Where is the missing lake?
It is hard to imagine not long ago, Taipei, as it is nowadays flourishing and thriving, comprised miles of vast farmland, and even earlier, a lake. From the characteristics of sedimentary strata, we are informed that the lake used to cover almost the entire Taipei Basin. Zhishanyan and Yuanshan were once islands in the lake.
The grain size and type of sediments deliver many useful messages, including the sources and the sedimentary environment. A considerable amount of oysters and other hyposaline fossils found distributed in strata of 6,000 to 10,000 years old thus serves as a perfect testament that Taipei Basin was once a lake!