(Table 3) Physical properties of DSDP Hole 72-515A, supplement to: Faas, Richard W; Crocket, David S (1983): Clay fabric development in a Deep-Sea Core: Site 515, Deep Sea Drilling Project Leg 72. In: Barker, PF; Carlson, RL; Johnson, DA; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 72, 519-535


Hole 515A was drilled in the southern Brazil Basin by the Glomar Challenger on DSDP Leg 72, using the newly developed hydraulic piston corer (HPC). A total of 108 m of undisturbed terrigenous mud (T1) and sandy mud (T2) was obtained (see site chapter, Site 515, this volume). The core was sampled at levels that corresponded to 50-kPa increments of overburden pressure to determine if a pattern of clay fabric development could be discerned. After criticalpoint drying and gold-palladium coating, 15 samples were analyzed with a scanning electron microscope (SEM). Clay fabric consists of randomly oriented, large and small domains of face-to-face (FF) stacked clay particles, frequently linked together by short "chains" in an edge-to-face (EF) orientation. As overburden pressure increases, linkages decrease, and the "chains" become incorporated into the domains. Distortion of platelike domains into "cornflake" structures (well-crystallized montmorillonite?) and spherical aggregates occurs at overburden pressures of 400 kPa. Orientation parallel with bedding occurs at 500 kPa as the "cornflake" structures become flattened and compressed. Maximum fabric development occurs at 590 kPa. Large plates and coalesced domains form a pervasive linear FF pattern, interrupted by a few large and small EF bridging structures. Deformation of the large EF-oriented plates occurs, forming circular, pitlike voids. Fabric development in cores from this deep-sea site follows well the developmental model suggested by Bennett and others (1981) for Mississippi Delta clays with high to medium void ratios.

DOI https://doi.org/10.1594/PANGAEA.811432
Related Identifier https://doi.org/10.2973/dsdp.proc.72.121.1983
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.811432
Creator Faas, Richard W; Crocket, David S
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 1983
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 130 data points
Discipline Earth System Research
Spatial Coverage (-36.503 LON, -26.238 LAT); South Atlantic/BASIN