Distribution of coarse and fine sediment fractions at Site 178-1095, supplement to: Moerz, Tobias; Wolf-Welling, Thomas C W (2001): Data report: Fine-fraction grain-size distribution data and their statistical treatment and relation to processes, Site 1095 (ODP Leg 178, western Antarctic Peninsula). In: Barker, PF; Camerlenghi, A; Acton, GD; Ramsay, ATS (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 178, 1-27

• Main Authors: Moerz, Tobias, Wolf-Welling, Thomas C W
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2001
• Subjects: DEPTH, sediment/rock; Sample code/label; Size fraction > 0.063 mm, sand; Size fraction < 0.063 mm, mud, silt+clay; Composite Core; DSDP/ODP/IODP sample designation; Grain size, sieving; Leg178; Joides Resolution; Helmholtz Centre for Ocean Research Kiel GEOMAR; Ocean Drilling Program ODP; Antarctic; Antarctic Peninsula; Ramsay; Antarc*
• Online Access: https://dx.doi.org/10.1594/pangaea.126304; https://doi.pangaea.de/10.1594/PANGAEA.126304

Fine-fraction (<63 µm) grain-size analyses of 530 samples from Holes 1095A, 1095B, and 1095D allow assessment of the downhole grain-size distribution at Drift 7. A variety of data processing methods, statistical treatment, and display techniques were used to describe this data set. The downhole fine-fraction grain-size distribution documents significant variations in the average grain-size composition and its cyclic pattern, revealed in five prominent intervals: (1) between 0 and 40 meters composite depth (mcd) (0 and 1.3 Ma), (2) between 40 and 80 mcd (1.3 and 2.4 Ma), (3) between 80 and 220 mcd (2.4 and 6 Ma), (4) between 220 and 360 mcd, and (5) below 360 mcd (prior to 8.1 Ma). In an approach designed to characterize depositional processes at Drift 7, we used statistical parameters determined by the method of moments for the sortable silt fraction to distinguish groups in the grainsize data set. We found three distinct grain-size populations and used these for a tentative environmental interpretation. Population 1 is related to a process in which glacially eroded shelf material was redeposited by turbidites with an ice-rafted debris influence. Population 2 is composed of interglacial turbidites. Population 3 is connected to depositional sequence tops linked to bioturbated sections that, in turn, are influenced by contourite currents and pelagic background sedimentation. : Original data have been corrected by C-D. Hillenbrand, AWI in 2003