Chemistry of earliest Cretaceous bentonites

Bentonites (i.e., smectite-dominated, altered volcanic ash layers) were discovered in Berriasian to Valanginian hemipelagic (shelfal) to eupelagic (deep-sea) sediments of the...膨润土（Bentonites，即蒙脱石（smectite）占主导的蚀变火山灰层）发现于贝里阿斯阶（Berriasian）至凡兰吟阶（Valanginian）的半远洋（hemipelagic，陆架）至远洋（eupelagic，深海）沉积物的……