Open AccessDiffuse spectral reflectance as a proxy for percent carbonate content in North Atlantic sediments
Author(s) -
Ortiz Joseph,
Mix Alan,
Harris Sara,
O'Connell Suzanne
Publication year - 1999
Publication title -
paleoceanography
Language(s) - English
Resource type - Journals
eISSN - 1944-9186
pISSN - 0883-8305
DOI - 10.1029/1998pa900021
Subject(s) - milankovitch cycles , geology , northern hemisphere , carbonate , glacial period , sediment , oceanography , atlantic equatorial mode , atlantic hurricane , climate oscillation , southern hemisphere , proxy (statistics) , north atlantic deep water , climatology , paleontology , climate change , thermohaline circulation , global warming , storm , materials science , machine learning , computer science , metallurgy , effects of global warming
Diffuse reflectance records from Feni Drift in the North Atlantic faithfully record sediment percent carbonate. A high‐resolution, reflectance‐based age model for these sediments derived from an orbitally tuned age model for western equatorial Atlantic, Ceara Rise sediments was generated by spectral frequency mapping. Power spectra of the Feni Drift record indicate statistically significant sub‐Milankovitch cyclicity at 7.6–8.4 and 4.8–6.1 kyr. We infer that these ∼8 and ∼5 kyr cycles document a linkage between North and equatorial Atlantic climate given our ability to correlate these records. These climate cycles influence Atlantic basin carbonate prior to the intensification of Northern Hemisphere glaciation and thus must arise from some portion of the climate system other than the dynamics of large ice sheets. The presence of these peaks, which could be related to equatorial clipped precession, implies a possible non‐linear response to Milankovitch forcing.