ribeira_valley - brazzil_magazine 2007

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A Few Proposals to Bring Sustainable Development to Brazil's Ribeira ValleyContributed by Helio Shimada and Sonia NogueiraSaturday, 16 June 2007

The Ribeira de Iguape River, one of the most important rivers in the Brazilian southeastern state of So Paulo, has sources in the Paran state, drains from Northwest to Southeast between So Paulo and Paran states through the Ribeira Valley (Vale do Ribeira) and reaches the Atlantic Ocean at Iguape, in the Southern coast of the first state.

Both sides of the Ribeira Valley are sectors of two developed and rich states in Brazil but they are still characterized bypoverty and underdevelopment. On the other side, the valley is known for its complex geology and natural richesrepresented by a large remnant of the exuberant Atlantic Rain Forest, preserved mangrove areas, a huge number oflimestone caves, important mineral resources, abundant water resources and agriculture and cattle breeding lands.

Gold and lead-silver mining were important in the past and limestone, sand and phosphate mining are presentlyexpressive, but mining and agriculture are facing strong limitations due to the creation of state parks and otherenvironmental protection areas and other problems.

Even outside the protected areas, agriculture is also limited by the mostly rough land, except in the lower valley wherethe land allows mechanization. Despite past and present efforts in mining and agriculture and in the more recent wavesof ecotourism and adventure tourism, the region still did not find its way to development and is even losing population inmany of the its 32 towns. The challenge is now the choice of ways to develop the Ribeira Valley in a sustainable form.

The Ribeira de Iguape River has an extension of 470 km (292 miles) and is the last important river in the Southeastern

Brazil without hydroelectric power plants. The river basin has a total area of 28,306 km (10,929 sq miles), with 11,191km (4,321 sq miles) in the Paran state and 17,115 km (6,608 sq miles) in the So Paulo state.

The river basin composed by the Ribeira de Iguape and its tributaries represents an important water resource to bothstates. It comprehends 32 towns - 9 in Paran and 23 in So Paulo - and the last official census, made by BrazilianInstitute of Geography and Statistics (IBGE), in 2000, shows a total of 481,224 inhabitants, distributed in 37.58% ruraland 62.42% urban populations.

There are among the population 9 communities formed in the past by evaded slaves, which are known as Quilombos orQuilombola Communities: Bombas, Cangume, Galvo, Ivaporunduva, Mandira, Morro Seco, Pedro Cubas, Porto Velho,So Pedro. Their status was recognized by the government and they are now receiving land ownership and economic

and technical support for a sustainable development.

Middle and upper Ribeira valleys are narrow, deep and characterized by rough land, with altitudes varying from 100 (328feet) to more than 1,300 m (4265 feet) above sea level. Lower valley is wide and has a mostly flat land with some smallhills and sided by sharp mountains.

The climate is hot and humid in the lower and middle valley with annual precipitation reaching more than 2,000 mm (79inches) and higher temperatures above 30 Celsius (86 Fahrenheit).

In the upper valley the climate is also hot and humid, but precipitation drops to about 1,500 mm and in the higher lands

temperatures drop to below 7 Celsius (45 Fahrenheit) in the winter as is the case of Apia, with an altitude of 1,040 m(3,412 feet).

It is remarkable the fact that more than 74% of the total area of the valley (21,000 km - 8,108 sq miles) is covered by

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forests, representing 21% of the Brazilian remnants of the Atlantic Rain Forest. Much of the preserved forest is in the SoPaulo State.

Other than the forest, there are in the coastal sector 150 km (58 sq miles) of salt marsh and 170 km (66 sq miles) ofwell preserved mangroves. All these environments are associated to specific and varied fauna. These are the reasons forcreation of several environmental protection areas in the last 50 years.

A remarkable aspect in the Ribeira Valley is its complex geology. In the upper and middle valley, there are mostlyPrecambrian metamorphic rocks such as meta-limestones, phyllites, schists, meta-sandstones, meta-siltites andquartzites. These rocks are mainly oriented to Northeast and intensely folded with axis in the same direction.

