Abstract:

This dataset contains sediment texture and composition data collected aboard R/V Weatherbird II cruises WB-0812 and WB-1012 and R/V Pelican cruise PE12-22 in the northern Gulf of Mexico from 2012-04-09 to 2012-10-18. Sediment texture and composition data were generated for selected core sub-samples at 2mm sampling intervals for “surficial unit” and 5mm sampling resolution intervals to the base of cores. Sediment texture values were expressed as percent gravel, sand, silt, and clay. Percent of mud can be calculated by combining percent silt and clay. Sediment composition was expressed as percent total organic matter (TOM) measured by loss on ignition (LOI), percent carbonate content measured by acid leaching, and the percent insoluble residue (IR), which was likely dominated by terrigenous clastic (land-derived) sediment sources. Cruise documentation was provided for each of the R/V Weatherbird II cruises. The cruises were led by chief scientists Dr. Steve Murawski and Dr. David Hollander (WB-0812), Dr. David Hollander (WB-1012). The R/V Pelican cruise PE12-22 was led by Mark Pagani and additional information regarding this cruise can be found in the R2R repository: https://www.rvdata.us/search/cruise/PE12-22.

Suggested Citation:

Gregg Brooks and Rebekka Larson. 2019. Sediment texture and composition data collected aboard R/V Weatherbird II cruises WB-0812 and WB-1012 and R/V Pelican cruise PE12-22 in the northern Gulf of Mexico from 2012-04-09 to 2012-10-18. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-bkvk-wr98

Purpose:

Determine if/how sediment texture and composition varies in sediment cores as an indicator of sediment sources and depositional mechanisms.

Data Parameters and Units:

Sediment core collection latitude and longitude (decimal degrees), water depth (m), core collection date (MM/DD/YY), site identification (ID), core identification (ID), top depth of interval (mm), bottom depth of interval (mm), average depth of interval (average of top and bottom depths, mm), percent gravel (by dry weight), percent sand (by dry weight), percent silt (by dry weight), percent clay (by dry weight), percent mud (calculated by adding percent silt and clay, by dry weight), percent carbonate (by dry weight), percent total organic matter (TOM) by loss on ignition (LOI) (by dry weight), percent other (non-carbonate, non-organic; by dry weight), laboratory/facility where analysis was performed.

Methods:

Sediment core preservation was not required for this analysis. Samples were freeze-dried and weighed for dry mass to calculate dry bulk density. Sediment texture and composition analyses were conducted on extruded samples and included grain size, and calcium carbonate content. Grain size was determined by wet sieving the sample through a 63µm screen. The fine-size (<63 µm) fraction was analyzed by pipette (Folk, 1968) to measure the relative percentage of silt and clay. The sand-size (>63 µm) fraction was volumetrically too small to analyze further and is reported here as percent sand. Percent of gravel was measured using a 2mm sieve. Carbonate content was determined by the acid leaching method according to Milliman (1974). Percent TOM (LOI) was determined by loss on ignition (LOI) at 550˚ C for at least 2.5 hours (Dean, 1974).

Instruments:

Ocean Instrument MC-800 Multicore, Shipek Grab Sampler.

Provenance and Historical References:

Dean, W. E. (1974). Determination of carbonate and organic matter in calcareous sediments and sedimentary rocks by loss on ignition; comparison with other methods. Journal of Sedimentary Research, 44(1), 242-248. doi:10.1306/74d729d2-2b21-11d7-8648000102c1865d Folk, R. L. (1968). Petrology of Sedimentary Rocks, Hemphill's, Austin, Texas. Milliman, J. D. (1974). Marine carbonates: Springer-Verlag. New York.

Individual Files: