Modern sand provenance and transport across the western Gulf of Mexico margin
Por:
Lawton T.F., Juárez-Arriaga E., Stockli D.F., Fildani A.
Publicada:
1 ene 2024
Ahead of Print:
1 jul 2023
Resumen:
Petrographic and detrital zircon U-Pb analysis of modern beach sands and river sands from major catchments in northeastern Mexico draining to the Gulf of Mexico provides evidence for a minimum of 650 km of littoral sand transport southward from the mouth of the Rio Grande at the Mexico-U.S. border to the central part of the state of Veracruz, Mexico. Principal tracers of Rio Grande sand include: (1) quartzose composition that contrasts with lithic compositions of sand in eastern Mexico rivers and (2) detrital zircon ages with Mesoproterozoic modes at 1.8–1.5 Ga and 1.4 Ga, age groups that are typical of basement and derivative sediment of the SW United States but are uncommon to rare in Mexican river catchments. In contrast, abundant Miocene and younger grains in beach sands of Veracruz indicate primary sediment derivation from active and recently active volcanoes in the Trans-Mexican volcanic belt in central Mexico. A proportional decrease in sand of Rocky Mountain provenance with distance southward along the coast from the mouth of the Rio Grande and absence of Miocene and younger zircon grains in beaches north of rivers draining the Trans-Mexican volcanic belt indicate net littoral sand transport southward along the eastern coast of Mexico, demonstrating that wintertime shoreline-parallel surface currents rather than north-directed summertime currents dominate sediment transfer. Sand samples of Tamaulipas beaches in northeastern Mexico commonly have equal or higher proportions of U.S.-derived Mesoproterozoic zircon grains than are present in river bar sand of the lower Rio Grande and the Rio Grande delta, and thus require that littoral processes rework and incorporate coastal dune and beach sands of northeastern Mexico that are enriched in predam Rio Grande sediment. Implied coastal erosion may be related to Holocene transgression or interruption of sediment supply to the coastal sediment transport system by dams in the Rio Grande drainage basin. Such coastal erosion is impacting long-term shoreline stability and viability of the littoral environment. © 2023 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license.
Filiaciones:
Lawton T.F.:
Bureau of Economic Geology, Jackson School of Geosciences, The University of Texas at Austin, Austin, 78758, TX, United States
Juárez-Arriaga E.:
Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Coyoacán, 04510, Mexico
Stockli D.F.:
Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, 78712, TX, United States
Fildani A.:
The Deep Time Institute, 23 Railroad Avenue #804, Danville, 94526, CA, United States
Green Submitted, Bronze, All Open Access; Bronze Open Access; Green Open Access
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