当浅水区的蓝细菌和其它微生物生长的时候，一些沉积物沉积在上面，它们结合在一起形成岩石一样的小石塔和石丘，最后逐渐形成层状叠层石。

Cyanobacteria and other microorganisms build stromatolites in shallow water as they grow, gradually trapping and binding sediments into the small rock-like towers and mounds.

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而化石沉积物中特有的层状构造，则显示沉积泥沙的水流不再往北，而改向东流。

And distinctive layered patterns in the fossilized sediments indicated that the water that deposited them was no longer flowing north; instead it flowed eastward.

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