Southern Ocean laminated diatom ooze: mat deposits and potential for palaeo-flux studies, ODP leg 177, Site 1093

• Published in: Deep Sea Research Part II: Topical Studies in Oceanography
• Main Authors: Grigorov, Ivo, Pearce, Richard, Kemp, Alan
• Other Authors: Université de Brest (UBO), National Oceanography Centre (NOC), NERC, Ocean Drilling Program Leg 177 Scietific Party
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2002
• Subjects: laminated sediments; sediment fabric; Thalassiothrix antarctica mats; flux records; Southern Ocean; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Antarc*; Antarctica
• Online Access: https://hal.univ-brest.fr/hal-00451245; https://hal.univ-brest.fr/hal-00451245/document; https://hal.univ-brest.fr/hal-00451245/file/Grigorov_et_al_2002._Southern_Ocean_laminated_diatom_ooze_mat_deposits_and.pdf; https://doi.org/10.1016/S0967-0645(02)00089-9

International audience Laminated diatom ooze samples collected during ODP Leg 177 were analysed using scanning electron microscope (SEM) and optical microscopy to test their potential as high-resolution records of Polar Front hydrography, surface production, and export. SEM analysis from two intervals, marine isotope stage (MIS) 29 and 12/11, respectively, recovered from 50°S in the Atlantic Ocean (ODP Site 1093, Hole A, sections 13H-4 0–18 cm and 23H-4 0–22 cm), show abundant and well-preserved Thalassiothrix antarctica mats, thought to be indicative of rapid export from the surface and deposition in the sediment. A preliminary analysis of laminae succession points to a possible annual couplet/triplet succession of laminae, and suggests exceptionally high local sedimentation rates of 57 and 80 cm kyr−1 for MIS 12/11 and 29, respectively. Such high accumulation rates imply that local export from the surface layer and sequestration of biogenic silica and organic matter to the sediments may have been much higher than previously suggested.