Paleoceanography
1944-9186
Cơ quản chủ quản: N/A
Các bài báo tiêu biểu
A Pliocene‐Pleistocene stack of 57 globally distributed benthic δ18O records
Tập 20 Số 1 - 2005
We present a 5.3‐Myr stack (the “LR04” stack) of benthic δ18O records from 57
globally distributed sites aligned by an automated graphic correlation
algorithm. This is the first benthic δ18O stack composed of more than three
records to extend beyond 850 ka, and we use its improved signal quality to
identify 24 new marine isotope stages in the early Pliocene. We also present a
new LR04 age model fo...
Glacial‐interglacial CO2 change: The Iron Hypothesis
Tập 5 Số 1 - Trang 1-13 - 1990
Several explanations for the 200 to 280 ppm glacial/interglacial change in
atmospheric CO2 concentrations deal with variations in southern ocean
phytoplankton productivity and the related use or nonuse of major plant
nutrients. An hypothesis is presented herein in which arguments are made that
new productivity in today's southern ocean (7.4 × 1013g yr−1) is limited by iron
deficiency, and hence th...
Deepwater source variations during the last climatic cycle and their impact on the global deepwater circulation
Tập 3 Số 3 - Trang 343-360 - 1988
The degree of similarity of the ∂13C records of the planktonic foraminiferal
speciesN. pachydermaand of the benthic foraminiferal genusCibicidesin the
high‐latitude basins of the world ocean is used as an indicator of the presence
of deepwater sources during the last climatic cycle. Whereas continuous
formation of deep water is recognized in the southern ocean, the Norwegian Sea
stopped acting as ...
Astronomic timescale for the Pliocene Atlantic δ18O and dust flux records of Ocean Drilling Program Site 659
Tập 9 Số 4 - Trang 619-638 - 1994
High‐resolution benthic oxygen isotope and dust flux records from Ocean Drilling
Program site 659 have been analyzed to extend the astronomically calibrated
isotope timescale for the Atlantic from 2.85 Ma back to 5 Ma. Spectral analysis
of the δ18O record indicates that the 41‐kyr period of Earth's orbital obliquity
dominates the Pliocene record. This is shown to be true regardless of
fundamental ...
Application of the Ce anomaly as a paleoredox indicator: The ground rules
Tập 5 Số 5 - Trang 823-833 - 1990
Much attention has been paid, in recent years, to the potential application of
the Ce anomaly, measured in various marine phases, as a paleoceanographic
indicator of widespread marine anoxia. In this paper we present and discuss
results from recent studies of present‐day rare earth element (REE)
distributions (and hence Ce anomaly distributions) in the marine environment
which are particularly per...
The timing of major climate terminations
Tập 12 Số 4 - Trang 577-585 - 1997
A simple, untuned “constant sedimentation rate” timescale developed using three
radiometric age constraints and eleven δ18O records longer than 0.8 Myr provides
strong support for the validity of the SPECMAP timescale of the late Quaternary
[Imbrie et al., 1984]. In particular, the present study independently confirms
the link between major deglaciations (terminations) and increases in northern
he...
El Niño variability off Peru during the last 20,000 years
Tập 20 Số 4 - 2005
Here we present a high‐resolution marine sediment record from the El Niño region
off the coast of Peru spanning the last 20,000 years. Sea surface temperature,
photosynthetic pigments, and a lithic proxy for El Niño flood events on the
continent are used as paleo–El Niño–Southern Oscillation proxy data. The onset
of stronger El Niño activity in Peru started around 17,000 calibrated years
before th...
Nannofossils and superplumes: The Early Aptian “nannoconid crisis”
Tập 9 Số 3 - Trang 483-501 - 1994
A group of calcareous nannoplankton named nannoconids experienced a crisis in
the early Aptian and recovered only later in the late Aptian after a period of
virtual absence. Although no extinctions occurred, the widespread nature of the
“nannoconid crisis” suggests a global causal factor. This crisis is recorded
within the Chiastozygus litterarius nannofossil and Globigerinelloides blowi
planktoni...
The 41 kyr world: Milankovitch's other unsolved mystery
Tập 18 Số 1 - 2003
For most of the Northern Hemisphere Ice Ages, from ∼3.0 to 0.8 m.y., global ice
volume varied predominantly at the 41,000 year period of Earth's orbital
obliquity. However, summer (or summer caloric half year) insolation at high
latitudes, which is widely believed to be the major influence on high‐latitude
climate and ice volume, is dominated by the 23,000 year precessional period.
Thus the geolog...
Enhanced productivity led to increased organic carbon burial in the euxinic North Atlantic basin during the late Cenomanian oceanic anoxic event
Tập 17 Số 4 - 2002
Three Cenomanian/Turonian (C/T, ∼93.5 Ma) black shale sections along a
northeast‐southwest transect in the southern part of the proto‐North Atlantic
Ocean were correlated by stable carbon isotope stratigraphy using the
characteristic excursion in δ13C values of both bulk organic matter (OM) and
molecular fossils of algal chlorophyll and steroids. All three sites show an
increase in marine organic ...