Fossil cold-water corals (Scleractinia and Gorgonacea) from the Burdwood Reef, Argentina Republic

• Published in: Acta Geológica Lilloana
• Main Authors: Isla, Federico Ignacio, Lamarchina, Salvador, Zamponi, Mauricio Oscar
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidad Nacional del Tucumán
• Subjects: Cold-water corals; Scleractinia; Gorgonacea; Burdwood Bank; https://purl.org/becyt/ford/1.5; https://purl.org/becyt/ford/1; Antarctic; The Antarctic; Drake Passage; Argentina; Fósiles; Rocas; Pasaje; Pasaje de Drake; Rocosa; Antarc*; Antártica; South Atlantic Ocean
• Online Access: http://hdl.handle.net/11336/221766

The Burdwood Bank is a rocky platform emerging from the abyssal plain to depths of 50-100 m between the South Atlantic Ocean and the Drake Passage. Regarding its geological affinity, it has a composition similar to the Staten Island (Isla de los Estados), therefore aligned to the Andes-Darwin Cordillera. This bank is crossed from south to north by the Antarctic Bottom Water; very cold and rich in nutrients. Rocks dredged from the shallower portions at its western portion are composed of carbonatic blocks. The analyses indicated fossil specimens of Desmophyllum sp. (Or-der Scleractinia) and Gorgonacea palmatum (Order Gorgonacea), genera living today in the region. In this sense, sectors of this western portion should be considered as an ancient reef composed mostly of cold-water corals. The major implications are assigned to oceanographic and climatic issues. During the Upper-Pleistocene low-stand, the sunlight was more available at shallower depths and therefore corals were very frequent at wave-dominated areas. Sea-level variations have therefore strong influence on some cold-water coral growths in the sense that nutrient availability by currents can significantly changed between glacial and interglacial periods. El Banco Burdwood es una plataforma rocosa que emerge de las planicies abisales a profundidades de 50-100 m entre el Océano Atlántico Sur y el Pasaje de Drake. Considerando su afinidad geológica, posee una composición similar a la Isla de los Estados, alineada entonces a la Cordillera de los Andes-Cordillera Darwin. Este banco está cruzado de sur a norte por la Corriente Antártica de Fondo, muy fría y rica en nutrientes. Las rocas extraídas de las porciones menos profundas de la porción occidental están compuestas de bloques carbonáticos. El análisis indicó especímenes fósiles de Desmophyllum sp. (Orden Scleractinia) y Gorgonacea palmatum (Orden Gorgonacea), géneros viviendo actualmente en la región. En este sentido, sectores de la porción occidental deberían ser considerados como un arrecife antiguo ...