Chesapeake Bay Foraminifera Counts and Paleosalinity Estimates ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Chesapeake Bay Foraminifera Counts and Paleosalinity Estimates LAST UPDATE: 10/2002 (Original Receipt by WDC Paleo) CONTRIBUTOR: Tom Cronin, U.S. Geological Survey IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2002-066 SUGGESTED DATA CITATION: Cronin, T., et al., 2002, Chesapeake Bay Foraminifera Counts and Paleosalinity Estimates, IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2002-066. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Cronin, T., D. Willard, A. Karlsen, S. Ishman, S. Verardo, J. McGeehin, R. Kerhin, C. Holmes, S. Colman, and A. Zimmerman, 2000, Climatic variability in the eastern United States over the past millennium from Chesapeake Bay sediments. Geology: Vol. 28, No. 1, pp. 3-6. ADDITIONAL REFERENCE: Stuiver, M. and Reimer, P. 1993. Extended 14C data base and revised CALIB 3.0 14C age calibration program. Radiocarbon v. 35, p. 215-230. GEOGRAPHIC REGION: Eastern North America, Chesapeake Bay PERIOD OF RECORD: 1450-1996 A.D. DESCRIPTION: Chesapeake Bay Foraminifera Counts and Paleosalinity Estimates. Age model developed from lead-210, cesium-137, pollen stratigraphy, and C-14 dates. Salinity estimates in ppt based on the relative proportions of salinity sensitive benthic foraminifera described in Cronin et al. 2000 Geology. 210Pb and 137Cs analyses performed at USGS Center for Coastal and Marine Geology, St. Petersburg, FL. 14C ages obtained by graphite preparation at USGS in Reston, VA and AMS facilities at Lawrence Livermore Laboratories (WW) and Woods Hole Oceanographic Institution (OS). To convert uncorrected marine shell radiocarbon ages to calendar years (five marine shells had d13C values averaging 0.4 0/00; an assumed value of 0 0/00 was used in 14C calculations), the CALIB Program of Stuiver and Reimer (1993) was used with and without a local reservoir correction ("delta R") for region-specific 14C activity differences due to ocean mixing processes other than global ocean and regional atmospheric 14C activity. Local reservoir correction was estimated to be < 100 years from 14C activity of shells at horizons dated by ragweed pollen. Ages in figures are without local correction pending further radiocarbon calibration. ABSTRACT Salinity oscillations caused by multidecadal climatic variability had major impacts on the Chesapeake Bay estuarine ecosystem during the past 1000 yr. Microfossils from sediments dated by radiometry (14C, 137Cs, 210Pb) and pollen stratigraphy indicate that salinity in mesohaline regions oscillated 10-15 ppt during periods of extreme drought (low fresh-water discharge) and wet climate (high discharge). During the past 500 yr, 14 wet-dry cycles occurred, including sixteenth and early seventeenth century megadroughts that exceeded twentieth century droughts in their severity. These droughts correspond to extremely dry climate also recorded in North American tree-ring records and by early colonists. Wet periods occurred every ~60-70 yr, began abruptly, lasted <20 yr, and had mean annual rainfall ~25%-30% and fresh-water discharge ~40%-50% greater than during droughts. A shift toward wetter regional climate occurred in the early nineteenth century, lowering salinity and compounding the effects of agricultural land clearance on bay ecosystems. DATA: TABLE 1. SITE AND GEOCHRONOLOGIC DATA FOR CHESAPEAKE BAY CORES Lab # Site and Water Lat Long Depth of 14C Material dated d13C 14C Age 1s Cal age 2 s Agricultural Core No. † Depth (m) (cm) (B.P.) Horizon** Radiocarbon dates* WW-1586 PRCK-3-P-2 24.3 38° 32.6349'N 76 25.689'W 121 mollusks NA 640 50 276 146-387 6-10 cm WW-1587 PRCK-3-P-2 24.3 38° 32.6349'N 76 25.689'W 257-262 mollusks NA 1160 40 682 639-764 WW-1588 PRCK-3-P-2 24.3 38° 32.6349'N 76 25.689'W 366-370 mollusks NA 1980 50 1521 1396-1638 OS-15679 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 81 mollusk 0.01 540 30 150 0-260 WW-1284 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 141 Mulinia lateralis 0.1 540 50 147 0-276 155-160 cm OS-15680 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 161 mollusks -0.29 885 35 500 450-540 OS-15681 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 211 mollusks 0.01 1150 25 675 650-710 WW-1589 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 222-228 mollusks NA 990 40 552 507-636 OS-17242 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 229 benthic forams -1.72 1230 30 750 680-830 OS-15689 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 297 mollusks 0.1 1530 70 1060 920-1230 OS-17508 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 331 benthic forams -2.41 2450 256 2080 1530-2710 OS-17241 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 392 benthic forams -1.94 2400 85 2000 1820-2270 OS-15678 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 409 mollusks -0.07 1130 80 660 540-830 WW-1285 PTMC-3-P-2 23.1 38 01.6118'N 76 13.1938'W 407-414 Anachis obesa 0.1 1240 50 761 667-896 WW-1590 PTXT-2-P-3 11.5 38°19.584'N 76°23.548'W 250 mollusks NA 720 50 328 266-460 110-120 cm WW-1591 PTXT-2-P-3 11.5 38°19.584'N 76°23.548'W 409-413 mollusks NA 740 50 386 276-473 WW-1291 PTXT-2-G-2 11.5 38°19.586'N 76°23.546'W 85-87 mollusks NA 510 60 121 0-271 75-80 cm WW-1292 PTXT-2-G-2 11.5 38°19.586'N 76°23.546'W 95-97 mollusks NA 520 50 128 0-267 WW-1293 PTXT-2-G-3 11.5 38 19.588'N 76 23.540'W 74-76 Mulinia lateralis NA 410 50 NA NA WW-1294 PTXT-2-G-3 11.5 38 19.588'N 76 23.540'W 94-98 mollusks NA 570 50 240 0-291 WW-1816 PTXT-2-P-5 12 38°20.0007'N 76°18.5801'W 298-304 Macoma NA 750 60 403 271-490 WW-1817 PTXT-2-P-5 12 38°20.0007'N 76°18.5801'W 388-392 Macoma NA 1030 50 608 517-665 137Cs maximum PTXT-2-G-4 11.5 38 19.588'N 76 23.540'W 36 bulk sediment NA A.D. 1964 PTMC-3-P-3 23.1 38 01.6118'N 76 13.1938'W 27 bulk sediment NA A.D. 1964 AZM-3 15 38 34.05 76 26.76 250 bulk sediment NA 210Pb profile from Zimmerman and Canuel *USGS (WW) or Woods Hole (OS) radiocarbon date number † Labeling convention: PTXT-2-P-5 is site PTXT-2, P=piston, B=box, G=gravity cores, 5 = fifth core taken. See Cronin et al., Geology 2000 for core location map **Agricultural horizon defined by increase in ragweed pollen from 1 to ~10% circa 1850 A.D. Foraminifer counts and Paleosalinity: Foraminifera