MoccAMeBo - Climate-driven initiation and development of cold-water coral mounds along the Moroccan Atlantic margin revealed by MeBo-cores

珊瑚礁冷水珊瑚(CWC)能够形成坚固的三维海底结构，即所谓的珊瑚丘。这些土丘由化学武器公约碎片和半深海沉积物组成，沉积了数千到数百万年。沿着摩洛哥大西洋边缘，数百个小型珊瑚丘存在于500至1000米深的水中，很少达到海底以上10-20米的高度。今天，在摩洛哥的大西洋珊瑚省(MACP)，几乎完全没有活的化学武器公约，而化石珊瑚堆积却很普遍。此外，已经表明，在摩洛哥大西洋边缘，化学武器公约的增长(因此是土丘的增长)在最后一次冰川期间最为显著，可能是由生产力的提高引发的，并随着全新世的开始而终止。然而，这些发现只涉及珊瑚丘的上部6米处，因为到目前为止还没有材料可用。在2014年春季与RV Maria S.Merian进行的MSM36探险期间，使用MARUM海底钻机MEBO在摩洛哥大西洋边缘收集了长达数十米的惊人恢复记录。因此，MACP的两个珊瑚丘可以完全深入到它们的底部。这两个人获得了“在投手丘上”的MEBO记录(达到最大。钻探深度约为47-52米)将使我们能够对摩洛哥珊瑚丘的启动和早期发展有一些实质性和详细的洞察，这一点到目前为止基本上是未知的。此外，在摩洛哥珊瑚丘之间达到最大钻探深度45米的区域恢复了一项“丘外”MEBO记录(包括两次平行钻探)，该记录将提供有关气候驱动的环境变化的独特古海洋学信息，涵盖几个冰川-间冰期周期，从而将能够测试在上一次冰川中确定的地表水生产力与化学武器公约增长之间的联系是否是MACP的一个长期特征。此外，堆外记录被放置在一个以许多掩埋的丘为标志的区域，这些掩埋的丘包括植根于不同反射器的不同世代的珊瑚丘，从而能够评估构成丘底部或一旦丘停止生长时的第一次覆盖的那些反射器的性质。总体而言，为拟议项目选择的四个MEBO岩芯提供了高质量的记录，这将显著提高我们对驱动控制MACP中化学武器的发生和发展的强迫因素的最终气候联系的理解。特别是，有了现有的完整的珊瑚丘记录，就可以讨论化学武器公约和珊瑚丘研究中的一些基本问题。

Scleractinian cold-water corals (CWC) are capable of forming substantial 3-dimensional seafloor structures, so-called coral mounds. These mounds are composed of CWC fragments and hemipelagic sediments, which deposited over thousands to millions of years. Along the Moroccan Atlantic margin, hundreds of small-sized coral mounds exist in water depths between 500 and 1000 m, which rarely reach elevations higher than 10-20 m above the seafloor. Today, living CWC are almost completely absent in this Moroccan Atlantic Coral Province (MACP) while fossil coral accumulations are widespread. Moreover, it has been shown that along the Moroccan Atlantic margin CWC growth (and thus mound accretion) was most pronounced during the last glacial, presumably triggered by enhanced productivity, and terminated with the onset of the Holocene. However, these findings just refer to the upper 6 meters of the coral mounds, as up to date no longer material was available. During expedition MSM36 with RV MARIA S. MERIAN in spring 2014, records with remarkable long recoveries of several tens of meters were collected along the Moroccan Atlantic margin with the MARUM sea floor drill rig MeBo. Thereby, two coral mounds of the MACP could be completely penetrated down to their bases. The two obtained "on-mound" MeBo records (reaching max. drilling depths of ~47-52 m) will allow to gain some substantial and detailed insight into the initiation and early development of the Moroccan coral mounds, which is essentially unknown so far. In addition, an "off-mound" MeBo record (comprising two parallel drillings) was retrieved from an area in between the Moroccan coral mounds reaching maximum drilling depths of 45 m. This record will provide unique palaeoceanographic information about climate-driven environmental changes covering several glacial-interglacial cycles, and thus, will allow to test if the link between surface water productivity and CWC growth as identified for the last glacial is a long-lasting feature in the MACP. Moreover, the off-mound record was placed in an area marked by numerous buried mounds which comprise different generations of coral mounds rooted on different reflectors, thus allowing for an assessment of the nature of those reflectors forming either the base of the mounds or the first coverage once the mounds stopped growing. Overall, the four MeBo cores selected for the proposed project offer high-quality records, which will significantly improve our understanding of the ultimate climatic link driving the forcing factors that control the occurrence and development of CWC in the MACP. In particular with the now available complete mound records some fundamental topics in CWC and coral mound research can be addressed.