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Jena Gray

4/17/13

Prado

HIST 131

Ecological Destruction in Minas Gerais during the Nineteenth Century

In 1720, Minas Gerais struck gold. Portuguese finally had a stake in luxurious metals,

although a century later than Spanish-American colonies. According to Burkholder and Johnson,

the veins of this prized metal “in Minas Gerais were among the richest found during the colonial

period and [because of this] Brazilian gold production nearly quintupled between 1700 and

1720.”1 Although Portugal prospered from this economic explosion gold offered, the

environment in Minas Gerais suffered extensively as a direct result. Within the Minas Gerais

district, the widespread frenzy of gold mining in order to maximize profits caused deforestation,

soil degradation, and water contamination throughout the nineteenth century.

Due to the interconnectedness of the environment, gold mining in Minas Gerais during

the 1800s caused an excess of environmental issues and widespread degradation. Ecological

harmony is dependent on the simultaneous health of the soil, water, and forest systems;

degradation in one category results in overall environmental imbalance. Human actions that

cause soil degradation, water contamination, or deforestation often compound into unintended,

large-scale environmental damage.

Sir Richard Francis Burton and John Mawe’s noted the climate of Minas Gerais,

especially within Ouro Prêto, the region with the highest gold production in Brazil. John Mawe

recounted his observations in 1822 explaining that “there are frequent showers of rain. Thunder-

1 Mark A. Burkholder and Lyman L. Johnson, Colonial Latin America, (New York: Oxford University Press, 2012), 154.

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storms are common…”2 Mawe illustrated an important feature of Ouro Prêto that Sir Richard

Francis Burton expanded upon a few years later in 1869, describing the city as one that “enjoys

few clear and serene days ; throughout the year, especially during the rains, the sky is covered,

and the clouds seem to have made their home upon the mountain tops… it is one of the dampest

places in the Highlands of the Brazil.”3 These two accounts affirm the climate of Brazil was

consistently wet or damp. The consequences of mining in Brazil were exacerbated due to the

tremendous amounts of rainfall which washed away weathered soil that had been exposed as a

result of deforestation.

Deforestation was strikingly apparent in the essential construction of each gold mine.

Observers plainly wrote about the unsightly destruction of land such as piles of upturned dirt and

barren hillsides in the nineteenth century. These eyewitnesses documented the inner workings of

mines within the Minas Gerais District with precise detail. John Mawe’s remarks from 1816

provide a baseline for comparison of tree loss within Minas Gerais; he noted there were “large

valleys well clothed with timber” and chronicled his encounter with “…a rich plain abounding

with the finest timber.”4 These expanses strewn with trees were vital to founding a successful

mine. Key aspects in determining a good location for a mine involved whether “1. The mine to

be is situated in a good central district… [and] 2. The pasture, the supply of timber and fuel, and

especially the water are abundant and of the best quality…”5 Easy access to resources such as an

2 John Mawe, Travels in the Interior of Brazil; with Notices on its Climate, Agriculture, Commerce, Population, Mines, Manners, and Customs: and a Particular Account of the Gold & Diamond Districts. Including a Voyage to the Rio de la Plata (London: Longman, Hurst, Rees, ORMF, and Brown, Paternoster Row, 1822) 239.3 Sir Richard Francis Burton, Explorations of the highlands of the Brazil: with a full account of the gold and diamond mines : also, canoeing down 1500 miles of the great river São Francisco, from Sabará to the sea (London: Tinsley brothers, 1869) 344-345. 4 John Mawe, Travels in the Interior of Brazil: Particularly in the Gold & Diamond Districts of that Country, by Authority of the Prince Regent of Portugal including a Voyage to the Rio de la Plata, and an Historical Sketch of the Revolution of Buenos Ayres (Philadelphia: M. Carey, 1816) 190, 133.5 Sir Richard Francis Burton, Explorations of the highlands of the Brazil: with a full account of the gold and diamond mines : also, canoeing down 1500 miles of the great river São Francisco, from Sabará to the sea (London: Tinsley brothers, 1869) 216.

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abundance of water and trees were at first common, even as late as the early nineteenth century,

but as the gold mines became exhausted from excessive use, the resources surrounding the mines

became drained as well.

