Molluscan biostratigraphy of the Miocene and Chatt in the southern Herzogtum Lauenburg (Schleswig-Holstein)

A study was made of the marine molluscan fauna from 12 borings in the Schwarzenbek area. In the fossil rich facies underlying the 'Braunkohlensande', the Neochatt and Vierland faunal sequences could be described and used to define the Oligocene/Miocene boundary. The Neochatt, defined by Pectinidae, seems to be more closely related to the Miocene than previously thought. Nevertheless, a sufficient number of additional molluscan species are present for placing the Neochatt/Vierland boundary. Overlying the Braunkohlensande, the sandy Reinbek fauna as well as Glimmerton faunas of the Reinbek and Langenfelde stages could be described.

Fossil record of Mollusca from Neogene sediments in Schleswig-Holstein, Germany

Über die Verbreitung, Gliederung und Ausbildung des Jungtertiärs im westlichen Schleswig-Holstein war bisher nicht viel bekannt. Am besten bearbeitet sind die glazial gestauchten Schollen von Morsum/Sylt. Eine Aufzählung erbohrter Miozänvorkommen mit nicht immer überzeugender Begründung lieferte H.-L. HECK 1935. S. THIELE (1941) hat die ihm bekannten Vorkommen hauptsächlich nach faziellen und petrographischen Gesichtspunkten bearbeitet. Er erkannte richtig die Stellung der Braunkohlensande. Die angekündigte palaeontologische Bearbeitung ist nicht erschienen. Eine allgemeine Übersicht über die Entwicklung des Jungtertiärs bringen W. WOLFE und H.-L. HECK 1949. W. HINSCH lieferte wertvolle Beiträge zur Molluskenfauna und zur Gliederung des Miozäns (1952, 1955). Über neue Vorkommen von Braunkohlen-Sanden berichtete E. DITTMER(1 956), eine erste Übersicht über neue Vorkommen der Hemmoorer Stufe gab derselbe Verfasser 1957.

Miocene molluscan biostratigraphy in Schleswig-Holstein, north Germany

Vierlandian, Behrendorfian (Lower Hemmoorian), Oxlundian (Upper Hemmoorian), Lower and Upper Reinbekian, Langenfeldian and Gramian stages could be proved by evaluation of marine molluscan faunas. The diachrone base of 'Braunkohlensande' is demonstrated by underlying Vierlandian mica clay in the E, and by Hemmoorian substages more to the W, at last the fluviatile facies is replaced completely by euhaline to brachyhaline sandy to silty sediments. Brachyhaline effects in adjacent environments make possible an approximate dating on fluviatile sedimentation. The widest extension of 'Braunkohlensand' is during upper Oxlundian, whilst slightly brachyhaline Katzheide beds, defined in this paper to be of Lower Reinbekian age, indicate a limit of 'Braunkohlensande' more to the E. Winnert-fauna was found to be a mixture of Oxlundian and Langenfeldian; the overlying lignitic sands belong to the Kaolinsand group. Upper mica clay overlying Miocene Braunkohlensande can be divided into beds of Upper Reinbekian, Langenfeldian and Gramian ages.

Distribution of molluscs on the Atlantic continental shelf off Southern Spanish Sahara, West Africa

Two hundred and seventy five mollusc species from the continental shelf off Southern Spanish Sahara (depth: 32-60 m) were identified. Their distribution pattern is strongly influenced by the nature of the bottom (firm substrate, shelter, stability of sediment) rather than other factors at that depth interval. This faunal assemblage shows great affinity to the Mediterranean and Lusitanian faunas, and comprises only few (22 %) exclusively Senegalese and species living south of Senegal.