A Silurian Cold-Seep Ecosystem From the Middle Atlas, Morocco

Other| December 01, 2004 A Silurian Cold-Seep Ecosystem From the Middle Atlas, Morocco ROBERTO BARBIERI; ROBERTO BARBIERI 1Dipartimento di Scienze della Terra e Geologico-Ambientali, Università di Bologna, Via Zamboni 67, 40126 Bologna, Italy, barbieri@geomin.unibo.it Search for other works by this author on: GSW Google Scholar GIAN GABRIELE ORI; GIAN GABRIELE ORI 2International Research School of Planetary Sciences, Università d'Annunzio, Viale Pindaro 42, Pescara, Italy Search for other works by this author on: GSW Google Scholar BARBARA CAVALAZZI BARBARA CAVALAZZI 3Dipartimento di Scienze della Terra e Geologico-Ambientali, Università di Bologna, Via Zamboni 67, 40126 Bologna, Italy Search for other works by this author on: GSW Google Scholar Author and Article Information ROBERTO BARBIERI 1Dipartimento di Scienze della Terra e Geologico-Ambientali, Università di Bologna, Via Zamboni 67, 40126 Bologna, Italy, barbieri@geomin.unibo.it GIAN GABRIELE ORI 2International Research School of Planetary Sciences, Università d'Annunzio, Viale Pindaro 42, Pescara, Italy BARBARA CAVALAZZI 3Dipartimento di Scienze della Terra e Geologico-Ambientali, Università di Bologna, Via Zamboni 67, 40126 Bologna, Italy Publisher: SEPM Society for Sedimentary Geology Accepted: 18 Mar 2004 First Online: 03 Mar 2017 Online ISSN: 1938-5323 Print ISSN: 0883-1351 Society for Sedimentary Geology PALAIOS (2004) 19 (6): 527–542. https://doi.org/10.1669/0883-1351(2004)019<0527:ASCEFT>2.0.CO;2 Article history Accepted: 18 Mar 2004 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation ROBERTO BARBIERI, GIAN GABRIELE ORI, BARBARA CAVALAZZI; A Silurian Cold-Seep Ecosystem From the Middle Atlas, Morocco. PALAIOS 2004;; 19 (6): 527–542. doi: https://doi.org/10.1669/0883-1351(2004)019<0527:ASCEFT>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyPALAIOS Search Advanced Search Abstract Geological and paleobiological attributes described in a carbonate unit from the upper Silurian of the Middle Atlas (Morocco) are interpreted as the result of chemosynthetic processes fueled by fluid seepage. These attributes include: the presence of authigenic carbonate accumulation embedded in siliciclastic rocks; tightly packed, monospecific megafaunal assemblages (atrypid brachiopods); microbial-derived products; precipitation of bio-induced minerals (especially hematite); and seep-derived carbonate phases. Evidence of in-situ growth of the dense brachiopod communities is that their shells are all articulated, and show a complete range of growth sizes. Products of microbial activity are shared with other fossil seep deposits and include clotted micrite concentrations, crusts, and laminated structures, microtufts, biofilms, and endolithic filaments. The best-developed microbial features were recovered in reddish mudstone beds below and within the brachiopod concentrations, where they consist of complex microbial frames morphologically comparable to the ones produced by Beggiatoa mats in modern chemosynthesis-based environments. These remnant mats are associated with early hematite precipitation, which has permitted their extensive mineralization and, consequently, the preservation of their stratigraphic relationships with the shell accumulations. Carbonate phases such as botryoids, splayed calcite, and stromatactoids form the infilling of cavity systems and microconduits. Repeated events of mineral precipitation and corrosion are documented in botryoids and stromatactoids, as well as in more extensive corrosion surfaces, as a result of changes in the ambient chemistry related to type and changing intensity of the seeping fluids. This carbonate unit is the oldest-known seep-derived unit, with a well preserved, voluminous, and diverse microbial component. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.