硒在干酪根中的两种不同赋存状态:TEM证据

对拉尔玛Se—Au矿床和渔塘坝硒矿床中干酪根的高分辨透射电镜(TEM)研究表明，两个矿床的Se在干酪根中的赋存状态是截然不同的。前者Se在干酪根中的富集可能主要以有机结合态的形式存在，主要是取代干酪根中的硫；而后者Se在干酪根中的富集主要以超微包体Se的形式吸附在干酪根中。两种不同的赋存状态可能主要取决于干酪根中硫含量的多少以及成矿时氧化还原条件的变化。研究表明，TEM是研究元素在干酪根中赋存状态的有效手段。

Different occurrence of selenium in kerogen: TEM evidence

The Laerma Se Au deposit and Yutangba Se deposit are two important deposits found recently in China. Se is closely related to the kerogen, and about75%selenium is enriched in the kerogen in the Laerma Se Au deposit and about 65.8%selenium enriched in the kerogen in the Yutangba selenium deposit. The results of the Transmission Electron Microscope (TEM) observation show that the occurrence of Se in the kerogen is completely different in the two deposits. Se occurs mainly in the form of ultramicro inclusion native Se in the Yutangba Se deposit. A lot of native selenium has been identified in samples of kerogen from the Yutangba Se deposit, which is adhered or wrapped in the sandwich, crannyor pore space of the kerogen, usually presented with the amorphous shape. However, there is no native selenium found in the kerogen from samples of the Laerma Se Au deposit. The observation of TEM and analysis of EDS suggest that selenium may be organic bonded and probably form covalent bonds with oxygen bearingradicals or combines with organism by substituting for sulfur. There are two direct factors for notion about the difference of occurrence of Se, that is sulfurcontent in the kerogen and the condition of redox. The potential significance of TEM EDS study is summarized and it is suggested that TEM EDS is a kind of effect method to study the occurrence of element in kerogen.