摘要
华北地台及其西缘地区奥陶纪地层广泛分布有泥晶灰岩(micrite),鲕状岩(oolith)以及生物礁、丘(bioherms)等,形成了典型的低纬度热水海域的沉积组合(Spjeldnaes,1981,p.206)。华北地台本部的笔石(穆恩之,1955),头足类(陈均远,1980),牙形刺(安太庠--见赖才根等,1982),三叶虫(Zhou and Fortey,1986)同样具有强烈的低纬度色彩。
Trilobite evidence indicates that the North China block may have been located in the tropic zone during the Ordovician (Zhou and Fortey, 1986).The North China carbonate Platform was covered by the extensive shallow sea gently deepening northeastwards in the early Ordovician (Tremadoc to Llanvirn) but southwards in the middle Ordovician (Llandeilo to middle Caradoc) (An et al., 1982: Lithologic identification of Cambrian and Ordovician in North China and their oil potentials.Oil & Gas Geol., 3).Although the peripheral facies belts have been much distroyed, they are still traceable in the present western marginal area of the platform according to incomplete data.Correlation between formations of different facies is mainly based on conodonts recently dealt with by An et al.(1983: The condonts of North China and the adjacent regions.Science Press, Beijing), Wang and Luo (1984: Late Cambrian and Ordovician conodonts from the marginal areas of the Ordos Platform, China.Bull.Nanjing Inst.Geol.& Palaeont.Acad.Sin.,8), An et al.(1985: Ordovician conodonts from Yaoxian and Fuping, Shaanxi and their stra-tigraphic significance.Acta Geol.Sin., 59), and Yu and Wang (1986: Conodonts from the Beiguoshan Formation in Longxian, Shaanxi.Acta Micropalaeont.Sin., 3).
出处
《古生物学报》
CAS
CSCD
北大核心
1989年第3期296-313,共18页
Acta Palaeontologica Sinica
