Middle Eocene Rhodoliths from Tropical and Mid-Latitude Regions
During the greenhouse conditions prevailing in the early−middle Eocene, larger benthic foraminifers (LBF) spread out on carbonate platforms worldwide while rhodolith beds were scarcely represented. This reduction in rhodolith beds coincided with a relative decrease in coralline algal diver...
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MDPI AG
2020-03-01
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| Online Access: | https://www.mdpi.com/1424-2818/12/3/117 |
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| author | Julio Aguirre Juan C. Braga Victoriano Pujalte Xabier Orue-Etxebarria Edward Salazar-Ortiz Daniel Rincón-Martínez Manuel Abad Fernando Pérez-Valera |
| author_facet | Julio Aguirre Juan C. Braga Victoriano Pujalte Xabier Orue-Etxebarria Edward Salazar-Ortiz Daniel Rincón-Martínez Manuel Abad Fernando Pérez-Valera |
| author_sort | Julio Aguirre |
| collection | DOAJ |
| description | During the greenhouse conditions prevailing in the early−middle Eocene, larger benthic foraminifers (LBF) spread out on carbonate platforms worldwide while rhodolith beds were scarcely represented. This reduction in rhodolith beds coincided with a relative decrease in coralline algal diversity and with a drastic decline of coral reef abundance. Middle Eocene rhodoliths from two tropical (San Jacinto Fold Belt in northern Colombia and Bahoruco Peninsula in the Dominican Republic) and two mid-latitude (Salinas Menores Ravine and Sierra del Zacatín in Southern Spain) localities were studied. Rhodolith rudstones in the tropical areas accumulated on relatively deep (several tens of meters) platform environments and were also redeposited in deeper settings downslope. In Salinas Menores, rhodoliths are dispersed in planktic foraminifer-rich marls. Miliolids are common in the infilling of constructional voids in these rhodoliths, indicating that they originally grew in shallow-water inner-shelf settings and afterwards they were transported to deeper environments. In Sierra del Zacatín, rhodoliths are scarce and coralline algae mainly occur as crusts attached to and intergrowing with corals. Here, LBF dominated shallow-water carbonate platforms. In terms of taxonomic composition, coralline algae of the order Hapalidiales are the most abundant in the study areas, followed by Sporolithales. The order Corallinales is poorly represented except in Salinas Menores, where it is relatively abundant and diverse. The impact of high temperatures due to high levels of atmospheric CO<sub>2</sub> during the Eocene and widespread oligotrophic conditions, which favored formation of LBF-rich lithofacies, might account for the low abundance of rhodolith beds at mid and high latitudes. In contrast, the more productive equatorial regions would have favored the formation of rhodolith beds. |
| first_indexed | 2024-04-11T11:04:14Z |
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| issn | 1424-2818 |
| language | English |
| last_indexed | 2024-04-11T11:04:14Z |
| publishDate | 2020-03-01 |
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| spelling | doaj.art-8b1748e8b3874ca7baf2dea03c5085162022-12-22T04:28:25ZengMDPI AGDiversity1424-28182020-03-0112311710.3390/d12030117d12030117Middle Eocene Rhodoliths from Tropical and Mid-Latitude RegionsJulio Aguirre0Juan C. Braga1Victoriano Pujalte2Xabier Orue-Etxebarria3Edward Salazar-Ortiz4Daniel Rincón-Martínez5Manuel Abad6Fernando Pérez-Valera7Departamento de Estratigrafía y Paleontología, Facultad de Ciencias, Avda. Fuentenueva s/n, Universidad de Granada, 18002 Granada, SpainDepartamento de Estratigrafía y Paleontología, Facultad de Ciencias, Avda. Fuentenueva s/n, Universidad de Granada, 18002 Granada, SpainDepartamento de Estratigrafía y Paleontología, Facultad