Structure of the Rio Grande rift in southern New Mexico and West Texas based on gravity interpretation

Abstract

Research Article| January 01, 1978 Structure of the Rio Grande rift in southern New Mexico and West Texas based on gravity interpretation IVAR B. RAMBERG; IVAR B. RAMBERG 1Department of Geology, University of Wyoming, Laramie, Wyoming 82071 Search for other works by this author on: GSW Google Scholar FREDERICK A. COOK; FREDERICK A. COOK 1Department of Geology, University of Wyoming, Laramie, Wyoming 82071 Search for other works by this author on: GSW Google Scholar SCOTT B. SMITHSON SCOTT B. SMITHSON 1Department of Geology, University of Wyoming, Laramie, Wyoming 82071 Search for other works by this author on: GSW Google Scholar Author and Article Information IVAR B. RAMBERG 1Department of Geology, University of Wyoming, Laramie, Wyoming 82071 FREDERICK A. COOK 1Department of Geology, University of Wyoming, Laramie, Wyoming 82071 SCOTT B. SMITHSON 1Department of Geology, University of Wyoming, Laramie, Wyoming 82071 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1978) 89 (1): 107–123. https://doi.org/10.1130/0016-7606(1978)89<107:SOTRGR>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation IVAR B. RAMBERG, FREDERICK A. COOK, SCOTT B. SMITHSON; Structure of the Rio Grande rift in southern New Mexico and West Texas based on gravity interpretation. GSA Bulletin 1978;; 89 (1): 107–123. doi: https://doi.org/10.1130/0016-7606(1978)89<107:SOTRGR>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Rio Grande rift, which is marked by a positive heat-flow anomaly in southern New Mexico, has been the subject of a gravity study based on 4,500 stations which cover a strip across New Mexico. The area consists of a series of basins and intervening ranges formed during Miocene time. This basin-and-range structure is strongly reflected in the Bouguer gravity anomalies, which range from −125 mgal over uplifts to −190 mgal over basins. Lineaments in trends of gravity anomalies are oblique to the predominant north-south trend of the rift and suggest that, in detail, the crust broke upon fractures oblique to the large-scale north-south trend. Thicknesses of Cenozoic sediments, determined from gravity measurements, range from 2 to 3 km in basins. The gravity effect of sediments is removed by stripping, and a broad +30-mgal gravity anomaly is located over the rift. Regional and residual Bouguer gravity anomaly maps have been constructed. The source of the 30-mgal gravity high is interpreted to be a shallow slab of basalt or a deep upwarp of the mantle that results in crustal attenuation. The low-velocity zone may project up toward the base of the crust under the Basin and Range province. Experiments and the observed fault pattern suggest an extensional origin for the Rio Grande rift fracture system. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.