ALBERT

Description: Abstract

Description: SEGY and supplementary data of the seismic reflection experiment in the Baza Basin (Southern Spain). Presented are unstacked and unmigrated data of three 2D vibroseis profiles which were carried out in October 2013 and all corresponding raw data. The dataset is archived at the GIPP Experiment and Data Archive. The Baza Basin is an intra-mountain evaporitic basin in the Betic Cordillera (Southern Spain). The basin is formed by Pliocene to Pleistocene sediments. It can be distinguished into three lithological zones corresponding to different paleo-environments (Gibert et al., 2007). The inner zone, interpreted as a central saline lake, is dominated by an alternation of gypsum and carbonate laminae. The intermediate zone is characterized by cyclic carbonate beds. This zone is interpreted as a mosaic of shallow lakes surrounding the inner zone. The marginal zone consists of lacustrine deposits which are surrounded by an alluvial belt. In the marginal zone, distal fan deposits and shallow lake sediments alternate as a result of fluctuations in the lake water level which are related to changes in climate (Gibert et al., 2007). Therefore, up to 2.5 km thick lacustrine and ancillary continental deposits are found in this part of the basin which provide an unique archive of climatic changes and paleo-climatic events. The basin is bounded to the West by the Baza fault zone (e.g., Alfaro et al., 2010). There are plans to analyze the sedimentary record of the central zone with regard to the paleo-climaste in the Mediterranean as well as on a global scale within a scientific drilling project. In preparation for future drilling activities, the project BASE (BAza Seismic Experiment) started in the middle of the year 2013 with a duration of 12 month. In the framework of this project, controlled-source seismic measurements were used to investigate the structure of the Baza Basin and to find local zones of neo-tectonic deformation bounding the basin to the west (Baza fault). The aim of the seismic work was to provide structural information for the planned scientific drilling project. The vibroseismic experiments were carried out in the vicinity of Baza during 21st and 29th October 2013. A net of three individual seismic profiles was conducted, each 18 km in length (Figure 1). Two simultaneously operating vibrators were used as source at 301 positions at each profile. The nominal source point spacing was 60 m. The receivers were spread along the active profile in a roll-along configuration with a nominal receiver spacing of 20 m. Depending on the proceeding of the vibrators, groups of receivers were picked up at the end of the spread and were moved to the front. With a total amount of ~340 receivers, an offset range of at least 3 km around the source point was covered during the entire registration of each profile. Additionally to the roll-along receivers at Line 2, 31 fixed recorders were spread with a spacing of 600 m over the full distance of this profile (far-field recordings).