During the 1970s and 1980s, Xie proposed and led the National geochemical mapping project and the China-Regional Geochemistry-National Reconnaissance (RGNR) Project. He also technically sponsored these programs, and initially emphasized and demonstrated by mapping the
gold mines in China's territory (see also
Gold mining in China). This RGNR project lasted for at least 24 years and scanned more than six million km2 of China's mainland surface. The useful information offered from this mega program also contributed to about 80% new
mineral discoveries within recent two
decades in China. In the 1990s, Xie also contributed to the international standardization for methodology of world geochemical mapping. Xie also further developed some new approaches of searching for buried giant
ore deposits. Xie also proposed several deep-penetrating geochemical techniques and methods. ==Academic assignments==