Hiatus mapping in and around the Gulf of Mexico Basin

Abstract:

It has been proposed that the Gulf of Mexico basin experienced uplift and tilt during the latter part of the Cenozoic based on onlapping strata and truncated sequences. The precise timing, spatial extent and amplitude of these vertical motions, as well as their dynamic causes, remain poorly constrained. Here, we analyze regional-scale unconformities from geologic maps, cross sections of the Gulf of Mexico Basin and borehole data, complemented by analysis of shoreline and subsurface geometries, to compile hiatus maps for Texas, Louisiana and Mississippi, at spatial scales of many hundreds of kilometers and at temporal scales of geologic epochs. At these spatial and temporal scales, the patterns of deposition and erosion and their changes through time are proxies for cycles of relative sea level rise and fall. Our analysis puts additional constraints on the geodynamic and tectonic history of the Gulf of Mexico basin, separating mantle-induced subsidence and uplift from eustatic seal-level variations, structural deformation and salt tectonics. Additionally, our analysis allows us to reconstruct the timing of the uplift and tilting on shore, and to locate the point of no tilt (hinge line) through time.