de Ciencias y Tecnología, Universidad del País Vasco (UVP/EHU), 48080 Bilbao, SpainDepartamento de Estratigrafía y Paleontología, Facultad de Ciencias y Tecnología, Universidad del País Vasco (UVP/EHU), 48080 Bilbao, SpainServicio Geológico Colombiano, Dirección de Geociencias Básicas, Bogotá 111321, ColombiaGerencia de Desarrollo Tecnológico, Centro de Innovación y Tecnología ICP-Ecopetrol S.A. kilómetro 7 vía Piedecuesta–Santander, Bogotá 110911, ColombiaDepartamento de Biología y Geología, Física y Química Inorgánica, ESCET, Universidad Rey Juan Carlos, c/ Tulipán s/n, 28933 Móstoles, SpainDepartamento de Ciencias de la Tierra y del Medio Ambiente, Universidad de Alicante, Campus San Vicent del Raspeig, 03690 Alicante, SpainDuring the greenhouse conditions prevailing in the early−middle Eocene, larger benthic foraminifers (LBF) spread out on carbonate platforms worldwide while rhodolith beds were scarcely represented. This reduction in rhodolith beds coincided with a relative decrease in coralline algal diversity and with a drastic decline of coral reef abundance. Middle Eocene rhodoliths from two tropical (San Jacinto Fold Belt in northern Colombia and Bahoruco Peninsula in the Dominican Republic) and two mid-latitude (Salinas Menores Ravine and Sierra del Zacatín in Southern Spain) localities were studied. Rhodolith rudstones in the tropical areas accumulated on relatively deep (several tens of meters) platform environments and were also redeposited in deeper settings downslope. In Salinas Menores, rhodoliths are dispersed in planktic foraminifer-rich marls. Miliolids are common in the infilling of constructional voids in these rhodoliths, indicating that they originally grew in shallow-water inner-shelf settings and afterwards they were transported to deeper environments. In Sierra del Zacatín, rhodoliths are scarce and coralline algae mainly occur as crusts attached to and intergrowing with corals. Here, LBF dominated shallow-water carbonate platforms. In terms of taxonomic composition, coralline algae of the order Hapalidiales are the most abundant in the study areas, followed by Sporolithales. The order Corallinales is poorly represented except in Salinas Menores, where it is relatively abundant and diverse. The impact of high temperatures due to high levels of atmospheric CO<sub>2</sub> during the Eocene and widespread oligotrophic conditions, which favored formation of LBF-rich lithofacies, might account for the low abundance of rhodolith beds at mid and high latitudes. In contrast, the more productive equatorial regions would have favored the formation of rhodolith beds.https://www.mdpi.com/1424-2818/12/3/117calcareous red algaelarger foraminifer lithofacieseocenesouthern spaincolombiadominican republic |
| spellingShingle | Julio Aguirre Juan C. Braga Victoriano Pujalte Xabier Orue-Etxebarria Edward Salazar-Ortiz Daniel Rincón-Martínez Manuel Abad Fernando Pérez-Valera Middle Eocene Rhodoliths from Tropical and Mid-Latitude Regions Diversity calcareous red algae larger foraminifer lithofacies eocene southern spain colombia dominican republic |
| title | Middle Eocene Rhodoliths from Tropical and Mid-Latitude Regions |
| title_full | Middle Eocene Rhodoliths from Tropical and Mid-Latitude Regions |
| title_fullStr | Middle Eocene Rhodoliths from Tropical and Mid-Latitude Regions |
| title_full_unstemmed | Middle Eocene Rhodoliths from Tropical and Mid-Latitude Regions |
| title_short | Middle Eocene Rhodoliths from Tropical and Mid-Latitude Regions |
| title_sort | middle eocene rhodoliths from tropical and mid latitude regions |
| topic | calcareous red algae larger foraminifer lithofacies eocene southern spain colombia dominican republic |
| url | https://www.mdpi.com/1424-2818/12/3/117 |
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