Docstoc

Isotopes - NOAA

Document Sample
Isotopes - NOAA Powered By Docstoc
					Mt. Arthur, New Zealand 31KYr Speleothem Stable Isotope Data
-----------------------------------------------------------------------
            World Data Center for Paleoclimatology, Boulder
                            and
                 NOAA Paleoclimatology Program
-----------------------------------------------------------------------
NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!!

NAME OF DATA SET:
Mt. Arthur, New Zealand 31KYr Speleothem Stable Isotope Data

LAST UPDATE: 9/2010 (Original receipt by WDC Paleo)
CONTRIBUTORS: Hellstrom, J., M. McCulloch, and J. Stone
IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2010-100

WDC PALEO CONTRIBUTION SERIES CITATION:
Hellstrom, J., et al. 2010.
Mt. Arthur, New Zealand 31KYr Speleothem Stable Isotope Data.
IGBP PAGES/World Data Center for Paleoclimatology
Data Contribution Series # 2010-100.
NOAA/NCDC Paleoclimatology Program, Boulder CO, USA.

ORIGINAL REFERENCE:
Hellstrom, J., M. McCulloch, and J. Stone. 1998.
A detailed 31,000-year record of climate and vegetation change,
from the isotope geochemistry of two New Zealand speleothems.
Quaternary Research, Vol. 50, pp. 167-178.
ARTICLE NO. QR981991

ABSTRACT:
Uranium-series dating and stable isotope analyses of two speleothems
from northwest Nelson, New Zealand, record changes in regional climate
and local forest extent over the past 31,000 years. Oxygen isotope
variation in these speleothems primarily represents changes in the
meteoric waters falling above the caves, possibly responding to
latitudinal changes in the position of the Subtropical Front in the
Tasman Sea. Seven positive excursions can be identified in the oxygen
isotope record, which coincide with periods of glacier advance,
known to be sensitive to northward movement of the Subtropical Front.
Four glacier advances occurred during oxygen isotope stage 2, with the
most extreme glacial conditions centered on 19,000 cal yr B.P.
An excursion in the oxygen isotope record from 13,800 to 11,700
cal yr B.P. provides support for a previously identified New Zealand
glacier advance at the time of the Younger Dryas Stade, but suggests
it began slightly before the Younger Dryas as recorded in Greenland
ice cores. Carbon isotope variations in the speleothems record changes
in forest productivity, closely matching existing paleovegetation
records. On the basis of vegetation changes, stage 2 glacial climate
conditions terminated abruptly in central New Zealand, from 15,700
to 14,200 cal yr B.P. Evidence of continuous speleothem growth at one
site suggests that depression of the local treeline was limited to
600-700 m below its present altitude, throughout the last 31,000 years.
GEOGRAPHIC REGION: South Pacific
PERIOD OF RECORD: 31 KYrBP - present
FUNDING SOURCES:


DESCRIPTION:
Continuous high-resolution stable isotope records from caves
in New Zealand over the last 31,000 yr. Mt. Arthur (1795 m)
is located northwestern corner of New Zealand's South Island,
underlain by many known cave systems, the two largest and
deepest being Exhaleair and Nettlebed Caves used for this study.

A 50-mm-diameter core sample was recovered from each site
by drilling into gently sloping flowstones (massive sheet
speleothems which form on cave walls and floors).
Core MD3 was dated at nine points, and Core ED1 was dated at
three points, using the mass-spectrometric 238U-234U-230Th method.

Site Locations:
Speleothems ED1 and MD3, Mt. Arthur, South Island, New Zealand:
ED1 (Exhaleair Cave): ~41°17'S, 172°38'E, 685m elev, ~200m below surface.
MD3 (Nettlebed Cave): ~41°15'S, 172°41'E, 390m elev, ~200m below surface.
Table 1. U-Series Data and Calculated Ages for Mt. Arthur Speleothems

Sample              U       Depth 234U/238U 2-sigma 230Th/238U 2-sigma                      Age 2-sigma
                (ppm)       (mm)     Activity  error    activity  error                   (yr)*a   error
MD3A1           0.052         105       1.37  0.044       0.067  0.003                     5401      275
MD3A5           0.049         297      1.355  0.004       0.108  0.009                     9018      782
MD3A6           0.091         374      1.362  0.007       0.136  0.013                   11,382    1157
MD3A7           0.113         451       1.41  0.013       0.169    0.01                  13,850      878
MD3A9           0.081         462      1.402  0.007       0.176  0.004                   14,499      322
MD3A19          0.092         486      1.413  0.005       0.191  0.001                   15,699      145
MD3A10          0.113         511      1.405  0.005       0.244    0.02                  20,533    1868
MD3A11          0.106         540      1.386  0.057       0.313  0.021                   27,469    2417
MD3.11C2        0.107         581      1.376  0.003       0.345  0.004                   31,012      442
ED1A1           0.073         103      1.246    0.01      0.086  0.003                     7786      239
ED1A2           0.068         173      1.225    0.03       0.17  0.009                   16,216      980
ED1A4             0.04        179      1.178  0.005       0.583  0.014                   72,777    2501

*a Two-sigma errors (bracketed) are propagated by Monte Carlo simulation, and can be considered symmetrical
 for young samples such as these.

