During ODP Leg 138, we tested a prototype instrument, developed
at Oregon State University, for measuring light reflectance in 511
channels of the visible and near-infrared bands. The technique of
reflectance spectroscopy has been used for some time in chemistry
and mineralogy (e.g., Hunt, 1977; Gaffey, 1986) and has found...
During Leg 138, we measured reflectance spectra in the visible and near-infrared bands (455-945 nm) every few centimeters on split core surfaces from eastern tropical Pacific Ocean sediments. Here, we evaluate predictions of the content of biogenic calcite, biogenic opal, and nonbiogenic sediments from the reflectance spectra. For Sites 844...
The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change
during the Neogene. Two north south transects were drilled (95° and 110°W) within the region of equatorial divergence driven
upwelling (and thus high accumulation rates and resolution) and spanning the major...
Ocean Drilling Program (ODP) Leg 138 was designed to study the late Neogene paleoceanography of the equatorial Pacific Ocean at time scales of thousands to millions of years. Crucial to this objective was the acquisition of continuous, high-resolution sedimentary records. It is well known that between successive advanced piston corer...
High resolution, continuous records of GRAPE wet bulk density (a carbonate proxy) from Ocean Drilling Program Leg 138
provide one the opportunity for a detailed study of eastern equatorial Pacific Ocean carbonate sedimentation during the last 6 m.y.
The transect of sites drilled spans both latitude and longitude in the...
Establishing true depths of recovered sediments is critical to determining sedimentation rates for high-resolution paleoclimatic
studies. We have corrected the composite depth scale, which accounts for the entire continuous sedimentary sequence, so that sediment
depths are consistent with logging depths, or "true" depths. We accomplished this by taking advantage of...
More than 7 km of long and relatively continuous sediment sequences
from 11 sites in the southeast and equatorial Pacific were recovered
during Leg 202 for the study of the Earth’s climate and biogeochemical
systems on scales that range from tectonic (millions of
years) to orbital (tens to hundreds of...
Isotopic characterization of carbon in the dissolved inorganic carbon (DIC) pool is fundamental for a wide array of scientific studies directly related to gas hydrate research. In order to generate integrated and internally consistent data of δ¹³C of DIC in pore waters from Hydrate Ridge, we used the modern continuous...
High-resolution records of δ¹⁸0 and relative abundances of planktonic foraminifers were generated for ODP Leg 138 Site 846 for the past 800 k.y., with an average sampling interval of 3.6 k.y. The time scale was constructed by correlating the benthic δ¹⁸0 record to the SPECMAP and ODP Site 677 δ¹⁸0...
Ocean Drilling Program (ODP) Leg 202 has opened a new window
into understanding late Paleogene and Neogene global environmental
change by providing high-quality sediment sequences from a previously
unsampled region, the eastern South Pacific. Eleven sites (1232–
1242) that record variations on timescales ranging from decades to tens
of millions...