Ammonoideos y bioestratigrafía del Triásico Medio (Anisiense superior-Ladiniense) en la sección de Calasparra (sector oriental de la Cordillera Bética, Murcia, España)

Abstract

A bioestratigraphic study has been understaken using ammonoids from the Upper Anisian and the Lower Ladinian in the SE Calasparra section (eastern of the Betic Cordillera). The section exposes 89 m of dolostones and fossiliferous limestones with the Muschelkalk facies. Five cephalopod genera and nine species have been identified, some of them are found in Spain for the first time, such as Paraceratitoides brotzeni and Gevanites epigonus. On the basis of the study of 10 levels with ammonoids, three biozones have been distinguished: the Brotzeni Zone (Upper Anisian), the Curionii Zone (Lower Ladinian) and the Epigonus Zone (Upper Ladinian). The position of Anisian-Ladinian boundary have been situated at the base of Curionii Zone by the ISTS (International Subcommision on Triassic Stratigraphy). The Curionii Zone could be subdivided in two Subzones: Curionii Subzone and Awadi Subzone. The ammonoid assemblages are typical from the Sepharadic Bioprovince, which include numerous species in common with Sinai and Negev (Israel) These assemblages can be correlated with other areas of NE Spain, other areas of the Tethys Province with other areas of North America, due to the presence of two species of wide geographic distribution, Eoprotrachyceras curionii ramonensis and «Eoprotrachyceras» cf. gredleri, which are recorded in the lower part of the Curionii and Epigonus Zones respectively.