ELSEVIER Palaeogeography, Palaeoclimatology, Palaeoecology 150 (1999) 309–330 Jurassic radiolarites in a Tethyan continental margin (Subbetic, southern Spain): palaeobathymetric and biostratigraphic considerations J.M. Molina a , L. O’Dogherty b , J. Sandoval c , J.A. Vera c,* a Depto. Geologı ´a, Facultad de Ciencias Experimentales, Universidad de Jae ´n, 23091-Jae ´n, Spain b Depto. Geologı ´a, Facultad de Ciencias del Mar, Universidad de Ca ´diz, 11510-Puerto Real, Ca ´diz, Spain c Depto. Estratigrafı ´a y Paleontologı ´a, Facultad de Ciencias, Universidad de Granada, 18071-Granada, Spain Received 17 November 1997; accepted 17 November 1998 Abstract A region of the pelagic Subbetic basin within the Southern Iberian Continental Margin is studied in lithostratigraphical and biostratigraphical detail. Jurassic radiolarites (Jarropa Radiolarite Formation, Bathonian–Oxfordian) interbedded with shallow-water marine limestones have been recognized. Underlying the radiolarites (Camarena Formation, Bajocian) are oolitic limestones showing shallowing-upward cycles with karstic surfaces on the top, corresponding to deposition on an isolated carbonate platform on volcanic edifices. The Milanos Formation (upper Kimmeridgian–Tithonian), overlying the radiolarites, contains calciclastic strata with hummocky cross-stratification, which indicate outer carbonate ramp deposition. In the Jarropa Radiolarite Formation some calcisiltite strata with hummocky cross-stratification have been found. The bathymetry of the Subbetic Jurassic pelagic sediments, including the radiolarites, is considered as moderate or shallow in depth. We suggest that the pelagic character of the Jurassic sediments in this margin and their equivalents in other Alpine domains is a consequence of distance from the continent (beyond the pericontinental platform) but not necessarily of depositional depth.  1999 Elsevier Science B.V. All rights reserved. Keywords: radiolarite; bathymetry; Jurassic; Tethys; Betic; Spain 1. Introduction Significant amounts of pelagic sediments, de- posited on the Tethyan continental margins during the Jurassic rifting phases (Bernoulli and Jenkyns, 1974; Hallam, 1975; Jenkyns, 1978; Garcı ´a-Herna ´n- dez et al., 1980; Vera, 1988), today appear folded in the External Zones of various Alpine mountain L Corresponding author. Fax: C34 58 248528; E-mail: jvera@goliat.ugr.es chains (Betic, Alps, Apennines, Carpathians, Dinar- ids, Hellenids, Rif, Tell, etc.). These pelagic sedimentary rocks do not normally show any direct sedimentary or ecological features allowing their depth of deposition to be pinpointed. They have frequently been compared with recent pelagic sediments and attributed to great deposi- tional depths. The deposition of some lithostrati- graphic units (especially for the radiolarite facies) was considered to be located below the Calcite Compensation Depth (CCD) (Grunau, 1965; Gar- 0031-0182/99/$ – see front matter  1999 Elsevier Science B.V. All rights reserved. PII:S0031-0182(98)00219-3