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 modern4 |
Age (yr BP5 ± one sigma) |
D14C (parts per thousand ± one standard deviation) |
d13C (parts per thou- sand) |
d13C lab6 |
||
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.). |