1957年,在秘鲁东南部马德雷德迪奥斯省的里奥马德雷德迪奥斯地区发现砂金矿。1990年,在该地区从事黄金开采的工人有5000～10000人。里奥因阿姆巴里和马尔多纳多西部地区,居民生活主要靠砂矿开采收入。该地区交通不便,所有物资供应全靠汽车运输。里奥马德雷德迪奥斯地区的砂矿为冲积型矿床,大多数砂矿的开采位于主河流之内 In 1957, placer gold was discovered in the Rio Madre de Dios region of Madre de Dios, southeastern Peru. In 1990, there were between 5,000 and 10,000 workers engaged in gold mining in the area. Rio Inamumbi and Maldonado in the western region, residents rely mainly on sand mining income. The area is inaccessible and all supplies are transported by car. The sand mines in the Rio Madre de Dios region are alluvial deposits and most of the placer mines are located within the main river