# Brazil Margin LGM-Holocene Benthic Stable Isotope Data
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#               World Data Center for Paleoclimatology, Boulder 
#                                  and 
#                     NOAA Paleoclimatology Program 
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# NOTE: Please cite original reference when using these data, 
# plus the Online Resource and date accessed.
#
# Description/Documentation lines begin with #
# Data lines have no #
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# Online Resource: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:13498
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# Archive/proxy:
# Paleoceanography
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# Contribution Date
#	Date: 11-06-2012
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# Title
#  Study_Name: Brazil Margin LGM-Holocene Benthic Stable Isotope Data
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#	Investigators: Hoffman, J.L. ; Lund, D.C.
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# Description and Notes
#   Description: The files include age model and stable isotopic data for KNR159-5-42JPC, 125GGC, 22GGC, and 54GGC.  
# Only stable isotopic data are available for 120GGC.
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# All calendar ages are based on the MARINE09 calibration curve assuming a deltaR of 0±200 years (1sigma  For details see Hoffman and Lund (2012).  
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# In the stable isotopic data benthic d13C and benthic d18O are reported per mil VPDB.   Isotopic measurements were based on individual tests of Cibicidoides spp.  Bioturbated samples are noted where appropriate.  Note that the isotopic data for KNR159-5-42JPC were initially published by Curry and Oppo (2005).  
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# Publication/Citation
#	Authors: Hoffman, J.L. and D.C. Lund
#	Journal Name: Paleoceanography
#	Published Title: Refining the stable isotope budget for Antarctic Bottom Water: New foraminiferal data from the abyssal southwest Atlantic
#	Published Date: 3-29-2012 
#	DOI: 10.1029/2011PA002216
#	Volume: 27
#	Issue: PA1213
#	Pages: 
#	Abstract: Stable isotope tracer budget results suggest the transport to vertical diffusivity ratio for Antarctic Bottom Water (AABW) in the Atlantic was higher at the Last Glacial Maximum (LGM). Reduced mixing across the upper boundary of AABW is consistent with movement of this surface away from the seafloor and may be a factor in sequestering CO2 in the abyssal Atlantic. Two key unknowns in the budget are the isotopic composition of AABW and the spatial representativeness of isolated vertical profiles of d18O and d13C. Due to a lack of core material below 3 km water depth, Lund et al. (2011) based their Holocene budget on water column data and their LGM budget on extrapolation of isotopic trends from shallower cores. Here we determine d18O and d13C for AABW using new isotopic records from 3 to 4 km water depth at the Brazil Margin. The core top data yield tracer budget parameters consistent with water column data in the broader Southwest Atlantic. At the LGM, benthic d18O reaches 4.9‰ at 4 km water depth, the highest LGM d18O value in the published literature. The corresponding d13C of -0.2‰ is less depleted than expected and >0.5‰ greater than d13C in the Southeast Atlantic. Our Peclet number estimates suggest d13C acted conservatively during both the Holocene and LGM. Both d18O and d13C imply the transport to vertical diffusivity ratio for AABW was an order of magnitude larger during the LGM, due to enhanced AABW transport or reduced mixing across its upper boundary. 
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# Funding Agency 
#	Funding Agency Name:   
#	Grant: 
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# Site Information 
#       Name: KNR159-5-120GGC
#	Region: South Atlantic
#	Country: 
#	Northmost Latitude: -28.5833
# 	Southmost Latitude: -28.5833
# 	Eastmost Longitude: -45.2333
# 	Westmost Longitude: -45.2333
# 	Elevation: -3353 m 
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# Data Collection  
#	Core Name: 120GGC2012
#	First Year: 18000
#	Last Year: 10000
#	Time Unit: Calendar Years before present 
#	Core Length: 1.035 m  
#	Notes: 
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# Chronology 
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# Variables
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# End Description/Documentation (lines begin with #)
# Data lines follow (have no #)
# Data line variables format:  Variables list, one per line, shortname-tab-longname-tab-longname components (8 components: material, error, units, anomaly, period, archive, detail, method) 
# Data line format: tab-delimited text, variable short name as header
## depth_cm	Depth, , , cm, , , ,,N 
## d13Ccibid	delta 13C ,Cibicidoides spp.,,per mil PDB,,paleoceanography,,,N 
## d18Ocibid	delta 18O ,Cibicidoides spp.,,per mil PDB,,paleoceanography,,,N
# Data:
# Missing values -999
depth_cm	d13Ccibid	d18Ocibid
11.5	0.75	3.12
11.5	0.92	2.84
43.5	-1	4.56
55.5	0.19	4.64
59.5	0.28	4.43
103.5	0.38	4.79
103.5	-0.27	4.66