Deforestation was inherent in the structural support and maintenance for each mine. In

1869, Burton was able to ‘tour’ mines in Minas Gerais and described “the interior” as being

“…walled with wood, cap pieces, and legs, with lathing of whole or split candeia trunks, and sometimes coarse planking to prevent the sides coming to. The sets of timbering were nowhere more than six feet apart. In the main levels, or arteries, first-class wood is used ; ordinary timber suffices for the slopes…”6

The timber was used for reinforcing the walls, ceiling, and slopes. Burton went on to quantify

just how large these main levels, arteries, and slopes were. For each mine there were roughly

nine levels, each level was separated by “seven fathoms” of which, Burton saw “294 of 178

feet.”7 Although the walls and ceilings of the mines were lined with the “hardest Brazilian

wood,” the lumber was frequently crushed or fragmented by the mass of the ground around the

mine. 8

Timber used to mend broken or split pieces of wood also had to be factored into the

quantity of trees cut down simply to support the functions and desires of one gold mine.

Although few records indicated just how many gold mines were in operation during the 1800s,

“more than 400,000 Portuguese colonists and half a million African slaves came to Minas Gerais

in early nineteenth century: by 1725, half the population of Brazil was living in the south east of

the country”9 indicating the obvious boom in gold mines and the subsequent deforestation to

6 Ibid., 335.7 Sir Richard Francis Burton, Explorations of the highlands of the Brazil: with a full account of the gold and diamond mines : also, canoeing down 1500 miles of the great river São Francisco, from Sabará to the sea (London: Tinsley brothers, 1869) 213.8 Ibid., 213.9 “Natural Resources: Minas Gerais, Brazil at 1,000m – The Minas Gerais gold rush,” Royal Geographical Society with IBG: Hidden Journeys: Explore the World from the Air, accessed April 21, 2013, http://hiddenjourneys.co.uk/Natural%20resources/Minas%20Gerais.aspx.

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construct them.10 Through extrapolation, deforestation was widespread throughout the Minas

Gerais district to feed the gold mines’ maintenance and upkeep.

Furthermore, mining excavations dramatically exacerbated erosion, weathering, and

runoff. Burton noticed that the view of the East side of Ouro Prêto, where the mines were, “[was]

hilly and “goldy,” turned up and rummaged by the miner…The slopes culminating here [were]

bald…”11 This description paints the picture of a hillside barren of trees with the earth’s light-

colored belly upturned and exposed from all of the “…extensive diggings [which] were

ignorantly driven…” with aims of reaching more gold to increase profit intake.12 The land was

picked apart, “…bored and excavated, riddled and honey-combed [in search] for veins and nests

of auriferous quartz” (Burton 343).13 These excavations for digging and restructuring the land to

suit the whims of the gold-washers always occurred “in valleys, where there [was] water”

carving and puncturing the earth with holes: “some of them fifty or a hundred feet wide, and

eighteen or twenty deep.”14 All of this digging, mining, and disturbing of the earth’s surface led

to erosion which was further intensified by lack of roots to hold the soil in place. The exposed

earth became susceptible to exhaustive weathering especially without tree coverage to protect it

from the elements. With the addition of a damp climate, rainwater runoff created a large

sediment load that was deposited into nearby water sources and polluted the local and

downstream areas.

10 Ibid.11 Sir Richard Francis Burton, Explorations of the highlands of the Brazil: with a full account of the gold and diamond mines : also, canoeing down 1500 miles of the great river São Francisco, from Sabará to the sea (London: Tinsley brothers, 1869) 363.12 Ibid., 337.13 Ibid., 343.14 John Mawe, Travels in the Interior of Brazil: Particularly in the Gold & Diamond Districts of that Country, by Authority of the Prince Regent of Portugal including a Voyage to the Rio de la Plata, and an Historical Sketch of the Revolution of Buenos Ayres (Philadelphia: M. Carey, 1816) 83

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The methodology of mining during this time period greatly influenced the levels of soil

degradation. Sir Richard Francis Burton cited “the admirable old naturalist, Pliny” who described

different ways of finding gold: “The first is by washing the sand of running waters for stream ore

