Seeking Evidence for Long-term Paleo-ENSO (El Nino-Southern Oscillation) Cycles from Loess-paleosol Sequence During the Last Glacial Period in the Central United States of America

从美国中部末次冰期的黄土-古土壤层序中寻找长期古ENSO（厄尔尼诺-南方涛动）周期的证据

• 批准号: 0001810
• 负责人: Hong Wang
• 金额: $ 4.02万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-10-01 至 2002-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0001810&HistoricalAwards=false
• 关键词: Seeking; Evidence; Long; term; Paleo

This award is for an exploratory study of evidence for long-term paleo-ENSO (El Nino-Southern Oscillation) cycles in the central United States, as reflected in evidence for fluctuations the ratio of C3/C4 vegetation types preserved in soils. Stable carbon isotope ratios and soil organic matter will be used as an indicator of the long-term average C3/C4 plant ratios. The stable isotope analyses will be done exclusively on rhizoconcretions (secondary carbonate encrustations on root tubes). Age control will be provided by radiocarbon analyses of soil organic matter and fossil remains.

该奖项是对美国中部长期古ENSO(厄尔尼诺-南方涛动)循环证据的探索性研究，这一证据反映在土壤中保存的C3/C4植被类型比率的波动。稳定的碳同位素比率和土壤有机质将被用作长期平均C3/C4植物比率的指标。稳定同位素分析将仅对根瘤(根管上的次生碳酸盐结皮)进行。年龄控制将通过对土壤有机质和化石遗骸的放射性碳分析来提供。