Gulf of Corinth IODP Expedition 381 Inorganic Geochemistry

在最后一个冰河时期，科林斯湾经历了从湖泊到海湾的反复变化，以应对海平面的波动。这种剧烈的环境变化将强烈影响科林斯湾的生态系统，以及碳和磷等生物必需元素的循环。在类似的情况下，湖泊被洪水淹没并因海水入侵而逐渐盐碱化，例如上一个冰河时代结束时的黑海或波罗的海，水体中形成了非常独特的地球化学机制，对化学性质产生了强烈的影响。水柱：顶部的新鲜湖水和底部的咸水之间形成了稳定的分层，这限制了水柱的混合。沃茨。结果，深水沃茨变得完全没有氧气，因此不适合多细胞生命--甚至由于产生硫化氢而有毒。目前尚不清楚科林斯湾是否经历了类似的剧烈环境变化和无氧深水团的发展。如果是这样的话，这将对沉积物中有机碳的保存产生重要影响--沉积物是我们现代石油和天然气资源的原材料--因为有机物质在缺氧条件下降解得少得多。我们的地球化学方法将使我们第一次能够跟踪科林斯湾几个代表性的湖泊到海洋和海洋到湖泊过渡中水柱和沉积物化学的变化。

The Gulf of Corinth has experienced repeated changes from a lake to a marine embayment in response to sea level fluctuations during the last ice ages. Such dramatic environmental changes will have strongly affected the ecosystem in the Gulf of Corinth, and with it the cycling of bioessential elements like carbon and phosphorus. In similar situations where a lake was flooded and gradually salinified by the incursion of seawater, like in the Black Sea or Baltic Sea at the end of the last ice age, very distinct geochemical regimes developed in the water column that had strong impacts on the chemistry of the water column: A stable stratification developed between fresh lake waters on top and saline seawater below, and this restricted mixing of the water column. As a result, the deep waters became completely free of oxygen, and thus inhospitable to multi-cellular life - even poisonous due to the production of hydrogen sulphide. It is currently unknown if the Gulf of Corinth experienced similarly dramatic environmental changes and the development of an oxygen-free deep water mass. If so, this would have had important implications for the preservation of organic carbon in the sediments - the raw material for our modern oil and gas resources - as organic matter is much less degraded under oxygen-depriven conditions. Our geochemical methods will allow usfor the first time, to track changes in water column and sediment chemistry across a couple of representative lake-to-ocean and ocean-to-lake transitions in the Gulf of Corinth.