Phosphorus cycling from the margin to abyssal depths in the proto-Atlantic during oceanic anoxic event 2

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doi: 10.1016/j.palaeo.2010.05.014
Author(s): Kraal, Peter; Slomp, Caroline P.; Forster, Astrid; Kuypers, Marcel M. M.
Author Affiliation(s): Primary:
University of Utrecht, Department of Earth Sciences, Utrecht, Netherlands
Royal Netherlands Institute for Sea Research, Netherlands
Max Planck Institute for Marine Microbiology, Federal Republic of Germany
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 295(1-2), p.42-54. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 120 refs.; illus., incl. charts, 3 tables, sketch map
Summary: Phosphorus (P) burial during the Cenomanian/Turonian oceanic anoxic event (OAE 2, ∼93.55 Ma) was studied using sediment records from four sites in the proto-Atlantic Ocean. The sites represent a variety of depositional settings, from the continental margin and slope to the abyssal plain. Strong links between changing marine conditions during OAE 2 and P cycling were observed in black shale sections on the continental margin and slope. Sedimentary P contents and P MARs increased around the onset of OAE 2, which may reflect enhanced productivity and P burial, partly in the form of biogenic apatite (fish debris). During the main stage of OAE 2, phosphorus was efficiently regenerated from the sediment, resulting in P-depleted sediments and high organic C (Corg)/total P ratios. The increased availability of dissolved P may have helped to sustain high productivity during OAE 2. The termination of OAE 2 was associated with a strong recovery of P burial efficiency in the sediment. Sedimentary records from the two deep sites do not reveal such close links between different stages of OAE 2 and the characteristics of P cycling. Here, OAE 2 was a period with maximum deposition of relatively thin black shale intervals that alternate with more oxic deep sea sediments. The black shale layers record enhanced P regeneration from organic matter and, in some cases, P enrichment relative to the oxic sediments. Detailed chemical P fractionation was performed on sediment from all sites, but the results were found to mostly reflect diagenesis and sample handling artifacts. In these ancient sediments, total P concentrations and the Corg/total P ratio appear to be the most robust indicators of P cycling and regeneration. Abstract Copyright (2010) Elsevier, B.V.
Year of Publication: 2010
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Angola Basin; Atlantic Ocean; Atlantic region; Bioclastic sedimentation; Black shale; Bones; Cape Hatteras; Cenomanian; Chordata; Clastic rocks; Cretaceous; DSDP Site 530; DSDP Site 557; DSDP Site 603; Dare County North Carolina; Deep Sea Drilling Project; Demerara Rise; Fragments; Geochemical cycle; Geochemistry; IPOD; Leg 75; Leg 82; Marine environment; Mesozoic; Mid-Atlantic Ridge; North Atlantic; North Carolina; Northwest Atlantic; OAE 2; Oceanic anoxic events; Paleo-oceanography; Phosphorus; Pisces; Productivity; Sedimentary rocks; Sedimentation; South Atlantic; Tarfaya Basin; Turonian; United States; Upper Cretaceous; Vertebrata; Walvis Ridge
Coordinates: N384957 N384957 W0323335 W0323335
S191116 S191115 E0092310 E0092308
N352939 N352940 W0700142 W0700143
Record ID: 2010084841
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands