Preliminary Study on Vascular Plant Flora in Seashell Islands Nature Reserve of the Yellow River Delta

The Characteristics of Microelements Content and Forms of Seashell Islands in Yellow River Delta

Based on the analysis of TOC,CaCO3,δ13Corg,δ18O,δ13C of shell bar sediments in the Qaidam basin and the comparison with grain size,the environmental change of the studied section are divided into five stages.

Based on the grain size analysis, carbonate, magnetic susceptibility measurements on the shell bar section at Qarhan Lake in Qaidam Basin, the translation and sedimentation processes of the materials have been discussed and the lake level change history is reconstructed.

The New Views on the Relations between the Development of Cheniers and the Neotectonic Movement on the West Coast of Bohai Bay;

The development scale, time span and geo-environmental information of the chenier plays a crucial role in the researches of Quaternary geology.

A set of average calibration ages,obtained from the lower part of cheniers indicate that Chenier Ⅰ along the west shoreline of Bohai Bay began to form in about 700～900 cal BP(1050-1250AD),and continued to develop until 18～19 centuries.

The transverse section of the younger cheniers (shell banks) on the west coast of Bohai Bay shows a convex morphology with its base tilting seawards.

Corresponding to four the micro-high sea-level phases, four cheniers were accumulated on Tianjin coastal plain respectively in the last 5000 years.