Sclerochronology of Mollusk Arctica islandica: Readme file
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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 THIS DATA!!!!!

NAME OF DATA SET: Sclerochronology of Mollusk Arctica islandica

CONTRIBUTORS: Marchitto, T.M., Jones, G.A., Goodfriend, G.A., and Weidman, C.R.
LAST UPDATE: 3/2001 (Original Receipt by WDCA Paleo)  


IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2001-027

SUGGESTED DATA CITATION: Marchitto, T.M., et al., 2001, 
Sclerochronology of Mollusk Arctica islandica, 
IGBP PAGES/World Data Center A for Paleoclimatology 
Data Contribution Series #2001-027.
NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. 

ORIGINAL REFERENCE: Marchitto, T.M., Jones, G.A., Goodfriend, G.A., 
and Weidman, C.R., 2000, Precise temporal correlation of Holocene 
mollusk shells using sclerochronology, 
Quaternary Research, 53: 236-246.


FUNDING SOURCES: US NSF, MIT/WHOI Joint Progran Education Office


GEOGRAPHIC REGION: North Atlantic, shoals off New England and northern Iceland
PERIOD OF RECORD: Latest Holocene (ca. AD 1840-1994)

LIST OF FILES: Readme_Marchitto2000b.txt (this file),
315d18o.txt, asparticacid.txt, compositesclero.txt,
distancetest.txt, iceland.txt, specimens.txt
(tab-delimited ASCII format).


DESCRIPTION: 
Arctica islandica growth band widths showing synchronization 
of growth among members of a population, including first composite 
sclerochronology incorporating dead-collected ("fossil") mollusks. 
Also given are aspartic acid, standardized SST (after Lazzari, 1995), 
and standardized temperature from shell d18O (after Weidman, 1995) data. 
Files and associated figures from Marchitto et al. (2000) are as follows:

iceland: Fig. 3
distancetest: Fig. 5
compositesclero: Fig. 6, 8
asparticacid: Fig. 7
315d18O: Fig. 9
specimens: Table 1

UNITS:
band widths: standardized (dimensionless)
SST: standardized (dimensionless)
temperature from d18O: standardized (dimensionless)
Asp: D/L ratio (dimensionless)

ANALYTICAL PRECISION:
band widths: ~0.01 mm
D/L Asp: ~3%