石油和天然气埋藏于地下。究竟应该到哪里去找它们呢? 一般人可能认为石油和天然气不像其他矿产那样,在地表常有出露的矿石或者找矿标志。其实不然,石油和天然气也常出露地表,形成所谓的油气苗。对于普查勘探新区或踏勘程度不高的地区来讲,地表油气苗仍然是找油的重要线索,具有重要的找油意义,而且有的大油苗本身就具有很大经济价值。世界上大多数油气田的发现,地表油气苗都起到了一定作用,特别是石油工业发展的初期,几乎都是在天然油气显示附近地带打钻,从而发现了油气田。地表油气苗丰富多彩,类型很多。有油泉、油河、石油沟、油砂、泥火山、沥青砂岩、沥青灰岩、沥青丘、沥青脉、沥青湖、地蜡以及各种油页岩等等。沥青丘是沥青类油苗中的一种。石油地质术语的沥青名称因地因人而异,取了许多名字,诸如地 Oil and gas are buried underground. Where should they go looking for them? Most people may think that unlike other minerals, oil and gas are often exposed in the surface ore or ore prospecting signs. In actual fact, oil and gas are often exposed surface, the formation of the so-called oil and gas Miao. For census exploration areas or exploration areas is not high, the surface oil and gas Miao Miao is still an important clues to find oil, oil has an important significance, but some big oil itself has great economic value. The discovery of most oil and gas fields in the world has played a role in surface gas and oil and gas fields. In the early days of the petroleum industry, oil and gas fields were found almost always in the vicinity of the natural gas and oil fields. Surface oil and gas seedlings rich and varied, many types. There are oil springs, oil rivers, petroleum ditch, oil sands, mud volcanoes, asphaltic sandstone, asphalt limestone, asphalt mound, asphalt veins, asphalt lake, wax and all kinds of oil shale and so on. Asphalt mound is a type of asphalt oil miner. Pitch names for petroleum geology terms vary from person to person and take many names, such as ground