Date of this Version
Marine and Petroleum Geology 127 (2021), 104964.
Integration of seismic, gravity, and magnetic data revealed variations in crustal architecture along the Yucatan passive continental margin. The crust beneath the Yucatan salt basin is ~10 km thick and is primarily a lower continental crust. In contrast, the crust beneath the Campeche salt basin is thicker and comprises both the upper and the lower crustal layers. These variations in crustal architecture explain the strikingly different tectonic histories of these basins outlined by previous authors. The rifting of the Yucatan margin was associated with extensive magmatism expressed as voluminous igneous intrusions in the lower crust, one of which is manifested as the Campeche magnetic anomaly. The zone of extrusive volcanic flows is also interpreted in the northern Yucatan coincident with the Seaward Dipping Reflectors (SDR) in seismic data. Integrated analysis of potential fields and seismic data demands high density and magnetic susceptibility for the rocks of the SDR zone. The presalt sedimentary basin with up to 5 km of sediments overlies the stretched and intruded continental crust adjacent to the Ocean-Continent boundary (OCB). This pre-salt basin is up to 100 km wide and pinches out at the northeastern tip of the Yucatan peninsula. It appears to be compartmentalized with the width of individual segments up to 100 km. All the tectonic elements, namely OCB, SDR, pre-salt sedimentary basin, and magmatic intrusions within the stretched continental crust, have their counterparts in the northeastern Gulf of Mexico and therefore represent important constraints for the prebreakup locations of individual crustal blocks.