1·The problem with ascribing all tillites to glaciation, however, is that tillite deposits are widespread in Precambrian sediments.
然而，使所有的黑土形成冰川作用的问题是，在前寒武纪沉积物中广泛分布有黑土。
2·An increasingly attractive theory holds that decreases in atmospheric carbon dioxide start the cooling trend that leads to glaciation.
一个越来越有吸引力的理论认为，大气中二氧化碳的减少引发降温趋势，这趋势导致冰川作用。
3·Eventually, Agassiz and others convinced geologists and the general public that a great continental glaciation had extended the polar ice caps far into regions that now enjoy temperate climates.
最后，阿加西和其他人说服了地质学家和普通大众，一个巨大的大陆冰川作用已经把极地冰帽延伸到了现在享受温带气候的地区。
4·Besides the Bow Valley, evidence of glaciation also appears in this image south of the lake, in the amphitheater-shaped cirque.
除了被迷你汪卡湖占据的弓河谷外，冰川作用的证据还可以在南部的圆形冰斗处找到。