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Rates and directions of crustal extension in a continental rift vary in time and space as the rift evolves, and these geologic records are often preserved along fault planes. Some fault-kinematic studies have been undertaken in the central to northern segments of the Rio Grande rift, but similar studies from the southern part of the Rio Grande rift of western Texas, USA, and northern Mexico are fewer. We present new fault-kinematic data from six locations in the southern Rio Grande rift of Trans-Pecos Texas, combined with U-Pb dating of calcite slickenlines, to constrain the directions and time scales of extension. All locations preserve NE-SW−oriented extension, and locations within the Sunken Block graben preserve a more complex kinematic history of multiple extension directions. Four U-Pb ages range from 30.1 ± 3.1 Ma to 13.7 ± 0.9 Ma. Combined with fault-kinematic data and assuming a constant stress regime between 30 Ma and 14 Ma, these data support the interpretation that earliest extension in the southern rift was oriented NE-SW, and extension rotated clockwise to E-W and NW-SE after 13.7 ± 0.9 Ma. Based on available data, this rotation was broadly coincident with rotation in the extension direction in the southern Española basin and in the Basin and Range Province. These differences suggest that extension in the Rio Grande rift responded to the evolving western boundary of the North American plate but included initial underlying driving forces that were supplanted by lateral forces as the transform margin lengthened. Additionally, geochronologic and kinematic data across the Sunken Block graben of the southern Rio Grande rift indicate that the locus of rifting concentrated with time toward the center of this basin; such structural narrowing has previously been demonstrated in the northern segment of the rift. This study provides a much-needed comparison between the southern and northern segments of the rift but highlights the need for more collection of combined kinematic and geochronologic data.
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2022 Annual Meeting
Title: Efficient Access and Manipulation of Big Seismic Data from Disparate Sources Seismological data recordings have been growing exponentially in the last three decades. For instance, the data archive at the IRIS Data Management Center (DMC) grew from less than 10 Tebibytes in 1992 to greater than 750 Tebibytes today (in 2022). In addition to such big data archives, retrieving and merging data from various disparate seismic sources also creates big data which will enable obtaining higher-resolution seismic images and understanding phenomena such as earthquake cycles. Moreover, recent progress in geosciences with the application of AI/ML using big data has shown the potential of discovering patterns that were not previously recognized. However, aggregating large seismic datasets introduces its own challenges. Some of these challenges arise from the fact that many data centers have their own way of distributing data, and the format of the data and metadata are different in many cases. The objective of this investigation is the development of data access and manipulation tools for retrieval, merging, processing, and the management of big seismic data from disparate seismic data sources. We develop a free, open-source, direct data accessing, gathering, and processing software toolbox for disparate sources using Python. Aggregating data from different data centers will enable us to investigate the seismic structure beneath a region of interest at a higher resolution by merging the seismic databases. Such a merged dataset can be applied on studies around the boundaries between countries if those countries have different networks. One boundary region of geologic interest to exemplify the benefits of aggregated seismic datasets from different networks in two countries is the southern side of the Rio Grande Rift including the bordering areas between the US and Mexico. Previous more detailed seismic studies on Rio Grande were conducted mostly on the US side of the Rift Valley.
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- Award ID(s):
- 2101080
- PAR ID:
- 10344964
- Editor(s):
- Caplan-Auerbach, Jackie; Schmidt, D.
- Date Published:
- Journal Name:
- Seismological Research Letters
- Volume:
- 93
- Issue:
- 2B
- ISSN:
- 0895-0695
- Page Range / eLocation ID:
- 1115 to 1372
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1785/0220220087
