Microbioirrigation of marine sediments in dysoxic environments: Implications for early sediment fabric formation and diagenetic processes
- 1 January 2001
- journal article
- Published by Geological Society of America in Geology
- Vol. 29 (10), 923-926
- https://doi.org/10.1130/0091-7613(2001)029<0923:momsid>2.0.co;2
Abstract
It is manifest in the study of dysoxic sediments from the geological record that infaunal burrowing is considered so severely limited by the lack of dissolved oxygen as to be nonexistent. Although the effects of megafauna and macrofauna on sedimentary and geochemical processes are well known, the effects of meiofauna are largely ignored. Here we document abundant meiofauna in the recent severely dysoxic, laminated sediments from the Santa Barbara basin, California margin, and also microcavities and microtunnels in laminated deglacial sediments from Palmer Deep, west Antarctic Peninsula, that we interpret to be open, relict nematode burrows. Santa Barbara basin box-core subcores were sieved to quantify metazoan abundance, and others were embedded with resin for examination of meiofaunal life positions using confocal microscopy. Metazoan densities in the surface centimeters of sediment range from 80.7 to 117.9 cm−3, and nematode populations, together with their abundant burrows, remain quite high to at least 3 cm. Scanning electron microscope analysis of fractured surfaces in Palmer Deep sediments revealed that the rigid diatom ooze framework aids the preservation of ∼50 μm diameter open nematode burrows. These structures were observed to at least 40 m below the seafloor surface. This is the first description of a nematode-produced open burrow network preserved in the geological record. Optical microscopy of resin-embedded thin sections revealed widespread sediment redistribution without significant lamina disruption. The implications of abundant nematode burrows in surface sediments, and their preservation in the geological record, are wide ranging for both modern and ancient dysoxic marine environments, including for determining early sediment fabric production, geochemical processes, and diagenetic reactions in the oxic and suboxic zones.Keywords
This publication has 25 references indexed in Scilit:
- Reaction pathways in the Fe–S system below 100°CChemical Geology, 2000
- The Santa Barbara Basin is a symbiosis oasisNature, 2000
- Novel epifluorescence microscopy method to determine life position of foraminifera in sedimentsJournal of Micropalaeontology, 1996
- Development of a Gold Amalgam Voltammetric Microelectrode for the Determination of Dissolved Fe, Mn, O2, and S(-II) in Porewaters of Marine and Freshwater SedimentsEnvironmental Science & Technology, 1995
- Pelletal structures in Peruvian upwelling sedimentsJournal of the Geological Society, 1995
- Pathways of organic carbon oxidation in three continental margin sedimentsMarine Geology, 1993
- Meiofauna and solute transport in marine mudsLimnology and Oceanography, 1992
- Benthic oxygen fluxes on the Washington shelf and slope: A comparison of in situ microelectrode and chamber flux measurementsLimnology and Oceanography, 1992
- Deep-sea lebensspuren: remarks on some echiuran traces in the Porcupine Seabight, northeast AtlanticDeep Sea Research Part A. Oceanographic Research Papers, 1989
- A semiquantitative field classification of ichnofabricJournal of Sedimentary Research, 1986