Counts Paleosalinity PTXT-2-P-5-Core Depth (cm) Elphidium spp. Ammonia parkinsoniana Ammobaculites Quinqueloculina sp. Total Date (A.D.) Salinity Estimate (ppt) 1 21 77 5 103 1996.640 14.349 3 23 73 3 99 1993.780 14.864 5 23 69 92 1990.920 15.184 7 40 60 100 1988.020 17.899 9 26 68 94 1985.080 15.665 11 14 86 100 1982.497 13.193 13 16 83 99 1980.271 13.584 15 65 30 95 1978.045 23.043 17 98 6 104 1975.396 27.715 19 101 2 5 108 1972.642 27.586 21 104 2 106 1969.895 28.417 23 82 13 95 1967.155 26.282 25 66 29 3 98 1964.443 22.849 27 73 32 1 106 1961.775 23.124 29 67 19 13 99 1959.340 22.908 31 62 10 28 100 1957.840 21.881 33 62 32 1 95 1956.340 22.472 35 55 26 19 100 1954.840 20.614 37 42 25 33 100 1953.042 18.261 39 42 37 21 100 1950.946 18.261 41 47 42 6 95 1948.878 19.614 43 48 53 16 117 1947.062 18.085 45 60 54 19 133 1945.245 18.824 47 48 33 15 96 1943.659 19.709 49 63 52 8 123 1942.171 19.930 51 83 11 94 1940.785 26.641 53 95 4 1 100 1939.635 27.854 55 95 12 4 111 1938.485 26.150 57 91 7 5 103 1937.594 26.650 59 89 8 9 106 1936.731 25.856 61 87 7 2 96 1935.965 27.062 63 103 3 3 109 1935.294 27.763 65 110 0 1 111 1934.629 28.596 67 104 2 4 110 1934.016 27.772 69 113 0 113 1933.404 28.759 71 94 0 94 1932.987 28.759 73 100 0 1 101 1932.653 28.580 75 86 3 2 91 1932.320 27.764 77 86 2 4 92 1931.987 27.579 79 98 7 1 106 1931.653 27.393 81 84 8 5 97 1930.994 26.333 83 85 7 92 1930.021 27.382 85 76 19 9 104 1929.048 23.886 87 70 0 10 80 1927.542 26.497 89 75 10 85 1925.995 26.630 91 54 23 25 102 1924.078 20.241 93 54 20 33 107 1921.474 19.794 95 117 9 14 140 1918.869 25.785 97 18 3 106 127 1914.536 13.224 99 34 11 93 138 1909.688 15.118 101 7 6 89 102 1904.333 11.901 103 70 26 68 164 1896.822 18.385 105 10 6 77 93 1889.311 12.605 107 71 63 48 182 1881.800 17.720 109 10 20 66 96 1874.289 12.544 111 26 7 59 92 1866.778 15.774 113 44 25 48 117 1859.267 17.466 115 24 12 115 151 1851.756 13.536 117 35 12 56 103 1846.321 16.809 119 46 13 98 157 1842.963 15.962 121 19 3 77 99 1839.604 14.133 123 82 14 10 106 1836.246 24.661 125 41 11 21 73 1832.888 20.825 127 85 24 23 132 1829.530 22.314 129 58 16 44 118 1826.172 19.556 131 70 11 8 89 1822.813 24.895 133 88 10 6 104 1819.455 25.974 135 59 19 14 92 1816.097 22.267 137 94 7 4 105 1812.739 26.863 139 86 27 4 117 1809.381 23.963 141 94 8 102 1806.022 27.339 143 109 6 115 1802.664 27.815 145 107 2 1 110 1799.306 28.265 147 91 3 94 1795.948 28.181 149 99 4 3 106 1792.590 27.564 151 63 5 26 94 1789.231 22.790 153 177 1 5 183 1785.873 28.166 155 135 0 2 137 1782.515 28.495 157 91 0 5 96 1779.157 27.816 159 86 0 28 114 1775.799 24.313 161 61 13 28 102 1772.440 21.484 163 30 0 70 100 1769.082 16.089 165 75 1 16 92 1765.724 25.414 167 66 2 32 100 1762.366 22.605 169 74 1 29 104 1759.007 23.538 171 69 0 13 82 1755.649 25.889 173 109 1 1 111 1752.291 28.433 175 91 2 7 100 1748.933 27.130 177 103 0 1 104 1745.575 28.585 179 104 1 12 117 1742.216 26.748 181 115 2 1 118 1738.858 28.299 183 111 7 8 126 1735.500 26.604 185 100 0 100 1732.142 28.759 187 106 3 9 118 1728.784 26.918 189 96 3 16 115 1725.425 25.769 191 83 0 37 120 1722.067 23.178 193 81 2 18 101 1718.709 25.175 195 63 