Ocean Science www.ocean-sci.net 1812-0784 1812-0792 1 2 2005 10.5194/os-1-113-2005 http://www.ocean-sci.net/1/113/2005/ http://www.ocean-sci.net/1/113/2005/os-1-113-2005.html http://www.ocean-sci.net/1/113/2005/os-1-113-2005.pdf 113 126 2005-10-25 Laminae type and possible mechanisms for the formation of laminated sediments in the Shaban Deep, northern Red Sea I. A. Seeberg-Elverfeldt C. B. Lange J. Pätzold G. Kuhn Research Center Ocean Margins, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany Center for Oceanographic Research in the eastern South Pacific (FONDAP-COPAS), Department of Oceanography, University of Concepción, P. O. Box 160-C, Concepci´on, Chile Foundation Alfred-Wegener-Institute for Polar and Marine Research, Columbusstrasse, 27568 Bremerhaven, Germany Laminated sediments in the Shaban Deep, a brine-filled basin in the northern Red Sea, were analyzed with backscattered electron imagery. Here we present possible mechanisms involved in the formation of laminae of various types and homogenous intervals arising from the detailed investigation of multicore GeoB 7805-1 (26°13.9' N and 35°22.6' E; water depth 1447 m) and gravity core GeoB 5836-2 (26°12.61' N, 35°21.56' E; water depth 1475 m). Sediment makeup includes six types: a) a laminated structure with alternating light (mainly coccoliths) and dark (diatom frustules) layers, where the diatom component is indicative of the intra-annual variability between stratification and mixing events; b) a pocket-like structure attributed to the sinking of particles within fecal pellets and aggregates; c) a matrix of tightly packed diatoms that relates to extended stratification/mixing periods of the water column; d) homogenous intervals that result from turbidity deposition; e) silt accumulations which origin may lie in agglutinated foraminifers; and f) pyrite layers with pyrite formation initiated at the seawater-brine interface.