Precambrian meta-igneous rocks contemporaries to the metamorphic ones, granite bodies of varied dimensions intrudingthem are also present. The ensemble is cut by Mesozoic diabase dikes oriented to Northwest. Remarkable are theMesozoic intruding alkaline complexes associated to the phosphate deposits.

Most of the mineral deposits in the valley are related to Precambrian rocks. In the flat areas of the lower valley, theancient rocks are covered by Tertiary and Quaternary unconsolidated clayey and sandy sediments. In the river flats

downstream from Sete Barras there are several peat deposits studied by Shimada et al. (1981) and Motta et al. (1982)for energetic purposes.

The large areas of meta-limestones and abundant water allowed the formation of hundreds of caves in the middle andupper Ribeira Valley. It is one of the most important speleological provinces of Brazil and its very complex karst systemswere only partially studied.

The caves were firstly studied by Krone (1898), but more intensively surveyed and studied from the 1960's (Le Bret1975; Guimares 1966). To protect a part of the caves it was created in 1958 the PETAR - Parque Estadual Turstico doAlto Ribeira. It comprehends parts of Apia and Iporanga municipalities with a total area of 357.72 km (138.12 sq miles).

Despite the abundance of natural resources, Ribeira Valley is in a difficult economic situation and many of its small townshad population declines in the last years.

THE HISTORY

Gold mining

The known history of the Ribeira Valley remounts to the 16th Century and is closely related to mining, though it is told theSpanish arrived to its coastal area in 1498, two years before the Portuguese first step in Brazil.

In 1531, a Portuguese expedition of 80 men led by Pero Lobo ascended the Ribeira Valley from Canania, then a villagein the coast, searching for gold deposits. They never returned and it is believed they were massacred by native ndios(Indians) in the upper valley.

Alluvial gold deposits were found in the late 16th Century in the region and there was established a village where ispresently the town of Iporanga, in the upper Ribeira Valley.

Gold bearing gravel deposits along the Piles, Bethary, Iporanga, Palmital and other local rivers were intensively minedduring the 17th Century and a gold smelting house, Casa da Oficina Real de Fundio de Ouro, was established at Iguape(Barbosa & Guimares 1946).

The way to reach the mines was the Ribeira de Iguape River and villages as Xiririca, Sete Barras and Registro werefounded along the river. In the 18th Century, the local gold deposits were almost exhausted and richer and bigger




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deposits had already been found in Minas Gerais state, causing the decline of local mining, which stopped by the end ofthe same century.

It was the end of the gold mining cycle in the upper Ribeira Valley, which was partially reactivated in the late 19thCentury when was put in operation the Morro do Ouro (Gold Hill) mine at Apia, an underground mine, which was closedby the government in 1942 because it was then operated by a Japanese company and never reopened (CPRM 1980).

Despite exploration efforts made by several mining companies in the past four decades, the search for a new economicgold deposit was unsuccessful (Morgental et al. 1981; Nogueira 1990). The organized gold mining ended, but there arestill few and seasonal gold prospectors working with primitive rockers and pans.

Lead-silver Mining

The region then remained almost forgotten up to the initial decades of the 19th Century, when lead-silver ore bearingveins were found. Then, many interested men studied those ore bodies along the 19th Century. Among them wasRichard Francis Burton, the famous English explorer and diplomat, who was the British Consul in Santos betweenSeptember 1865 and October 1869.

He traveled to Iporanga at the end of 1866, staying there between December 29 1865, and January 1st, 1866, visitingthe Morro do Chumbo (Lead Hill), a limestone hill with several lead-silver ore veins (Burton 1866, in Krug 1938).

After this trip, Burton decided to become a successful miner, made a request and obtained the mining permission bymeans of imperial decree nr. 3706 of September 26 1866, but he never started to mine in the region.

In the 1870's, it was made an attempt to mine the main ore veins of the Morro do Chumbo by means of some 200 m (656feet) of underground works, but it was stopped before cutting the veins due to the lack of financial resources (Bauer1890).

