Zoop hycos ICHNOFABRIC IN LIMESTONES OF TAIYUAN FORMATION,NORTH CHINA

Occurrence and constitution features of trace fossils in limestones of Taiyuan Formation, Upper Carboniferous, within sedimentary stratum areas, North China, are demonstrated with ichnofabric analysis method. Combined with sedimentation analysis, 5types of the ichnofabric are firstly suggested as follows:Type A-Zoop hycos being dominat, with low differentiation degree, BI(bioturbation index)=2, commonly occurred in lagoon or bay environmets; Type B-consisting mainly of Thalassinoides and Zoop hycos, being of high differentiation degree and abundance, BI=3, occurred in upper part between norm wether wave base and storm wave base; Type C-consisting of Zoop hycos, Thalassinoides, Planolites, Taenidium, Palaeop hycos and Teichichnus and so on, BI=3~4, occureed in lower part between norm weather wave base and storm wave base; Type D-consisting mainly of Zoop hycos and Chondrites, being of high abundence, but low differentiation degree, BI=5, formed near storm wave base or land-locked sedimentary environmetnts; Type E-being of strong bioturbation, BI=2~6, a few of Zoop hycos and Chondrites may be occasionally distinguished in some beds, commonly formed in limitary sedimentary environments such as estuary or environments below storm wave base.