ESenckenbergianalethaea I 84 I (1/2) 1125-139 ] 4text-fig, 2pls Dedicated to Professor Kurt Ruchholz on the occasion of his 80th birthdm,. 125 Frankfurt am Main, 30.12.2004 I Famennian brachiopod and gastropod occurrences on top of Devonian seamounts, Elbingerode and Iberg Reefs, Harz Mts., Germany EBERHARD GISCHLER, ANDRZEJ BALINSKI, ARNOLD FUCHS 8 91 DORIS HEIDELBERGER With 4 Text-figures and 2 Plates A b stract Famennian brachiopods and gastropods occur locally on top of the Elbingerode and Iberg Reefs (Harz Mts.). The Elbingerode occurrence is found in a small depression of the former reef surface and belongs to the Palmatolepis triangularis conodont-zone. It is a brachiopod-gastropod packstone, which also contains limited numbers of crinoids, solitary corals, and trilobites. The Iberg occurrence is a crinoid grainstone, which contains few brachiopods and solitary corals. The grainstone is found in two neptunian dikes cutting the reef, and belongs to the Palmatolepis marginifera conodont-zone. Five brachiopod and five gastropod taxa are described, with the new species Holopea ruchholzi. Stable isotopes (?~3C, 91 of cement and matrix of Famennian limestones suggest no relation to a methane seep, as described for the different, late Visean brachiopod limestone on top of the Iberg Reef. K e y w o r d s : Devonian, Famennian, brachiopod, gastropod, limestone, reef, Harz Kurzfasssung Brachiopoden und Gastropoden des Famenne treten lokal begrenzt auf dem Elbinger6der und Iberger Riff (Harz) auf. Das Elbinger6der Vorkommen liegt in einer Vertiefung der ehemaligen Riffoberfl~iche und geh6rt stratigraphisch in die Palmatolepis triangularis Conodonten-Zone. Es handelt sich um Brachiopoden-Gastropoden-Packstones, in denen untergeordnet auch Crinoiden, so[it~ire Korallen und Trilobiten vorkommen. Das Iberger Vorkommen ist ein Crinoiden-Grainstone, in dem untergeordnet auch Brachiopoden und Korallen vorliegen. Der Kalk tritt in zwei neptunischen Spalten im Riff auf und ist stratigraphisch in die Palmatolepis marginifera Conodonten-Zone einzustufen. Insgesamt werden f'ª Brachiopoden-und f'ª Gastropoden-Taxa beschrieben, darunter die neue Art Holopea ruchholzi.