Paleontología y ambientes sedimentarios del Triásico medio, Muschelkalk, de la Cordillera Ibérica 1: Cuencas y Valencia. España

Abstract

The Muscbelkalk Facies of tbe SE. Iberian Ranges is formed by tbe Landete Dolomites (d.L.), Mas Sandstones, Marls and Gypsum (a.m.y.M) and Cañete Dolomites and Limestone (d.c.C.) Formations. This paper deals on tbe paleontology and sedimentary environments of the two carbonatic Formations (d.L. and d.c.C.). Ten sections all over the area have been studied in detail and nine facies associations, each one formed by sequences less than 2m. thick, have been differenciated. Possibly, due to the dolomitization, fossil register is in general considered to be scaree and badly preserved. The analysis of the sequences reveals three different subenvironments (shoal, lagoon and sabkha). Two episodes can be differenciated for each carbonatic formation during the development of the depositional system: first, a short-lived transgression fol1owed by a longer regresive period. By far, the most abundant fossils are Molluscs of Bivalvia Class, forming a benthonic association dominated by suspensivores. The bivalves are found in both carbonated units, although in the upper one the faunistic richness and specific diversity are higher.
The taphonomic analysis reveals some autochtonous associations in both formations. The bivalve association found at the last beds of the upper Muschelkalk Facies of the lberian Ranges is known as tbe «Teruel Fauna», well represented in the Villora and Henarejos sections. The association consists on endo and epibisate Bivalves and some cemented ones, and represents different shallow carbonatic marine subenvironments. A Section Type has been cboosen and divided into 4 and 5 main levels or parts (for d.L. and d.c.C. respectively). Each of these parts is dominated by the abundance of one of the facies associations.