亚洲内陆荒漠化和干旱化与中国西部人类生存环境和社会可持续发展密切相关。中国西部地区的气候自晚更新世以来经历了多次冷暖、干湿变化,研究其晚更新世古气候变化,有助于预测未来气候的变化趋势。文章分析了宁夏南部清水河盆地晚更新...亚洲内陆荒漠化和干旱化与中国西部人类生存环境和社会可持续发展密切相关。中国西部地区的气候自晚更新世以来经历了多次冷暖、干湿变化,研究其晚更新世古气候变化,有助于预测未来气候的变化趋势。文章分析了宁夏南部清水河盆地晚更新世中晚期的孢粉记录,结果显示孢粉序列可从下至上划分为4个组合带,反映了该地区晚更新世中晚期植被和气候变化规律。研究表明研究区晚更新世中期(75~50 ka B.P.)是植被以蒿属为主的干草原,气候温凉偏干;晚更新世晚期(25~15 ka B.P.)由荒漠草原-干草原和疏林草原交替出现逐渐过渡到荒漠草原,该时期冬季风呈现逐渐增强的趋势,致使气候逐渐变冷变干,气候类型由温凉偏湿过渡到冷干。宁夏南部清水河盆地晚更新世中晚期孢粉记录的深入研究对于正确认识黄土高原自然环境历史演变和黄土高原治理决策的制定具有重要指导意义。展开更多
The first study of erratic boulder exposure ages in the Grove Mountains, interior Antarctica, indicates the two erratic boulders （060131-1 and 060131-2, collected from a typical nunataks, Zakharoff Ridge in the Grove...The first study of erratic boulder exposure ages in the Grove Mountains, interior Antarctica, indicates the two erratic boulders （060131-1 and 060131-2, collected from a typical nunataks, Zakharoff Ridge in the Grove Mountains） have 10 Be minimum exposure ages of 1.24 ±0. 11 Ma, 1.37 ±0. 12 Ma, and ^26Al ages of 0.90 ±0.12 Ma,0.44 ±0.04 Ma, respectively. Meanwhile, another erratic boulder sample 060131-4, coming from vicinal ice surface, has ^10Be and ^26Al minimum exposure ages of 0.47 ±0.3 Ma and 0. 44 ±0.04 Ma, respectively. The exposure ages of the three erratic boulders are nearly similar to the bedrocks with the similar elevation. Thus, using the technique of in situ produced terrestrial cosmogenic nuclides, the ice sheet evolution histories in the Grove Mountains reflected by erratic boulder and bedrock exposure ages are basically consistent.展开更多
文摘亚洲内陆荒漠化和干旱化与中国西部人类生存环境和社会可持续发展密切相关。中国西部地区的气候自晚更新世以来经历了多次冷暖、干湿变化,研究其晚更新世古气候变化,有助于预测未来气候的变化趋势。文章分析了宁夏南部清水河盆地晚更新世中晚期的孢粉记录,结果显示孢粉序列可从下至上划分为4个组合带,反映了该地区晚更新世中晚期植被和气候变化规律。研究表明研究区晚更新世中期(75~50 ka B.P.)是植被以蒿属为主的干草原,气候温凉偏干;晚更新世晚期(25~15 ka B.P.)由荒漠草原-干草原和疏林草原交替出现逐渐过渡到荒漠草原,该时期冬季风呈现逐渐增强的趋势,致使气候逐渐变冷变干,气候类型由温凉偏湿过渡到冷干。宁夏南部清水河盆地晚更新世中晚期孢粉记录的深入研究对于正确认识黄土高原自然环境历史演变和黄土高原治理决策的制定具有重要指导意义。
基金supported by the National Science Fund of China (No.40631004 and 40506003)the Chinese Polar Science Strategy Research Fund (No.20070219)
文摘The first study of erratic boulder exposure ages in the Grove Mountains, interior Antarctica, indicates the two erratic boulders （060131-1 and 060131-2, collected from a typical nunataks, Zakharoff Ridge in the Grove Mountains） have 10 Be minimum exposure ages of 1.24 ±0. 11 Ma, 1.37 ±0. 12 Ma, and ^26Al ages of 0.90 ±0.12 Ma,0.44 ±0.04 Ma, respectively. Meanwhile, another erratic boulder sample 060131-4, coming from vicinal ice surface, has ^10Be and ^26Al minimum exposure ages of 0.47 ±0.3 Ma and 0. 44 ±0.04 Ma, respectively. The exposure ages of the three erratic boulders are nearly similar to the bedrocks with the similar elevation. Thus, using the technique of in situ produced terrestrial cosmogenic nuclides, the ice sheet evolution histories in the Grove Mountains reflected by erratic boulder and bedrock exposure ages are basically consistent.