A successful lead-silver mine would be opened only in 1920, when the Furnas mine, located in the municipality ofIporanga started to operate and it operated discontinuously up to 1992. After Furnas, some 60 other mines were openedin the Paran and So Paulo sides of the valley (Beljavskis et al. 1981).

The mines were mostly small with limited ore reserves and had ephemeral duration. The most important and larger oneswere located in Paran such as Panelas (Zaccarelli 1988), operated by Plumbum Minerao e Metalurgia S.A., controlledby Pearroya Group, Perau, Rocha and Canoas (Daitx 1996).

In 1934, it was made a first attempt to install a lead smelter plant close to the Esprito Santo mine, also in Iporanga, but it

was stopped after producing only 5 tons of metal. In 1940, the government of So Paulo established a 10 t/day smelter atApia to process the ore from several small mines, but it stopped operation in 1942, just after passed to private control(Barbosa & Guimares 1946; Felicssimo Jr. & Guimares 1950).

In 1945, Plumbum started to operate a smelter at close to the Panelas mine, at Adrianpolis, which operated during 50years and an important amount of silver and some gold were produced as byproducts of lead refining. Some zinc orewas also produced, but its concentrate was sold to companies outside the Ribeira Valley.

Plumbum was sold to a Brazilian Group in 1987 and the lead-silver mining cycle ended in 1995 with the closing ofCanoas mine and the smelter at Panelas. Some of the closed mines such as Furnas and Panelas left environmentalproblems represented by soil and water contamination by lead and other heavy metals bearing tailings (Moraes et al.2002; Lopes Jr. 2005).

The rice cycle - Prosperity and Disaster




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In the early 19th Century, the lower Ribeira Valley, downstream from Sete Barras, was an important and rich rice croparea. The rice was transported by boat in the Ribeira de Iguape River to the port of Iguape and then shipped to themarkets.

But there was an obstacle: the river was very sinuous and even after reaching the sea at Barra do Ribeira (Mouth ofRibeira) it was necessary to sail close to the coast for 35 km (22 miles) to the South. It was costly and took too long to

reach the port.

Then it was decided to dig the Valo Grande, a narrow shortcut channel to spare 53 km (33 miles) of navigation. Diggingwas started in 1827, 18 km (11 miles) upstream from Barra do Ribeira, in a straight line to Iguape, and it was concludedin 1852.

The original width of Valo Grande was about 4 m (13 feet), just enough to allow the navigation of small boats. But theshortcut radically altered the river flow and accelerated erosion soon took place and the channel width jumped to 200 m(656 feet) only 50 years after its opening.

The huge amount of transported sediments quickly sanded the Mar Pequeno, the sea in front of Iguape, a zone betweenthe town and the Comprida Island. The port has become useless, rice crops dwindled and aggravated by the end ofslave trade, the local economy went bankrupt.

This was the first major environmental disaster caused by men in Brazil, and Richard Francis Burton wisely predicted it inthe report of his trip to Iporanga, published in the Revista Commercial de Santos (Burton 1866, in Krug 1938).

The Valo Grande had a width of 300 m (984 feet) by 1970 and was closed by a dam in 1978, but the barrier causedintense floods upstream in 1981 and 1983, with serious damages to banana crops and also to the population along theriver. Then it was decided to partially reopen the Valo Grande for flood control.

THE PRESENT

In March 1912, the government of So Paulo made a deal with a Japanese colonization company and donated lands inthe Iguape region to place immigrants (Handa 1987). At the same epoch, scientists of the Commisso Geographica eGeologica do Estado de So Paulo ascended the valley making land survey and also geological, botanical and soilstudies (CGG 1914).

The Japanese immigration was the origin of banana plantations now spread mainly to Iguape, Registro, Pariquera-Au,Sete Barras, Eldorado, Juqui and Miracatu, with tens of millions of trees. But banana crops are experiencing a veryserious problem: a plague known as Black Sigatoka, a leaf spot disease. It causes significant reductions in leaf area,

yield losses of 50% or more and premature ripening, a serious defect in exported fruit. It is more damaging and difficult tocontrol than the related Yellow Sigatoka disease, and has a wider host range.

