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首页> 外文期刊>Earth and Planetary Science Letters: A Letter Journal Devoted to the Development in Time of the Earth and Planetary System >Late pleistocene to holocene composite speleothem O-18 and C-13 chronologies from south island, new Zealand-did a global younger dryas really exist?
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Late pleistocene to holocene composite speleothem O-18 and C-13 chronologies from south island, new Zealand-did a global younger dryas really exist?

机译：从新西兰南岛的晚更新世到全新世的复合杂种O-18和C-13年代-确实存在全球年轻的树精吗？

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摘要

Oxygen and carbon data from eight stalagmites from northwest South Island are combined to produce composite records of delta(18)O and delta(13)C from 23.4 ka to the present. The chronology is anchored by 43 thermal ionization mass spectrometry (TIMS) uranium series ages. Delta O-18 values are interpreted as having a first order positive relationship to temperature, but also to be influenced by precipitation in a complex manner. Delta C-13 is interpreted as responding negatively to increases in atmospheric CO, concentration, biological activity and precipitation amount.Six climatic phases are recognized. After adjustment of 1.2parts per thousand for the ice volume effect, the delta(18)O record between 23 and 18 ka varies around -3.72parts per thousand compared to the Holocene average of -3.17parts per thousand. Late-glacial warming commenced between 18.2 and 17.8 ka and accelerated after 16.7 ka, culminating in a positive excursion between 14.70 and 13.53 ka. This was followed by a significant negative excursion between 13.53 and 11.14 ka of up to 0.55parts per thousand depth that overlapped the Antarctic Cold Reversal (ACR) and spanned the Younger Dryas (YD). Positive delta(18)O excursions at 11.14 ka and 6.91-6.47 ka represent the warmest parts of the Holocene. The mid-Holocene from 6 to 2 ka was marked by negative excursions that coincide with increased glacial activity in the South Island. A short positive excursion from 0.71 to 0.57 ka was slightly later than the Medieval Warm Period of Europe.Delta C-13 values were high until 17.79 ka after which there was an abrupt decrease to 17.19 ka followed by a steady decline to a minimum at 10.97 ka. Then followed a general increase, suggesting a drying trend, to 3.23 ka followed by a further general decline. The abrupt decrease in delta-values after 17.79 ka probably corresponds to an increase in atmospheric CO2 concentration, biological activity and wetness at the end of the Last Glaciation, but the reversal identified in the delta(18)O record from 13.53 to 11.14 ka was not reflected in delta(13)C changes. The lowest delta(13)C values coincided with the early Holocene climatic suboptimum when conditions were relatively wet as well as mild.Major trends in the delta(18)O(c) record are similar to the Northern Hemisphere, but second order detail is often distinctly different. Consequently, at the millennial scale, a more convincing case can be made for asymmetric climatic response between the two hemispheres rather than synchronicity. (C) 2004 Elsevier B.V. All rights reserved.
机译：来自南岛西北部的8个石笋的氧气和碳数据相结合，生成了从23.4 ka到现在的delta（18）O和delta（13）C的复合记录。年表以43个热电离质谱（TIMS）铀系列年龄为基础。 ΔO-18值被解释为与温度具有一阶正相关，但也受降水影响的复杂方式。 δC-13被解释为对大气CO，浓度，生物活性和降水量增加的负面响应。认识到六个气候阶段。将冰量效应调整为千分之1.2后，记录在23到18 ka之间的delta（18）O大约为千分之-3.72，而全新世的平均值为千分之3.17。晚冰期变暖开始于18.2和17.8 ka之间，并在16.7 ka之后加速，最终在14.70和13.53 ka之间出现正偏移。随后是在13.53和11.14 ka之间的显着负偏移，每千个深度最多有0.55份，这与南极寒流（ACR）重叠并跨越了年轻树妖（YD）。在11.14 ka和6.91-6.47 ka处的正delta（18）O偏移表示全新世的最暖部分。从6到2 ka的全新世中期特征是负偏移，与南岛的冰川活动增加相吻合。从0.71到0.57 ka的短时正向偏移略晚于欧洲中世纪暖期.Delta C-13值一直很高，直到17.79 ka，之后突然下降到17.19 ka，然后稳定地下降到最小值10.97 K a。然后总体上升，这表明干燥趋势，至3.23 ka，然后进一步普遍下降。在17.79 ka之后，δ值的突然下降可能对应于末次冰川结束时大气中CO2浓度，生物活性和湿度的增加，但在delta（18）O记录中发现的逆转是从13.53 ka到11.14 ka未反映在delta（13）C变化中。当条件相对潮湿和温和时，最低的delta（13）C值与早期全新世气候次最佳值相符.delta（18）O（c）记录的主要趋势与北半球相似，但二阶细节是通常明显不同。因此，在千禧年尺度上，两个半球之间的气候响应不对称而非同步是一个更有说服力的理由。 （C）2004 Elsevier B.V.保留所有权利。

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