Climate-ocean interactions in the eastern subtropical Cretaceous Atlantic: Integrating long-term and punctuated Late Aptian to Early Albian climate records from the Mazagan Plateau (DSDP Site 545)

阿普提亚晚期至阿尔卑斯早期代表了中白垩世构造、火山活动、气候和海洋浮游生物群落的重大转变，导致了气候-碳循环的一系列全球和局部扰动。这项多代理研究的目标是建立覆盖500万年时间段的东部亚热带大西洋区域(DSDP站点545)的补充气候记录。总体目标是从海洋沉积物中破译全球和地方气候特征，以解决环境和气候变化的根本驱动机制和反馈问题。我们的结果首次量化了上阿普提安的长期冷却趋势，通过使用TEX86得出的海表面温度估计，最终导致了一次“寒流”。“寒流”与碳酸盐生产者群落的变化有关。我们还发现了三个持续时间小于150ka的短期温度事件，一个加热脉冲(+4°C)和两个冷却脉冲(-2°到-2.5°C)，它们叠加在长期的冷却趋势上。我们初步将短期变暖与一次(以前未知的)超热事件联系起来，并将冷期与北大西洋深水环流的大范围重组联系起来，这可能与大洋门户的开放有关。在项目第二阶段，我们建议通过研究福克兰高原(南大西洋511站)的一个补充核心，并通过进一步调查545站观测到的短气候脉冲，来破译观测到的温度发展的全球或局部方面。

The Late Aptian to Early Albian represents a major transition in mid-Cretaceous tectonics, volcanic activity, climate and marine plankton communities, leading to a cascade of global and local perturbations of the climate-carbon cycle. The goal of this multi-proxy study is to develop complementary climate records in the eastern subtropical Atlantic region (DSDP Site 545) covering a time period of 5 million years. The overall aim is to decipher global and local climate signatures from marine sediments in order to address the underlying driving mechanisms and feedbacks of environmental and climate change. Our results quantify for the first time a long term cooling trend for the Upper Aptian that culminated in a „cold snap‟ by using TEX86-derived sea surface temperature estimates. The „cold snap‟ was associated with changes in the community of carbonate producers. We also recognize three short term temperature events with durations of less than 150 ka, a heating pulse (+4°C) and two cooling pulses (-2° to -2.5°C), which are superimposed onto the long term cooling trend. We tentatively relate short term warming to a (previously unknown) hyperthermal event, and the cooling periods to large scale re-organizations in North Atlantic deep water circulation, possibly related to the opening of oceanic gateways. In project phase two we propose to decipher the global or local aspects of the observed temperature development by studying a complimentary core from the Falkland Plateau (DSDP Site 511, South Atlantic) and by further investigation of the observed short climate pulses at Site 545.