In 1919, Torazo Okamoto, a Japanese immigrant of Registro, decided to cultivate tea because it was all imported at thattime, but there were no available good quality seedlings. He solved the problem by means of a trip to former Ceylonwhere he got, with difficulty, some seeds from local English tea crops.

In the ship travel back to Brazil, the seeds were put into bottles filled with local soil and he arrived with a collection ofseedlings ready to plant (Handa 1987). The enterprise was so successful that the company founded by Okamoto stillexists and the original tea shrubs are now preserved as historical relics in a yard in the company's tea crop.

Banana and tea are still the main agricultural products, but there are now a variety of other plantations such as tomato,passion fruit, pupunha palm and chayote. The rural properties are mainly of small sizes with areas of less than 0.5 km(0.19 sq mile).




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In the state of Paran, where the forest was much more devastated, the soil is jeopardized in the rough land areas dueto mechanical and chemical losses by erosion, but the same type of agriculture is observed and there are alsoreforestation areas for economic purposes.

Mining is still an important economic activity in the Ribeira Valley, but the sector has experienced decline if compared tothe 1970's when lead-silver mines were active and there were also some illegal mines of other substances. The authors

carried out an assessment between 2002 and 2004 in all 23 municipalities of the So Paulo side of the valley (Nogueiraet al. 2004).

There were identified 54 active mining enterprises. They are composed by sand (33), clay (10), limestone (4), mineralwater (3), phosphate rock (2), kaolin (1) and ornamental quartzite (1).

Sand for construction, with increasing importance, is dredged from the river bed in the lower valley comprehendingEldorado, Sete Barras, Jacupiranga, Registro, Pariquera-Au, Iguape, Juqui, Miracatu and Pedro de Toledo.

The sand sector is well organized and is operating in environmentally compatible form. Sand is mainly sold to the coastal

market. There are two type of clay being mined: clay from river flats for ceramic industry and clay form weathered finegrained metamorphic rocks for blending with limestone in the cement industry at Apia and Cajati.

The local ceramic industry, mostly in the lower valley (Registro, Iguape and Jacupiranga) and operated as small familiarbusinesses making bricks, is facing a serious crisis due to the competition with products from other states.

Limestone mining started in 1958 in the region and is now represented by one large open pit quarry at Itaca for a cementindustry at Apia with an installed capacity of about 1,5 million tons/year, and three small quarries for lime, soil correctiveand animal ration, located at Ribeira and Apia, except for one in the lower valley at Pariquera-Au.

It is remarked that also dolomitic limestone and dolomites are mined in some of these quarries. Mineral water extractionis ruled by mining law in Brazil and the two wells are located in Registro and one in So Loureno da Serra.

Phosphate rocks are related to alkaline complexes and mining started in 1939 at Cajati and there is presently inoperation another smaller mine at Registro. The Cajati phosphate mine, with about 5,4 million tons of Run Of Mine/year,is the most important mine in the Ribeira Valley and its main product is destined to animal nutrition and the calciumcarbonate, a byproduct from ore dressing, is sold to a cement factory close to the mine with an installed capacity of 1,4million tons/year.

Kaolin for fine ceramic industry is produced in a small but well organized mine at Tapira, in the upper basin of a tributaryof Ribeira de Iguape River. Ornamental quartzite plates are mined by hand in small scale at Brao locality in the Eldorado

municipality.

There are also dozens of abandoned mines without land reclaiming in the valley, but the ancient Morro do Ouro goldmine at Apia was successfully transformed thanks to a Shimada suggestion (2002) in a tourism mine by the localadministration, which is also intent on protecting water resources in the area.

In the Paran side of the valley, mining was also more important in the past when expressive lead-silver and fluoritemines existed. Presently there are mostly limestone quarries to supply raw materials to lime and cement industry. Brazil'sbiggest cement industry is located at Rio Branco do Sul in the Paran sector of the valley.

