| 11:00 AM-5:00 PM, Monterrey, Mexico: |
CANCELED: Searching for the Mojave-Sonora Megashear in Northeastern Mexico
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| Primary Leader: Gary G. Gray |
| Leader(s): Justin Murphy, Timothy F. Lawton |
| Field Trip Description: The controversial Mojave Sonora Megashear (MSM) hypothesis has been debated for over three decades. Regardless of whether you are a fan or detractor of the original MSM hypothesis, the concept of a megashear, or system of megashears, has become very important in plate tectonic models for the Mesozoic evolution of Mexico and the Gulf of Mexico basin. This 3 day trip will take place around Saltillo, Mexico and will examine evidence for and against the existence of "the" megashear in eastern Mexico. Part of the reason these ideas remain controversial is due to the thick sedimentary cover deposited after these structures were active, and the subsequent extreme deformation of that cover during the Late Cretaceous-Early Tertiary. Gravity and magnetics data provide a remarkably clear picture of the basement structural configuration, and suggest the presence of several strike-slip fault systems and linking grabens. Clues to the deeper basement configuration are also provided by facies trends, and the Laramide-age structural styles and trends. In addition to developing an understanding of the basement structural patterns, we will touch on themes of basement involved vs. basement detached tectonics within foldbelts and the role of salt in the distribution of structural styles in the region.
Participants should arrange their own transportation to Monterrey, and lodging if arriving earlier or staying later. The excursion will begin from the Monterrey airport at approximately 10:00 AM on 10 October and end at the Monterrey airport at approximately 5:00 PM on 12 October. |
| Field Trip will span: 3 days |
| Sponsor(s): GSA Structural Geology and Tectonics Division |