概括
在最后一个冰川时期,大西洋海底的土原材料流量比今天更高. 在脱冰和全新纪期间,流量减少,深水循环可能会影响沉积物运输.
科学领域:
- 海洋地质学 海洋地质学
- 古代海洋学 古代海洋学 古代海洋学
- 地质化学 地质化学
背景情况:
- 了解沉积物向海洋输送的过去变化对于重建海洋学条件至关重要.
- 地质流提供了对大陆气候变化,侵蚀和运输过程的见解.
研究的目的:
- 量化不同水深的赤道大西洋海底的原生流量.
- 重建从最后一个冰川时期到全新纪的土著输入中的时间变化.
主要方法:
- 针对多余的-230 (230Th) 流量的土壤原生流量的正常化.
- 分析了来自赤道大西洋两处不同水深的两处地点的沉积物核心.
主要成果:
- 与今天相比,在最后一个冰河时期,地质流量明显高于今天.
- 在脱冰过程中,流量减少,在全新世纪中期达到最低值.
- 从15000年前到5000年前,观察到水深低于2800米的流量增加.
结论:
- 在最后一个冰川时期,大西洋海底的土著物质投入量大幅增加.
- 沉积物运输动态,可能与加剧的深水循环有关,在全新纪期间影响了流动模式.
- 沉积物的再悬浮和横向运输可能在观察到的依赖深度的流量增加中发挥了作用.
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