Possible extension of the Midcontinent Rift in west Texas and eastern New Mexico

Abstract

The Midcontinent Rift System forms one of the most prominent gravity features in North America. The recognized geophysical anomaly extends in an arc from southern Oklahoma to Lake Superior and then into southern Michigan. The Midcontinent Rift System was active between 1185–1010 Ma, as indicated in the Lake Superior region by age determinations on intrusive igneous rocks. We suggest that the period of formation of the Midcontinent Rift was also a time of extensive igneous activity in Texas and New Mexico. This activity is represented by intrusions beneath the Central basin platform (Texas and New Mexico), intrusions which crop out at the Pajarito Mountain in the Sacramento Mountains (New Mexico), a basaltic debris flow in the Franklin Mountains (Texas), basalt flows at Van Horn (Texas), and the Crosbyton geophysical anomaly (east of Lubbock, Texas). These bodies and other bodies located by geophysical anomalies and wells drilled into mafic Precambrian rocks may be related to the Midcontinent Rift System. Alternatively this magmatism could be related to Grenville age tectonics in Texas. The mafic igneous rocks in this area form a 530 km diameter Middle Proterozoic igneous province, which formed between 1070 and 1220 Ma. Comparison of the Midcontinent Rift System and its extensions proposed here with the Mesozoic and Cenozoic African rift systems indicates that these features are of comparable scale and complexity.

Geologic influence on induced seismicity: Constraints from potential field data in Oklahoma

“…Gravity lows are observed over the Anadarko and Arkoma basins, while highs are associated with the Arbuckle uplift, the southern Oklahoma aulacogen (aligned with the Wichita uplift), and the Cherokee platform in Osage County. The gravity high associated with the inferred extension of the Midcontinent coincides with a group of rounded magnetic highs and has been interpreted as Keweenawan intrusive rock (Figure c) [ Lyons , ; Luza and Lawson , ; Adams and Keller , , and references therein]. The Arkoma basin is associated with a much steeper gravity low than the Anadarko basin even though it is not as deep.…”

Ambient seismic noise tomography and structure of eastern North America

“…However, this LVB extends further southward to intersect the Oklahoma Aulocogen. Adams and Keller [1993] studied the stratigraphy, the ages and lithologic properties of volcanic rocks and found strong similarities between those in western Oklahoma, Texas and eastern New Mexico with the identified MCR and suggested that the MCR may actually extend further southwest from its west limb terminus in Kansas. Their suggestions are also supported by Yarger [1985] and Nixon [1988].…”

Aeromagnetic Data Reveal Potential Seismogenic Basement Faults in the Induced Seismicity Setting of Oklahoma

“…Associated tectonic events might be extension that did not proceed long enough to generate significant mafic rocks, mantle heating due to upwelling or diapirism, or dextral slip (Anderson & Morrison, 2005;Bickford et al, 1986;Thomas, 2006). Additional tectonic activity may have occurred during rifting of the midcontinent 1200-1000 Ma ago; extension of this rift is suggested through southern Kansas and northwestern Oklahoma (Adams & Keller, 1994;Luza & Lawson, 1982;Lyons, 1959;Robbins & Keller, 1990).…”