Remote sensing research in biogeochemistry of the Hetai gold deposit, Guangdong Province, China
Authors: Ruisong, Xu; Yueliang, Ma
Source: International Journal of Remote Sensing, Volume 25, Number 2, 2004 , pp. 437-453(17)
Publisher: Taylor and Francis Ltd
Abstract:The vegetation has been poisoned by Au in the Hetai gold deposit region, Guangdong Province, China. The Au content in the leaves of plants is up to 269 times higher than that of the abundance, the chlorophyll content is 10-30% lower than that of the vegetation in metamorphic terrains, and 10-20% higher than that in granite terrains. The carotenoid content is 10-44% lower than the background value. The Au content in the chlorophyll is up to 97 times higher than the abundance; the Fe and Mg of the pigment is 60% and 1.4-8.6% of the abundance. The water content in leaves is 10-20% lower than the background value. The temperature of the leaf surface is 8% lower than the background value. Cells of leaves are deformed and broken. The leaf surface shows yellow or dark green spots. Spectral reflectance of the leaf surface is 5-30% higher than the background value; the spectral shape has shifted 5-15 nm to the short wavelength in the 300-800 nm band, and to the long wavelength in the 800-2500 nm band. The greyscale values of the canopy in images from Landsat Thematic (TM) and Airborne Imaging Scanner (AIS) are 10-100% higher than the background value. On Landsat TM and AIS false colour images, plants poisoned by Au display a yellow colour, which distinguishes them from background plants. According to the spectral and image features of Au biogeochemical effects, a gold deposit information system has been constructed, and thus more than 20 gold deposit target areas have been identified rapidly, economically and accurately in Northeast China, Northwest China, South China and the Qinling mountain range in China, which is covered extensively by vegetation.
Document Type: Research Article
Affiliations: Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 P.R. China
Publication date: January 1, 2004