; the second is by sinking shafts or seeking it [gold] among the debris of the mountains…15

Burton expounded on the destructive methodology gold-washers adapted in the nineteenth

century: “the first exploitation was by simply panning the auriferous sand taken from the stream-

beds…The washers always chose an inclined plane, and a head stream was conducted to the

cuttings by split bamboos or hollow trees [“hydraulicking”].”16 The ways in which the water flow

was forcefully diverted in the nineteenth century to suit the needs of the gold-panners began

tipping the scales that would eventually throw nature out of balance. Water was coerced into

leaving its carved path for the purpose of washing over large piles of auriferous sediments. Since

“the washers always chose an inclined plane” in which “all the diggings are on the right bank of

the streamlet, which rises eighteen feet during the rains,” runoff was expedited.17 The water

would have been rushing at higher speeds than usual (since it was diverted over and down an

incline to reach the piles of auriferous sediments) thus accelerating erosion rates. Consistent

reports showed that all mines were right beside a local water source. Heavy rains and flooding

assured that the substantial load of sediment cascaded into streams which created deposition of

sediment load within rivers and on shore banks further downstream. As a result, contamination

spread through the waters near Minas Gerais.

15 Sir Richard Francis Burton, Explorations of the highlands of the Brazil: with a full account of the gold and diamond mines : also, canoeing down 1500 miles of the great river São Francisco, from Sabará to the sea (London: Tinsley brothers, 1869) 209.16Sir Richard Francis Burton, Explorations of the highlands of the Brazil: with a full account of the gold and diamond mines : also, canoeing down 1500 miles of the great river São Francisco, from Sabará to the sea (London: Tinsley brothers, 1869) 209. 17 Ibid., 209, 339.

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The common practice for ‘unclogging’ debris-ridden mines was to flush vast amounts of

water through the mines in order to free “large amount[s] of the usual dead, unproductive matter”

from the mines.18 This “matter” was not only visible “accumulation[s] of mud, crushed ground,

and foreign matter” that had to be cleared away, but also bits of gold that were washed into the

nearby streams. Gold “is sensitive to biochemical leaching (Baker, 1973)” which means it is

“soluble in, and is removed by, ground water (Boyle 1979).” 19 This property of gold allowed for

particulates to be “lost to the ocean to be eventually contained in marine sediments.”20 These

facts identify the longevity of the repercussions from large sediment piles of unnaturally

upturned earth, comprised of metallic particulates, flushed into nearby streams during the

nineteenth century.

Water contamination was obvious to the naked eye according to the etymology the Rio

Negro and Ouro Prêto. When John Mawe fearlessly ventured into the interiors of Brazil in 1822,

he observed “a rather deep river called Rio Negro, on account of the blackness of its waters,

caused by the decomposition of bituminous [coal].”21 The chemical makeup of bituminous coal

is enriched with metals such as platinum and gold.22 The Rio Negro (“Black River,” today known

as Amazon River) and its resulting streams and streamlets stretched into the Minas Gerais district

according to a map drawn with impeccable detail by cartographers Colton, G.W.; Fisher, Richard

Swainson in 1858. The river had visibly black waters during the 1800s, nearly a century after the 18 Sir Richard Francis Burton, Explorations of the highlands of the Brazil: with a full account of the gold and diamond mines : also, canoeing down 1500 miles of the great river São Francisco, from Sabará to the sea (London: Tinsley brothers, 1869) 339.19 Ibid., 209, 339.Lindgren L.Chyi, “The Distribution of Gold and Platinum in Bituminous Coal,” Economic Geology (Vol. 77, 1982: pp. 1592-1597) 1595.20 C. A. Cousins and F. C. Vermaak. “The Contribution of Southern African Ore Deposits to the Geochemistry of the Platinum Group Metals,” Economic Geology, (Vol. 71, 1976: pp. 287-805).21 John Mawe, Travels in the Interior of Brazil; with Notices on its Climate, Agriculture, Commerce, Population, Mines, Manners, and Customs: and a Particular Account of the Gold & Diamond Districts. Including a Voyage to the Rio de la Plata (London: Longman, Hurst, Rees, ORMF, and Brown, Paternoster Row, 1822) 296.22 Lindgren L.Chyi, “The Distribution of Gold and Platinum in Bituminous Coal,” Economic Geology (Vol. 77, 1982: pp. 1592-1597) 1592.

