【作者】 侯红明；

【导师】 刘东生； 郑洪汉； 罗又郎；

【作者基本信息】 中国科学院广州地球化学研究所 ， 地球化学， 2000， 博士

【摘要】 对南沙海区N94－93和NS94-24两柱样系统的古环境变化研究表明，南 沙海区在末次冰期期间，海水水体交换微弱，沉积物以陆源沉积为主，碳酸 盐溶解强烈，碳酸盐溶跃层深度和CCD深度大幅上升；巽他陆架于14. 9kaBP Cal age（13. 2kaBP 14Cage）开始被海水淹没，约经历600年左右巽它陆架趋于 稳定；在末次冰期期间，夏季风明显减弱而且不稳定。巽它陆架被海水淹没 后，水体交换显著增强，沉积作用发生了明显的改变，沉积物中生源物质明 显增加。研究还表明，南沙海区在15. 1—15. 7kaBP Cal age(对应于13. 4－ 13. 8kaBP ¹⁴Cage)存在Heinrich 1冷事件，13. 6─14. 0kaBP Cal age(对应于 12. 1─12. 4kaBP ¹⁴C age)记录中仙女木事件（Older Dryas Cooling event）； 10. 8—12. 6kaBP cal age(对应于10─11. 2kaBP ¹⁴C age)有新仙女木冷事件的存 在，但降温幅度并不明显。10kaBP以后，进入前北方期，至 8. 7kaBP(¹⁴C age) 以后，南沙海区才正式进入全新世暖期，此后，气候的变化仍表现为不稳定 性和旋回性的特点，至4. 4kaBP南沙海区的古气温达到全新世最暖期。此后 又存在一小幅降温一升温的旋回，南沙海区的气候变化显示与全球变化具有 同时性，南沙海区古气候变化事件均可以从季风变化和水文状况的改变找到 线索，亦支持全球变化主要由大气环流变化的假设。更多还原

【Abstract】 Paleoenvironment changes were discussed in Nansha Water since Last Glacialbased on systematic study of Core NS94-93 and NS94-24. During last glacial,water exchange was very poor and sediments are dominated by terrigenous matter,accompanying with higher CCD and intensive dissolution of carbonate. SundaShelf was drown by seawater at l3. 2kaBP ¹⁴C age（14. 9 kaBP Cal age） and becamestable after about 600a. Summer monsoon was weak and unstable during lastglacial. Afterward, water exchange was evidently intensified when Sunda Shelfwas completely drown out, and biogenous matters in sediments was markedlyincreased. Research also testified the existence of Heinrich 1(13. 4-13. 8kaBP ¹⁴Cage), Older Dryas Cooling Event(12. 1-12. 4kaBP ¹⁴C age), Younger Dryas CoolingEvent(10-11. 2kaBP ¹⁴C ages), but the temperature drops of these events were verysmall. In Nansha Waters, Holocene began at 10kaBP ¹⁴C age, and the temperaturedidn’t evidently raised during the Preboreal period(10-8. 7kaBP ¹⁴C age). After8. 7kaBP, climate of Nansha Waters behaved unstably and cyclically, and achievedwarmest period at 4. 4kaBP. The climate of Nansha Watrs simultaneously changedwith global climate, and could trace by the changes of monsoon and hydrologyindex, supported that the global changes was mainly caused by atmospherecirculation.更多还原