Geochemical record of Holocene to Recent sedimentation on the Western Indus continental shelf, Arabian Sea
Limmer, David R.
Kohler, Cornelia M.
Cooper, Matthew J.
Tabrez, Ali R.
Clift, Peter D.
MetadataShow full item record
We present a multiproxy geochemical analysis of two cores recovered from the Indus Shelf spanning the Early Holocene to Recent (<14 ka). Indus-23 is located close to the modern Indus River, while Indus-10 is positioned ∼100 km further west. The Holocene transgression at Indus-10 was over a surface that was strongly weathered during the last glacial sea level lowstand. Lower Holocene sediments at Indus-10 have higher εNd values compared to those at the river mouth indicating some sediment supply from the Makran coast, either during the deposition or via reworking of older sediments outcropping on the shelf. Sediment transport from Makran occurred during transgressive intervals when sea level crossed the mid shelf. The sediment flux from non-Indus sources to Indus-10 peaked between 11 ka and 8 ka. A hiatus at Indus-23 from 8 ka until 1.3 ka indicates non-deposition or erosion of existing Indus Shelf sequences. Higher εNd values seen on the shelf compared to the delta imply reworking of older delta sediments in building Holocene clinoforms. Chemical Index of Alteration (CIA), Mg/Al and Sr isotopes are all affected by erosion of detrital carbonate, which reduced through the Holocene. K/Al data suggest that silicate weathering peaked ca. 4–6 ka and was higher at Indus-10 compared to Indus-23. Fine-grained sediments that make up the shelf have geochemical signatures that are different from the coarser grained bulk sediments measured in the delta plain. The Indus Shelf data highlight the complexity of reconstructing records of continental erosion and provenance in marine settings.
Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 13 (2012): Q01008, doi:10.1029/2011GC003845.
Showing items related by title, author, creator and subject.
Baumgartner, Mark F.; Brink, Nancy J.; Ostrom, William M.; Trask, Richard P.; Weller, Robert A.; Dickey, Thomas D.; Marra, John F. (Woods Hole Oceanographic Institution, 1997-07)The Arabian Sea is characterized by strong, large-scale atmospheric forcing during the summer (southwest) and winter (northeast) monsoons. To investigate air-sea interactions related to this unique surface forcing, a ...
Marra, John F.; Dickey, Thomas D.; Plueddemann, Albert J.; Weller, Robert A.; Kinkade, Christopher S.; Stramska, Malgorzata (2014-12)We review bio-optical and physical data from three mooring experiments, the Marine Light–Mixed Layers programme in spring 1989 and 1991 in the Iceland Basin (59°N/21°W), and the Forced Upper Ocean Dynamics Experiment in ...
Arabian Sea mixed layer dynamics experiment mooring recovery cruise report : R/V Thomas Thompson Cruise Number 52, 14 October-25 October 1995 Ostrom, William M.; Way, Bryan S.; Weller, Robert A.; Ware, Jonathan D.; Trask, Richard P. (Woods Hole Oceanographic Institution, 1996-09)An array of surface and subsurface moorings was deployed in the Arabian Sea to provide high quality time series of local forcing and upper ocean currents, temperature, and conductivity in order to investigate the dynamics ...