Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 73, No. 1, 1999

On the Age of the Xigeda Formation in Luding, Sichuan, and Its Neotectonic Significance Speculations of the Early Cretaceous Yarlung Zangbo Palaeoophiolite in Southern Tibet Tectonic Evolution of the Hefel Basin and Analysis of Its Petroleum Potential Geochemical and Nd and Sr Isotopic Compositions of 3.8 Ga Trondhjemitic Rocks from the Anshaa Area and their Significance Quantitative Simulation of Formation of the Rhythmic Layering in Layered Intrusions– A Case Study of the Panzhihua Layered Intrusion, Sichuan Comparison between Palaeozoic and Cenozoic Lithospheric Mantle in the Eastern Part of the North China Block — With a Discussion of Mantle Evolution Possible Contribution of Magmatic Fluids to Sea-floor Ore-forming Hydrothermal System in the Okinawa Trough Comparative Experiments on Gold Enrichment and Mineralization by Bacteria and Algae, Organic Material and Clay Minerals Temporal and Spatial Distribution and Evolution of Ore Deposits in the West Sector of the Northern Qilian Mountains Controls of the Topography, Climate and Lake Level Fluctuation On the Depositional Environment of a Shallow-Water Delta—A Case Study of the Cretaceous Putaohua Reservoir in the Northern Part of Songliao Basin