Sucesion volcano-sedimentaria del Plioceno superior-Pleistoceno inferior, previa a la erupcion de las calderas La Reforma y El Aguajito, Baja California Sur, Mexico
Por:
Marcela Lira-Beltran, R., Macias, Jose L., Garcia-Tenorio, Felipe, Garcia-Sanchez, Laura, Osorio-Ocampo, Susana, Gonzalez-Barba, Gerardo, Schwennicke, Tobias
Publicada:
1 dic 2022
Categoría:
Geology
Resumen:
We present the results of a stratigraphic study of an upper Pliocene to
lower Pleistocene volcano-sedimentary succession exposed in and around
the La Reforma and El Aguajito calderas, north of Santa Rosalia, Baja
California Sur, Mexico. This succession is part of the pre-calderas
sub-strate and is related to the sedimentary formations described in the
Santa Rosalia basin. The succession has nine lithological units that
includes effusive and pyroclastic deposits accumulated in subaqueous and
suba -erial settings, that include fossiliferous siliciclastic and
carbonate rocks. These units were defined Based on previous studies, our
stratigraphic descriptions, a regional correlation and we defined
recognized these units were grouped into two stratigraphic successions
that are: (1) The Infierno Formation dated 2.5 Ma near its base and 1.8
Ma atop. It is a volcano-sedimentary succession more complex than
previously described that includes: Mesa de Enmedio ignimbrite (giant
pumice block deposit), El Yaqui fossiliferous sandstone (lower
Pleistocene), Cueva Amarilla ignimbrite (2.4 Ma), El Carrizo ignimbrite
(1.89 Ma), El Azufre lava (1.8 Ma) and the Cueva de Los Fosiles
fossiliferous sandstone. (2) The Pre-Reforma volcano-sedimentary
succession that, rests unconformably over the Infierno Formation and
consists of three units: El Contrabando volcano-sedimentary (1.43 Ma),
Punta Candeleros lava (1.36 Ma) and the La Zorra volcano-sedimentary
unit (1.35 Ma). The sedimentary units of the Infierno Formation contain
abundant fossils with predominance of Pectinid bivalves of the
Pectinidae family. The fossil record suggests that The Infierno
Formation emplaced in tropical-subtropical waters, which varied from
intertidal zones and sheltered bays, to inner shelf zones with less than
100 m depth.
Filiaciones:
Univ Nacl Autonoma Mexico, Fac Ciencias, Circuito Invest Cient, Ciudad Univ, Ciudad De Mexico 04510, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis Unidad Michoacan, Antigua Carretera Patzcuaro 8701, Morelia 58190, Michoacan, Mexico
Univ Autonoma Baja California Sur, Dept Acad Ciencias Marinas & Costeras, Museo Hist Nat, Carretera Sur Km 5-5, La Paz 23080, Bcs, Mexico
Univ Autonoma Baja California Sur, Dept Acad Ciencias Tierra, Carretera Sur Km 5-5, La Paz 23080, Baja California, Mexico
All Open Access; Gold
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