Santa Barbara Basin ODP 893A MIS 6/5 Stable Isotope and Biogenic Silica Data: Readme file
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               World Data Center for Paleoclimatology, Boulder
                                  and
                     NOAA Paleoclimatology Program
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NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!!

NAME OF DATA SET: Santa Barbara Basin ODP 893A MIS 6/5 Stable Isotope and Biogenic Silica Data
LAST UPDATE: 5/2002 (Original Receipt by WDC Paleo)

CONTRIBUTORS: Julie E. Friddell, Robert C. Thunell, Linda E. Heusser.

IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2002-027

SUGGESTED DATA CITATION: Friddell et al., 2002,
Santa Barbara Basin ODP 893A MIS 6/5 Stable Isotope and Biogenic Silica Data, 
IGBP PAGES/World Data Center for Paleoclimatology 
Data Contribution Series # 2002-027.
NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.

ORIGINAL REFERENCE: Friddell, J. E., R. C. Thunell, and L. E. Heusser, 2002, 
Direct comparison of marine and terrestrial climate variability during 
marine isotope stages 6 and 5:  Results from Santa Barbara Basin ODP Hole 893A, 
Paleoceanography, v. 17, no. 1, pp. 2-1 to 2-12. 

FUNDING SOURCE: National Science Foundation (USA) ATM-9808508 and OCE-0117112.

GEOGRAPHIC REGION: Santa Barbara Basin, southern California Continental Borderlands

PERIOD OF RECORD: 150,000 years BP to 80,000 years BP

LIST OF FILES: Readme_Friddell2002.txt (this file),
age_model.txt, bull_d18O.txt, pachy_left_d18O.txt,
pachy_right_d18O.txt, silica.txt 
(tab-delimited text files).


PRECISION:  
G. bulloides d18O: 0.14 permil 
N. pachyderma d18O (both right- and left-coiling): 0.09 permil
Silica concentration:  2.93%

DESCRIPTION: 
Santa Barbara Basin Marine Isotope Stage 6/5 Stable Isotope and Biogenic Silica Data

ODP Core 893A 
Latitude 34'N, Longitude 120'W, 576.5 mbsf, Core length 196.5m.

The age model is based on converting depth to age via the benthic 
foraminiferal d18O record from the same core (ODP Hole 893A) and SPECMAP ages 
as well as three U-Th dates.  Depths (and therefore ages) have been corrected 
for voids and grey layers.  G. bulloides and N. pachyderma (both left- and 
right-coiling) are planktonic foraminifera that live in the sea surface and 
thermocline, respectively.  The d18O value of their calcite shells is indicative 
of the water temperature during growth.  Sedimentary biogenic silica content 
(percent of silica in bulk sediment) is a proxy for productivity and is generally 
higher during upwelling periods.


ABSTRACT: Planktonic foraminiferal d18O, pollen, and opal records from 
Santa Barbara Basin are used to evaluate climate changes in the northeast Pacific 
during marine isotope stages (MIS) 6 and 5. While the oak and foraminifera record 
the major glacial-interglacial changes, opal is not correlated with these 
large-scale transitions. Surface water warming in the basin was synchronous with 
terrestrial warming but earlier than ice sheet melting and increasing Northern 
Hemisphere insolation at Termination II. During and immediately after deglaciation, 
our marine proxies indicate the presence of an isothermal upper water column. 
Later in substage 5E, the water column thermally stratified, surface productivity 
increased, and laminated sediments began accumulating. Sediment trap and hydrographic 
data suggest these changes were due to the onset of a strong seasonal cycle similar 
to that seen today in the basin. A series of rapid coolings within MIS 5 appears 
to be synchronous with North Atlantic ice-rafting events and Greenland stadials.