Metals and minerals in Southwest China and highland Southeast Asia
In the way of introducing the general background to this research, this page presents (1) the geology and the formation of mineral deposits, (2) the mountain environment and its vertical landscapes, and (3) human societies and their history in this environment. The history section focusses on the period 1400-1850, but I added a section on the modern transformation to outline what happened over the last century-and-a-half and what you may expect to find at historic mining sites if you visit them today.
1 The geology: Mineralogical Riches
The region of southwestern China and the adjoining higher mountainous areas of Myanmar, Laos, Thailand and Vietnam is the crunch zone of the Himalayas. The mountains are young in geological terms, and extremely folded. This means that gradients are extreme. The arc produced by the push of eastern corner of the Indian plate also means that the forces shaped this mountain zone changed over time, producing some neat ranges and much broken terrain without much evident order to it. The “untidy” formations are in part due to numerous fault systems, including faults running in different directions that took shape at different times during the mountain formation. In short: the region is geologically complex and active. The processes are still active, as the frequency of earthquakes and the presence of volcanism shows. Earthquakes can be highly destructive, both directly and because they can cause landslides, block river valleys, and destroy man-made structures, such as dams. Thankfully, the volcanic activity is a lesser concern for us; the specimens in the best-known volcanic area in Tengchong are mostly small and well-behaved. Through historic times, thy only produced minor eruptions that caused little destruction to human societies.
More landscape pictures here ->
High geological activity and numerous faults mean that minerals concentrate, in some cases near the surface. Very simplistically, we might say that the same forces that produce hot springs – which are numerous throughout the region – also produce mineral deposits.
The high gradients and the sub-tropic climate help to expose such formations and to produce secondary enrichment in the layers near the surface. Again greatly simplified you might imagine that minerals are originally distributed evenly in a rock layer get transformed and condensed, especially when exposed to heat and mechanical forces along faults. If these come the be located near the surface, they might get enriched again. This happens when minerals in the eroded materials near the surface oxidise when exposed to the air, are leached by rain, which is slightly acid, washed down and collect in cracks in the rocks. Near the underground water level, this enrichment can be remarkable. Since underground water levels can change over time, such enriched veins might form at more than one level in a given deposit.
Another aspect that affected the formation of rich deposits in the region is the massive limestone layers. Where these dominate the surface layers, we find karst ore formations. Here, the porosity of limestone can lead to the leaching out of metals by acid water through massive layers. This material can get deposited in caves and near the contact zone between the limestone and other, less porous rock. At the same time, because limestone disintegrates in acidic humidity, ore can get distributed in fine grain in the surface soil. Hence, we might find ore deposits that are not very rich but very easily worked by digging up the mud between limestone pillars and washing it, as well as less easily worked but very rich ore deposits underground, or both.
Why did I mention the gradients and the sub-tropical climate? The terrain comes in because veins are more likely to become exposed to the surface on steep slopes and people might discover them. The sub-tropical climate is relevant for two reasons: Monsoons bring heavy rain for over half the year or roughly from April through September. Vegetation thrives in a warm and humid climate, and rich vegetation creates slightly acidic soils. For both reasons, the leaching processes in this region are particularly efficient, as there is a lot of precipitation and sufficient acidity around.
We have no impressive pictures of deposits. The photos in this link show the reason: All important deposits have been exploited to the point where not much of the original formations can be seen!
2 The environment: Bio-diversity and vertical landscapes
The region is not only geologically complex but home to an astounding biodiversity as well as to a great diversity of peoples who speak different languages and possess different ethnic and cultural identities. A look at environmental diversity provides an idea of how this diversity formed and how it was maintained. The key again is the extreme gradients. For Yunnan province, level plateaus and mild slopes constitute no more than 3.5% of the total area. The so-called plateaus (bazi 坝子) are sediment-filled pans and high valleys and can in fact be almost perfectly flat when large enough. The rest (omitting the lakes and rivers that occupy only a small fraction of the area) are mountains. Most of these are relentless slopes rising to over 5000 m in the north and around 2000 m in the south and descending to deeply cut valleys. The major rivers run at around 1000 m in the north and at 300 m in the south. Forests reach to over between 4000 and 4300 m, permanent snow if found above about 4600 m. Regional climates extend from cold Tibetan highlands and snow-covered peaks to conifer forests, evergreen broadleaf forests, to tropically hot valleys. The situation in the adjoining areas is comparable, with a slightly larger percentage of relatively level land in highlands of Guizhou, and more intensely tropical conditions and lower altitudes as we proceed south into Southeast Asia.
