沉积学报2018，Vol.36Issue(3)：608-616,9.DOI:10.14027/j.issn.1000-0550.2018.038
白云岩成岩相与地球化学特征——以鄂尔多斯盆地中东部马家沟组马五5—马五1亚段为例
Diagenetic Facies and Its Geochemical Characteristics of Dolomite: A case study of Ma55-Ma51 Sub-Members of Majiagou Formation in central-east-ern Ordos Basin
摘要
Abstract
It is important to study on the diagenetic facies of dolomite for the restoration of its diagenetic environment. The cores and thin sections as well as the whole rock major and trace element geochemistry, O, C and Sr isotopic compositions were analyzed to study the diagenetic facies types and lithofacies of the dolomite as well as the geochem-istry of different diagenetic facies of Ma55-Ma51 sub-members of Majiagou Formation in the central-eastern Ordos Ba-sin, respectively. The results show that the diagenetic facies of dolomite of Ma55-Ma51 sub-members in central-eastern Ordos Basin mainly include the gypsum and salt dissolution, active reflow seepage dolomitization and implicit reflux seepage dolomitization diagenetic facies in a near-surface diagenetic tract, and weathering karstific breccia diagenetic facies in an epidiagenetic tract. The former dolomite samples display lowerδ18 O andδ13 C values than those of the Or-dovician seawater, higher Mn and lower Fe contents, medium-strong cathodoluminescence, higher 87 Sr/ 86 Sr ratios than the coeval seawater as well as their high Al and Ti contents may be caused by the effects of fresh water or mixed water, while the latter dolomite samples may be affected by the epigenetic coeval seawater shows relatively high Mn and significant high Fe contents, weak or non-cathodoluminescence, obvious higher 87 Sr/ 86 Sr values than those of the coeval seawater, significant high Al and Ti contents. The results implicate that theδ18 O ,δ13 C, 87 Sr/ 86 Sr, major and trace elements are the effective indicators for identifying the diagenetic facies of dolomite.关键词
鄂尔多斯盆地中东部/马五5—马五1亚段/白云岩/成岩相/地球化学特征Key words
central-eastern Ordos Basin/Ma55-Ma51 sub-members/dolomite/diagenetic facies/geochemical char-acteristics分类
天文与地球科学引用本文复制引用
李百强,王起琮,张小莉,魏巍..白云岩成岩相与地球化学特征——以鄂尔多斯盆地中东部马家沟组马五5—马五1亚段为例[J].沉积学报,2018,36(3):608-616,9.基金项目
国家科技重大专项(2017ZX05005-002-004)National Science and Technology Major Project,No.2017ZX05005-002-004 （2017ZX05005-002-004）
