Linear depressions and collapse features in the Northwest Hueco Basin, West Texas
Date
1997
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Texas A&M University
Abstract
The Northwest Hueco Basin, located in the Northern Chihuahuan Desert, is a fault bounded basin filled predominantly with Plio-Pleistocene unconsolidated sediments. The basin contains long linear depressions that dominate the surface topography. The depressions are basin parallel, striking north-northeast, and range in length from less than one to about thirty kilometers. The depressions initially formed as a result of intragraben normal faulting associated with the southern extent of the Rio Grande basin and range. Excavation into the scarp of a representative depression revealed a vertical fault plane and deformation of the upper Camp Rice sand and gravel. The depressions are about 500,000 years old based on the relative ages of the deformed upper Camp Rice sand and gravel and the undeformed upper caliche horizon in the La Mesa surface. The process that dominates the maintenance of the depressions is subsidence caused by a loss in volume in the La Mesa surface due to the transport of material from the lower boundary of the La Mesa surface into the pore space of the underlying coarse, unconsolidated Camp Rice sand and gravel. Economic sand and gravel, found on the margins of the depressions, are preserved as thick laterally extensive deposits. The normal faulting, that initially formed the depressions, preserved the sand and gravel by dropping it down relative to the basin floor protecting the unconsolidated material from erosion. Scarp height may be a function of the nature of the sand and gravel. The coarser the sand and gravel, the greater its storage capacity which causes more subsidence to occur during the maintenance process. Where the scarp heights are the greatest, the quality of sand and gravel will also be at its greatest. diameter, were discovered in the La Mesa surface and are distributed throughout the Northwest Hueco Basin. These collapses could be a hazard to new residential and commercial development. The features were fon-ned by the collapse of once horizontal overlying strata due to a loss in volume in the underlying fine grained material, which is transported into the pore space of the Camp Rice sand and gravel.
Description
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Includes bibliographical references: p.65-68.
Issued also on microfiche from Lange Micrographics.
Includes bibliographical references: p.65-68.
Issued also on microfiche from Lange Micrographics.
Keywords
geology., Major geology.