摘要
沥青、自然铜常常与石英出露于杏仁状玄武岩暗色团块的矿物颗粒间或间隙中。自然铜的晶出是在成矿热液中的有机质几乎裂解为沥青和天然气之后。自然铜与沥青的产出互为负相关关系,即暗色团块中的沥青或沥青与石英越发育,沥青中的自然铜含量越低,其附近或周围的自然铜与石英也越发育,但这两者晶出的时间与空间间隔极短,它们之间形成的先后关系依次为:石英→沥青→自然铜。沥青的碳同位素、化学组成及红外光谱测试表明,暗色团块及裂隙石英脉中玄武岩捕虏体中的沥青是生物成因的石油沥青。包裹体测温与拉曼分析给出,成矿热液中的有机质需在较高温度下(>350℃)才能裂解为沥青与天然气(CH4),成矿热液温度越高,有机质成熟度就越高,沥青中的有机碳含量也越高,残存在沥青中的自然铜含量就越低。
Bitumen, natural copper and quartz generally occur in the interstitial site of mineral grains in dark mass in amygdaloidal basalt from Puge County, southern Sichuan. Natural copper formed after the decomposition of organic matter into bitumen and gases. The authors detected that the content of bitumen and that of natural copper exhibit negative correlation. In the dark clumps, the higher the bitumen and quartz, the lower the copper, but the higher the natural copper and quartz in nearby places, and the interval of crystallization time and space between natural copper and bitumen is very short. The commonly recognized sequence is quartz →bitumen→ native copper. The carbon isotope and infrared spectrum suggest that bitumen is of biogenesis and originated from the carbonate rocks in Permian strata. The results from the homogenization temperature of inclusions in quartz and Raman spectrum indicate that the organic matter in the hydrothermal fluids can be decomposed into bitumen and natural gas （CH4） under the temperature 〉350℃; the higher the temperature, the higher the maturity of organic matter, the higher the content of organic carbon in bitumen, the lower the natural copper content in residual bitumen.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2017年第6期925-932,共8页
Acta Petrologica et Mineralogica
基金
国家自然科学基金项目(41562003
41172054)~~
关键词
杏仁状玄武岩
暗色团块
沥青和自然铜
川南普格
amygdaloidal basalt
dark mass
bitumem and natural copper
Puge County, southern Sichuan
