placer deposits

例句：

1. 1. The placer deposits are rich in gold and silver.
   这些矿床富含黄金和白银。
2. 2.Mining is a major industry in this region, with placer deposits being the main source of wealth.
   这个地区是矿业的主要地区，矿床是财富的主要来源。
3. 3.The discovery of new placer deposits has sparked interest in alternative energy sources.
   新矿床的发现激发了对替代能源的兴趣。