Title: THE MIDDLE JURASSIC TO EARLY CRETACEOUS DINOFLAGELLATE ASSEMBLAGE SEQUENCE FROM EASTERN HEILONGJIANG
Abstract: Marine Jurassic to Cretaceous strata in China, except Taiwan and the vast areas of SW China including Qinghai-Xizang (Tibet) Plateau and the western Tarim Basin, are only distributed in eastern Heilongjiang and contain rich bivalve and dinoflagellate fossils. They consists of the following five formations, in ascending order: the Callovian Suibin, Late Jurassic—Valanginian Dongrong, Early Cretaceous Didao, Chengzihe and Muling Formations. According to previously published data, seven dinoflagellate assemblage zones are proposed and described for the Middle Jurassic (Callovian) to Early Cretaceous (Berriasian—Barremian) sediments from subsurface and outcrop sections in the area. Middle to Late Jurassic strata are restricted only to the Suibin area of eastern Heilongjiang and contain three assemblage zones, in ascending order as Middle to Late Callovian Pareodinia ceratophora-Nannoceratopsis pellucida developed in the Suibin Formation, Late Oxfordian to Early Kimmeridgian Gonyaulacysta jurassica (peak zone) taken from the lower part of the Dongrong Formation, and Tithonian Amphorula delicata from the upper part of the Dongrong Formation; Early Cretaceous sediments developed largely in Jixi Basin of eastern Heilongjiang include four assemblage zones: Berriasian to Valanginian marine Oligosphaeridium pulcherrimum (peak zone) occurring only in the uppermost part of the Dongrong Formation of the Suibin area, or contemporary slightly brackish to brackish Vesperopsis didaoensis-Lagenorhytis granorugosa distributed in the Didao Formation of the Jixi Basin, Late Hauterivian Odontochitina operculata-Muderongia tetracantha recovered from the lower part of the Chengzihe Formation, Middle Barremian Canningia reticulata from the upper part of the Chengzihe Formation, and Late Barremian Cribroperidinium? parorthoceras peak zone from the lower part of the Muling Formation. Among them, Odontochitina operculata-Muderongia tetracantha zone is subdivided into two subzones. This is the first complete dinoflagellate zonation scheme for the Callovian to Barremian in eastern Heilongjiang, but the sequence of dinoflagellate zones (Table 1) is less continuous and preliminary because the Early Cretaceous sequence is interrupted by non-marine intervals. Ages of zones are based mainly on the first appearance or latest occurrence or the high abundance of dinoflagellate taxa and comparisons with some European dinoflagellate assemblages, with some additional control being provided by the associated bivalves, but without ammonite zonal control because the collected ammonites are poorly preserved and difficultly identified, of which, the ages of Upper Jurassic zones are in complete accord with those of bivalve Buchia zones proposed by Chen Jin-hua Huang Guan-jun (1992).
Publication Year: 2003
Publication Date: 2003-01-01
Language: en
Type: article
Access and Citation
Cited By Count: 4
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot