Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 18. 1996. (Budapest, 1996)

(4) Felsőörs. This classical section is exposed artificially in two parallel trenches on the southwestern slope of the Forrás-hegy (Hill). The lowermost part of the sequence studied here in detail belongs to the Felsőörs Formation and consists of grey, wellbedded limestone alternating with more or less altered, yellowish tuffitic clays (in about 4 m thickness). Above the uppermost thick limestone layer the tuffites of the Buchenstein Formation become predominant. In this 18 m thick, variegated tuffitic complex only thin and nodular ochre-yellow cherty limestone interbeds can be found. The uppermost member of the exposed sequence is a light-coloured, nodular, cherty limestone which still contain some tuffitic clay seams. (Earlier descriptions of the section can be found in SZABÓ et al. 1980 and in KOVÁCS et al. 1990). The diagnostic taxa of the rich ammonoid fauna (nearly 700 specimens, 22 taxa) are the following: Paraceratites, Asseretoceras, Lardaroceras, Semiornites, Longo bard ites, Norites, Kellnerites, Reitziites, Hungarites, Parakellnerites Ptychites Flexoptychites, and Discoptychites. The sequence accumulated in a basin of high rate of sedimentation and represents the uppermost part of the Anisian Trinodosus Zone and the Lower Ladinian Reitzi Zone (Camunum to Avisianum subzones). (5) Vörösberény. This section is a road-cut between Vörösberény (Balatonalmádi) and Szentkirályszabadja. Here the uppermost part of the Felsőörs Formation (limestone beds with clay seams) and the lower part of the tuffitic Buchenstein Formation is exposed in about 10 m thickness. The rich ammonoid fauna (more than 1000 specimens, 16 taxa) consists of the following main elements: Paraceratites, "Beyrichites", Semiornites, Asseretoceras, Megaceratites, Lardaroceras, Ptychites, Discoptychites and Flexoptychites. It is a basinal sequence representing chiefly the Upper Anisian Camunum and Pseudohungaricum subzones; the Lower Ladinian Felsoeoersensis subzone is almost barren of ammonoids. (6) Szentkirály szabadj a. The lower part of the sequence consists of thick dolomite beds alternating with yellow clays. Higher up the dolomite becomes thin-bedded and crumbly and contains volcanoclastic admixture; then alternates with limestone, but the crumbly and tuffitic character remains constant throughout the sequence. The uppermost beds are again massive dolomites but since they contain a few ammonite "ghosts" they must have been pelagic limestones dolomitized secondarily. The rich ammonoid fauna (750 specimens, 18 taxa) contains the following main elements: Kellnerites, Hyparpadites, Parakellnerites, Reitziites, Hungarites Flexoptychites and Discoptychites. The sequence was deposited during a pelagic episode on a drowned and later revived carbonate platform and represents the the uppermost part of the Anisian Trinodosus Zone and the Lower Ladinian Reitzi Zone (Pseudohungaricum to Reitzi subzones). METHODS In the first step a re-evaluation of the paleogeography of the Balaton area has been done with special attention to the distributon and changes of the sedimentary environments during the Late Anisian to Early Ladinian times. A slightly revised version of the paleogeographic map of BUDAI & VÖRÖS (1992) has been constructed