The most extreme situation are found in the great valleys. Four of the region’s major rivers, the Jinshajiang, the Lancanjiang/Mekong, the Nujiang/Salween and the Irrawaddy descend from the Himalayas following the arched folds of the mountain zone and run in parallel valleys separated by mountain ranges only 15-70 km in depth through northern Yunnan and Myanmar. These valleys form extreme slopes. Within a few kilometres, climate and habitat zones range from cool alpine to tropical conditions. Although this is the most extreme situation, the steep mountains involve frequent changes climate zones, and in soils as well.
Habitats of plants and many animals form bands defined by suitable altitude rages. This intricate patchwork created the rich biodiversity of the region. The original vegetation throughout the region was dominated by evergreen broadleaf forests, mixed with cypresses and firs at higher, and tropical hardwoods at lower altitudes. Under this canopy and in the open spaces lived an immense variety of smaller plants and animals. The majority were specialists adapted to a certain habitat, shaping landscapes that were arranged in vertical bands. Large mammals with high mobility, such as elephants, tigers, and humans could roam across these bands, profiting from advantageous or comfortable conditions through the seasons.
From the human point of view, the region was at once inviting and forbidding: On the one hand, it offered a great range of resources, on the other, moving into it and within was hard and could be challenging: you easily loose orientation in a huge ancient forest, you might end up facing an insurmountable cliff, and – worst of all – you could encounter diseases endemic to certain habitats.
3 Human history: Diversity in patchworks and networks
The above has shown that region is geologically complex, rich in minerals and inhabited by a great range of plants and animals. To get to the history of human exploitation of minerals we need some idea of the societies in the region.
Although societies of the past have nothing to do with this, history as an academic
discipline cannot help but be influenced by present political and linguistic boundaries. We therefore have to be aware of foci and possibly divisions that are introduced into history by research histories. As mentioned, the bulk of the region is part of southwestern China, specifically almost all of Yunnan province, the southern corner of western Sichuan, the western rim of Guizhou and the southwestern rim of Guangxi. The adjoining mountain zone in Southeast Asia is largely congruent with the Shan State of Myanmar, the northern tip of Thailand, northern Laos, and the northern arc of Vietnam. For the purpose of this research, our work is largely confined to China and mainly focuses on Yunnan. Thanks to Vu Duong Luan, however, we are able to include some important sites in northern Vietnam. We may add in this context that the karst highlands in northern Myanmar and northern Vietnam bordering Yunnan and Guangxi are the areas with major deposits that became important mines in the historic period. This does not mean that other areas have no mineral deposits but that these did not develop into important mining centres in the last five centuries before industrialization. As silver and copper mines were the largest and economically most important historic mines, their distribution shows this point.
In the following, I try to consider the region in general, but due to my background and linguistic limitations to European languages and Chinese, any more specific knowledge generally is from southwestern China.
In its narrow sense, history is the story of human societies who know writing and left written records. By this definition, pre-history lasted into the last century for some societies in the investigated region because they knew no writing and even remained stateless, such as the Wa or Parauk in the Yunnan-Myanmarese border region. The reliance on written records for the historic period almost exclusively relies on Chinese records for the topic that interests us here, and the same employs – although not exclusively - for all other topics. Chinese records relevant for mining and metallurgy are few and far between, but there are some. Other peoples who employed writing were Dali, Yi (formerly usually called Lolo), and Thai in the region, and Myanmarese, Vietnamese, and Tibetans in adjoining regions. Surviving records are either concerned with genealogies and matters of religion, or not with the region investigated here. With the exception of a few relatively late Chinese, Vietnamese and Burmese records, none contain direct information on minerals and metals.
You find a bit more on sources, what we can find out and on why we approach our research the way we do here.
This introduction confines itself to a rough outline of the complex histories of the peoples of the region and the empires whose zones of influence or direct control reached into the region. The environment was and is the setting for human societies. Overall, its biodiversity made the region a friendly environment for hunter-gatherers, while its topography made the situation more complicated for agricultural societies, and quite difficult for state control. Agricultural societies faced tight limitations because flat land and mild slopes that were easily cultivated constitute only a small fraction of the region. Moreover, many plateaus were occupied by shallow lakes and bogs. Agriculturalists had the choice between a heavy investment in draining and irrigation systems, which might be extended by the even more laborious construction of terraced fields and permitted fully settled life and high population densities, and swidden agriculture (or fire-fallow cultivation) that involved less work but moving on every few years to clear new land and low population densities. Over time, the more intensive, settled forms developed on most plateaus and in suitable pockets of less steep land on certain altitudes, while swidden agriculture remained the usual practice in the lower lying mountain areas.
