STUDY ON Au BIOGEOCHEMICAL EFFECTS USING REMOTE SENSING 
TECHNIQUE IN WESTERN GUANGDONG AND HAINAN PROVINCE, CHINA 
Xu Ruisong, Lu Huiping, Ye Suqun, Ma Yueliang 
Guangzhou New Technical Institute of Geology, Chinese Academy of Sciences 
P.O. Box 1131, Guangzhou, China, 510640 Fax: 008620-5516932 
ABSTRACT 
It is found that the Vegetations have been poisoned by Au in the Au deposits of Guangdong and Hainan province, 
China. This can be evidenced by the following facts: Au contents in leaves are 10-2000 times higher than its 
vegetable abundence, chlorophyll is 10-30% lower than that of vegetation grown in metamorphic rock, and 10- 
20% higher than that in granite; carotenoid is 10-44% lower than the background value; moisture of leaves is 
10-20% lower than the normal value; the temperature of leaves surface is 2-3'C lower than that of the normal 
leaves; the cell of leaves are abnormal and broken; the leaf color becomes into yellow or dark green. As a 
result, there are some abnormalism in spectral reflection feature. For example, the spectral reflectance of 
leaves surface is 5-30% higher than the background value and the spectral wave shape moves toward to short 
weve by 5-15nm. The image gray level of Landsat TM and Airborn Imaging Scanner (AIS) is 10-100% higher 
than background value. The color of gold deposit is quite different from background color in TM and AIS 
false color image. Using the results discribed above, the gold resource information system and detecting experts 
system have been set up and two gold deposits and two gold minerlization zones are found quickly, economicly 
and accurately in area covered with vegetation in Western Guangdong and Hainan province, China. 
Key words: Guangdong and Hainan province of China; Gold deposit; Remote sensing of Au biogeochemical effects. 
  
PREFACE 
Western Guangdong and Hainan province of China are 
located in the tropics and subtropics covered with the 
tropical rain forest and subtropical secondary forest. 
The covered ratio of vegetation is larger than 28% and 
that in study area is high up to 50-90%. It is very 
difficult to search for the mineral resources with high 
covered ratio of vegetation and sharp and high 
mountain. The gold deposit occurred in broken and 
altered belt is the main type in Western Guangdong and 
Hainan province. It is commonly developped in the 
contact | aureole between argillaceous, carbonaceous 
sedimentary rocks and reutral acid magmatic rocks 
located on the side of fold axis and abyssal fault. The 
altered belt is paralled to the fault. The altered belt is 
a few metre to a few kilometre in width. Au is usually 
associated with Ag, Cu, Pb, Zn, As, B, Sb etc. The 
broken and altered belts are rich in water which is 
favorable for the vegetations growing. The aim of this 
paper is to propose a good way for mineral resource 
exploration under the vegetation—covered area. 
1. ECOLOGICAL AND PHYSIOLOGICAL 
CHARACTERISTICS OF VEGETATIONS CAUSED BY 
Au BIOGEOCHEMICAL EFFECTS 
62 
"The authors found the following ecological and 
physiological characteristics of the vegetations caused by 
Au and its associated elements biogeochemical effects in 
Western Guangdong and Hainan province, China. 
(1) Leaves of plant has curned into small, displaying 
a few yellow spots on leaf surface. The leaves of Pinus 
massoniana changes to dark green; 
(2) Cell structure shape of leaves has been changed 
even broken; 
(3) Enrichment index of elements in plant leaves is: 
Au» Ag » Mn » Cu, Pb, Zn. Those of Au, Ag, Mn 
are larger than 1, but those of Cu, Pb, Zn less than 
1. That of Au is as high as 1961 (Table 1,2) ; 
(4) Chlorophyll is 10-30% lower than that of 
vegetation grown in metamorphic rock and 10-70% 
higher than that in granite, cartenoid is 10-44% lower 
than background value. The content of water in leaves 
is 10-20% lower than the normal value. The temperature 
of leaves surface is 2-3°C lower than background value 
(Table 1) . 
Tal