Use of erosional features for tectonic reconstructions and interbasin correlation: An example from the Rio Grande rift, northern New Mexico
Mark A. Gonzalez
Worldwide study of continental rifts has led to the development of several models depicting the evolution of rift basins. These models generally unravel rift-basin history by analyzing rift-margin structures and syntectonic sediment. This work builds on existing models by including spatial analysis of geologic features about intrarift accommodation zones to supplement documented patterns related to rift-margin structures, and by using geomorphic and erosional data to supplement syntectonic sedimentary data. These supplemental data provide process-based information on the tectonic evolution of rift basins, and a context for regional (interbasin) correlation of erosional features. Intrarift accommodation zones, such as the Embudo fault zone, are scissors faults that reverse the polarity of asymmetric half-graben basins. This causes depositional facies and erosional features to be mirrored, occurring on opposing sides of rifts in adjacent basins. The tectonic history, constructed from syntectonic sedimentation in hanging-wall depocenters, can be augmented by erosional history on rift-margin footwall blocks and along the hinge zone of half-grabens where basin-subsidence rates are lowest or uplift occurs. Delineation of spatial patterns of geomorphic and erosional surfaces and the processes of their genesis is valuable in rift settings where syntectonic sediments are buried, and rift-margin structures are inactive and/or poorly exposed.
- Gonzalez, Mark A., 1995, Use of erosional features for tectonic reconstructions and interbasin correlation: An example from the Rio Grande rift, northern New Mexico, in: Geology of the Santa Fe Region, Bauer, Paul W.; Kues, Barry S.; Dunbar, Nelia W.; Karlstrom, K. E.; Harrison, Bruce, New Mexico Geological Society, Guidebook, 46th Field Conference, pp. 139-145.