TABLE 11A. Physical and chemical data for samples from core SB1c, St. Bernard Parish, Louisiana. | ||||||||||||
St. Bernard core SB1c (location: 29o58"53' N., 89o55"27' W.; sampled 03/20/1996). Percent compaction (applied linearly): 29.1. OC, organic carbon. N, nitrogen. Ppt, parts per thousand. | ||||||||||||
Sample I.D.1 |
Mate- rial |
Sampled interval (cm) |
Uncor- rected depth sample midpoint (cm) |
Cor- rected depth sample midpoint (cm)2 |
Total OC (%)3 |
Mineral matter (%)4 |
d13C (ppt) |
Total N (%) |
d15N (ppt) |
C:N ratio |
H2O, air- dried (%) |
Bulk density, air- dried (g/cm3) |
SB1c-10 | fibrous peat | 0-55 | 10 | 14.1 | -- | -- | -- | -- | -- | -- | 89 | 0.1 |
SB1c-21.5 | same | 0-55 | 21.5 | 30.3 | 31.9 | 36.2 | -15.8 | 1.9 | 0.57 | 17 | -- | -- |
SB1c-40 | same | 0-55 | 40 | 56.4 | 34 | 32 | -19 | 1.9 | 0.34 | 18 | -- | -- |
SB1c-45 | same | 0-55 | 45 | 63.5 | -- | -- | -- | -- | -- | 89.7 | 0.09 | |
SB1c(65) | fibrous peat, more compact | 55-69 | 65 | 91.7 | 32.7 | 34.7 | -20 | 1.8 | -1.53 | 18.3 | -- | -- |
SB1c(79) | fibrous peat as above, color change | 69-82.5 | 79 | 111.4 | 20.9 | 58.1 | -20.5 | 1.1 | -1.65 | 19 | -- | -- |
SB1c(83) | clay | 82.5-86.5 | 83 | 117 | 10.9 | 78.2 | -23.5 | 0.6 | -0.71 | 17.9 | -- | -- |
SB1c-84 | clay | 82.5-86.5 | 84 | 118.4 | -- | -- | -- | -- | -- | -- | 63.4 | 0.28 |
SB1c(97) | fibrous peat | 86.5-121 | 97 | 136.8 | 21.2 | 57.7 | -19.4 | 0.9 | -1.45 | 22.8 | -- | -- |
SB1c-108 | same | 86.5-121 | 108 | 152.3 | -- | -- | -- | -- | -- | -- | 80.8 | 0.14 |
SB1c(110) | same | 86.5-121 | 110 | 155.1 | 26.1 | 47.8 | -19.9 | 1.3 | -1.29 | 20.9 | -- | -- |
SB1c(128) | peat changing downward | 121-140.5 | 128 | 180.5 | 21.6 | 56.8 | -20.2 | 1 | -0.88 | 20.8 | -- | -- |
SB1c(145) | organic clay | 140.5-162.5 | 145 | 204.5 | 10.3 | 79.5 | -16 | 0.4 | -0.89 | 29.3 | -- | -- |
SB1c(145)D | same | 140.5-162.5 | 145 | 204.5 | 10.2 | 79.5 | -- | -- | -- | -- | -- | -- |
SB1c-158 | same | 140.5-162.5 | 158 | 222.8 | -- | -- | -- | -- | -- | -- | 71.4 | 0.23 |
SB1c-158D | same | 140.5-162.5 | 158 | 222.8 | -- | -- | -- | -- | -- | -- | -- | 0.23 |
SB1c(177) | fibrous peat | 162.5-218 | 177 | 249.6 | 38.2 | 23.6 | -19.7 | 1.6 | -1.03 | 23.4 | -- | -- |
SB1c-194 | same | 162.5-218 | 194 | 273.5 | -- | -- | -- | -- | -- | 85.7 | 0.09 | |
SB1c(202) | same | 162.5-218 | 202 | 284.8 | 37.7 | 24.7 | -26 | 2.3 | -0.33 | 16.7 | -- | -- |
SB1c-227.5 | organic clay | 218-233.5 | 227.5 | 320.8 | -- | -- | -- | -- | -- | -- | 62.4 | 0.29 |
SB1c(229) | same | 218-233.5 | 229 | 322.9 | 12.6 | 74.8 | -26.1 | 0.7 | -0.43 | 17.5 | -- | -- |
SB1c(250) | peat | 233.5-277 | 250 | 352.5 | 37.3 | 25.5 | -26.8 | 2.1 | -0.58 | 17.8 | -- | -- |
SB1c-251 | same | 233.5-277 | 251 | 353.9 | -- | -- | -- | -- | -- | -- | 81.2 | 0.12 |
SB1c(265) | same | 233.5-277 | 265 | 373.7 | 32.7 | 34.5 | -26.5 | 2 | -0.09 | 16.4 | -- | -- |
SB1c-280 | gray clay | 277-285 | 280 | 394.8 | -- | -- | -- | -- | -- | -- | -- | -- |
SB1c(284) | same | 277-285 | 284 | 400.4 | 1.8 | 96.3 | -28.2 | < 0.05 | 5.05 | -- | -- | -- |
1Chemical analyses were not done on samples with depths in parentheses. “D”, duplicate sample. | ||||||||||||
2Corrected depth equals original depth (midpoint of sample interval) multiplied by 1.41 to correct for compaction. | ||||||||||||
3Computed as the difference between total carbon and inorganic carbon. Inorganic carbon less than 0.01% for all samples. | ||||||||||||
4Percent mineral matter computed by: 100 - (2 x organic carbon). | ||||||||||||
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.). |