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Các bài báo tiêu biểu
Barium in Deep‐Sea Sediment: A Geochemical Proxy for Paleoproductivity
Tập 7 Số 2 - Trang 163-181 - 1992
We used sediment traps to define the particulate fluxes of barium and organic
carbon and investigate the use of barium as a proxy for ocean fertility. Strong
correlations between Corg and Ba fluxes indicate a link between upper ocean
biological processes and barium flux to the seafloor. The ratio of organic
carbon to barium decreases systematically with water depth. Data from 10 sites
indicate tha...
Mo–total organic carbon covariation in modern anoxic marine environments: Implications for analysis of paleoredox and paleohydrographic conditions
Tập 21 Số 1 - 2006
Sedimentary molybdenum, [Mo]s, has been widely used as a proxy for benthic redox
potential owing to its generally strong enrichment in organic‐rich marine facies
deposited under oxygen‐depleted conditions. A detailed analysis of [Mo]s–total
organic carbon (TOC) covariation in modern anoxic marine environments and its
relationship to ambient water chemistry suggests that (1) [Mo]s, while useful in
...
Calibration of Mg/Ca thermometry in planktonic foraminifera from a sediment trap time series
Tập 18 Số 2 - 2003
Paired Mg/Ca and δ18O measurements on planktonic foraminiferal species (G. ruber
white, G. ruber pink, G. sacculifer, G. conglobatus, G. aequilateralis, O.
universa, N. dutertrei, P. obliquiloculata, G. inflata, G. truncatulinoides, G.
hirsuta, and G. crassaformis) from a 6‐year sediment trap time series in the
Sargasso Sea were used to define the sensitivity of foraminiferal Mg/Ca to
calcificatio...
Processes controlling the organic carbon content of open ocean sediments
Tập 3 Số 5 - Trang 621-634 - 1988
Use of sedimentary organic carbon concentrations as a record of
paleoceanographic conditions is complicated by an insufficient understanding of
the mechanisms controlling present‐day variations in the organic matter content
of surface open ocean sediments. This paper is a review of organic carbon
distributions in marine sediments, the global marine balance of particulate and
dissolved organic carb...
Benthic phosphorus regeneration, net primary production, and ocean anoxia: A model of the coupled marine biogeochemical cycles of carbon and phosphorus
Tập 9 Số 5 - Trang 677-692 - 1994
We examine the relationships between ocean ventilation, primary production,
water column anoxia, and benthic regeneration of phosphorus using a mass balance
model of the coupled marine biogeochemical cycles of carbon (C) and phosphorus
(P). The elemental cycles are coupled via the Redfield C/P ratio of marine
phytoplankton and the C/P ratio of organic matter preserved in marine sediments.
The mode...
Global variations of surface ocean productivity in low and mid latitudes: Influence on CO2 reservoirs of the deep ocean and atmosphere during the last 21,000 years
Tập 3 Số 3 - Trang 361-399 - 1988
Based on detailed reconstructions of global distribution patterns, both
paleoproductivity and the benthic δ13C record of CO2, which is dissolved in the
deep ocean, strongly differed between the Last Glacial Maximum and the Holocene.
With the onset of Termination I about 15,000 years ago, the new (export)
production of low‐ and mid‐latitude upwelling cells started to decline by more
than 2‐4 Gt car...
Paleoenvironmental Changes in the Japan Sea During the Last 85,000 Years
Tập 6 Số 4 - Trang 499-518 - 1991
Five distinct changes in the paleoenvironment of the Japan Sea within the last
85,000 years are revealed from the sedimentary record of a piston core recovered
from the Oki Ridge. Changes in both surface and deepwater conditions are
registered by changes in lithology, calcium carbonate content, organic carbon
content, oxygen and carbon isotope ratios, and microfossil assemblages including
calcareo...
Early Cenozoic decoupling of the global carbon and sulfur cycles
Tập 18 Số 4 - 2003
Changes in carbon and sulfur cycling over geologic time may have caused
considerable modification of atmospheric and oceanic composition and climate.
Here we calculate pyrite sulfur (Spy) and organic carbon (Corg) burial rates
from recently improved Cenozoic stable isotope records, and from these rates we
infer global changes in Corg burial environments. Given predominantly normal
shelf‐delta orga...
Potential links between surging ice sheets, circulation changes, and the Dansgaard‐Oeschger Cycles in the Irminger Sea, 60–18 Kyr
Tập 15 Số 4 - Trang 425-442 - 2000
Surface and deepwater paleoclimate records in Irminger Sea core SO82‐5 (59°N,
31°W) and Icelandic Sea core PS2644 (68°N, 22°W) exhibit large fluctuations in
thermohaline circulation (THC) from 60 to 18 calendar kyr B.P., with a dominant
periodicity of 1460 years from 46 to 22 calendar kyr B.P., matching the
Dansgaard‐Oeschger (D‐O) cycles in the Greenland Ice Sheet Project 2 (GISP2)
temperature re...
Fluctuations in the trophic resource continuum: A factor in global diversity cycles?
Tập 2 Số 5 - Trang 457-471 - 1987
The trophic resource continuum (TRC) in euphotic zones of the world's oceans is
the spectrum of conditions from the richest runoff and upwelling areas to the
most nutrient deficient subtropical seas. That spectral range has likely varied
through geologic history as more efficient phytoplankton taxa evolved, as
oceanic circulation rates changed, and in response to oceanic‐mixing events.
Reduced rat...