本文選題：湖相沉積 + 云質(zhì)巖　； 參考：《地球科學(xué)》2017年02期

【摘要】：二連盆地阿南凹陷下白堊統(tǒng)騰格爾組發(fā)育一套湖相的富含致密油云質(zhì)巖段,包括云質(zhì)泥巖、云質(zhì)沉凝灰?guī)r和云質(zhì)砂巖,但這類云質(zhì)巖中的白云石巖石學(xué)特征及成因尚不明確.通過巖心、薄片、掃描電鏡及碳氧同位素分析,將云質(zhì)巖中的白云石分為兩類:(1)分布在紋層狀和星點(diǎn)狀云質(zhì)泥巖或云質(zhì)沉凝灰?guī)r的非平直晶面、半自形微粉晶白云石;(2)分布在塊狀云質(zhì)沉凝灰?guī)r或云質(zhì)砂巖的非平直-平直晶面、自形粉細(xì)晶白云石.兩類白云石的成因機(jī)制不同:(1)半自形微粉晶白云石具偏高的δ~(13)C_(PDB)值(平均為5.4‰),主要受產(chǎn)甲烷菌的代謝活動(dòng)影響,其δ~(18) O_(PDB)值負(fù)偏移量較小(平均為-13.0‰),計(jì)算形成溫度約50~75℃,推測(cè)為成巖早期成因白云石,Mg~(2+)離子主要來源于富火山灰的凝灰物質(zhì)大量水解.(2)自形粉細(xì)晶白云石晶體較大、晶形好,其δ~(13) C_(PDB)值偏低(0.2‰~0.7‰),受產(chǎn)甲烷菌的代謝活動(dòng)和深層有機(jī)質(zhì)熱催化共同影響,其δ~(18) O_(PDB)值較低(平均為-19.4‰),計(jì)算形成溫度約119℃,推測(cè)為成巖晚期埋藏成因白云石,Mg~(2+)離子可能與粘土礦物水解及深部流體上涌有關(guān).
[Abstract]:The lower Cretaceous Tengger formation in Erlian Basin developed a set of lacustrine dense oil-rich dolomite formations, including dolomitic mudstone, cloud-precipitated tuff and dolomite sandstone. However, the petrological characteristics and genesis of dolomite in this type of dolomite are still unclear. By means of core, thin slice, scanning electron microscope and carbon and oxygen isotope analysis, dolomite in the dolomite is divided into two types: 1) distributed on the non-straight crystal plane of laminated and starlike dolomite mudstone or cloud-precipitated tuff. The semi-automorphic micrystalline dolomite is distributed on the flat and flat crystal planes of massive cloud-precipitated tuff or cloud-like sandstone, and self-shaped silt fine-grained dolomite. The genetic mechanism of the two types of dolomite is different: 1) the semi-automorphic micro-powdered dolomite has a high 未 ~ (13) C ~ (-1) PDBs (an average of 5.4 鈥，

本文編號(hào)：1970387