Interstitial water chemistry, Deep Sea Drilling Project, Leg 96 ...

• Main Authors: Presley, Bob J, Stearns, Steven
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1986
• Subjects: Deep Sea Drilling Project DSDP; Orca
• Online Access: https://dx.doi.org/10.1594/pangaea.786678; https://doi.pangaea.de/10.1594/PANGAEA.786678

On Leg 96 of the Deep Sea Drilling Project (DSDP), holes were drilled in Orca and Pigmy basins on the northern Gulf of Mexico continental slope and on the Mississippi Fan. The holes on the fan encountered interbedded sand, silt, and mud deposited extremely rapidly, most during late Wisconsin glacial time. Pore-water chemistry in these holes is variable, but does not follow lithologic changes in any simple way. Both Ca and SO4 are enriched in the pore water of many samples from the fan. Two sites drilled in the prominent central channel of the middle fan show rapid SO4 reduction with depth, whereas two nearby sites in overbank deposits show no sulfate reduction for 300 m. Calcium concentration decreases as SO4 is depleted and Li follows the same pattern. Strontium, which like Li, is enriched in samples enriched in Ca, does not decrease with SO4 and Ca. Potassium in the pore water decreases with depth at almost all sites.Sulfate reduction was active at the two basin sites and, as on the fan, this resulted in ...