The Texas mud blanket: Understanding fine-grained sediment flux in the NW Gulf of Mexico during the previous transgression

[摘要] The evolution and source of the Texas Mud Blanket (300 km3) was determined from 26 new radiocarbon dates and from ∼3000 km of 2D seismic data. Sediment flux (km3/ka) was calculated from this combined dataset. XRD reveals its origins are mostly from the Colorado and Brazos Rivers. Between LGM and 17 ka, sediments filled the deepest accommodation behind a productive reef trend. 17-9 ka was a time of rapid eustatic rise (∼7 mm/year) and low sedimentation (flux=0.4 km3/ka). At ∼9 ka, sediment flux to the mud blanket increased to 41 km3/ka because of ravinement of Brazos and Colorado deltas. By ∼5.5 ka, Texas was experiencing a climatic optimum, which reduced sediment supply from local rivers. During the last 3.5 ka the mud blanket received 172 km3 of fine-grained Colorado and Brazos sediments. The most pronounced trend is the anti-correlation of mud blanket growth and rates of eustatic rise.

[发布机构] Rice University

[效力级别] Geophysics