The geochemistry of biogenic carbonates as a paleoenvironmental tool for the Lower Pleistocene Barranco Leon sequence (BL-5D, Baza Basin, Spain)

被引：24
作者：
Anadon, Pere [1 ]
Oms, Oriol [2 ]
Riera, Violeta [2 ]
Julia, Ramon [1 ]
机构：
[1] CSIC, ICTJA, E-08028 Barcelona, Spain
[2] Univ Autonoma Barcelona, Fac Ciencies, Dept Geol, Unitat Estratig, E-08193 Barcelona, Spain
来源：
QUATERNARY INTERNATIONAL | 2015年 / 389卷
关键词：
Lacustrine deposits; Stable isotopes; Trace elements; Skeletal carbonates; Pleistocene; Southern Spain;
D O I：
10.1016/j.quaint.2014.09.062
中图分类号：
P9 [自然地理学];
学科分类号：
0705 ; 070501 ;
摘要：
The Barranco (creek) Leon section is located in the NE marginal area of the lacustrine Plio-Pleistocene Baza Basin (Southern Spain). The Barranco Leon BL-5D mammal and archeological site has delivered abundant lithic tools and a hominin tooth; the age ascribed to this site is comprised between the Olduvai and Jaramillo subchrons, close to 1.4 Ma, based on magnetostratigraphy, biostratigraphy and ERS dating. The studied BL-5 section consists from base to top, of dark sandy mudstones and lutites with interbedded sandy marls. The lower part of the dark sandy mudstones contains a brackish fauna of foraminifera, ostracods, and mollusks. Sandy carbonate mudstones and sandy lutites with freshwater-oligosaline ostracods and mollusks form the upper part of the archeological excavation sequence. Stable isotope (delta C-13, delta O-18) and trace element analyses on ostracod and mollusk shells allow depicting the paleoenvironmental conditions recorded in the lacustrine sequence. Moreover, indications on provenance for waters have been obtained from Sr-87/Sr-86 ratios from shells and opercula from mollusks. The isotopic composition of the biogenic carbonates shows a strong correlation between delta C-13 and delta O-18, which is noticeable for some gastropod shells. This correlation is a characteristic feature of closed lake settings. In our case, the more negative isotopic values reflect the input of meteoric waters and the more positive ones the skeletal carbonates formed in more isotopically concentrated waters. Some of the more negative isotopic values correspond to biogenic carbonates from the BL-5D level. They correspond to isotopically diluted waters, although the trace element data and the invertebrate fauna indicate oligosaline to mesosaline waters. Moreover, the presence in BL-5D of shells from Melanopsis tuberculata, a thermophilous gastropod, together with their isotopic signatures suggest the input of oligosaline waters with a thermal influence. The available geochemical data indicate a first stage of varying influence of several water types under changing water level in a closed lake recorded in the base of the studied sequence (brackish fauna level). The overlying beds record a through flowing open lacustrine environment mainly fed by meteoric surface and ground waters with significant inputs of stream waters. (C) 2014 Elsevier Ltd and INQUA. All rights reserved.
引用
收藏
页码：70 / 83
页数：14
相关论文
共 75 条
[1]  
Agusti J., De Marfa R., Santos-Cubedo A., Roedores y lagomorfos (Mammalia) del Pleistoceno inferior de Barranco León y Fuente Nueva 3 (Orce, Granada), (2010)
[2]  
Agusti J., Blain H.-A., Furio M., De Marfa R., Santos-Cubedo A., The early Pleistocene small vertebrate succession from the Orce region (Guadix-Baza Basin, SE Spain) and its bearing on the first human occupation of Europe, Quaternary International, pp. 162-169, (2010)
[3]  
Anadon P., Gabas M., Paleoenvironmental evolution of the Early Pleistocene lacustrine sequence at Barranco León archeological site (Orce, Baza Basin, Southern Spain) from stable isotopes and Sr and Mg chemistry of ostracod shells, Journal of Paleolimnology, 42, pp. 261-279, (2009)
[4]  
Anadon P., Julia R., Hydrochemistry from Sr and Mg contents of ostracodes in Pleistocene lacustrine deposits, Baza Basin (SE Spain), Hydrobiologia, 197, pp. 291-303, (1990)
[5]  
Anadon P., Julia R., Estudio petrológico de los clastos de las excavaciones de Barranco León (BL-5) y Fuente Nueva-3 (FN-3). Pleistoceno inferior. Orce (Granada), pp. 77-96, (2010)
[6]  
Anadon P., de Deckker P., Julia R., The Pleistocene lake deposits of the NE Baza Basin (Spain): salinity variations and ostracod succession, Hydrobiologia, 143, pp. 199-208, (1986)
[7]  
Anadon P., Julia R., de Deckker P., Rosso J.C., Soulie-Marsche I., Contribución a la Paleolimnologia del Pleistoceno inferior de la cuenca de Baza (sector Orce- Venta Micena), Paleontologia i Evolució, Special Memoir, 1, pp. 35-72, (1987)
[8]  
Anadon P., Utrilla R., Julia R., Palaeoenvironmental reconstruction of a Pleistocene lacustrine sequence from faunal assemblages and ostracode shell geochemistry, Baza Basin, SE Spain, Palaeogeography, Palaeoclimatology, Palaeoecology, 111, pp. 191-205, (1994)
[9]  
Anadon P., Julia R., Oms O., Estratigrafía y estudio sedimentológico preliminar de diversos afloramientos en Barranco León y Fuente Nueva (Orce, Granada), Monografías de Arqueología. Junta de Andalucía- Consejería de Cultura 17, pp. 47-72, (2003)
[10]  
Anadon P., Martin-Rubio M., Robles F., Rodriguez-Lazaro J., Utrilla R., Vazquez A., Variation in Sr uptake in the shell of the freshwater gastropod Bithynia tentaculata from Lake Arreo (northern Spain) and culture experiments, Palaeogeography, Palaeoclimatology, Palaeoecology, 288, pp. 24-34, (2010)
12345678