TABLE 2. Data for 14C age determinations for peat samples from core SB1a, St. Bernard Parish, Louisiana.
St. Bernard core SB1a (location: 29o58"53' N, 89o55"27' W; sampled: 03/18/1996).
Percent compaction (applied linearly): 6.8.
Cor-
rected
depth
sample
mid-
point
(cm)1
Original
depth
sample
mid-
point
(in)2
Lab
I.D.
(WW-
nnn)3
Mate-
rial
Fraction
modern
4
Age
(yr BP
5
± one
sigma)
D14C
(parts per
thousand
± one
standard
deviation)
d13C
(parts
per
thou-
sand)
d13C
lab
6
 
6.8 2.7 796 peat 1.1304 >MODERN 124.1 9.1 -18.5 D
9.5 3.5 797 peat 1.2081 >MODERN 201.4 8.2 -17.9 D
12.3 4.5 798 peat 1.2698 >MODERN 262.7 7.0 -17.5 D
15.0 5.5 763 peat 1.5288 >MODERN 520.3 8.4 -17.2 D
17.7 6.5 764 peat 1.2950 >MODERN 287.8 7.1 -26.8 D
20.4 7.5 765 peat 1.0319 >MODERN 26.2 6.7 -17.3 D
23.2 8.5 766 peat 0.9889 90 60 -16.5 6.5 -17.2 D
25.9 9.5 767 peat 0.9699 250 60 -35.5 6.3 -24.1 D
28.5 10.5 768 peat 0.9546 370 50 -50.7 5.3 -22.2 D
31.3 11.5 769 peat 0.9515 400 50 -53.7 5.3 -21.2 D
34.0 12.5 770 peat 0.9488 420 60 -56.4 5.9 -20.6 D
36.7 13.5 771 peat 0.9497 410 60 -55.6 6.2 -22.4 D
 
6.8 2.5 799 grass 1.1203 >MODERN 114.1 7.1 -16.5 D
9.5 3.5 800 grass 1.1892 >MODERN 182.6 7.6 -14.5 D
12.3 4.5 801 grass 1.2398 >MODERN 232.9 8.0 -16.1 D
15.0 5.5 772 grass 1.5530 >MODERN 544.4 10.0 -15.9 D
17.7 6.5 773 grass 1.5518 >MODERN 543.2 9.9 -17.0 D
20.4 7.5 774 grass 1.4642 >MODERN 456.0 9.4 -16.7 D
23.2 8.5 775 grass 1.1208 >MODERN 114.6 6.3 -15.4 D
25.9 9.5 776 grass 0.9726 220 60 -32.8 6.4 -17.3 D
28.5 10.5 777 grass 0.9729 220 50 -32.5 5.5 -14.9 D
31.3 11.5 778 grass 0.9673 270 50 -38.1 5.5 -14.0 D
34.0 12.5 779 grass 0.9661 280 50 -39.3 5.5 -15.0 D
36.7 13.5 780 grass 0.9725 220 50 -32.9 5.4 -14.3 D
 
25.9 9.5 781 seeds 0.9693 250 60 -36.0 6.1 -27.8 D
1Corrected depth equals original depth (midpoint of sample interval) converted to centimeters (2.54 cm in-1) and multiplied by 1.0743 to correct for compaction.
2Top 2 inches (5.08 cm) discarded in the field.
3 14C data are archived in a world-wide database indexed by U.S. Geological Survey laboratory I.D. numbers "WW-nnn" where "WW" indicates AMS ages.
4Ratio of the 14C activity of the sample to the activity of the modern standard, which is used in various calculations related to radiocarbon ages.
5 14C age determinations not calibrated to tree-ring ages and not corrected for 14C enrichment by seawater.
6R=Reston, VA; D=Denver, CO; M=Menlo Park, CA.
Source: U.S. Geological Survey Open-File Report 98-36. Carbon storage and late Holocene chronostratigraphy of a Mississippi River deltaic marsh, St. Bernard Parish, Louisiana (H.W. Markewich, ed.).

Last Updated on 2/5/98
By Gary R. Buell