Moreover, peoples across the region tended to develop their specific adaptations through their use of plants and domestic animals. This permitted the existence of distinct societies with distinct languages and identities alongside each other. Some simply lived in different landscapes and hence rarely came into conflict over resources, while competition over favourable sites certainly occurred, and other societies came to profit from exchange across different zones. The crucial boundaries were not formed by the morphology, but by germs, specifically by lethal forms of malaria and possibly other tropical disease. As in China, the southward migration of peoples from the north was a slow process. It involved the expansion of irrigated agriculture that for some reason reduced instance of certain forms of malaria, as well as immunological adaptation over many generations. In the Southwest, in-migrants from northern and central China, Yi, Han and Muslim Chinese, kept to heights above 1500 m, while Thai, Mon, and some other peoples of Southeast Asia and South China settled around 1000 m and below.
In short, human societies in the Southwest formed a patchwork, with different sedentary groups occupying different heights in different pockets and less sedentary peoples engaged in herding and swidden agriculture living in high altitudes and lower mountains.
The islands of relatively large and well-organised communities on the plateaus could form small states, at times even integrating several plateaus, while mountain peoples often had little use for state formation. The Dian kingdom of the 3rd to 1st century BCE is the earliest known state and centered on a capital city at the southern end of Lake Dianchi (south of modern Kunming). The Nanzhao (750-902 CE) and the Dali 937–1253 kingdoms were relatively large states centered on a capital near modern Dali. The Thai and Yi aristocracy ruled over small states that could assume vassal status to larger states and empires in a loose feudal system.
The large states located around the region and ranged by distance were Vietnam, Burma and China. Han China expanded into central and southern Yunnan in the early 2nd century CE, establishing considerable cultural influence at least among the elites, as documented in excavated graves. Direct control did not last. Another period of control over Guizhou and central Yunnan lasted about a century during the 7th and 8th century heyday of the Tang dynasty. The Dali kingdom fell to the Mongol invaders in 1253, and the Mongol Yuan dynasty incorporated much of the area of modern Yunnan, western Sichuan, and Guizhou with the empire.
Through the early modern period, the Thai and Yi polities largely preserved their independence, while at various times acknowledging the overlordship of more powerful rulers. Polities in what is now the Shan State in Myanmar and adjoining borderlands with Yunnan province at times became tributary to the Ming, the Qing, or the Taungoo dynasty, those in the mountain borderlands of northern Vietnam became tributary to the Nguyễn dynasty (1802–1945). In Southwestern China, the Yuan set up a borderland structure that assigned the status of tusi (native chieftains or aboriginal officials) to the lords. The Ming and Qing inherited this system and gradually strengthened imperial control through demanding hereditary succession to conform with Chinese norms of male lineages and stability of territories. Through several centuries, the number of tusi shrank, the remaining ones often ruling over larger territories but often gradually losing full control over their subjects. Nevertheless, to the end of the imperial period (1911), a system of layered state control still existed in the borderland and in some interior areas.
Mineral exploitation took part in this patchwork of local societies and networks. Far-flung networks of trade and exchange existed throughout, as the cowrie shells, Theravada Buddhism, and Han-Chinese seals attest. Cowries, which usually originate from the Indian Ocean around Sri Lanka, were used as a store of value since antiquity, the Dali kingdom adopted Theravada Buddhism long before any other culture in the region, and Chinese seals (some of which possibly fakes) were regarded as important signs of legitimacy in a presumably mostly illiterate society. For these reasons, we expect local metallurgical traditions alongside a considerable mobility of mining and metallurgical specialists. On account of the influence of the Chinese empire and the over-regional importance of the Chinese market, we expect these specialists to have usually come from China, while other exchange cannot be ruled out.
