A Method for Quantifying Deep-Sea Carbonate Dissolution Using¹⁴C Dating

Abstract

ABSTRACT. We quantified the rate of carbonate dissolution with increasing water depth by taking the difference in the carbonate mass accumulation rate of deep (3393-4375 m) core top sediments from the shallowest one 3208 m which w assumed was unaffected by dissolution. This method depends on high quality 14C dates that ( l e for calculating sedimentation rates. Our results show low from 0 tp, we calibrated to calendar years (ranging 3 g cm-2 ka-1) and high (ranging from 1.5 to 1.7 g cm-2 ka-1) carbonate dissolution rates, above and below 4000 m, respectively. Therefore, we interpret the sudden increase in the carbonate dissolution rate at 4000-m water depth to mark the lysocline.

Oxygen Isotope Variability of Planktonic Foraminifera Provide Clues to Past Upper Ocean Seasonal Variability

“…Between 728‐ and 828‐cm core T90‐9p was sliced into 1‐cm samples at ~4‐cm intervals; this section of T90‐9P (Feldmeijer et al, ; Lototskaya et al, ; Lototskaya & Ganssen, ; Metcalfe et al, ; van Kreveld et al, ) covers the transition from MIS 8 and MIS 7 (Figures and ). The age depth relationship (Table ) is that of Feldmeijer et al (), with the downcore record of G. inflata tuned to the “planktonic foraminifera” depth‐derived δ 18 O stack of Huybers (Huybers, ) to both avoid circular reasoning and preclude the evaluation of orbital parameters (Huybers, ; Huybers & Wunsch, ).…”

Dissolução do carbonato na Bacia de Santos durante o último ciclo glacial (150 mil anos): registros micropaleontológicos, geoquímicos e sedimentares

“…Diversos estudos se propuseram a reconstruir a profundidade da lisoclina durante o último máximo glacial (CURRY; LOHMANN, 1986;VAN KREVELD et al, 1995;MCCORKLE;MARTIN, 1998;HENRICH, 2007). Ao comparar registros de dissolução do carbonato do Holoceno com dados do UGM observou-se que, durante o UGM, houve uma redução na produção de APAN, dando oportunidade para que ocorresse a expansão da massa d'água de origem sul, mais corrosiva ao carbonato (DUPLESSY et al, 1988b;HOROWITZ, 2000).…”