Chinese scientists have successfully drawn a national geochemistry map showing the distribution of 39 naturally-occurring chemical elements and oxides including gold, silver, copper and lead. The map, which took three years to complete, indicates the natural distribution of these chemical elements in China. On May 23, the map was appraised by the China Geological Survey (CGS).

In 1978, China started on a nation-wide geochemistry survey. Over the course of 30 years, the survey, covering a total area of 6.5 million square kilometers in 28 provinces, regions and municipalities, analyzed 1.42 million chemical samples and tested 39 chemical elements, retrieving 55.4 million pieces of original data. In 2001, the Research and Development Center of the CGS compiled the data collected and set up a database to support regional geochemistry surveys.

The survey found 2,900 natural mines and over 700 metalliferous deposits including gold, silver, copper, lead, zinc, stannum, tungsten and molybdenum. Among them, over 70 are middle-sized to large deposits, providing abundant resources for economic construction.

According to Meng Xianlai, director of the CGS, the geochemistry map displays features and rules of geochemistry reflected in different geological backgrounds, and indicates the distribution features and rules of China's hydrographic deposits and the geochemistry figure of elements of earth's crust. The map provides important information that can be used for research on the structure of stratum and magnetic rock.

The map also reveals that these elements do not occur in isolation. The distribution of nitrogen, phosphor, kalium, boron and manganese, and harmful elements such as cadmium, mercury, lead and arsenic is also indicated on the map. This is of great significance to environmental protection efforts.

(China.org.cn by Wang Qian, May 29, 2005)