Extinction, dissolution, and possible ocean acidification prior to the Cretaceous/Paleogene (K/Pg) boundary in the tropical Pacific

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doi: 10.1016/j.palaeo.2017.06.032
Author(s): Dameron, Serena N.; Leckie, R. Mark; Clark, Kendra; MacLeod, Kenneth G.; Thomas, Deborah J.; Lees, Jackie A.
Author Affiliation(s): Primary:
University of Massachusetts at Amherst, Department of Geosciences, Amherst, MA, United States
University of Missouri, United States
Texas A&M University, United States
University College London, United Kingdom
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Vol.485, p.433-454. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 146 refs.; illus., incl. 1 table, sketch map
Summary: Biotic perturbations and changes in ocean circulation during the Maastrichtian stage of the latest Cretaceous raise questions about whether the biosphere was preconditioned for the end-Cretaceous mass extinction of calcareous plankton. A brief acme of inoceramid clams at ∼ 71 Ma on Shatsky Rise in the tropical North Pacific was followed by their extinction during the "mid-Maastrichtian event" at 70.1 Ma associated with an abrupt warming of deep waters. This was later followed by an interval of intense dissolution beginning ∼ 67.8 Ma at ODP Site 1209 (2387 m). The late Maastrichtian dissolution interval was initially gradual, and is characterized by a low planktic/benthic (P/B) ratio, highly fragmented planktic foraminifera, mostly an absence of larger taxa, low abundances of smaller taxa, extremely low planktic foraminiferal numbers, and low planktic foraminiferal and nannofossil species richness. A partial recovery in carbonate preservation and calcareous plankton simple diversity began ∼ 250 kyr prior to the K/Pg boundary associated with the incursion of a younger (more enriched δ13C) deep water mass, although total abundances of planktic foraminifera in the sediment remained a tiny fraction of their earlier Maastrichtian values. A second, brief dissolution event occurred ∼ 200 kyr before the boundary evidenced by renewed increase in planktic fragmentation, but without a decrease in P/B ratio. Our data show that changing deep water masses, coupled with reduced productivity and associated decrease in pelagic carbonate flux was responsible for the first ∼ 1.6-Myr dissolution interval, while Deccan Traps volcanism (?) may have caused surface ocean acidification ∼ 200 kyr prior to the K/Pg mass extinction event.
Year of Publication: 2017
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Acidification; Benthic taxa; Biostratigraphy; Bivalvia; C-13/C-12; Campanian; Carbon; Cenozoic; Cretaceous; Danian; Deccan Traps; Foraminifera; Inocerami; Inoceramidae; Isotope ratios; Isotopes; K-T boundary; Leg 198; Lower Paleocene; Maestrichtian; Mesozoic; Microfossils; Middle Maestrichtian; Mollusca; Nannofossils; North Pacific; Northwest Pacific; O-18/O-16; ODP Site 1209; ODP Site 1210; ODP Site 1211; Ocean Drilling Program; Oxygen; Pacific Ocean; Paleo-oceanography; Paleocene; Paleogene; Planktonic taxa; Pteriina; Pterioida; Sedimentation; Sedimentation rates; Shatsky Rise; Solution; Stable isotopes; Stratigraphic boundary; Tertiary; Thermohaline circulation; Tropical environment; Upper Campanian; Upper Cretaceous; Volcanism; West Pacific
Coordinates: N321300 N321300 E1581600 E1581600
N320000 N320000 E1575100 E1575100
N323900 N324000 E1583100 E1583000
Record ID: 2018006615
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands