In:
Paleoceanography, American Geophysical Union (AGU), Vol. 3, No. 1 ( 1988-02), p. 39-59
Abstract:
We have generated ∼300 Kyr records of biogenic opal, calcite, and organic carbon (C org ) for three cores in the eastern and central equatorial Pacific Ocean and have compared the records to determine whether common periods of biogenic sedimentation have occurred throughout the region. We find that C org has been deposited in common pulses throughout the area, while opal has a much more local pattern of variation. Calcite varies regionally, but the record is shaped by superimposed dissolution and productivity processes. The most intense C org peak occurs at 18 ka and can have greater than 2 times the Holocene C org content. Other major C org peaks occur 150 ka and perhaps at 280 ka. We have compared the C org record in one of the cores, V19–28, to a model deepwater oxygen record developed from ∂ 13 C data in the nearby V19–30 to test whether the C org record has been mostly shaped by degradation or by the rain of organic matter from the euphotic zone. We found no coherence between the two records, implying that the C org record is primarily a measure of productivity. By comparing the opal, calcite, and C org records in V19–28, a core which is at or above the lysocline, we found that both increased calcite and opal deposition matches high C org accumulation. We also found, however, that the calcite and opal records were uncorrelated, so that episodes of high opal deposition do not necessarily accumulate calcite rapidly. We hypothesize that at least two different plankton communities have been dominant in the waters above this site, one rich in opal‐secreting plankton and one more dominated by calcite producers. The opal‐rich plankton community was dominant during the intervals 10–15 ka and 35–60 ka. Supplement data (Table 2) is available with entire articleon microfiche. Order from American Geophysical Union,2000 Florida Avenue, N.W., Washington, DC 20009.Document P88001; $2.50. Payment must accompany order.
Type of Medium:
Online Resource
ISSN:
0883-8305
,
1944-9186
DOI:
10.1029/PA003i001p00039
Language:
English
Publisher:
American Geophysical Union (AGU)
Publication Date:
1988
detail.hit.zdb_id:
637876-6
detail.hit.zdb_id:
2015231-0
detail.hit.zdb_id:
2916554-4
SSG:
16,13
SSG:
13
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