A Detailed Study of the Physical Properties of Recently Deposited Sediments from a Minibasin, Northwest Gulf of Mexico
Abstract
High-resolution seismic data from lower slope basins of Bryant Canyon suggest the recent occurrence of thin mud flows events, which influence the physical properties of the shallow sediments of Kaskida Minibasin. Therefore to understand the affection of these events on the the physical properties, is mandatory a very high spatial resolution investigation of: bulk density, grain density, shear strength, water content, calcium carbonate content, compressional wave velocity, and the relative elemental composition, in the first 5 meters of the seabed sediments.
The availability of the gravity cores JPC-29 and JPC-36, extracted on either side to better represent the minibasin, provide the undisturbed portions of marine sediments to measure these properties. We used the: multisensor core logger, miniature vane, fall cone, pycnometer, coulometer and X-ray fluorescence scanner, in a very high sampling resolution, to obtain profiles able to represent accurately the variation of the properties with depth. We compared values of the same property obtained by independent techniques, determined the relationships among the properties, investigated how the properties vary with depth in the two cores, and examined how sampling resolution influences the expression of features in downcore profiles of the properties.
The results of the research demonstrate that the MSCL is a efficient method to calculate the bulk density of the marine sediments; the fall cone and the mini vane test are a consistent in theirs results. The water content and the bulk density have an inverse relationship, and the variety in grain sizes diminish the pore space that can be occupied by seawater and increases the contact between grains resulting in a high shear strength. The profiles obtained in general terms showed that bulk density and shear strength increases with depth, while water content and calcium carbonate content decreases with depth. Two interesting features of high bulk density were explained trough the relation among physical properties. Finally the sampling resolution is important to express actual variations in the seabed’s characteristics, and resolve seabed features that allow an accurately representation of the physical properties of the marine sediments and therefore a correct understanding of their relationship.
Citation
Santos Castaneda, Marco 1974- (2012). A Detailed Study of the Physical Properties of Recently Deposited Sediments from a Minibasin, Northwest Gulf of Mexico. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /192000.