Blog
About

  • Record: found
  • Abstract: found
  • Article: found
Is Open Access

Expedition 342 summary

Read this article at

ScienceOpenPublisher
Bookmark
      There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

      Abstract

      Integrated Ocean Drilling Program Expedition 342 was designed to recover Paleogene sedimentary sequences with unusually high deposition rates across a wide range of water depths. The drilling area is positioned to capture sedimentary and geochemical records of ocean chemistry and overturning circulation beneath the flow of the Deep Western Boundary Current in the northwest Atlantic Ocean. The expedition was primarily targeted at reconstructing the Paleogene carbonate compensation depth (CCD) in the North Atlantic for reference to recently obtained high-fidelity records of the CCD in the equatorial Pacific. We find evidence of carbonate deposition events following the Cretaceous/Paleogene (K/Pg) boundary mass extinction, the Paleocene/Eocene Thermal Maximum, and the Eocene–Oligocene transition (EOT). These deposition events may reflect the rebalancing of ocean alkalinity after mass extinctions or abrupt global climate change. Expedition 342 recovered sequences with sedimentation rates high enough to enable studies of the dynamics of past abrupt climate change, including both transitions into “greenhouse” and “icehouse” climate states, the full magnitudes of hyperthermal events, and rates of change in the CCD. An unexpected finding was the recovery of a number of Cretaceous “critical boundaries.” These include the K/Pg boundary, the Campanian–Coniacian interval, the Cenomanian/Turonian boundary and Oceanic Anoxic Event (OAE) 2, and the Albian/Cenomanian boundary OAE 1d.

      Related collections

      Most cited references 239

      • Record: found
      • Abstract: found
      • Article: not found

      Trends, rhythms, and aberrations in global climate 65 Ma to present.

      Since 65 million years ago (Ma), Earth's climate has undergone a significant and complex evolution, the finer details of which are now coming to light through investigations of deep-sea sediment cores. This evolution includes gradual trends of warming and cooling driven by tectonic processes on time scales of 10(5) to 10(7) years, rhythmic or periodic cycles driven by orbital processes with 10(4)- to 10(6)-year cyclicity, and rare rapid aberrant shifts and extreme climate transients with durations of 10(3) to 10(5) years. Here, recent progress in defining the evolution of global climate over the Cenozoic Era is reviewed. We focus primarily on the periodic and anomalous components of variability over the early portion of this era, as constrained by the latest generation of deep-sea isotope records. We also consider how this improved perspective has led to the recognition of previously unforeseen mechanisms for altering climate.
        Bookmark
        • Record: found
        • Abstract: not found
        • Article: not found

        The least-squares line and plane and the analysis of palaeomagnetic data

          Bookmark
          • Record: found
          • Abstract: not found
          • Article: not found

          Evidence for general instability of past climate from a 250-kyr ice-core record

            Bookmark

            Author and article information

            Journal
            10.2204/iodp.proc.342.2014
            Proceedings of the IODP
            Integrated Ocean Drilling Program
            1930-1014
            03 March 2014
            10.2204/iodp.proc.342.101.2014

            This work is licensed under a Creative Commons Attribution 4.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

            Product
            Self URI (journal page): http://publications.iodp.org/

            Comments

            Comment on this article