摘要
对鄂尔多斯盆地石油氯仿沥青的稀土元素地球化学特征研究表明,石油氯仿沥青的稀土元素球粒陨石标准化曲线具有三种明显不同的稀土模式,分别与幔源型花岗岩、后太古代页岩和上地壳沉积岩特征相似,反映了石油沥青与这些岩石具有某种成因联系。其中,位于基底断裂带和构造热活动相对强烈的区域的石油沥青,其稀土模式与幔源型花岗岩、后太古代页岩特征相似,显示这些沥青在运移过程中可能与深部岩石有过相互作用,抑或有深部流体物质的直接加入;在基底断裂不发育且构造稳定的区域原油沥青,其稀土模式具有与上地壳沉积岩相似的特征。由此反映了不同构造位置的原油沥青其物质成分的来源不同,尤其是沥青在运移过程中不断萃取不同深度的物质或有深部流体物质的直接加入,导致石油沥青的稀土元素地球化学特征的复杂性和多样性。
The REE geochemical features of petroleum chloroform bitumen in the Ordos Basin has been studied in this paper, and the results show that the chondrite-standardized REE curves for the bitumen is characterized by three explicit REE patterns, which are similar to those for mantle-derived granite, post-Archean shale and supracrust sedimentary rock, and indicate that the bitumen is well correlated with these rocks in terms of origin. Therefore, the REE patterns for bitumen in areas located in basement fault zones characterized by intense tectono-thermal activity are similar to those for mantle-derived granite and post-Archean shale. Also, the study shows that bitumen may interact with deep rocks, or deep fluid may be interfused into the bitumen in the process of bitumen migration; The REE patterns for bitumen is similar to those for supracrustal sedimentary rocks in areas with no basement faults but stabilized structural settings. These indicate that the origins for petroleum bitumen are different in different tectonic areas. Especially, as bitumen extracts components at different depths, and deep fluids are interfused into bitumen directly, the complexity and multiplicity of the geochemical features of REEs in the bitumen is resulted.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2007年第2期245-250,共6页
Geotectonica et Metallogenia
基金
国家重点基础研究发展计划(973)项目"多种能源矿产共存成藏(矿)机理与富集分布规律"(2003CB2146)资助
关键词
鄂尔多斯盆地
石油沥青
稀土元素
深部流体
Ordos Basin
petroleum bitumen
rare earth elements （REE）
deep fluid
