2007: Xie Xuejing

 The AAG awarded the Gold Medal to Prof. Xie Xuejing at the 23rd International Geochemical Exploration Symposium banquet in Oviedo, Spain (June 2007). 

Gold Medal Xie Xuejing

Prof. Xie Xuejing - September 28, 2006 (photo taken by Bob Eppinger)

Citation given by Rob Bowell on June 2007 in Oviedo, Spain

Professor Xie is truly the father of exploration geochemistry in China. He conducted the first geochemical exploration in that country in 1951 in Anhui Province with the systematic sampling and chemical analysis of rocks, soils, and stream sediments in the search for copper mineralization. He has also been instrumental in developing techniques to aid in the search for buried ore deposits. This began in the late 1950s with the study of element zonation in primary halos during which he developed methods that were widely applied in China. These methods successfully identified extensions to some known deposits. For example, the Qingchengzi lead-zinc deposit in Liaoning Province, northeastern China, was discovered in the 1940s and closed in the 1960s. Prof. Xie and his colleagues identified a large new ore body at depth and the mine is once again in operation. This discovery is described in Chinese-language textbooks on geochemical exploration. His work on exploration for concealed deposits has continued with his supervision of the more recent development of two techniques that have been used for wide-spaced geochemical mapping in concealed terrains. One method, called Nanoscale Metals in EarthGas (NAMEG), involves the analysis of soil gases collected onto polyurethane foam. The second method, called Mobile Forms of Metals in Overburden (MOMEO), involves sequential extractions of overburden material to look at 1) ions from water-soluble salts, 2) metals sorbed on clay minerals, 3) metals bound to organic matter, and 4) metals absorbed by oxides.

One of Prof. Xie's most remarkable achievements has been his planning and technical supervision of China's Regional Geochemistry National Reconnaissance (RGNR) Project. Over the past 28 years, this national-scale geochemical mapping effort has covered more than six million square kilometres of China. About six million samples (primarily stream sediments) have been collected throughout the country and approximately 1.5 million composite samples analyzed. His work has led to China's having the most remarkable national-scale geochemical database in the world. According to statistics from the former Ministry of Geology and Mineral Resources, 517 mineral deposits have been discovered as a direct result of follow-up studies of anomalies identified by the RGNR Project. The most exciting of these are perhaps two world-class gold deposits (each containing gold reserves in excess of 500 metric tons). One occurs in the greenstone belt located at Xiaoqinling near the border between Henan and Shanxi provinces. The other is the Lannigou gold deposit, which occurs in the carbonate terrain of Guizhou Province, southwestern China. This region has become the second largest province for Carlin-type deposits in the world (next only to those near Carlin, Nevada, USA). As a leader in national-scale geochemical mapping, Prof. Xie played an important role in establishing the protocols for geochemical mapping at the global scale as a member of the steering board for the International Geological Correlation Program's Project 259 (International Geochemical Mapping). He continues to be an active member of the International Union of Geological Sciences Working Group on Global Geochemical Baselines.

Prof. Xie received one of the highest scientific honours in China when, in 1980, he was elected as a member of Academica Sinica. He is an adjunct Professor at both Changchun Geological College in Jilin Province and at Beijing University. As such, he has mentored seventeen Master's and PhD students who are currently taking on leadership roles in both geochemical exploration and environmental geochemistry in China.

Prof. Xie Xuejing please accept the Gold Medal Award of the Association of Applied Geochemists in recognition for your achievements in the field of applied geochemistry over a remarkable career that exceeds 55 years and is still going strong.


Acceptance speech by Prof. Xie

Dear Mr. President and Colleagues,

I feel deeply honoured today, to receive this Gold Medal from the Association of Applied Geochemists. The medal is a great honour for me, and not only for me. It is also an honour for those colleagues and students in China, who have worked with me in geochemical mapping for more than 30 years. I am also thankful to my colleagues all over the world for their acknowledgement of China's contributions in the field of geochemical mapping, from the regional to the global level.

In the 21st century, applied geochemistry will continue its development as an indispensable tool in solving crucial problems that confront humanity, in finding new resources and in remedying environmental degradation. It is my belief that geochemical mapping, from regional to global, will be increasingly fundamental in meeting these challenges.

In so many of the earth sciences—geography, geology, pedology, hydrology, oceanography, meteorology and others besides—multi-level spatial mapping is vital. But there is one striking hold-out: geochemical mapping has not been closely correlated with the modern PURE geochemistry as founded by Clarke and Goldschmidt. Geochemical mapping arose mainly as a result of the activities of exploration geochemists.

In April of this year, I was in Guilin to attend the symposium on eco-geochemical mapping and assessment of Eco-geochemical systems. It was there that I heard the sad news of the passing away of John Webb and Arthur Darnley. As you know, these men were pioneers in the development of geochemical mapping.

Immediately a verse by Huang Tingjian, a famous poet of the 11th century sprang to mind:

"Li Cheng is no more, Guo Xi is dead.
What now of the hundred cliffs and thousand summits"

When he wrote those lines, Huang was visiting Guilin and Lijiang. With their scenery of winding rivers and soaring karst pillars. Li Cheng and Guo Xi were famous painters but they had died and Huang wonders who now will be able to paint the beautiful landscape of Lijiang.

That day at the symposium, I found myself refashioning the lines:

"Darnley is no more, Webb is dead,
What now will become of geochemical mapping"

It is a joy to see that the geochemical mapping pioneered by such men as Hawkes, Webb, Boyle and Barnley is now being pressed forward by so many successors. This progress has been warmly endorsed in the first-day keynote address. A whole days general session of this symposium is being devoted to it. I also rejoice to see that both the government and the general public in China and many other countries are finally aware of the importance of geochemical mapping for resources and environmental issues.

I am now an old man in body. I have, rather to my astonishment, reached the age of 84. But I believe that I still have some time left; to join you in working for the advancement of the young science of applied geochemistry; to help in working out the global picture of mineral resource potential and environmental conditions.

I look forward with great excitement to new efforts to use geochemical mapping to make fundamental contributions to the study of the earth system as a whole.

Many thanks to you all!

Prof. Xie Xuejing