Cattle and buffalo breeding are growing activities in the lower Ribeira Valley, but are still not that representative in theregional economy. In 2002, the cattle population was about 78,000 for 1,800 breeders and the main destination is meat.

Buffalos are well adapted to the local conditions, totalizing about 65,000 animals and their milk is being processed in 16




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FINAL CONSIDERATIONS

The future of the Ribeira Valley necessarily passes by sustainable procedures in the economic activities as theenvironmental preservation is definitive. This is the main way to take and its branches must be carefully considered.

Such procedures should be object of more intense government actions by providing knowledge, orientation andfinancing. These actions will help the mentality change of the economic agents now characterized by lack of knowledge,disorientation and some individualism.

It is also imperative a government effort to establish ecological and economical zoning of the whole valley to clearly setrules, to organize the economic activities and to make development and preservation compatible. The base of such azoning is the information provided by studies and researches in all areas of the related knowledge.

This means investment in science without immediate profits which is not always understood as important bygovernments and politicians. And sometimes the new rules would antagonize local interests in the benefit of a whole.

Naturally investments in the presently weak infra-structure are also desirable.

One realizes the attractions of Ribeira Valley are not well known outside the valley and after the necessary improvementin the reception facilities campaigns should be made in and outside of the country to publicize it.

The question of the HPPs along the Ribeira de Iguape River is a serious dilemma as the country desperately needs toimprove energy production to follow the general economic growth. The society must exhaustively discuss it to choose thebest way.

For more information:

Barbosa, A.F. & Guimares, J.E.P. 1946. Contribuio ao conhecimento da provncia metalogentica da regio da Ribeira,Estado de So Paulo, Brasil. In: Congresso Panamericano de Engenharia de Minas e Geologia, 2, Petrpolis, Anais, p. 35-100.

Bauer, H.E. 1890. As minas do Iporanga. Revista de Engenharia, 1890, Rio de Janeiro, p. 85-87, transcrito para O IGG,So Paulo, 1949, v. 7, no 4, p. 367-371.

Beljavskis, P.; Gonzales Filho, F.; Shimada, H.; Suslick, S. B. 1981. Mapa de jazidas e ocorrncias minerais do Estadode So Paulo. SICCT - Secretaria da Indstria, Comrcio, Cincia e Tecnologia do Estado de So Paulo. Programa de

Desenvolvimento de Recursos Minerais - PR-MINRIO/IPT (Publicao IPT n. 1171).

Brandi, R. & Shimada, H. 2006. O Ncleo Caboclos e o seu papel na histria das mineraes, no estudo das cavernas enos primrdios do PETAR. O Carste, Grupo Bambu de Pesquisas Espeleolgicas, Belo Horizonte, 2006, v. 1, n. 2, p. 40-65.

CGG - Commisso Geographica e Geologica do Estado de So Paulo. 1914. Explorao do Rio Ribeira de Iguape.Typographica Brazil de Rotschild & Co., So Paulo, 2 edio, 34 p.

CPRM - Cia. de Pesquisa de Recursos Minerais. 1980. Ouro nas regies aurferas dos Agudos Grandes e Morro do Ouro- Vale do Ribeira. Relatrio final. So Paulo, CPRM/SUREG-SP, 63 p.

CPRM/DNPM - Cia. de Pesquisa de Recursos Minerais/Depto. Nacional da Produo Mineral. 1972. Projeto Calcriopara Cimento. Relatrio Final, So Paulo, CPRM/SUREG-SP.




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Daitx, E.C. 1996. Origem e evoluo dos depsitos sulfetados tipo Perau (Pb-Zn-Ag), com base nas jazidas de Canoas ePerau (Vale do Ribeira, PR). Tese de doutoramento, Instituto de Geocincias e Cincias Exatas, UNESP, Rio Claro,453 p.

