pdf basics of physical stratigraphy and sediment

In the case of ODP Site 1092 (Gersonde et al. Although these works gave their own revised splice interval tables that describe the stratigraphic positions of top and bottom of chosen splice intervals as well as offsets necessary for adjusting cores to the revised depth, it was not easy to find correspondence between the original depth scale and the revised one. Splices for IODP Expedition (Exp.) 320 (Lyle et al., 2009) were revised in the Expedition research results and summarized by Westerhold et al. ( 2013) recommended to return to the original splice based on the re-examination of a detailed shore-based magnetostratigraphy (Channell and Guyodo, 2004). ( 2012) through inspection of magnetostratigraphic reversals and the addition of epibenthic δ 18O records although Lawrence et al. The original splice for ODP Site 982 (Jansen et al. This revision was further modified by choosing better intervals in different holes (Lourens 2004). 1996) was fully reassessed using core photograph and shipboard color data and revised by Sakamoto et al. The splice for ODP Site 964 (Emeis et al. Revisions of spliced sequences after the cruise have been also common for the high-resolution paleoceanographic researches, which were required for a precise orbital tuning and inter-site correlations. These physical properties are compared between the drilled holes, and inter-hole correlations are recognized according to the fluctuation patterns of these properties. Splicing is usually performed onboard using physical properties such as magnetic susceptibility (MS), gamma-ray attenuation (GRA) density, natural gamma-ray radiation (NGR), and the lightness and color of sediments measured immediately after drilling. Multi-hole drilling has been widely used by scientific drilling operations such as Ocean Drilling Program (ODP) and Integrated Ocean Drilling Program (IODP) that allow us to establish continuous sedimentary records through splicing fragmented intervals from top to bottom of the sequence (Ruddiman et al. The continuous records established for these sites will allow a much more detailed understanding of the long-term variability in East Asian paleoclimate and North Pacific oceanography.Įstablishment of a continuous sedimentary sequence is an unavoidable starting point for the interpretation of the sedimentary records as events in earth history (Doyle and Bennett 1998). Same kind of efforts to correct the shipboard splices were also achieved for Plio-Miocene intervals at Sites U1425 and U1430.

346 to the corresponding undisturbed intervals, nearly perfectly continuous sediment columns and physical property records for the Pleistocene intervals of Sites U1422-U1427 and U1430 collected from the Japan Sea have been established.

After extensive efforts to replace the disturbed, missed, or duplicated intervals found in spliced sediment sequences constructed onboard during IODP Exp. Integrated Ocean Drilling Program (IODP) Expedition (Exp.) 346 drilled high-quality sediment archives with more than three holes each at nine sites that enable us to establish continuous sedimentary sequences through splicing technique.

Establishment of sedimentary sequence is essential for the interpretation of the sedimentary records.

Pdf basics of physical stratigraphy and sediment