Paleoambiente y paleontolog赤a de la Formaci車n Andapaico (Paleozoico superior, Precordillera Central, Argentina) Paleoenvironment and paleontology of the Andapaico Formation (upper Paleozoic, central Precordillera, Argentina)

作者：Gustavo A Correa; Maria L Carrevedo; Pedro R Gutierrez

来源：Andean Geology, 2012.

• Ambientes costeros
• Permico
• Palinologia
• Ferugliocladus
• Eucerospermum
• Formacion Andapaico
• Argentina
• Nearshore environments
• Permian
• Palynology
• Ferugliocladus
• Eucerospermum
• Andapaico Formation
• Argentina

Se presenta un estudio sedimentol車gico, paleontol車gico y paleoambiental de la Formaci車n Andapaico (sector austral de la Cuenca Paganzo, San Juan). Esta unidad se apoya en discordancia angular sobre la Formaci車n Punta Negra, posee un espesor de 430 m de sedimentitas silicocl芍sticas, que incluye dep車sitos originados en ambientes predominantemente costeros. Se identificaron dep車sitos de frente de playa inferior (asociaciones de facies I), r赤os anastomosados con planicie (II), r赤os de alta sinuosidad (III), playa (IV), sistema e車lico (V), isla barrera (VI) y laguna de llanura costera (VII). Las asociaciones de facies I (sector inferior de la unidad) y VII (sector superior) brindaron microfloras, que permiten referirlas al Cisuraliano temprano (I) y al Cisuraliano tard赤o-Guadalupiano temprano (VII, Biozona Lueckisporites-Weylandites). De la facies I, adem芍s, se obtuvo una asociaci車n de plantas f車siles referida a la Superzona de Ferugliocladus del P谷rmico temprano de la Cuenca Tepuel-Genoa, lo que reforzar赤a la hip車tesis de esta edad para la secci車n inferior de la Formaci車n Andapaico. A sedimentological, paleontological and paleoenvironmental study of the Andapaico Formation is presented (southern sector of the Paganzo Basin, San Juan). This unit overlies with an angular unconformity the Punta Negra Formation, and has a thickness of 430 m of siliciclastic sediments, that include deposits formed predominantly in nearshore environments. Lower shoreface (facies association I), anastomosed rivers and floodplain (II), high sinuosity rivers (III), beach (IV), eolian system (V), barrier island (VI) and lagoon (VII) deposits were identified. Facies association I (lower part of the unit) and VII (upper part) and their associated palynoflora assign them to the early Cisuralian (I) and late Cisuralian-early Guadalupian (VII, Lueckisporites-Weylandites Biozone). From the facies I association a fossil plant assemblage was obtained that allows it to be referred to the Ferugliocladus Superzone of the early Permian of the Tepuel-Genoa Basin, which reinforces the hypothesis of this age for the lower part of the Andapaico Formation.