During the five centuries of the period of investigation (ca. 1350-1850) or the Ming (1368-1644) and Qing (1644-1911, ending with the mid-19th century rebellions), Chinese records increase for the Chinese southwest, recording mainly the official imperial administration, with some information on Chinese and a little on non-Chinese inhabitants of the region. The sources allow outlining the tusi system but generally not much concerning the political structures within a tusi statelet. The records on the Han-Chinese and other registered inhabitants involves the usual discrepancies between the fully official administration sanctioned by the central government and actual structures and conditions on the ground. These problems concern population figures, taxation, and mines. They do not concern the metallurgical industry because it does not receive any mention in the records anyhow. (On the issue, see Kim, Nanny and Yang Yuda, 2019)
Discernible trends are a steady influx of Han-Chinese into the Chinese southwest, which also reached mining centres in the borderlands outside the imperial borders, accompanied by the in-migration of Miao from central western China. Overall populations are extremely difficult to estimate for the Ming period, but overall steady population growth, especially in the in-migration areas appears probable. Figures extrapolated from James Lee’s study for the Qing suggest about 6 million about 1700, perhaps 12 million by 1800 and 16-17 million by 1850, followed by a population collapse caused by the civil wars, leaving at most 10 million across the region by the late 19th century. For comparison: Yunnan province alone has close to 50 million inhabitants today. Overall, we see a long-term population growth driven by in-migration. We expect that this development let to the predominance of Han populations on the plateaus by the end of the Ming, and further expansion beyond the plateaus in the accelerating growth from the late 17th to the mid-19th centuries. Because we found clusters of Han villages at most important mines, with beginnings corresponding to the expansion of mining, we also believe that the exploitations of minerals was an important factor that attracted people into the region.
On account of these pattern in the history and distribution of populations, we expect that mining and metallurgical technologies largely coalesced into region-wide applications in the hands of Chinese specialists around the mid-Ming. At the same time, however, local technological traditions may have survived in pockets, especially in the treatments of less valuable metals. This is expected to apply specifically to iron, as local productions presumably supplied local markets in many small areas, allowing local traditions to survive.
4 The modern transformation
The mining industry collapsed in the mid-19th century civil wars. In Yunnan, these began with pogroms against Muslim Chinese in the southwest and south of the province. Armed resistance flared up in silver mines of the south and the region of southern central Yunnan. Events led to civil war with an organised Muslim-Chinese rebellion in western Yunnan that founded the Dali sultanate, and fighting along often shifting lines of groups with common identities or interests in other parts. The eastern parts of the region were affected by the Taiping wars, with remnants of the Taiping army reaching western Guizhou. Sichuan largely escaped violent conflict. The extreme devastation of the Lower Yangzi Area (Jiangnan) in the Taiping wars destroyed the economic centre of China and thus the commercial fabric. Violent conflict broke out in all mining areas with the exception of western Sichuan, the Gejiu area, and several sites in northwestern Guizhou and the Guizhou-Yunnan border zone.
Devastations of the civil wars in the southwest came close to the Thirty Year’s War in Europe. When an exhausted peace was finally restore by 1873, many formerly densely inhabited plateaus were depopulated, survivors impoverished, and commercial networks disrupted. Mining did revive, but with few exceptions exploitations were taken up only on a minor scale and often shifted to re-exploiting historic slags.
Economic restoration was a halting process, with severe setbacks caused by several major droughts in the late 19th and early 20th centuries. Moreover, the shift of transport to maritime routes and the increasing influence of economic globalization and industrialization relegated the far-inland regions to the distant periphery in terms of economic development. Nevertheless, the mining industry saw some development during the first half of the 20th century, employing both traditional and industrial technologies, usually working existing sites but often for different metals.
During WW II, the remoteness became an asset for a few years, when the Chinese government, institutions of higher education and refugees too refuge in Yunnan. After 1949, the southwest again became a backwater, remote and backward. Although metal production was forcibly expanded during the Great Leap and more in step with the general gradual economic development from the 1970s and 1980s, industrial development concentrated on a few centres. It took off in the two decades from the 1990s, when general development, the price rise in many metals and minerals, and great improvements in transport networks combined to a mining boom.
To reduce the complicated story of the last century-and-a-half on the general effects with regard to the topic investigated here: Much of the modern period is a situation of small-scale exploitation with limited industrial technologies; with an extreme outburst not necessarily successful productivity during the Great Leap; and followed by the recent boom that still initially employed traditional technologies in the remoter areas and has now again subsided or transformed to fully industrial technology that erased many historic sites.
The following notes on specific metals and minerals outline what we know about their respective histories of exploitation:
(If you must know: The metals are listed roughly in the order of their history of human exploitation, while the other minerals are tacked on ordered by the scope of mining)
