Global dominance of coralline red-algal facies: A response to Miocene oceanographic events

Abstract

Research Article| June 01, 2005 Global dominance of coralline red-algal facies: A response to Miocene oceanographic events Jochen Halfar; Jochen Halfar 1Institut für Geologie und Paläontologie, Universität Stuttgart, Herdweg 51, 70174 Stuttgart, Germany Search for other works by this author on: GSW Google Scholar Maria Mutti Maria Mutti 2Institut für Geowissenschaften, Universität Potsdam, Postfach 60 15 53, 14415 Potsdam, Germany Search for other works by this author on: GSW Google Scholar Geology (2005) 33 (6): 481–484. https://doi.org/10.1130/G21462.1 Article history received: 13 Dec 2004 rev-recd: 31 Jan 2005 accepted: 04 Feb 2005 first online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jochen Halfar, Maria Mutti; Global dominance of coralline red-algal facies: A response to Miocene oceanographic events. Geology 2005;; 33 (6): 481–484. doi: https://doi.org/10.1130/G21462.1 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 SocietyGeology Search Advanced Search Abstract Rhodoliths (free-living coralline red algae) can thrive under a wide range of temperatures, reduced light, and increased nutrient levels, and often form a distinct so-called rhodalgal lithofacies that is an important component of Cenozoic shallow-water carbonates. Global distributions illustrate that from the late-early to early-late Miocene (Burdigalian–early Tortonian), rhodalgal facies reached peak abundances and commonly replaced coral-reef environments, accompanied by a decline in other carbonate-producing phototrophs. We argue that the dominance of red algae over coral reefs was triggered in the Burdigalian by enhanced trophic resources associated with a global increase in productivity, as evidenced by a long-term shift toward higher carbon isotope values. Rhodalgal lithofacies expanded further in the middle Miocene when strengthened thermal gradients associated with the establishment of the East Antarctic Ice Sheet led to enhanced upwelling while climate change generated increased weathering rates, introducing land-derived nutrients into the oceans. Globally cooler temperatures following a climatic optimum in the early-middle Miocene contributed to sustain the dominance of red algae and prevented the recovery of coral reefs. The global shift in nearshore shallow-water carbonate producers to groups tolerant of higher levels of trophic resources provides further evidence for increased nutrient levels during that time interval and shows the sensitivity of shallow-water carbonate facies as indicators of past oceanographic conditions. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.