Cretaceous Research (1997) 18, 713–729 New biostratigraphic data on the Early Cretaceous platform carbonates of the Tatra Mountains, Western Carpathians, Poland *Jean-Pierre Masse and †Alfred Uchman *Centre de Se ´ dimentologie-Pale ´ ontologie , UPRESA 6019 du CNRS , Universite ´ de Provence , Place Victor Hugo , Case 67, 13331 Marseille cedex 03, France †Institute of Geological Sciences , Jagiellonian University, Oleandry 2a, 30-063, Krako ´ w, Poland Revised manuscript accepted 17 February 1997 The biostratigraphy of platform carbonates outcropping in the Polish Tatra Mountains is reappraised after a study of three sections located in the autochtonous (including the Wysoka Turnia type section for Urgonian limestones) and allochtonous tectonic units. Age assignments are mainly based on calcareous algae, benthic foraminifera and rudists. Heterochrony of coral-rudist facies and their associated bioclastic and orbitolinid facies shows that the platform development and demise occurred at different times in different places. Regional tectonic processes are recognized as the dominant factors of these phenomena. The majority of foraminifera as well as rudists are considered cosmopolitan whereas some dasyclads could be potential palaeobiogeographic markers of the Preapulian Domain. ÷ 1997 Academic Press Limited KEY WORDS: carbonate platforms; Lower Cretaceous; biostratigraphy; calcareous algae; foraminifera; rudists; Carpathians; Poland. 1. Introduction In the Western Carpathians, Cretaceous carbonate platforms are mainly docu- mented from allochthonous exotic limestone clasts found in conglomerates of Late Cretaceous or early Tertiary age. A comparable situation is recorded in the Northern Calcareous Alps (Schlagintweit, 1990). Well preserved shallow water successions are known only from the northern part of the Inner Western Carpathians, ascribed to the Southern Tatric Platform (Lefeld, 1962, 1968, 1985, 1988; Michalı ´k, 1988, 1994; Michalı ´k & Sota´ k, 1990; Misäı ´k, 1990). ‘Urgonian facies’ (coral and rudist limestones) of Barremian –Early Aptian age are described from the region of Manı ´n (Slovakia) and Tatra Mountain (Poland) (Passendorfer, 1930, 1949; Kuhn & Andrusov, 1942; Morycowa & Lefeld, 1966; Lefeld, 1968, 1974; Misäı ´k, 1990). In these localities platform demise was considered to fall within the ‘mid-Aptian crisis’ postulated by Masse (1989a,b) for the Mediterranean platform systems. Nevertheless, data from allodapic facies and reworked limestone clasts show that platform growth was still active during the Late Aptian –Albian (Misäı ´k, 1990) in some regions of the Carpathians. The objective of the present paper is to show that in the Tatra Mountains, carbonate platform sequences previously regarded as mainly Barremian –Aptian in age are of various ages in different localities. This result is based on the study of three main sections of the High Tatric series in the Tatra Mountains (Figure 0195–6671 / 97 / 050713 1 17 $25.00 / 0 / cr970082 ÷ 1997 Academic Press Limited