Gulf of Corinth IODP Exp 381 Sediment supply rate variations

裂谷盆地的演化过程主要是断裂下陷侧的沉降和裂谷两侧的隆升。因此，随着时间的推移，周围景观中的斜坡会随着与裂谷有关的地形的变化而变化，但也会随着时间的推移而发生侵蚀。坡度越高（地势越高），在任何给定的气候条件下，相关的侵蚀速率就越高。因此，向盆地提供沉积物的速率提供了裂谷构造在活动裂谷一生中演变的记录。沉积物的供应还与裂谷内的构造沉降速率以及随着时间的推移海平面（或湖泊）的波动相互作用，以确定盆地是沉积物不足，还是逐渐被沉积物填满，最终被沉积物填满。科林斯裂谷目前处于未充填料状态，水深超过800米，但考虑到给定的构造沉降速率（取决于沉积物输入盆地的短期速率），可能存在优先充填料期和盆地加深期。裂谷盆地相关沉积几何形状的预测是油气勘探的一个重要方面，因此更好地了解这些过程可以减少商业勘探工作中的不确定性。研究一个年轻而活跃的海相大陆裂谷系统（世界上只有少数）意味着我们可以使用各种绝对和相对定年方法准确地确定沉积物的年代。在过去的几个冰河时期，我们也已经对海平面变化和地中海东部地区的古气候变化有了准确的记录和了解。这意味着381号考察队的新岩心将能够详细量化过去几十万年来沉积速率的变化。这将使我们第一次确定在这段时间内沉积物侵蚀速率和向裂谷输送的变化幅度，以及这些沉积速率的变化与短期气候波动的关系，这些气候波动的时间跨度只有几千年到几万年。这将有助于我们理解未来气候变化如何影响沉积物在更大范围的沉积盆地中从陆上向海上转移。

Rift basins evolve through subsidence on the downthrown side of faults and uplift of the rift flanks, on the upthrown side of the main rift faults. As a result, slopes in the surrounding landscape evolve through time in response to growing rift-related topography, but in competition with erosion that also occurs through time. The higher the slope angles (the higher the relief), the higher are the associated rates of erosion for any given climatic setting. Rates of sediment supply to the basin therefore provide a record of rift structural evolution over the life of an active rift. Sediment supply also interacts with rates of tectonic subsidence within the rift, and with any fluctuations in sea (or lake) level through time, to determine whether the basin is underfilled with sediment or alternatively gets progressively filled and ultimately overfilled with sediment. The Corinth Rift is currently underfilled, with water depths in excess of 800m, but there may have been periods of preferential infilling and other periods of basin deepening, for given tectonic subsidence rates, depending on the shorter-term rates of sediment input to the basin. The prediction of associated sedimentary geometries within rift basins is an important aspect of hydrocarbon exploration and so a better understanding of these processes could reduce uncertainties in commercial exploration efforts.Studying a young and active marine continental rift system (of which there are only few in the world) means that we can date the sediments accurately, using a variety of absolute and relative dating methods. Over the last several ice ages, we also already have an accurate record and understanding of sea level changes and of palaeoclimate changes in the eastern Mediterranean region. This means that the new cores from Expedition 381 will allow detailed quantification of variations in sedimentation rates over the last few hundreds of thousands of years. This will allow us to establish for the first time the magnitude of variations in sediment erosion rates and transport into the rift during this interval, and how these variations in sedimentation rates relate to short-term climate fluctuations, over time periods of only thousands to tens of thousands of years. This will aid our understanding of how future changes in climate may impact upon sediment transfer from the onshore landscape to the offshore in a wider range of sedimentary basins.