Felicssimo Jr., J. & Guimares, J.E.P. 1950. Apanhado sobre os recursos minerais do Estado de So Paulo. O IGG,Instituto Geogrfico e Geolgico, So Paulo, V. VIII, abril-junho/1950.

Guimares, J.E.P. 1966. Grutas Calcrias. Boletim do Instituto Geogrfico e Geolgico, So Paulo, n.. 47, p. 9-70.

Handa, T. 1987. O imigrante japons: Histrias de sua vida no Brasil. So Paulo: T.A. Queiroz/Centro de Estudos Nipo-Brasileiros, 1987, 220 p.

IBGE - Instituto Brasileiro de Geografia e Estatstica. 2000. Censo demogrfico2000.(http://www.ibge.gov.br/home/estatistica/populacao/default_censo_2000.shtm)

Le Bret, M. 1955. Maravilhoso Brasil subterrneo. Editora Japi, 1995. Traduo do original Merveilleux Bresil Souterrain,1975.

Lopes Jr., I. 2005. Atlas geoqumico do Vale do Ribeira: geoqumica dos sedimentos ativos de corrente. CPRM -Companhia de Pesquisa de Recursos Minerais, So Paulo, 2005, 77p. Il.

Krone, R. 1898. As grutas calcreas de Iporanga. Revista do Museu Paulista, So Paulo, 1898, v.3.

Krug, E. 1938. A Ribeira de Iguape. Boletim de Agricultura - Srie 39 - 1938, Diretoria de Publicidade Agrcola,Secretaria da Agricultura, Indstria e Commrcio do Estado de So Paulo, So Paulo, 1939.

Moraes, R.; Gerhard, P.; Andersson, L.; Shimada, H.; Sturve, J.; Rauch, S.; Molander, S. 2002. Assessing EcologicalRisks of Abandoned Lead Mines to Aquatic Fauna. Department of Environmental Systems Analysis, Chalmers Universityof Techology, ESA-Report 2002:3 (ISSN 1404-8167), Gteborg, Sweden 2002, 33 p.

Morgental, A.; Paiva, I.P.; Borin Jr, T.; Pinto, G.G.; Carmo, L.S. 1981. Pesquisa de ouro no Vale do Ribeira - Atuao daCPRM. In: Simpsio Regional de Geologia, 3, Curitiba, Anais...,SBG, v.1, p. 56-70.

Nogueira, S.A.A. 1990. Estudo das mineralizaes filoneanas aurferas do depsito de Piririca, Vale do Ribeira, SP.Dissertao de Mestrado, Universidade de So Paulo, Instituto de Geocincias, 91 p. (indito).

Nogueira, S. A. A.; Teixeira, A. L.; Shimada, H.; Negri, F. A.; Montanheiro, T. J. 2004. Planejamento da Minerao no Valedo Ribeira e Litoral Sul do Estado de So Paulo. In: Congresso Brasileiro de Geologia, 42, Arax, Anais (CD-ROM)...,SBG, Belo Horizonte, Simpsio 04, trab. 964.

Shimada, H.; Motta, J. F. M.; Cabral Jr., M.; Nakano, S. 1981. Prospeco de turfa no Estado de So Paulo. In: SimpsioRegional de Geologia, 3, Curitiba, Atas..., SBG, 1981, p.259-273.

Motta, J.F.M.; Nakano, S.; Shimada, H.; Nucci, O.; Milko, P.E.; Coelho, J.C.1982. Turfa : a experincia do IPT noscampos geolgico e tecnolgico. In: Congresso Brasileiro de Geologia, 32, Salvador, Anais..., SBG, 1982, 5:2238-2251.

Shimada, H.; Silva, M. H. B. da; Robles, R. A.; Reis, J. M. dos. 1998. Antigas minas de chumbo-prata do ParqueEstadual Turstico do Alto Ribeira (SP): estudos para recuperao e insero no contexto do desenvolvimento sustentvel.In: Congresso Brasileiro de Geologia, 40, Anais..., SBG, Belo Horizonte, p. 205.




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