一、沉積在地表的砂錫礦 我們偉大祖國的礦產資源是無限豐富的,不但在地底下埋藏着各種各樣的礦產,而在很多地表面、山谷和古河床裏,也同樣蘊藏着許多寶藏。箇舊——我國偉大的錫礦區,就是這樣,在地底下藏有多少年來尚未開採完的脈錫,在地表面,在山谷平地和平緩的山坡上,在石灰岩造成的喀斯特地形的低窪部分,到 First, the deposition of sand and tin mine on the surface Our great motherland’s mineral resources are infinitely rich, not only buried under the ground a variety of minerals, but also in many surface, valleys and ancient river bed, also contains many treasures .箇 Old - Our country’s great tin mining area, is the case, in the underground hidden for many years not yet completed mining pulse tin, on the ground surface, in the valley and gentle slopes, in the karst topography caused by limestone low-lying part, To