The Effect of Oxidation-Reduction Nature of Depositional Environments on the Formation of Diasteranes
- Received Date: 1996-01-08
- Publish Date: 1997-12-10
-
Key words:
- diasteranes /
- depositional environment /
- oxidation-reduction nature /
- maturity /
- clay min-erals
Abstract: The GC /MS analyses for alkanes from Late Jurassic source rocks of the Liudong depression, KailuBasin, northeastern China showed that the concentration of diasteranes in some samples decreasesanomalously with depth, suggesting that in this case the formation of these compounds may be not de-pended on maturity.On the other hand, there is not an obvious relationship between the content of di-asteranes and the composition of clay minerals in rocks,indicating that the acid catalytic nature of differ-ent clay minerals is similar.It is found that the formation of diasterane is related to the oxidation-reduc-tion nature of depositional environment.The anoxic and high reducing deposits(Pr /Ph < 0.5) may lead tosuppress the acid catalyzed rearrangement process of sterene formed early during diagenesis.So, thesesediments contain a low content of diasteranes.Conversely, when the depositional condition becomes lessanoxic and oxic, with an increase in Pr /Ph, the concentration of diasteranens increases significantly.Itseems that the oxicity of sediments during diagenesis may be responsible for the formation of diaster-anes.
Citation: | Zhu Yangming, Zhang Chunming, Zhang Ming, Mei Bowen, Jin Diwei, Xao Qinanhua. The Effect of Oxidation-Reduction Nature of Depositional Environments on the Formation of Diasteranes[J]. Acta Sedimentologica Sinica, 1997, 15(4): 103-108. |