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peak of the gold-mining boom in Brazil, due to years of auriferous sedimentary deposition. The

town Ouro Prêto, which in Portuguese means “Black Gold”, was named so due to the coat of

iron oxide which created a black sheen on the auriferous contents of the stream Belo Horizonte

(“Beautiful Horizon”) which runs through Minas Gerais. The mere fact that major landmarks

such as the Amazon River and Ouro Prêto were named after a black hued body of water

exemplifies the significance and extent of water contamination from that time period due to the

methodology of gold mining.

In conclusion, the lack of trees contributed to immense weathering from exposure to the

elements. During heavy storms, which were common to the Minas Gerais district, rain poured

down the inclined slopes of the mining regions. The rain proceeded over the large piles of

auriferous sediment and other “mud, crushed ground, and foreign matter,” further eroding away

the stream banks and flushing sediment downstream.23 Meanwhile, most of the gold particles that

were unintentionally swept away were “either lost to the ocean directly or lost during subsequent

leaching from the delta coal swamp.”24 The displacement of gold created discoloration in large

bodies of water within the close vicinity of major mining areas such as the Rio Negro (Amazon

River) and Ouro Prêto. Nineteenth century mining methodology and the thirst for money created

the classic case of the tragedy of the commons in Minas Gerais—each mine consumed large

quantities of resources in order to maximize profits which destroyed the environment and proved

to be yet another example of an unsustainable, self-consuming industry.

Bibliography

23 Sir Richard Francis Burton, Explorations of the highlands of the Brazil: with a full account of the gold and diamond mines : also, canoeing down 1500 miles of the great river São Francisco, from Sabará to the sea (London: Tinsley brothers, 1869) 209, 339.24 Ibid., 209, 339.

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Baker, W. E., “The role of Humic Acids from Tasmanian Podzolic Soils in Mineral Degradation and Mineral Mobilization: Geochim. et Cosmochim. Acta, Vol. 87, 1978: pp. 269-281.

Boyle, R. W., “The Geochemistry of Gold and its Deposits.” Bulletin, Geological Survey of Canada, 1979: pp. 280, 579.

Burkholder, Mark A., and Lyman L. Johnson. Colonial Latin America. New York: Oxford University Press, 2012.

Burton, Richard Francis, Sir. Explorations of the highlands of the Brazil: with a full account of the gold and diamond mines : also, canoeing down 1500 miles of the great river São Francisco, from Sabará to the sea. London: Tinsley brothers, 1869.

Chyi, Lindgren L. “The Distribution of Gold and Platinum in Bituminous Coal.” Economic Geology, Vol. 77, 1982: pp. 1592-1597.

Cousins, C. A., and F. C. Vermaak. “The Contribution of Southern African Ore Deposits to the Geochemistry of the Platinum Group Metals.” Economic Geology, Vol. 71, 1976: pp. 287-805.

Mawe, John. Travels in the Interior of Brazil: Particularly in the Gold & Diamond Districts of that Country, by Authority of the Prince Regent of Portugal including a Voyage to the Rio de la Plata, and an Historical Sketch of the Revolution of Buenos Ayres. Philadelphia: M. Carey, 1816.

Mawe, John. Travels in the Interior of Brazil; with Notices on its Climate, Agriculture, Commerce, Population, Mines, Manners, and Customs: and a Particular Account of the Gold & Diamond Districts. Including a Voyage to the Rio de la Plata. London: Longman, Hurst, Rees, ORMF, and Brown, Paternoster Row, 1822.

Royal Geographical Society with IBG. “Natural Resources: Minas Gerais, Brazil at 1,000m – The Minas Gerais gold rush.” Hidden Journeys: Explore the World from the Air. 2013. April 21, 2013. http://hiddenjourneys.co.uk/Natural%20resources/Minas%20Gerais.aspx.