Doomed pioneers: Gravity-flow deposition and bioturbation in marine oxygen-deficient environments

Research Article| November 01, 1990 Doomed pioneers: Gravity-flow deposition and bioturbation in marine oxygen-deficient environments Karl B. Föllmi; Karl B. Föllmi 1Earth Sciences Board, University of California, Santa Cruz, California 95064 Search for other works by this author on: GSW Google Scholar Kurt A. Grimm Kurt A. Grimm 1Earth Sciences Board, University of California, Santa Cruz, California 95064 Search for other works by this author on: GSW Google Scholar Geology (1990) 18 (11): 1069–1072. https://doi.org/10.1130/0091-7613(1990)018<1069:DPGFDA>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Karl B. Föllmi, Kurt A. Grimm; Doomed pioneers: Gravity-flow deposition and bioturbation in marine oxygen-deficient environments. Geology 1990;; 18 (11): 1069–1072. doi: https://doi.org/10.1130/0091-7613(1990)018<1069:DPGFDA>2.3.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 SocietyGeology Search Advanced Search Abstract Isolated horizons of Thalassinoides and Gyrolithes burrows appear in exclusive association with gravity-flow deposits within sequences of nonbioturbated hernipelagic sedimentary rocks of the Miocene Monterey Formation of California and the Oligocene-Miocene San Gregorio Formation of Baja California. These burrowed levels are not associated with other ichnogenera such as Zoophycos and Chondrites. We infer a causal relation between gravity flow deposition and the presence of Thalassinoides and Gyrolithes and suggest that these gravity flows entrained thalassinidean crustacea. Upon deposition in oxygen-deficient environments, the surviving borrowers reworked substantial quantities of aminated, commonly organic-rich sediments in an environment from which they were previously excluded. The persistence of or the ecologically rapid return to oxygen-depleted conditions limited the survival time and ecological complexity of the transported infaunal dwellers and rendered them doomed pioneers. Ecological and physiological data support this hypothesis: thalassinidean crustacea have the capability to endure turbulent transport and survive up to 5-7 days of anoxia without being severely limited in their biological activities.The accurate recognition of doomed pioneer trace-fossil assemblages as ephemeral ecological phenomena in otherwise laminated successions may contribute to a better understanding and interpretation of paleo-oxygen levels and basin history. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.