Editing Geography of Brazil (section)

== Geology, geomorphology and drainage ==
In contrast to the [[Andes]], which rose to elevations of nearly {{convert|7000|m|ft|0|sp=us}} in a relatively recent epoch and inverted the Amazon's direction of flow from westward to eastward, [[Geology of Brazil|Brazil's geological formation]] is ancient.<ref name="Hudson-1998" /> [[Precambrian]] crystalline shields cover 36% of the territory, especially its central area.<ref name="Hudson-1998" /> The dramatic granite [[bornhardt|sugarloaf mountains]] in the city of Rio de Janeiro is an example of the terrain of the Brazilian shield regions, where continental basement rock has been sculpted into towering domes and columns by tens of millions of years of [[erosion]], untouched by mountain-building events.

The principal mountain ranges average elevations under {{convert|2000|m|ft|0|sp=us}}.<ref name="Hudson-1998" /> The [[Serra do Mar]] Range hugs the Atlantic coast, and the [[Serra do Espinhaço]] Range, the largest in area, extends through the south-central part of the country.<ref name="Hudson-1998" /> The highest mountains are in the Tumucumaque, [[Pacaraima]], and Imeri ranges, among others, which traverse the northern border with the Guianas and Venezuela.<ref name="Hudson-1998" />

In addition to mountain ranges (about 0.5% of the country is above {{convert|1200|m|ft|0|abbr=on|disp=or}}), Brazil's Central Highlands include a vast central plateau ([[Planalto Central]]).<ref name="Hudson-1998" /> The plateau's uneven terrain has an average elevation of {{convert|1000|m|ft|0|sp=us}}.<ref name="Hudson-1998" /> The rest of the territory is made up primarily of sedimentary basins, the largest of which is drained by the [[Amazon River|Amazon]] and its tributaries.<ref name="Hudson-1998" /> Of the total territory, 41% averages less than {{convert|200|m|ft|0|sp=us}} in elevation.<ref name="Hudson-1998" /> The coastal zone is noted for thousands of kilometers of tropical beaches interspersed with [[mangrove]]s, [[lagoon]]s, and [[dune]]s, as well as numerous [[coral reef]]s.<ref name="Hudson-1998" /> A recent global remote sensing analysis also suggested that there were 5,389&nbsp;km<sup>2</sup> of tidal flats in Brazil, making it the 7th ranked country in terms of how much tidal flat occurs there.<ref>{{cite journal |last1=Murray |first1=N.J. |last2=Phinn |first2=S.R. |last3=DeWitt |first3=M. |last4=Ferrari |first4=R. |last5=Johnston |first5=R. |last6=Lyons |first6=M.B. |last7=Clinton |first7=N. |last8=Thau |first8=D. |last9=Fuller |first9=R.A. |title=The global distribution and trajectory of tidal flats |journal=Nature |date=2019 |volume=565 |issue=7738 |pages=222–225 |doi=10.1038/s41586-018-0805-8 |pmid=30568300 |s2cid=56481043 |url=https://www.nature.com/articles/s41586-018-0805-8}}</ref>

The [[Parcel de Manuel Luís Marine State Park]] off the coast of [[Maranhão]] protects the largest coral reef in South America.<ref>{{citation |title=Decreto nº 11.902 de 11 de Junho de 1991 |language=pt |author1=Edison Lobão|author2=Fernando César de Moreira Mesquita|date=11 June 1991|publisher=State of Maranhão |url=https://documentacao.socioambiental.org/ato_normativo/UC/305_20100823_151217.pdf|access-date=2016-08-03}}</ref>

[[Image:Brazil topo.jpg|thumb|250px|Topographic map of Brazil]]