*b Ages recalculated to allow for the effect of detrital thorium, by assuming 230Th/232Th activity was equal to 1
at time of formation. Corrected ages are not used in the text of this paper, as, with the exception of samples
MD3A5, ED1A1, and ED1A4, the correction is not significant, and it introduces additional assumptions to the dating technique.
              230Th/232Th          Corrected
                   Activity        Age (yr)*b
                        82              5380
                        10              8140
                      564            11,370
                      177            13,790
                      260            14,450
                      193            15,620
                      103            20,350
                      173            27,330
                        85           30,700
                        15              7260
                        22           15,490
                        42           71,520

dered symmetrical


y was equal to 1
n of samples
mptions to the dating technique.
Hellstrom et al. 1998 Mt. Arthur Speleothem Stable Isotope Data

          Speleothem MD3                                                     Speleothem ED1
             A                      d18O
Depth MD3 (mm) ge MD3 d13C MD3 (PDB) MD3 (PDB)                    Depth ED1 (mm)Age ED1 d13C ED1 (PDB)
2.5              128.6        -7.51         -5.73                 2.5           189.9225
2.5              128.6     -7.6329       -5.5918                  7.5           569.7675     -4.4276
7.5              385.8        -6.31         -5.78                 12.5          949.6125     -5.1096
12.5               643        -4.05         -5.95                 17.5          1329.458     -4.9756
17.5             900.2        -4.94         -5.99                 22.5          1709.302     -5.2805
22.5            1157.4        -5.19         -5.86                 27.5          2089.147     -4.6432
27.5            1414.6        -5.09         -5.93                 32.5          2468.992     -5.2419
32.5            1671.8        -5.05          -5.8                 37.5          2848.837     -5.7895
37.5              1929        -5.15         -5.94                 42.5          3228.683     -5.2251
42.5            2186.2        -5.78         -5.99                 47.5          3608.528     -5.0022
47.5            2443.4        -6.08         -5.96                 52.5          3988.373     -5.1588
52.5            2700.6        -6.22            -6                 57.5          4368.217        -4.97
57.5            2957.8        -4.73         -5.87                 62.5          4748.063     -5.7208
62.5              3215        -6.03         -5.68                 67.5          5127.908     -5.7588
67.5            3472.2        -6.45         -5.73                 72.5          5507.752     -6.1331
72.5            3729.4        -6.46         -5.78                 77.5          5887.598     -6.0199
77.5            3986.6        -6.12         -5.62                 82.5          6267.442        -6.25
82.5            4243.8        -6.26         -5.88                 87.5          6647.288     -5.7185
87.5              4501        -6.16         -5.86                 92.5          7027.132     -5.1977
92.5            4758.2     -5.8247       -5.9706                  97.5          7406.978     -5.3184
97.5            5015.4        -6.11         -5.87                 102.5         7786.823     -5.0791
102.5           5272.6        -5.63            -6                 107.5         8388.878     -4.8974
107.5           5448.3        -5.56         -5.73                 112.5         8990.934     -4.5193
112.5           5542.5        -5.37         -5.92                 117.5         9592.988     -4.5582
117.5           5636.7        -5.37         -5.65                 122.5         10195.04     -3.9271
122.5           5730.9        -5.63         -5.94                 127.5           10797.1    -5.2726
122.5           5730.9     -5.6323       -5.8791                  132.5         11399.16      -5.263
122.5           5730.9     -5.5921       -5.8696                  137.5         12001.21     -4.9958
