The prospectors in the field obtain their information in many ways. The panning of samples of river gravel, even the color or taste of water, may lead to a mineral lode upstreams.

• 野外的勘探人员有许多办法来获取这些资料。淘洗河沙样品，甚至于水的颜色或水的味道，都可能预示着上游的矿脉。