Simulation of adsorption of gold nanoparticles carried by gas ascending from the Earth’s interior in alluvial cover of the middle–lower reaches of the Yangtze River

The adsorption onto other minerals of charged gold nanoparticles, carried by gas ascending from the Earth’s interior, is an important component of their transport and deposition in surficial cover such as alluvial, aeolian, and glacial sediments. To simulate the adsorption of these particles, an experiment was conducted in which a flow of air that contained gold nanoparticles was passed upward through a sample of alluvium from the middle–lower reaches of the Yangtze River. These experiments showed that gold nanoparticles are adsorbed on kaolinite, halloysite, goethite, and hematite in the alluvial cover. Both the gold nanoparticles and minerals (i.e., kaolinite, halloysite, goethite, and hematite) carry surface charges that provide them with excellent adsorption properties. This study showed that the specific mineral composition of surficial alluvial cover affects the concentration of gold nanoparticles in the ascending gas. This phenomenon may plausibly be used in exploration for concealed gold, copper–gold, and silver–gold deposits in areas of thick alluvial cover. Geofluids (2010) 10 , 438–446     

A note on the geomorphological environment of Çatal Hüyük, Turkey

It had previously been proposed (Cohen, 1970) that after large-scale Early Holocene alluviation, no post-occupational sediment accumulated around the neolithic site of Çatal Huyuk in south-central Anatolia. Data presented here, however, indicate that several metres of archaeological deposit at both east and west mounds are overlain by alluvium. This implies that the modern distribution of soil and water resources cannot be used directly to assess past agricultural potential in the vicinity of the site.