北黄海浅表层沉积物微量元素的分布及其早期成岩作用探讨

DISTRIBUTIONS OF MINOR ELEMENTS IN NEAR SURFACE SEDIMENTS IN NORTH YELLOW SEA AND THE EARLY DIAGENESIS

摘要: 探讨北黄海早期成岩过程中微量元素的分布特征及其对古环境判别指标的影响,结果显示,沉积物中微量元素分布主要受陆源碎屑控制,而早期成岩过程对这种受源岩控制的微量元素分布特征影响不大。早期成岩作用对Mn、Ni、V、Zn影响剧烈。U/Th、V/Cr比值表明古底层水环境为氧化环境,V/(V+Ni)比值揭示底层水为厌氧环境,这与V、Ni受早期成岩作用影响较大有关,其不能真实地记录古底层水的氧化还原环境。

Abstract: We discussed the distributions of minor elements in near surface sediments of the North Yellow Sea and the influence of early diagenesis on paleoenvironment proxies. The results showed that minor elements mainly came from debris. The distributions of Mn, Ni, V and Zn were also controlled by early diagenesis. Geochemical ratios, including U/Th, V/Cr and V/(V+Ni), also indicate paleoenvironment conditions for sediment. Based on previously established thresholds, U/Th and V/Cr ratios showed oxic conditions during sediment accumulation in the area. V/(V+Ni) ratios tended to indicate anoxic conditions. This may have something to do with great early diagenesis influence on V and Ni.