Abstract: Kerogens are classified into three types: the sapropel type, the humus type and the mixed type, on the basis of microscopic identification of kerogem, combined with analytical data of infrared spectra and differential thermal analyses. In the infrared spectra, kerogen of sapropel type is characterized by a high hump for the C-H group(2920cm^-1) and a low hump for the oxy-group (1700cm^-1), with a ratio between the two humps greater than 2.5. The ratio between the high and low humps for kerogen of humus type is less than 1.5. The H/C ratio of kerogen of sapropel type from elementary analysis is 1.31 and that of humps type 0.85, close to that of coal which is 0.70 The mixed type lies between the two in all respects. The spectra of differential thermal analyses are double-humped, with the temperature of the fore-hump below 400℃ and that of the aft-hump around 500℃. The ratio between the two humps and the loss of weight due to heating vary with the difference of type and maturity of kerogen. The vertical and lateral variations of geochemical and optical characteristics of kerogen of Paleogene in the Liaohe depression correspond with the changes of depositional environment. Kerogen of sapropel type is derived primarily from deposits in deep lakes. The property of the original organic matter, which is closely related to depositional environment, is one of the controlling factors that determine the type of kerogen. Kerogen in different horizons of the Liaohe depression are different in property. Kerogen of sapropel type predominates in Paleogene in the western part of the depression.

摘要： 本文以干酪根镜下鉴定为基础,结合元素、红外光谱及有机差热的分析资料,将岩石干酪根划分为腐泥、腐殖、混合三种类型。腐泥型干酪根的红外谱图特征是:反映C-H基团峰(2920cm^-1)高,含氧基团峰(1700cm^-1)低,该两峰比值大于2.5。腐殖型的上述两峰比值小于1.5。腐泥型干酪根元素分析的H/C值为1.31,腐殖型的H/C平均值为0.85,接近于煤的0.70。混合型干酪根上述特征皆介乎腐泥、腐殖二者之间。干酪根的差热图谱呈双峰形,前峰温度值多小于400℃,后峰温度值在500℃左右,前后两峰的比值及热失重值,皆随干酪根炎型及其成熟度的差异而变化。辽河拗陷下第三系干酪根的地球化学和光学特征,深水湖相沉积以腐泥型干酩根为主。干酪根类型主要控制因素之一是有机质性质,而原始有机质特点与沉积环境密切相关。