The ocean redox structure and nitrogen utilization are investigated in the Holocene sapropel depositions in the Sea of Marmara, based on inorganic, organic, and isotopic analyses and grain-size distribution of the sediments of a piston core from Çınarcık Basin. Two sapropel units are identified in the core studied, the lower (main) sapropel of the early Holocene and the upper sapropel of the middle-late Holocene. Relatively high C/N ratios (10–11) and smaller δ¹³C_org values (~−26‰) in the lower Holocene sapropel unit indicate that the organic matter is mainly of terrestrial origin. Up to 5.5‰ δ¹⁵N values and Mo concentration (6.5 ppm) above crustal values in the bottom of the lower sapropel unit strongly suggest that bottom-water conditions were denitrifying and suboxic-dysoxic, suitable for the preservation and burial of the organic matter. Such bottom-water conditions were induced by water stratification that resulted from the transgression from the Aegean Sea coupled with a riverine influx from the Black Sea that provided the terrestrial organic matter. A progressive upward decrease of C/N ratios and increase of δ¹³C_org values in the upper sapropel unit might have been caused by the additional supply of organic matter of mainly marine origin and improved ventilation of the lower water, which resulted in the oxidation of the organic nitrogen pool and a decrease of δ¹⁵N values (below 3‰) under nitrate-rich conditions. Mn enrichment in the upper sapropelic sediments also supports a relatively oxidative environment.

基于无机盐，有机物和同位素分析以及Çnarcık盆地活塞芯沉积物的粒度分布，研究了马尔马拉海全新世腐烂沉积物中的海洋氧化还原结构和氮利用。在研究的岩心中确定了两个腐殖质单元，即全新世早期的下部（主要）腐殖质和中晚全新世的上部腐殖质。相对高的C / N比（10-11）和更小的δ ¹³ Ç_有机值（〜-26‰）在较低的全新世腐泥单元指示该有机物主要是陆地起源。高达5.5‰δ ¹⁵下部腐殖质单元底部的N值和高于地壳值的Mo浓度（6.5 ppm）强烈表明，底部水的条件是反硝化和亚缺氧-低氧的，适合于有机物的保存和埋葬。这种底部水条件是由爱琴海的海侵和黑海的河涌引起的水分层引起的，黑河的涌入提供了陆生有机质。C / N比和δ的增加的渐进向上减少¹³ Ç_有机上部腐泥单元的值可能已经造成的主要海洋来源和下部水的改进的通风有机物的附加供给，这导致在氧化氮池的变化和δ的降低在富含硝酸盐的条件下，N值为¹⁵ N（低于3‰）。上部腐泥沉积物中的锰富集也支持相对氧化的环境。