graduate College; Geosciences
Degree Grantor:
University of Arizona
Committee Chair:
Wilson, Richard F.

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