Calcium carbonate concentrations of ODP Sites 113-689 and 113-690 ...

• Main Author: O'Connell, Suzanne B
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1990
• Subjects: Drilling/drill rig; Leg113; Joides Resolution; Ocean Drilling Program ODP; Antarc*; Antarctica; Weddell Sea
• Online Access: https://dx.doi.org/10.1594/pangaea.754384; https://doi.pangaea.de/10.1594/PANGAEA.754384

An almost continuous Upper Cretaceous through Pleistocene biogenic sediment section was recovered from two sites on Maud Rise, a volcanic edifice in the Weddell Sea, off eastern Antarctica. Calcium carbonate values were determined for 1100 closely spaced samples using a Coulometrics CO2 Coulometer.Following a very brief decrease in the percentage of calcium carbonate immediately above the Cretaceous/Tertiary boundary, values remain high (~70%-80%), throughout most of the Paleocene, with variations primarily attributed to changes in the relative abundance of terrigenous and biogenic components. A small general decrease in calcium carbonate is observed from the upper Paleocene to lower middle Eocene. Eocene values continue to show small to moderate fluctuations. These fluctuations become more pronounced in the Oligocene as biosiliceous and carbonate sediments are mixed and interlayered. A distinct decrease in the calcium carbonate component is observed in the upper Oligocene through lower middle Miocene. ... : Supplement to: O'Connell, Suzanne B (1990): Variations in upper Cretaceous and Cenozoic calcium carbonate percentages, Maud Rise, Weddell Sea, Antarctica. In: Barker, PF; Kennett, JP; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 113, 971-984 ...