Mineralogical evidence for warm and dry climatic conditions in the Neo-Tethys (eastern Turkey) during the middle Eocene

Autor(es)

Rego, E. S. ^[1] ; Jovane, L. ^[1] ; Hein, J. R. ^[2] ; Sant'Anna, L. G. ^{[3, 4]} ; Giorgioni, M. ^{[1, 5]} ; Rodelli, D. ^[1] ; Ozcan, E. ^[6]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Oceanog, BR-05508120 Sao Paulo - Brazil

^[2] US Geol Survey, Santa Cruz, CA 95060 - USA

^[3] Univ Sao Paulo, Escola Artes Ciencias & Humanidades, BR-03828000 Sao Paulo - Brazil

^[4] Univ Sao Paulo, Inst Energia & Ambiente, BR-03828000 Sao Paulo - Brazil

^[5] Univ Brasilia, Inst Geociencias, BR-70910900 Brasilia, DF - Brazil

^[6] Istanbul Tech Univ, Dept Geol Engn, Fac Mines, TR-34469 Istanbul - Turkey

• Tipo de documento: Artigo Científico
• Fonte: PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY; v. 501, p. 45-57, JUL 15 2018.
• Citações Web of Science: 1

Resumo

Minerals in stratigraphic sections are valuable tools for reconstructing past environmental conditions. Given the state of preservation of clay minerals, it is possible to determine under what conditions they formed, which provides clues about continental weathering (inherited minerals) and geochemical conditions in the water column or pore waters (neoformed or transformed) of the sedimentary environment. This study presents new mineralogical and chemical data from the Baskil section, a well-preserved middle Eocene Neo-Tethys sequence from eastern Turkey. Greater terrigenous input is marked by the increase of silicate minerals (e.g. phyllosilicates, quartz, and albite) in the section from 40.5 to 40 Ma, which diluted the marine carbonate content. This period is correlative with the global Middle Eocene Climatic Optimum (MECO) event. Authigenic palygorskite increased from the middle to the uppermost portion (similar to 40 to 37.3 Ma) of the section, indicating dryer conditions in the continent and availability of Si and Mg in the water column and pore waters favorable for its formation. Additionally, we suggest a stratified water column with warmer and more saline conditions at greater depths (e.g. > 200 m) after similar to 40 Ma favoring palygorskite and possibly authigenic dolomite precipitation. The mineralogical variations and element chemistry of rocks in the Baskil section reflect how detrital sources and weathering regimes changed in this area during the middle Eocene, and how these changes can be related to global, regional, and local processes. (AU)

• Processo FAPESP: 11/22018-3 - Avaliação da produtividade primária marinha através do estudo das bactérias magnetotáticas em sedimentos
• Beneficiário: Luigi Jovane
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Jovens Pesquisadores
• Processo FAPESP: 15/16501-4 - Variação no aporte de minerais e argilominerais no Oceano Atlântico e Neo-Tethys: novas evidências de aquecimento global durante o Eoceno médio
• Beneficiário: Eric Siciliano Rego
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 12/15995-5 - Geoquímica dos isótopos estáveis como instrumento para entender a paleoceanografia e o paleoclima no período Eoceno e Oligoceno
• Beneficiário: Martino Giorgioni
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 16/02288-0 - Variação no aporte de minerais e argilominerais no Neo-Tethys e no Oceano Austral: novas evidências de aquecimento global durante o Eoceno médio
• Beneficiário: Eric Siciliano Rego
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Mestrado