Read it through once

The surface-soil of Ballarat was full of gold. This soil the miners ripped and tore and trenched and harried and disembowled, and made it yield up its immense treasure. Then they went down into the earth with deep shafts, seeking the gravelly beds of ancient rivers and brooks—and found them. They followed the courses of these streams, and gutted them, sending the gravel up in buckets to the upper world, and washing out of it its enormous deposits of gold. The next biggest of the two monster nuggets mentioned above came from an old river-channel 180 feet under ground.