Mineralization kinetics of biosiliceous sediments in hot subseafloors
Year: 2024
Type: article
Abstract: Temperature affects the timing of the transformation of amorphous silica (opal-A) into crystalline (opal-CT) exponentially. Thus, in hot subseafloor environments opal-A is expected to convert into opal-CT at relatively shallow burial depths, where in situ temperatures do not exceed ∼56 °C, as it has been previously observed at various deep-sea sites and in onshore rock outcrops as well as assessed during lab experiments. The response of biosilica (biogenic opal-A) diagenesis to steep geothermal gradients (∼224–529 °C/km) at extremely high sedimentation rates (∼1 m/kyr) was examined in cores from off-axis boreholes drilled by the International Ocean Discovery Program (IODP) Expedition 385 in the actively spreading, intrusive sill-riddled Guaymas Basin at the Gulf of California (Mexico) rifted margin. At three sites drilled by IODP Expedition 385 (U1545, U1546, and U1547), the conversion from amorphous opal (−A) to crystalline opal (−CT) occurs in relatively deep (up to ∼330 mbsf) and unexpectedly hot (in situ temperatures of ∼74–79 °C) subseafloor conditions. This observation indicates a significantly slower reaction kinetics of biosilica transformation than previously reported. A compilation of empirical data that include biosiliceous basins with a similarly hot subseafloor (Sea of Japan and Bering Sea) yield new kinetic parameters that account for the slower rates of silica transformation. Thus, current kinetic models for the prediction of opal-A to −CT conversion face limitations when burial rates exceed those typical of biogenic sedimentation in open-ocean conditions. At Guaymas Basin Site U1545, where there is no evidence of sill-related metamorphic overprint, the d-spacing of the opal-CT (1 0 1) peak correlates linearly with in situ temperature between ∼75 and 110 °C throughout the opal-CT zone, thus, providing a local silica paleothermometry proxy that can be used to calculate the maximum temperature to which opal-CT sediment has been subjected.
Source: Geochimica et Cosmochimica Acta
Authors: Ivano W. Aiello, Tobias W. Höfig, Armelle Riboulleau, Andreas P. Teske, Daniel Lizarralde, Jeanine L. Ash, Diana P. Bojanova, Martine D. Buatier, Virginia P. Edgcomb, Christophe Y. Galerne, Swanne Gontharet, Verena B. Heuer, Shijun Jiang, Myriam A.C. Kars, Ji-Hoon Kim, Louise M.T. Koornneef, Kathleen M. Marsaglia, Nicolette R. Meyer, Yuki Morono, Raquel Negrete-Aranda, Florian Neumann, Lucie C. Pastor, Manet E. Peña-Salinas, Ligia L. Pérez-Cruz, Lihua Ran, John A. Sarao, Florian Schubert, S. Khogenkumar Singh, Joann M. Stock, Laurent Toffin, Wei Xie, Toshiro Yamanaka, Guangchao Zhuang
Institutions: San Jose State University, Moss Landing Marine Laboratories, University of North Carolina at Chapel Hill, Forschungszentrum Jülich, Projektträger Jülich, Texas A&M University, Centre National de la Recherche Scientifique, Université de Lille, Laboratoire d’Océanologie et de Géosciences, Woods Hole Oceanographic Institution, Rice University, University of Southern California, Laboratoire Chrono-Environnement, Université Bourgogne Franche-Comté, University of Bremen, Sorbonne Université, Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques, Institut de Recherche pour le Développement, Hohai University, Marine Core Research Institute, Kochi University, Kōchi University, Korea Institute of Geoscience and Mineral Resources, University of Plymouth, California State University, Northridge, Stanford University, Japan Agency for Marine-Earth Science and Technology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ifremer, Universidad Autónoma de Baja California, Instituto de Geofísica, Universidad Nacional Autónoma de México, GFZ Helmholtz Centre for Geosciences, California Institute of Technology, Tokyo University of Marine Science and Technology, Qingdao National Laboratory for Marine Science and Technology
Language: English
Subfield: Geochemistry and Petrology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,840
Awards: G474478745, A Proposal to Manage the U.S. Science Support Program Office associated with the International Ocean Discovery Program (USSSP-IODP), Linkage of the Earth's tipping points and the subseafloor biosphere, MRI: Acquisition of X-Ray Diffraction Instrumentation for Mineralogical Research, Management and Operations of the JOIDES Resolution as a Facility for the International Ocean Discovery Program (IODP)
OpenAlex ID: W4400618243