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新疆克拉玛依乌尔禾沥青脉产出于达尔布特断裂东南侧.沥青的Ph.Sr,Nd同位素组成表明:(1)~(206)Pb/~(204)Pb=18.110～18.675,~(207)Pb/~(204)Pb=15.391～15.768,具有明显壳幔混合特征,Pb平均模式年龄为116Ma;(2)~(87)Sr/~(86)Sr=0.706 426～0.714 761,Rb-Sr等时线年龄为293 Ma,Sr同位素初始值为0.705 70±9;(3)~(143)Nd/~(144)Nd=0.512 587～0.513 389,Nd含量从0.02到6.7×10~(-6),低Nd含量的样品(<0.3×10~(-6))具有近MORB的亏损地幔值(+6～+16),而较高Nd含量的样品近于原始地幔值(-0.8～+0.8);Rb-Sr等时线记录了石油形成的时间,可能表明了与深部壳幔相互作用的成因关系;(4)_(ε_(Nd))(t)～ε_(Sr)(t)关系、~(143)Nd/~(144)Nd-~(206)Pb/~(204)Pb关系均反映了三元混合趋势.
The asphalt veins of the Karamay Urho in Xinjiang are derived from the southeastern side of the Dalbot fault.The Ph.Sr and Nd isotopic composition of the bitumen shows that the Pb isotopic compositions of (1) ~ (206) Pb / ~ (204) Pb = 18.110 ~ 18.675 ~ ) Pb / ~ (204) Pb = 15.391 ~ 15.768, with obvious crust-mantle mixing characteristics. The average age of Pb is 116Ma; (2) ~ (87) Sr / ~ (86) Sr = 0.706 426 ~ 0.714 761, The Sr isochron age is 293 Ma, and the Sr isotope initial value is 0.705 70 ± 9; (3) ~ (143) Nd / ~ (144) Nd = 0.512 587 ~ 0.513 389, Nd content is from 0.02 to 6.7 × 10 ~ -6). The sample with low Nd content (<0.3 × 10 -6) has a depleted mantle value (+ 6 ~ + 16) near MORB, while the sample with higher Nd content is near the original mantle value (-0.8 ~ + 0.8). The Rb-Sr isochronal line records the time of oil formation, which may indicate the genetic relationship with the deep crust-mantle interaction. (4) _ (ε Nd) (t) ~ ε Sr The relationship of ~ (143) Nd / ~ (144) Nd ~ (206) Pb / ~ (204) Pb reflects the ternary mixing trend.