TY - JOUR
T1 - Multiple calcrete profiles in the Tabernas Basin, southeast Spain
T2 - their origins and geomorphic implications
AU - Nash, David J.
AU - Smith, Roger F.
PY - 1998/11/1
Y1 - 1998/11/1
N2 - This paper describes a sequence of Pliocene(?) to Quaternary age calcretes developed within alluvial fan and fluvial gravels in the Tabernas Basin, Almeria Province, southeast Spain. Calcrete profiles are described from sites adjacent to major tributaries of the Rambla de Tabernas. Six distinct calcrete units are identified within the basin. These have variable distributions but have developed in an identifiable evolutionary sequence. Two pairs of calcrete units are widely present across the basin preserving two former land surfaces. Each of the former land surfaces has been planated and subsequently buried by alluvial fan or fluvial gravels. A massive calcrete unit is present at the base of each gravel sequence, immediately in contact with the underlying bedrock, with a less well developed calcrete unit situated at the top of the gravel sequence. The lowest two calcrete units within the basin are more spatially restricted and are confined to the floors and flanks of incised drainage lines. The geochemistry, macro- and micromorphological properties and geomorphological positions of the calcrete units are outlined and, on the basis of this information, their mode of origin identified. Two main modes of calcrete genesis appear to be present: massive calcretes situated in direct contact with bedrock are suggested to have formed by groundwater processes, whilst calcretes situated at the top of gravel sequences are likely to have developed by pedogenic processes. Calcrete genesis is subsequently considered in the context of the reconstruction of the early phases of landscape development, and is suggested to have been controlled by phases of uplift and stability within the Tabernas Basin.
AB - This paper describes a sequence of Pliocene(?) to Quaternary age calcretes developed within alluvial fan and fluvial gravels in the Tabernas Basin, Almeria Province, southeast Spain. Calcrete profiles are described from sites adjacent to major tributaries of the Rambla de Tabernas. Six distinct calcrete units are identified within the basin. These have variable distributions but have developed in an identifiable evolutionary sequence. Two pairs of calcrete units are widely present across the basin preserving two former land surfaces. Each of the former land surfaces has been planated and subsequently buried by alluvial fan or fluvial gravels. A massive calcrete unit is present at the base of each gravel sequence, immediately in contact with the underlying bedrock, with a less well developed calcrete unit situated at the top of the gravel sequence. The lowest two calcrete units within the basin are more spatially restricted and are confined to the floors and flanks of incised drainage lines. The geochemistry, macro- and micromorphological properties and geomorphological positions of the calcrete units are outlined and, on the basis of this information, their mode of origin identified. Two main modes of calcrete genesis appear to be present: massive calcretes situated in direct contact with bedrock are suggested to have formed by groundwater processes, whilst calcretes situated at the top of gravel sequences are likely to have developed by pedogenic processes. Calcrete genesis is subsequently considered in the context of the reconstruction of the early phases of landscape development, and is suggested to have been controlled by phases of uplift and stability within the Tabernas Basin.
KW - Calcrete
KW - Groundwater calcretization
KW - Pedogenesis
KW - Southeast Spain
KW - Tabernas basin
UR - http://www.scopus.com/inward/record.url?scp=0032451756&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1096-9837(1998110)23:11<1009::AID-ESP918>3.0.CO;2-Z
DO - 10.1002/(SICI)1096-9837(1998110)23:11<1009::AID-ESP918>3.0.CO;2-Z
M3 - Article
AN - SCOPUS:0032451756
VL - 23
SP - 1009
EP - 1029
JO - Earth Surface Processes and Landforms
JF - Earth Surface Processes and Landforms
SN - 0197-9337
IS - 11
ER -