Ever since people had begun to catalog the strata in particular outcrops, there had been the hope that these could somehow be used to calculate geological time.
Geologist Gerard Bond noticed that some of the sediment grains were stained with iron oxide, evidence that they originated in locales where glaciers had overrun outcrops of red sandstone.
地质学家杰拉德·邦德注意到，一些沉积物颗粒被氧化铁染色，这表明它们起源于冰川覆盖红砂岩露头的地方。
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Occasional volcanic eruptions had layered minerals throughout the outcrops.