Lake-level stratigraphy and geochronology revisited at Lago (Lake) Cardiel, Argentina, and changes in the Southern Hemispheric Westerlies over the last 25 ka
Lake-level stratigraphy and geochronology revisited at Lago (Lake) Cardiel, Argentina, and changes in the Southern Hemispheric Westerlies over the last 25 ka
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DOI：
10.1016/j.quascirev.2017.10.006
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发表时间：
2017-12
影响因子：
4
通讯作者：
J. Quade;M. Kaplan
中科院分区：
文献类型：
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作者：
J. Quade;M. Kaplan
阿根廷南部卡迪尔湖（Lago）周围的古海岸线（S48.9°，W71.3°；∼275 m）记录了过去 25 ka 中湖泊面积的巨大变化。我们的结果与之前的研究相结合表明，在末次盛冰期（或末次盛冰期，23-21ka）期间，该湖的水位接近现代水平，但在大约13ka时几乎干涸。在 11.3 至 10.1 ka 之间，该湖达到了最高点（+54-58 m），并且至少在过去 40 ka 中达到了最大范围。此后湖水位下降，并经历了两个低湖期：8.5-7.5ka和5-3.3ka；以及两个较高的湖泊时期：7.4-6 ka和∼5.2 ka。在过去的 3.5ka 中，该湖的水位总体保持在接近或略高于目前的水平。拉戈卡迪尔湖的深度和表面积主要受湖泊和周围集水区的降水、气温和水温以及与南半球西风带 (SHW) 局部强度相关的风速控制。我们的湖平面重建结合其他研究的证据表明，平均而言，在与末次盛冰期相关的深湖阶段，SHW的核心位于卡迪尔盆地的北部（<45°S），而在全新世早期卡迪尔水文最大值期间，SHW的核心位于卡迪尔盆地的南部（>55°S？）。当我们推断SHW强烈集中在南纬49°的卡迪尔纬度附近时，20.0-11.5、8.5-7.5和5.0-3.3ka的湖的较低阶段通常对应于其他记录中的寒冷条件。
Paleoshorelines around Lago (Lake) Cardiel in southern Argentina (S48.9°, W71.3°; ∼275 m) record substantial changes in lake area over the past 25 ka. Our results combined with previous research show that during the last glacial maximum (or LGM, 23–21 ka), the lake stood at near modern levels, but had nearly dried up by ∼13 ka. Between 11.3 and 10.1 ka the lake reached its highest point (+54–58 m) and greatest extent in at least the last 40 ka. Lake levels dropped thereafter and experienced two lower-lake periods: 8.5–7.5 ka and 5–3.3 ka; and two higher-lake periods: 7.4–6 and ∼5.2 ka. In the last 3.5 ka, the lake has remained generally near or slightly above its present level.The depth and surface area of Lago Cardiel are controlled mainly by precipitation onto the lake and surrounding catchment, air and water temperature, and wind-speed related to local strength of the Southern Hemispheric Westerlies (SHW). Our lake-level reconstruction combined with evidence from other studies suggest that on average the core of the SHW was located well to the north (<45°S) of the Cardiel basin during the deep lake phase associated with the LGM, and was well to the south (>55°S?) during the hydrologic maximum of Cardiel in the early Holocene. The lower phases of the lake at 20.0–11.5, 8.5–7.5, and 5.0–3.3 ka generally correspond to cold conditions in other records, when we infer that the SHW were strongly focused around the latitudes of Cardiel at 49°S.