Abstract: The carbondioxide gas fields are a kind of high economic nonhydrocarbon ones. It is very important to research origin of carbondioxide gas fields in theory and practice on exploration and development and utilization. The carbondioxide gas fields in Jiyang basin are researched in detail on the analysis of origin, geological conditions and tectonic background in this paper. On the basis of gas ingredients and carbon isotopes, the carbondioxide gas in Jiyang basin is from mantlevolcanic magma. According to the locations of carbondioxide gas fields, volcanics and faults, the carbondioxide gas fields are closely relative to the Middle and Late Neozoic volcanoes. The NW Shicun fault is the regional transporting path of carbondioxide gas. NE and nearly EW faults control the local reservoir structures. The Tanlu fault zone to the east of Jiyang basin may be the source of mantle magma with carbondioxide gas on the basis of tectonic background.

Key words: Jiyang basin, carbondioxide, volcanoes and faults, mantle-volcanic magma

摘要： 二氧化碳气田是具有很高经济价值的飞烃类天然气田，弄清其成因成藏规律，对进行勘探开发及综合利用具有重要的理论和实践意义。通过成因、地质条件及成藏的大地构造背景分析对济阳坳陷二氧化碳气田进行详细研究。根据二氧化碳气田气体组分和碳同位素分析，认为济阳坳陷二氧化碳气的成因为幔源-火山岩浆型。根据二氧化碳气田的分布，对比火山岩和断裂的时空分布，认为本区二氧化碳气与新生代中晚期的火山岩浆活动密切相关，北西向石村断裂为二氧化碳气的区域性运移通道，北东向和近东西向断裂为局部控藏构造。从大地构造背景分析，济阳坳陷东侧的郯庐断裂带可能是本区携带幔源二氧化碳的岩浆源区。

关键词: 济阳坳陷, 二氧化碳, 火山和断裂, 幔源-火山岩浆型