| Molecular fossil is the moleculars existing in geological environment origin from variety oforganisms. These moleculars are stable in chemical property, and they can almost keep theiroriginal carbon chains although influenced by geological actions. So they can provide accurateinformation about environment change, and play an important role in environment study. A peatsample 48cm below moss hommock was researched as the investigated target in this thesis. Theauthor then select such moleculars as n alkane, n alkanol, ketone, ash, hygroscopic and humicacid to disclose the relationship between organic biomakers and environment change as well as tofind out organic moleculars with environment significance. After analyzing the experimental dataand comparing the study of this area, conclusions have been drawn as follow:1.The n alkanes in the samples are dominated by long chains, with a maximum abundance atC25, C27 and C29, but C25was not found in every sample. And the distribution of most alkanesis consistent with the vegetation of this area.2.According to the relationship between biomarkers and vegetation, the precipitation inJinchuan increased from 1711 A.D to 1752 A.D and 1509A.D to 1549 A.D. Furthermore,submerged plant and floating plants constituted the main species of the peatland at that time,and the ashes increased greatly in the second period.3.Between 1833A.D and 1874A.D, JinChuan Peatland evoluted from eutrophic fen tooligotropuic swamp with the maximum biomass.4.The content of phthalic acid esters decreased with the depth, which showed that the peatlandwas polluted with the development of industry.5. Furthermore, the result proved that n alkane C23 is molecular fossil related to climate factorsespecially the temperature.
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