ODP 658C

ODP 658C
Name	ODP 658C
Location	North Atlantic Ocean
Expedition	Ocean Drilling Program
Lithology	Pelagic sediments
Period	Paleogene

ODP 658C is a deep-sea drill core recovered during scientific ocean drilling that has informed studies of Paleogene climate, biostratigraphy, and paleoceanography. The site yielded sedimentary sequences used by researchers associated with the Ocean Drilling Program, the Deep Sea Drilling Project, and later Integrated Ocean Drilling Program expeditions to correlate records with other sites such as DSDP Hole 401, ODP Site 690, and IODP Site U1334. Multiple institutions including the United States Geological Survey, Woods Hole Oceanographic Institution, and Scripps Institution of Oceanography have archived data and samples from the site.

Discovery and Naming

ODP 658C was recovered as part of an Ocean Drilling Program expedition organized under the auspices of the Joint Oceanographic Institutions and the National Science Foundation, following reconnaissance work by the Deep Sea Drilling Project and seismic surveys conducted by research vessels associated with the British Antarctic Survey, the Alfred Wegener Institute, and the Lamont–Doherty Earth Observatory. The nomenclature follows ODP drilling conventions used by the Ocean Drilling Program, the Integrated Ocean Drilling Program, and the International Ocean Discovery Program, consistent with site numbering schemes employed at locations like ODP Sites 689, 690, and 738. The designation reflects operations coordinated among institutions such as the University of Tokyo, Universidade de São Paulo, and the French National Centre for Scientific Research.

Geographic and Stratigraphic Context

Located in the North Atlantic Ocean near margins sampled by DSDP and ODP transects, the site lies within a region mapped by seismic lines from the Geological Survey of Canada, the Instituto Oceanográfico, and the British Geological Survey. Stratigraphically the core intersects pelagic sequences correlated to reference sections used in studies of the Paleocene, Eocene, and Oligocene like the GSSP sections at El Kef, Walvis Ridge, and Zumaia, and has been integrated into regional frameworks alongside drill sites such as ODP Site 925, IODP Site U1313, and DSDP Site 87. Tectonic and paleoceanographic settings reference plate reconstructions by the Paleomap Project, the USGS, and the Geological Society of London and are cross-referenced with basin analysis from the Norwegian Petroleum Directorate and the European Marine Board.

Lithology and Core Description

The lithologic assemblage comprises hemipelagic clay, nannofossil ooze, diatomaceous intervals, and carbonate-rich layers similar to those described from ODP Sites 690, 689, and 761, with siliciclastic turbidites comparable to sequences at DSDP Site 603 and IODP Site U1308. Core descriptions prepared by technicians at the British Ocean Sediment Core Research Facility, the IODP Bremen Core Repository, and the USGS Core Research Center noted color changes, magnetic susceptibility trends, and X-ray fluorescence elemental variations analogous to records from the Ocean Margin Drilling Program and the International Continental Scientific Drilling Program. Physical properties logs and smear-slide analyses conducted by teams affiliated with the Max Planck Institute for Chemistry, Kyoto University, and the University of Cambridge documented textural transitions and mineralogical assemblages.

Paleontology and Microfossils

Microfossil assemblages include calcareous nannofossils, planktonic foraminifera, benthic foraminifera, radiolarians, and diatoms, enabling biostratigraphic correlations with classic sites such as Zumaia, El Kef, and ODP Sites 690 and 738. Taxonomic work by researchers from the Natural History Museum, the Smithsonian Institution, and the Royal Netherlands Institute for Sea Research identified key index taxa used in frameworks developed by scholars at the International Commission on Stratigraphy, the Micropalaeontological Society, and the Paleontological Society. Paleoecological interpretations leveraged morphotypes referenced in monographs from Cambridge University Press, Elsevier, and Springer, and compared community shifts to records from the North Atlantic recorded at IODP Site U1403 and DSDP Hole 401.

Chronology and Age Determination

Age models for the core were constructed using biostratigraphy, magnetostratigraphy, and stable isotope stratigraphy tied to established polarity chrons from the Geomagnetic Polarity Time Scale and isotope excursions like the Paleocene–Eocene Thermal Maximum and the Eocene–Oligocene transition recognized at sections such as Mill Bay, El Kef, and Walvis Ridge. Radiometric calibrations referenced geochronological syntheses from the International Commission on Stratigraphy, the USGS, and the Berkeley Geochronology Center, and age ties were cross-validated against astronomically tuned chronologies developed at institutions including Utrecht University, the University of Bergen, and GFZ German Research Centre for Geosciences.

Paleoenvironmental Interpretations

Paleoenvironmental reconstructions infer changes in productivity, carbonate compensation depth, and bottom-water oxygenation, paralleling interpretations made for ODP Sites 690, 738, and IODP Sites U1333–U1334 and tied to climatic drivers discussed in literature from the Intergovernmental Panel on Climate Change, the Royal Society, and the American Geophysical Union. Analyses by teams from the University of Oxford, Princeton University, and the University of California compared isotope records and faunal turnovers to global events documented at the Paleomap Project, the International Ocean Discovery Program synthesis reports, and serial studies published through Nature, Science, and Earth and Planetary Science Letters.

Scientific Impact and Subsequent Studies

Data and samples from the core have been cited in multidisciplinary work by researchers at institutions such as the Scripps Institution of Oceanography, the Woods Hole Oceanographic Institution, and the Max Planck Institute for Meteorology, influencing studies on Paleogene climate change, carbon cycle perturbations, and ocean circulation linked to events discussed at conferences of the American Geophysical Union, the European Geosciences Union, and the AGU Chapman Conferences. Follow-up investigations integrated geochemical proxies, micropaleontology, and sedimentology in collaborative projects supported by the National Science Foundation, the European Research Council, and national research councils in Japan, Germany, and the United Kingdom, and contributed datasets to repositories managed by the British Oceanographic Data Centre, PANGAEA, and the IODP-USIO.

Category:Ocean Drilling Program sites