New chronology for the late Paleocene thermal maximum and its environmental implications

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doi: 10.1130/0091-7613(2000)28<927:NCFTLP>2.0.CO;2
Author(s): Röhl, U.; Bralower, T. J.; Norris, Richard D.; Wefer, G.
Author Affiliation(s): Primary:
Bremen University, Department of Geosciences, Bremen, Federal Republic of Germany
University of North Carolina at Chapel Hill, United States
Woods Hole Oceanographic Institution, United States
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 28(10), p.927-930. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. With GSA Data Repository Item 200096. 19 refs.; illus., incl. sketch map
Summary: The late Paleocene thermal maximum (LPTM) is associated with a brief, but intense, interval of global warming and a massive perturbation of the global carbon cycle. We have developed a new orbital chronology for Ocean Drilling Program (ODP) Site 690 (Weddell Sea, Southern Ocean) by using spectral analysis of high-resolution geochemical records. The LPTM interval spans 11 precessional cycles yielding a duration of 210 to 220 k.y. The δ13C anomaly associated with the LPTM has a magnitude of about -2.5 per mil to -3 per mil; we show that about -2 per mil of the excursion occurs within two steps that each were less than 1000 yr in duration. The remainder developed through a series of steps over ∼52 k.y. The timing of these steps is consistent with a series of nearly catastrophic releases of methane from gas hydrates, punctuated by intervals of relative equilibria between hydrate dissociation and carbon burial. Further, we are able to correlate the records between ODP Sites 690 and 1051 (western North Atlantic) on the scale of 21 k.y. cycles, which demonstrates that the details of the δ13C excursion are recognizable between distant sites. Comparison of cycle records at Sites 690 and 1051 suggests that sediment representing the interval ∼30 k.y. just prior to and at the onset of the LPTM are missing in the latter location. This unconformity probably resulted from slope failure accompanying methane hydrate dissociation within 10 k.y. of the start of the LPTM.
Year of Publication: 2000
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Antarctic Ocean; Atlantic Ocean; Blake Nose; Blake Plateau; Carbon; Carbon cycle; Cenozoic; Cyclostratigraphy; Geochemical cycle; Global change; Global warming; Leg 113; Leg 171B; North Atlantic; ODP Site 1051; ODP Site 690; Ocean Drilling Program; Paleo-oceanography; Paleocene; Paleoclimatology; Paleogene; Paleotemperature; South Atlantic; Southern Ocean; Spectra; Tertiary; Upper Paleocene; Weddell Sea; X-ray fluorescence spectra
Coordinates: N300311 N300311 W0762128 W0762128
S650938 S650937 E0011218 E0011218
Record ID: 2000073579
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States