24 17 104 1715.351 21.623 197 105 1 2 108 1711.993 28.256 199 70 8 14 92 1708.634 24.431 201 93 0 1 94 1705.276 28.566 203 67 24 7 98 1701.918 23.033 205 106 13 2 121 1698.560 26.515 207 58 33 5 96 1695.201 21.594 209 119 1 120 1691.843 28.608 211 95 33 5 133 1688.485 23.588 213 127 32 159 1685.127 25.116 215 51 54 105 1681.769 19.450 217 55 11 61 127 1678.410 18.498 219 64 34 5 103 1675.052 21.906 221 97 8 105 1671.694 27.380 223 108 11 119 1668.336 27.086 225 210 2 212 1664.978 28.588 227 85 12 3 100 1661.619 26.044 229 128 13 35 176 1658.261 23.823 231 102 4 2 108 1654.903 27.753 233 193 4 197 1651.545 28.391 235 88 5 93 1648.187 27.786 237 110 4 114 1644.828 28.124 239 101 1 102 1641.470 28.582 241 110 1 111 1638.112 28.596 243 104 8 112 1634.754 27.466 245 83 8 91 1631.396 27.168 247 98 7 105 1628.037 27.552 249 104 1 10 115 1624.679 27.028 251 55 6 46 107 1621.500 19.963 253 62 1 58 121 1618.500 19.933 255 30 2 60 92 1615.500 16.561 257 93 2 7 102 1612.500 27.162 259 85 3 17 105 1609.500 25.311 261 130 4 5 139 1606.500 27.587 263 105 1 7 1 114 1603.500 27.330 265 180 1 2 183 1600.500 28.462 267 117 1 2 120 1597.500 28.307 269 96 0 3 99 1594.500 28.211 271 88 0 12 100 1591.500 26.587 273 130 3 133 1588.500 28.351 275 91 1 16 108 1585.500 25.910 277 138 4 1 143 1582.500 28.126 279 94 2 4 100 1579.500 27.673 281 120 4 1 125 1576.500 28.035 283 52 0 38 90 1573.500 21.117 285 99 2 3 104 1570.500 27.889 287 12 3 86 101 1567.500 12.809 289 64 0 36 100 1564.500 22.243 291 31 1 65 97 1561.500 16.444 293 34 0 58 92 1558.500 17.348 295 68 0 33 101 1555.500 22.845 297 111 2 2 115 1552.500 28.129 299 88 2 3 93 1549.500 27.786 301 87 0 4 91 1547.090 27.963 303 103 1 4 1 109 1545.270 27.763 305 109 1 110 1543.450 28.594 307 120 1 2 123 1541.630 28.318 309 109 1 1 111 1539.810 28.433 311 93 3 2 98 1537.990 27.836 313 103 0 1 104 1536.170 28.585 315 129 1 1 131 1534.350 28.483 317 90 0 90 1532.530 28.759 319 115 2 2 119 1530.710 28.151 321 94 1 95 1528.890 28.568 323 103 0 103 1527.070 28.759 325 111 0 1 112 1525.250 28.597 327 126 1 1 128 1523.430 28.476 329 88 0 3 91 1521.610 28.162 331 89 5 9 103 1519.790 26.299 333 105 1 106 1517.970 28.588 335 90 0 7 97 1516.150 27.453 337 87 1 6 94 1514.330 27.411 339 86 4 10 100 1512.510 26.225 341 86 0 6 92 1510.690 27.579 343 99 2 10 111 1508.870 26.802 345 77 3 4 84 1507.050 27.251 347 72 1 19 92 1505.230 24.824 349 61 0 61 1503.410 28.759 351 13 6 86 105 1501.590 12.900 353 36 1 66 103 1499.770 16.985 355 52 1 40 93 1497.950 20.779 357 84 2 4 90 1496.130 27.552 359 76 2 15 93 1494.310 25.450 361 93 2 6 101 1492.490 27.325 363 18 0 3 21 1490.670 26.173 365 88 3 91 1488.850 28.162 367 97 5 1 103 1487.030 27.705 369 142 0 142 1485.210 28.759 371 95 0 95 1483.390 28.759 373 107 0 107 1481.570 28.759 375 109 0 109 1479.750 28.759 377 101 0 101 1477.930 28.759 379 102 0 102 1476.110 28.759 381 84 0 84 1474.290 28.759 383 88 1 89 1472.470 28.556 385 149 1 2 152 1470.650 28.402 387 92 0 92 1468.830 28.759 389 96 0 96 1467.010 28.759 391 92 1 93 1465.190 28.564 393 113 0 113 1463.370 28.759 395 129 1 130 1461.550 28.620 397 118 0 118 1459.730 28.759 399 134 1 9 144 1457.910 27.502