EXTENSIONAL EVOLUTION OF THE GULF OF MEXICO BASIN AND THE DEPOSITION OF TERTIARY EVAPORITES, by H. H. Wilson
JPG 26(4), 403-428
DISCUSSION
by C. Talbot*
*Hans Ramberg Tectonic Laboratory, Department of Earth Sciences, Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden.
email: Christopher.Talbot@geo.uu.se
Wilson (2003) has renewed his longstanding challenge to the consensus view that most of the salt at high stratigraphic levels in the Gulf of Mexico is remobilised Jurassic salt repeatedly extruded through clastic sediments prograding basinward. Science advances by continually reassessing multiple hypotheses and, as it is notoriously difficult to date salt bodies directly, we must accept Wilson´s plea to consider all reliable and pertinent geological observations -- but that includes learning lessons from subaerial salt extrusions. While unable to deny most of Wilson´s reinterpretations, I show here that most are unnecessarily complicated and thus vulnerable to Occam´s Razor. With the aim of correcting several misunderstandings about salt tectonics revealed in Wilson´s onslaught, I use new observations to show how younger sediments and microfossils can be incorporated within emergent older salt and use classical arguments to explain how such younger shales are later extended into planar layers concordant with the salt layering.