Map of near-surface mineral raw materials 1 : 50 000 (KOR50) - Sands and special sands

Map of the distribution of shallow sands, including special sands. Attribute values allow an outline according to the degree of exploration in suspected, inferred and explored.本数据集为浅砂（shallow sands，含特殊砂（special sands））分布地图，其属性值可依据勘探程度划分为推测级、推断级与已勘探级三类概略等级。