calcareous

The more recent calcareous, or calcium carbonate, deposits that make up the tufa formations are closer to the bottom and lighter in color..钙质或碳酸钙越近现代，所构成凝灰岩地层的沉积物越靠近底部，颜色也比较浅。

If critters were able to control pH at their calcification sites by buffering the acid in the surrounding water, as the calcareous green algae did, they also fared better..如果这些海洋生物象富含钙质的绿藻那样，能够通过缓解周围水中的酸性来控制钙化部位的pH值，它们也可能会应对得更好一些。

The calcareous white stones of the river Piave constitute this land..皮亚韦河钙质的白色石头构成了这片土地。

calcareous soil,石灰土