The Quaternary in the Qaidam Basin is an ideal site to study biogenetic gas.Based on the analysis of the forming environment of biogenetic gas and in combination with the results of modeling experiments of biogenetic gas generation

we have concluded that the generation of terrestrial biogenetic gas is under the control of various factors including temperature

bacterial group types

groundwater properties and sedimentary rates

etc.The survival temperature of bacterium which produces methane is 0-80℃

and the most favorable temperature to produce methane is 30-55℃.The peak of gas generation occurs at 35℃

which corresponds to a burial depth of 500m.The groundwater in the Quaternary of the Qaidam Basin has the characteristics of high salinity.Its salinity decreases with the increasing of depth.In addition

there are sulfate reduction zone in the shallow strata.These factors restrain the activity of methane bacteria in the shallow and surface areas

making it favorable to generate gas in the deeper strata.The rapid sedimentation buries organic matters quickly

which provide abundant organic sources for later microbial activities.