122.5           5730.9      -5.661       -5.9157                  142.5         12603.27     -5.6009
122.5           5730.9     -5.6177       -5.9797                  147.5         13205.32     -5.6611
127.5           5825.1         -6.8         -5.94                 152.5         13807.38     -6.0264
132.5           5919.3        -6.57          -5.8                 157.5         14409.43     -4.8681
137.5           6013.5        -6.99         -5.66                 162.5         15011.49     -3.7765
142.5           6107.7        -6.68         -5.88                 167.5         15613.54     -3.3361
147.5           6201.9        -7.16         -5.75
152.5           6296.1        -6.53          -5.4
157.5           6390.3        -6.91         -5.83
162.5           6484.5        -7.47         -5.97
167.5           6578.7        -7.08         -5.62
172.5           6672.9        -6.86         -5.39
177.5           6767.1        -6.89         -5.51
182.5           6861.3        -6.88         -5.96
187.5           6955.5        -7.19         -5.98
192.5           7049.7        -6.85         -5.73
197.5           7143.9        -6.75         -5.61
202.5           7238.1        -6.77         -5.49
207.5           7332.3        -6.59         -5.69
212.5           7426.5        -5.47         -5.51
217.5      7520.7      -6.79      -5.69
222.5      7614.9      -6.96      -5.63
227.5      7709.1       -6.8      -5.54
232.5      7803.3       -6.3      -5.24
237.5      7897.5      -6.04       -5.1
242.5      7991.7   -7.5683    -5.7307
247.5      8085.9   -6.3673    -5.3692
252.5      8180.1   -6.7137    -5.1786
257.5      8274.3   -6.4133    -5.2371
262.5      8368.5   -6.0169    -5.3725
267.5      8462.7   -6.9025    -5.2642
272.5      8556.9      -6.85      -5.21
277.5      8651.1   -5.3616    -5.2256
282.5      8745.3   -4.8917    -5.1165
287.5      8839.5      -4.52         -5
292.5      8933.7   -5.9497    -5.1137
297.5    9034.275   -4.9515    -5.2946
302.5    9187.725   -5.2513     -5.064
307.5    9341.175   -4.9632    -5.0338
312.5    9494.625   -5.8132    -5.2595
317.5    9648.075   -5.1716    -5.0599
322.5    9801.525   -3.8288    -4.9305
327.5    9954.975   -4.9808     -5.168
332.5   10108.425   -6.2409    -5.1633
337.5   10261.875   -5.8252    -5.1953
342.5   10415.325   -7.1752    -5.1394
347.5   10568.775      -7.16      -5.28
352.5   10722.225      -7.31      -5.51
357.5   10875.675      -7.18      -5.28
362.5   11029.125      -7.06      -5.37
367.5   11182.575      -7.05      -5.46
372.5   11336.025      -6.69      -5.37
377.5    11491.65      -6.25      -5.46
382.5    11651.95   -5.7123    -5.2459
387.5    11812.25   -5.6294    -5.2215
392.5    11972.55   -6.1129    -5.0869
397.5    12132.85   -6.7359    -5.1263
402.5    12293.15    -6.748    -5.2404
407.5    12453.45   -6.2914    -4.9803
412.5    12613.75   -5.9618    -5.1113
417.5    12774.05   -5.3583    -5.0743
422.5    12934.35   -6.0583    -5.0954
427.5    13094.65   -6.8586     -5.084
432.5    13254.95   -6.7817    -5.1982
435.5    13351.13   -7.4826    -5.1425
436.5    13383.19   -6.3661    -5.2111
437.5    13415.25   -5.9558    -5.2172
438.5    13447.31   -5.9026    -5.1916
439.5    13479.37   -5.6195     -5.078
440.5    13511.43   -5.8573    -5.2056
441.5    13543.49   -6.2161    -5.2525
443.5    13607.61   -5.9788    -5.1039
444.5   13639.67    -5.925    -5.0201
445.5   13671.73    -6.724    -5.4468
446.5   13703.79    -6.136    -5.2772
447.5   13735.85   -6.3013    -5.0543
448.5   13767.91   -6.0475    -4.8387
448.5   13767.91   -6.0799     -4.818
451.5    13879.5   -7.4169    -5.6605
452.5    13938.5   -7.0268    -5.4813
453.5    13997.5   -7.2323    -5.3945
454.5    14056.5   -7.5361     -5.281
455.5    14115.5   -7.8244    -5.2985
456.5    14174.5   -7.8152     -5.405
457.5    14233.5   -7.6887    -5.4023
458.5    14292.5   -7.5598    -5.3613
459.5    14351.5   -7.3268     -5.241
460.5    14410.5   -6.1741    -5.2049
461.5    14469.5   -6.2321    -5.4545
462.5      14522   -5.7652    -5.3671
463.5      14572    -4.534    -5.3081
464.5      14622   -5.4581    -5.3693