Brazil has one of the world's most extensive [[river system]]s, with eight major [[drainage basin]]s, all of which drain into the Atlantic Ocean.<ref name="Hudson-1998" /> Two of these basins—the [[Amazon basin|Amazon]] and Tocantins-Araguaia account for more than half the total drainage area.<ref name="Hudson-1998" /> The largest river system in Brazil is the Amazon, which originates in the Andes and receives tributaries from a basin that covers 45.7% of the country, principally the north and west.<ref name="Hudson-1998" /> The main Amazon river system is the Amazonas-Solimões-Ucayali axis (the {{convert|6762|km|mi|0|adj=on|sp=us}}-long Ucayali is a Peruvian tributary), flowing from west to east.<ref name="Hudson-1998" /> Through the Amazon Basin flows one-fifth of the world's fresh water.<ref name="Hudson-1998" /> A total of {{convert|3615|km|mi|0|sp=us}} of the Amazon are in Brazilian territory.<ref name="Hudson-1998" /> Over this distance, the waters decline only about {{convert|100|m|ft|-1|sp=us}}.<ref name="Hudson-1998" /> The major tributaries on the southern side are, from west to east, the Javari, Juruá, Purus (all three of which flow into the western section of the Amazon called the [[Solimões]]), [[Madeira River|Madeira]], [[Tapajós]], [[Xingu River|Xingu]], and [[Tocantins River|Tocantins]].<ref name="Hudson-1998" /> On the northern side, the largest tributaries are the [[Branco River|Branco]], [[Japurá River|Japurá]], [[Jari River|Jari]], and [[Rio Negro (Amazon)|Rio Negro]].<ref name="Hudson-1998" /> The above-mentioned tributaries carry more water than the Mississippi (its discharge is less than one-tenth that of the Amazon).<ref name="Hudson-1998" /> The Amazon and some of its tributaries, called "white" rivers, bear rich sediments and hydrobiological elements.<ref name="Hudson-1998" /> The black-white and clear rivers—such as the Negro, Tapajós, and Xingu—have clear (greenish) or dark water with few nutrients and little sediment.<ref name="Hudson-1998" />

The major river system in the Northeast is the [[São Francisco River|Rio São Francisco]], which flows {{convert|1609|km|mi|0|sp=us}} northeast from the south-central region.<ref name="Hudson-1998" /> Its basin covers 7.6% of the national territory.<ref name="Hudson-1998" /> Only {{convert|277|km|mi|0|sp=us}} of the lower river are navigable for oceangoing ships.<ref name="Hudson-1998" /> The [[Paraná River|Paraná]] system covers 14.5% of the country.<ref name="Hudson-1998" /> The Paraná flows south among the [[Río de la Plata Basin]], reaching the Atlantic between Argentina and Uruguay.<ref name="Hudson-1998" /> The headwaters of the Paraguai, the Paraná's major eastern tributary, constitute the [[Pantanal]], the largest contiguous wetlands in the world, covering as much as {{convert|230000|km2|sqmi|-3|sp=us}}.<ref name="Hudson-1998" />

Below their descent from the highlands, many of the tributaries of the Amazon are navigable.<ref name="Hudson-1998" /> Upstream, they generally have [[Rapids|rapid]]s or [[waterfall]]s, and boats and barges also must face sandbars, trees, and other obstacles.<ref name="Hudson-1998" /> Nevertheless, the Amazon is navigable by oceangoing vessels as far as {{convert|3885|km|mi|0|sp=us}} upstream, reaching [[Iquitos]] in [[Peru]].<ref name="Hudson-1998" /> The Amazon river system was the principal means of access until new roads became more important.<ref name="Hudson-1998" /> Hydroelectric projects are [[Itaipu Dam|Itaipu]], in Paraná, with 12,600 MW; Tucuruí, in [[Pará]], with 7,746 MW; and [[Paulo Afonso]], in [[Bahia]], with 3,986 MW.<ref name="Hudson-1998" />

=== Natural resources ===
Natural resources in Brazil include bauxite, gold, iron ore, manganese, nickel, phosphates, platinum, tin, clay, rare earth elements, uranium, petroleum, hydropower, and timber.<ref name="World Factbook">{{citation-attribution|1={{Cite CIA World Factbook|country=Brazil|access-date=2020-10-29|year=2020}}}}</ref>