Middle-late Proterozoic tectonics of west Texas and eastern New Mexico: A geophysical interpretation
- Univ. of Texas, El Paso, TX (United States). Dept. of Geological Sciences
The Midcontinent rift system forms one of the most prominent gravity features in North America. The geophysical anomaly extends in an arc from Oklahoma to Lake Superior and then into Kentucky. The Midcontinent Rift System was active between 1.19--1.01 Ga as indicated in the Lake Superior region by age dating of intrusive igneous rocks. The authors suggest that the period of formation of the Midcontinent rift was a time of extensive igneous activity in Texas and New Mexico which is represented by intrusions beneath the Central Basin Platform (TX-NM), Pajarito Mountain in the Sacramento Mountains (NM), the Mundy Breccia in the Franklin Mountains (TX), lava flows in the Allamore Formation near Van Horn (TX), and the Crosbyton geophysical anomaly (east of Lubbock, TX). These bodies were intruded between 1.07--1.22 Ga. These bodies and other bodies located by geophysical anomalies and wells drilled into mafic Precambrian rocks may be related to the Midcontinent rift system by a rift jump or splay. Alteratively this magmatism could be related to Grenville age tectonics in Texas. The Central Basin Platform, is divided in two on gravity maps by the Abilene minimum, an ENE trending 900 km long 100 km wide gravity low. This gravity low is not associated with basement topography and must be an intra-basement feature. One possible source of this body is a continental arc batholith. This batholith must have been intruded near a suture zone prior to 1166 Ma the age of the Central Basin Platform intrusion. A possible age for this intrusive would be 1,350--1,400 Ma. This age would coincide with formation of the Chaves Granite Gneiss terrain and the Red River-Tillman metamorphic belt, a possible foreland basin. This date would also coincide with regional metamorphism in north-central New Mexico.
- OSTI ID:
- 6003847
- Report Number(s):
- CONF-9303212-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:1; Conference: 27. annual Geological Society of America (GSA) South-Central Section meeting, Fort Worth, TX (United States), 15-16 Mar 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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