2006(2):243-251.
DOI: 1
CSTR:
Abstract:
Abundant trace fossils including Rusophycus, Cruziana, Didymaulichnus, Diplichnites, Dimorphichnus, Beaconichnus, Monomorphichnus, Lophoctenium, Planolites, Palaeophycus, Gordia, Cochlichnus, Oldhamia, Phycodes, Bifungites, Arenicolites, Treptichnus and Rhizocorallum have been found in the Lower-Middle Cambrian Kaili Formation at Balang, Taijiang County, Guizhou Province, China. The Kaili Biota in the Kaili Formation is similar to that in the Burgess Shale (Zhao et al., 1994, 1999, 2002). There are different views on its sedimentary environments (Yang, 1994; Zhang, 1996). This paper deals with the sedimentary environments of the Kaili Formation,ichnocoenosis in it and taphonomy of the Kaili Biota.The Kaili ichnocoenosis belonging to Cruziana ichnofacies of Seilacher (1964, 1967) is composed of predominant resting, crawling, walking, swimming and feeding traces produced by arthropods (trilobite) and some dwelling burrows. Ichnological studies indicate that the Kaili Formation was deposited in open-shelf environments between daily wave base and storm wave base with normal salinity and abundant light. Varied pelagic, swimming and sessile organisms lived in the calm and aerobic environments. Epirelic and shallow endirelic traces made by different trace makers in the Kaili Formation are abundant. After organisms died, the decay and decomposition of corpses resulted in richness of organic materials and flourish of deposit-feeding organisms. Along with continual covers of deposits and decay and decomposition of corpses, reducing environments became dominant and the process of the decay and decomposition ceased.