466        14697   -5.6988    -5.2192
467.5      14772   -5.9877    -5.1727
468.5      14822   -3.6916    -5.1591
468.5      14822   -3.7028    -5.1914
469.5      14872   -4.6221     -5.286
471.5      14972   -2.8643    -5.2613
472.5      15022   -5.0978    -5.2071
473.5      15072   -5.5306    -5.2063
473.5      15072   -5.5504    -5.2362
474.5      15122   -4.0873    -5.2533
475.5      15172   -4.5233    -5.3296
476.5      15222    -3.926    -5.3377
477.5      15272   -3.5533    -5.2206
478.5      15322   -2.1902    -5.1475
479.5      15372   -2.3326    -5.1152
480.5      15422   -3.1798    -5.1409
481.5      15472   -3.2536     -5.134
482.5      15522   -3.6656    -5.1511
483.5      15572      -3.19   -5.0101
484.5      15622   -2.5129    -4.9196
485.5      15672   -2.0002    -4.9581
486.5   15797.64   -1.6077    -4.9848
487.5      15991   -1.9496    -4.8162
488.5   16184.36   -2.0047    -4.6596
488.5   16184.36   -2.0949    -4.8161
489.5   16377.72   -2.0181    -4.5977
490.5   16571.08    -1.985    -4.6579
491.5   16764.44    -2.021    -4.8324
492.5    16957.8   -2.1391    -4.7752
493.5   17151.16   -1.9273    -4.8271
494.5   17344.52    -1.633    -4.8556
494.5   17344.52   -1.6911    -4.8924
495.5    17537.88   -1.3854       -4.96
496.5    17731.24   -0.9863    -4.9937
497.5     17924.6   -0.5691       -4.87
499.5    18311.32    0.3027    -4.7053
500.5    18504.68    0.5468     -4.714
501.5    18698.04    1.0881    -4.1728
502.5     18891.4    1.1686    -4.0709
502.5     18891.4    1.0135    -4.3949
503.5    19084.76    0.7849    -4.3608
504.5    19278.12    0.5484    -4.2138
505.5    19471.48    0.4475    -4.4367
506.5    19664.84    0.4485    -4.6449
507.5     19858.2    0.3318    -4.6408
508.5    20051.56   -0.2095    -4.6923
509.5    20244.92   -0.2436    -4.7866
510.5    20438.28       1.05      -4.72
511.5   20654.455       1.58      -4.63
512.5   20893.625       1.06      -4.81
513.5   21132.795        0.2      -5.03
514.5   21371.965   -0.8061    -4.8309
515.5   21611.135    -1.591    -5.1533
516.5   21850.305   -1.6011    -5.1594
517.5   22089.475   -0.2646    -5.0155
518.5   22328.645    0.2933    -4.8472
519.5   22567.815    0.1635    -5.0353
520.5   22806.985   -0.2457    -4.9476
521.5   23046.155    -0.466    -4.7577
522.5   23285.325   -0.5072    -4.6718
523.5   23524.495   -0.5001       -4.67
524.5   23763.665   -0.6101    -4.6913
526      24122.42   -0.4964    -4.8004
528      24600.76   -0.8658    -5.2222
528      24600.76   -0.8976    -5.1807
530       25079.1   -0.1215    -5.0508
532      25557.44    -0.392    -4.9982
532      25557.44   -0.4058    -4.9795
534      26035.78   -1.6001    -5.0735
536      26514.12    -2.403    -5.0838
538      26992.46   -2.8415    -5.1596
540       27470.8   -3.6869    -5.3893
542      27641.64   -4.4576    -5.6095
544      27814.48   -4.2798    -5.5933
546      27987.32   -4.3133    -5.4478
548      28160.16   -4.5448    -5.5223
550         28333    -4.463    -5.2876
552      28505.84   -4.5728    -5.5428
554      28678.68   -4.5576    -5.6974
556      28851.52   -4.3944    -5.6293
558      29024.36   -4.1481    -5.7632
558      29024.36   -4.1361    -5.7154
560       29197.2   -3.9805    -5.7709
562      29370.04   -2.7494    -5.3827
564   29542.88   -2.9485   -5.4557
566   29715.72   -2.8997   -5.3736
568   29888.56   -3.0931   -5.3142
570    30061.4   -3.1286   -5.4274
572   30234.24   -2.7007   -5.3113
574   30407.08   -2.8306   -5.4457
576   30579.92   -2.9494   -5.2113
578   30752.76   -2.9184   -5.1757
580    30925.6   -2.8354   -5.3205
582   31098.44   -2.7348   -5.4077
584   31271.28   -2.6891      -5.32
d18O ED1 (PDB)

     -6.339
    -6.4862
     -6.562
    -6.5328
    -6.4949
    -6.6334
    -6.6331
    -6.6991
    -6.4327
    -6.2964
    -6.2115
    -6.2222
    -6.4183
     -6.613
    -6.4476
    -6.5488
    -6.5631
       -6.23
    -6.1318
    -5.9688
    -5.7458
    -5.7688
    -5.6362
    -5.4763
     -5.476
    -5.6102
    -5.6376
    -5.4915
    -5.3885
    -5.5915
    -5.4688
    -5.1314
    -5.0963

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:6
posted:2/26/2012
language:
pages:10