The regional distribution of salt in the northwestern Gulf of Mexico: styles of emplacement and implications for early tectonic history
Simmons, Gregory Raymond
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The regional distribution of salt in the northwestern Gulf of Mexico reflects a complex interplay between tectonic basin architecture and subsequent salt kinematics. Persistent northwest-southeast structural trends across the Texas - Louisiana margin are attributed to a structural fabric of the transitional crust upon which the Louann Salt was deposited, and which formed during the Late Triassic to Middle Jurassic as the Yucatan block moved southeast out of the northwestern Gulf. Major transfer faults divide the Gulf Coast into segments characterized by markedly different salt abundances and structural styles. Major depocenters developed above subsidiary basins containing thicker accumulations of Louann Salt. Isolated supralobal basins are subsiding into a nearly continuous substrate of overthrusting salt wedges across the lower slope. Across the upper to middle slope numerous lateral intrusions of allochthonous salt are spreading from the crests of isolated domes and massifs forming distinct inter - lobal basin margins. As the lateral intrusions converge interlobal areas are reduced. Eventually source layers are almost completely evacuated and the salt redistributed in the shallow subsurface as allochthonous canopies.