The Borborema Plateau (

Portuguese Portuguese may refer to: * anything of, from, or related to the country and nation of Portugal ** Portuguese cuisine, traditional foods ** Portuguese language, a Romance language *** Portuguese dialects, variants of the Portuguese language ** Portu ...

''Planalto da Borborema'', also known as the ''Serra da Borborema'') is a plateau in northeastern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

which extends across the states of

Pernambuco Pernambuco () is a state of Brazil, located in the Northeast region of the country. With an estimated population of 9.6 million people as of 2020, making it seventh-most populous state of Brazil and with around 98,148 km², being the ...

Paraíba Paraíba ( Tupi: ''pa'ra a'íba''; ) is a state of Brazil. It is located in the Brazilian Northeast, and it is bordered by Rio Grande do Norte to the north, Ceará to the west, Pernambuco to the south and the Atlantic Ocean to the east. Paraíba ...

, and

Rio Grande do Norte Rio Grande do Norte (, , ) is one of the states of Brazil. It is located in the northeastern region of the country, forming the northeasternmost tip of the South American continent. The name literally translates as "Great Northern River", re ...

. The plateau is the northeasternmost portion of the

Brazilian Highlands The Brazilian Highlands or Brazilian Plateau ( pt, Planalto Brasileiro) are an extensive geographical region, covering most of the eastern, southern and central portions of Brazil, in all approximately half of the country's land area, or some 4 ...

and is the most relevant watershed of its region. It ranges approximately from north to south and from east to west. More than 100 rivers originate from the plateau, including the Moxotó, Mundaú, Pajeú,

Paraíba do Norte Paraíba ( Tupi: ''pa'ra a'íba''; ) is a state of Brazil. It is located in the Brazilian Northeast, and it is bordered by Rio Grande do Norte to the north, Ceará to the west, Pernambuco to the south and the Atlantic Ocean to the east. Paraíb ...

, Seridó, and

Una Una and UNA may refer to: Places * 160 Una, the asteroid "Una", an asteroid named after the Faerie Queene character * Una River (disambiguation), numerous rivers * Una, Himachal Pradesh, a town in India ** Una, Himachal Pradesh Assembly constit ...

. The Borborema Plateau serves as an

orographic Orography is the study of the topographic relief of mountains, and can more broadly include hills, and any part of a region's elevated terrain. Orography (also known as ''oreography'', ''orology'' or ''oreology'') falls within the broader disci ...

barrier, despite its relatively low elevation, against the moist easterly winds of the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. Areas west of the plateau, which make up part of the

sertão The ''sertão'' (, plural ''sertões'') is the "hinterland" or "backcountry". In Brazil, it refers both to one of the four sub-regions of the Northeast Region of Brazil (similar to the specific association of " outback" with Australia in Englis ...

, are arid and prone to drought. The Pajeú River, the largest tributary of the

São Francisco River The São Francisco River (, ) is a large river in Brazil. With a length of , it is the longest river that runs entirely in Brazilian territory, and the fourth longest in South America and overall in Brazil (after the Amazon, the Paraná and t ...

, originates from the Borborema.

Geology

The Borborema Plateau is part of a huge

anastomosing An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal ...

shear zone In geology, a shear zone is a thin zone within the Earth's crust or upper mantle that has been strongly deformed, due to the walls of rock on either side of the zone slipping past each other. In the upper crust, where rock is brittle, the she ...

. The plateau is composed primarily of

igneous Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or ...

and

metamorphic Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...

rock.

References

Mountain ranges of Brazil {{RioGrandedoNorte-geo-stub