Dark solid bitumen associated with silicified wood and carbon scraps or coal string was found in many places in continental Jurassic basins in thewestern Hubei province.For a long time

people took it for“coal”or“seepage”.Through surveying and research of the solid bitumen in Zigui

Dangyang basins

it was identified that it belongs to the derivative from humic typeof solid and liguid hydrocarbons.It can be called coal bitumen

because it soccurrence

distribution

organic component and stnucture all show a geneticre lationship with coal and humic type of source bed.Study of the humic type of coal bitumen indicates that the oil could be“generated”indeed during the process of incoalation.However

the liguid hydrocarbon of humic type and its derivative are a kind of heavy and vis-cous fluid characterized by high content of non-hydrocarbons and aromatichydrocarbons

which is difficult to move through a long distance

and unfa-vourable for accumlation of hydrocarbon.Therefore

its distribution is inscareity.Furthermore

its“oil-generated amount”is limited too

and it isnot suitable in our practical works to consider all sorts of the solid bitumenas sapropelic type of petroleum bitumen

and it is necessary to here solidbitumen to be genetically classified in order to give a correct assessment.