Distribution of carbonate in surface sediments of the Pacific Ocean

Abstract

The distribution of carbonate on the floor of the Pacific has been remapped on the basis of 1313 points from 80 references stored in the World Ocean Sediment Data Bank of Scripps Institution of Oceanography. Percent distribution maps and carbonate versus depth diagrams generally agree with previously published information and reflect the major controlling factors of carbonate sedimentation (depth, hydrography, fertility, and sedimentary processes). While carbonate distributions are of limited use in attempting to construct dissolution profiles, major trends are identifiable. In particular, the degree of lowering of the equatorial calcite compensation depth (CCD) together with an estimate of the differences in supply rates between the equator and the subtropical gyre can be used to estimate dissolution rate increase below the lysocline. There is considerable variation in the sharpness of the ‘CCD transition’ a concept defined here. This variation is thought to reflect both geographic differences in dissolution rate gradients and redeposition processes (carbonate, deep‐sea sediments, calcite, and compensation depth).

Facies Evolution, Carbonate Dissolution Cycles in Sediments from the Eastern South Atlantic (DSDP Leg 40) Since the Early Cretaceous

“…Operationally it is often difficult to find the exact depth level where this occurs (Berger and Winterer, 1974). These operational difficulties are very obvious in the different methods used to fix the CCD level in recent publications (Berger et al, 1976;Biscaye et al, 1976;Venkatarathnam et al, 1976). The CCD as here understood is the boundary between calcareous and carbonate-free pelagic sediments.…”

“…This level is considered equivalent to the "foraminiferal-lysocline:" In the Rio Grande Rise area it is 500 meters higher than the CCD (Melguen and Thiede, 1974). Elsewhere this depth difference can vary by several hundred meters (Berger et al, 1976;Biscaye et al, 1976;Venkatarathnam et al, 1976). However, refinements of the depth difference between "lysocline" and "CCD" are not contemplated here, considering estimated uncertainties of paleodepth reconstruction of 200-300 meters at each DSDP site.…”

Climatic forcing of Quaternary deep-sea benthic communities in the North Pacific Ocean

“…1). Although recent research suggests that ostracods can survive below the carbonate compensation depth (4400 m in northwestern Pacific [Berger et al 1976]) and at least some abyssal species (or closely related species complexes) may have pan-abyssal distribution (Yasuhara et al 2008a), they lack a dispersal stage and most taxa do not swim. Moreover, recent ecological and molecular studies suggest that ostracods, like nematodes and isopods, have lower gene flow and dispersal than foraminifera (Alve and Goldstein 2003;Brandt et al 2007;Pawlowski et al …”

Calcareous nannoplankton biocoenosis : sediment trap studies in the equatorial Atlantic, central Pacific, and Panama Basin

“…Bottom sediments in the area consist of consolidated clay with alternating thin ferro-manganese laminations (R/V KANA KEOKI Cruise Report, September 1978, Hawaii Institute of Geophysics). Calcium carbonate comprises less than 10% of the sediment (Berger et al, 1976).…”