PRECAMBRIAN-CAMBRIAN TRANSITIONAL ACRITARCH BIOSTRATIGRAPHY OF THE YANGTZE PLATFORM

前寒武紀－寒武紀過渡的疑源類生物地層

尹磊明(LEIMING YIN)

《Collection and Research》 10期 (1997/12) Pp. 217-231

摘要

The fossil remains including microflora, seaweeds (macroalgac), vase-shaped forms, hard part-bearing fauna, etc. have been found from the Precambrian-Cambrian transition strata of the Yangtze Platform. The radiation and extinction of phytoplankton, happened in the terminal Proterozoic epock are more remarkable in evolution of Proterozoic biosphere. The Lower Cambrian microflora of the Yangtze Platform is represented by the Micrhystridium-Paracymatiosphaera-Megathrix and Skiagia-Annulum-Achaeodiscina assemblages corresponding to the small shelly Anabarites-Circotheca-Protohertizilna Zone of the Meishucun Stage and the Eoredlichia-Parabadiella trilobite Zone of the Qiongzusi Stage, respectively. The microflora near the base of the Cambrian is characterized by the Micrhystridium-Paracymatiosphaera-Megathrix assembrage which is roughly coeval with the Asteridium tornatum-Comasphaeridium velvetum biozone or East Europe. They are believed to indicate a stratigraphic level close to the Cambrian-Precambrian boundary marked by the first appearance of Phycodes pedum in eastern Newfoundland.

關鍵字

Yangtze Platform ； Precambrian-Cambrian Transition ； Acritarch biostratigraphy

並列摘要

揚子地台下寒武統的微體植物群，在Anabarites-Circotheca-Protohertizina小殼化石帶和Eoredlichia-Parabadiella三葉蟲化石帶分別是以Micrhystridium-Paracymatiosphaera-Megathrix和Skiagia-Annulum-Achaeodiscina爲代表的組合，近寒武系底部的Micrhystridium-Paracymatiosphaera-Megathrix組合與東歐的Asteridium tornatum-Comasphaeridium velvetum生物帶大體相當。它們出現的層位與紐芬蘭東部以Phycodes pedum首次出現所標明的前寒武系－寒武系界線相接近。

並列關鍵字

揚子地台 ； 前寒武－寒武紀過渡 ； 疑源類生物地層