Pliocene marine deposits at Punta Maldonado, Guerrero state, Mexico

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• 作者：Edgar Juá ; rez-Arriaga ; Ana Luisa Carreñ ; o and José ; Luis Sá ; nchez Zavala
• 关键词：Biostratigraphy ; Foraminifera ; Middle American trench ; Ostracoda ; Storm ; Transgressive
  Palabras clave ; Biostratigrafí ; a ; Foraminifera ; Ostracoda ; Tormenta ; Transgresivo ; Trinchera Mesoamericana
• 刊名：Journal of South American Earth Sciences
• 出版年：2005
• 出版时间：September 2005
• 年：2005
• 卷：19
• 期：4
• 页码：537-546
• 全文大小：542 K

文摘

Diverse and abundant Foraminifera and Ostracoda assemblages were recovered from a measured stratigraphic section at Punta Maldonado, Guerrero state, Mexico. The planktonic species indicate an early Pliocene age, between 5.3 and 3.6 Ma; an early late Pliocene (around 2.4 Ma) planktonic assemblage also was recorded from isolated deposits. These ages contradict the Cretaceous–Paleogene age previously assigned to the sedimentary succession at Punta Maldonado. All indicators—benthic assemblages, ichnofacies, lithology, grain size, primary structures, mineralogy, body rock geometry, and facies—suggest deposition in the foreshore and offshore transition zones of a storm-dominated shallow siliciclastic shelf. The Ostracoda and Foraminifera indicate deposition around the outer neritic/upper bathyal boundary, which suggests an uplift of 320–400 m in the area during the Pliocene. This study represents the first report of Pliocene marine rocks in the southwestern coast of Mexico; the data presented contribute to regional geotectonic models.