The Chahe copper deposit occurs in the Early Proterozoic metamorphicseries in the area of Chahe and its chalcopyrite yielded a Pb-Pb isochron age of 951±36 Ma, providing evidence for copper mineralization at the ...The Chahe copper deposit occurs in the Early Proterozoic metamorphicseries in the area of Chahe and its chalcopyrite yielded a Pb-Pb isochron age of 951±36 Ma, providing evidence for copper mineralization at the early stage of the Jinningmovement. The ore-forming material came from terrestrial clastic sediments and marinevolcanic eruption and the ores were deposited in a relatively open beach environment.The Jinning movement led to folding and metamorphism of country strata, as well asto the rebomilization and transport of copper, resulting in ore deposition in structurallyweak locations. This deposit is a volcano-sedimentary metamorphic deposit.展开更多
With the combination of historical data, field observations and satellite remotely sensed images (Landsat TM/ ETM+ and CBERS), changes in Huanghe (Yellow) River estuary since 1996 when artificial Chahe distributary wa...With the combination of historical data, field observations and satellite remotely sensed images (Landsat TM/ ETM+ and CBERS), changes in Huanghe (Yellow) River estuary since 1996 when artificial Chahe distributary was built up were studied, mainly including water and sediment discharge from the river, tides, tidal currents, suspended sediment diffusion, coastline changes and seabed development. During following six and half years (up to the end of 2002), runoff and sediment loads into the river mouth declined dramatically. At the beginning of the re-routing, abundant sediment loads from the river filled up nearshore shallow water areas so that the newborn delta prograded quickly. With rapid decrease of sediment loads transported to the estuary, the delta retrograded. In 1997, subaerial tip of the abandoned delta receded 1.5km; its annual mean recession rate was about 150 m in following years. In addition, marine dynamic condition near the artificial outlet had also changed. Under the interaction of ocean and river flow, most of incoming sediment loads deposited in the vicin- ity of the outlet. Seabed erosion occurred at the subaqueous delta front. Between 1999 and 2002, erosion thick- ness averaged at 0.3 m in the subaqueous delta of 585.5 km2.展开更多
文摘The Chahe copper deposit occurs in the Early Proterozoic metamorphicseries in the area of Chahe and its chalcopyrite yielded a Pb-Pb isochron age of 951±36 Ma, providing evidence for copper mineralization at the early stage of the Jinningmovement. The ore-forming material came from terrestrial clastic sediments and marinevolcanic eruption and the ores were deposited in a relatively open beach environment.The Jinning movement led to folding and metamorphism of country strata, as well asto the rebomilization and transport of copper, resulting in ore deposition in structurallyweak locations. This deposit is a volcano-sedimentary metamorphic deposit.
基金The work was supported by the National High-tech Research and Development Program of China (863 Program, No. AA633010-05) and key project of Natural Science Foundation of China (No. 50339050)
文摘With the combination of historical data, field observations and satellite remotely sensed images (Landsat TM/ ETM+ and CBERS), changes in Huanghe (Yellow) River estuary since 1996 when artificial Chahe distributary was built up were studied, mainly including water and sediment discharge from the river, tides, tidal currents, suspended sediment diffusion, coastline changes and seabed development. During following six and half years (up to the end of 2002), runoff and sediment loads into the river mouth declined dramatically. At the beginning of the re-routing, abundant sediment loads from the river filled up nearshore shallow water areas so that the newborn delta prograded quickly. With rapid decrease of sediment loads transported to the estuary, the delta retrograded. In 1997, subaerial tip of the abandoned delta receded 1.5km; its annual mean recession rate was about 150 m in following years. In addition, marine dynamic condition near the artificial outlet had also changed. Under the interaction of ocean and river flow, most of incoming sediment loads deposited in the vicin- ity of the outlet. Seabed erosion occurred at the subaqueous delta front. Between 1999 and 2002, erosion thick- ness averaged at 0.3 m in the subaqueous delta of 585.5 km2.
