Integration of Petrology with Aqueous Geochemistry in a Recent Mixing Zone, Southeastern Barbados, West Indies

晚更新世， 巴巴多斯为早期调查提供了无与伦比的环境， 碳酸盐岩的近地表成岩作用 白云岩一直是 在现代混合带的岩芯样本中发现的 巴巴多斯东南部 这些白云岩可能是近代的， 与现代水化学有关。 我们会进一步调查 这个白云岩产状与额外的岩心钻探，岩性， 地球化学和水文地球化学研究。 将有四个钻孔 在沿着迎风的东南海岸线的海崖上钻探， 在有大量大气潜水流地区 和可能较厚的混合区。 巴巴多斯东南部 提供了理想的场地来测试混合与海洋模型， 直接采样新鲜的，混合的，和正常的海洋孔隙沃茨， 与碳酸盐沉积物和岩石接触， 成岩作用 混合区模型尚未得到普遍应用 验收 因此，记录发生的情况非常重要 和地球化学的白云岩和孔隙流体的问题， 检验模型的有效性。 这将通过以下方式实现： 矿物学，岩相学，微量元素，稳定同位素，锶 同位素、流体包裹体和绝对定年技术。 在 与R. K.史托塞尔，钻孔里的孔隙沃茨 将以温度，盐度，电导率，pH值， Eh，碱度，溶解氧，溶解硫化氢，主要 微量元素和离子、饱和指数和稳定同位素 组合物的 鉴于巴巴多斯的地质/水文环境， 流体/岩石的相互作用必须 必须限制在正常海水或混合海水中 流星/海洋模型 这种综合的岩石学和 水文地球化学方法是一种综合努力， 回答关于早期神秘的过程的重要问题， 的可行性，并将直接测试每一个 这些可能的模型。

Late Pleistocene raised reef terraces on the island of Barbados provide an unparalleled setting to investigate early, near-surface diagenesis in carbonate rocks. Dolomite has been encountered in core samples from within the modern mixing zone in southeastern Barbados. This dolomite may be Recent in age and related to the modern water chemistry. We well further investigate this dolomite occurrence with additional core-drilling, lithologic, geochemical, and hydrogeochemical studies. Four boreholes will be drilled atop sea-cliffs along the windward southeastern coastline, in an area where there is significant meteoric phreatic discharge and a potentially thick mixing zone. Southeastern Barbados provides the ideal site to test the mixing versus marine models and to directly sample fresh, mixed, and normal marine pore waters in contact with carbonate sediments and rocks actively undergoing diagenesis. The mixing zone model has not received universal acceptance. It is therefore important to document the occurrence and geochemistry of the dolomite and pore fluids in question to test the validity of the model. This will be accomplished through minerologic, petrographic, trace element, stable isotope, strontium isotope, fluid inclusion, and absolute dating techniques. In collaboration with R. K. Stoessell, pore waters from the boreholes will be characterized by temperature, salinity, conductivity, pH, Eh, alkalinity, dissolved oxygen, dissolved hydrogen sulfide, major and minor elements and ions, saturation indices and stable isotopic compositions. Given the geologic/hydrologic setting of Barbados, the fluid/rock interactions responsible for dolomitization must necessarily be confined to either a normal seawater or mixed meteoric/marine model. This integrated petrologic and hydrogeochemical approach represents a comprehensive effort to answer important questions regarding the enigmatic process of early dolomitization, and will directly test the viability of each of these possible models.