RELEVO BRASILEIRO | Tipos, Formas e Características

Geography of Brazil: Understanding Its Relief

Overview of Brazilian Relief

• The geography of Brazil is closely linked to its relief, characterized by low and medium altitudes. The predominant landforms are plateaus and depressions, which cover about 95% of the territory.

• The remaining 5% consists of plains. Relief refers to the shapes on Earth's surface formed by tectonic movements and volcanism, influenced by both internal and external factors.

Classification of Brazilian Relief

• In the 1990s, geographer Jurandyr Ross proposed a classification system identifying 28 relief units in Brazil based on three main forms: plateau, plain, and depression.

Types of Plateaus

• Plateaus are elevated flat terrains above 300 meters characterized by erosive wear. They can be classified into:

• Sedimentary Plateau: Formed from sedimentary rocks.

• Crystalline Plateau: Composed of magmatic and metamorphic rocks.

• Basaltic Plateau: Made up of volcanic rocks.

Characteristics of Plains

• Plains are flat areas with altitudes below 100 meters where sediment accumulation predominates. Types include:

• Coastal Plain: Formed by marine action.

• Fluvial Plain: Created by river activity.

• Lacustrine Plain: Resulting from lake actions.

Depressions Explained

• Depressions arise from erosion processes with altitudes lower than surrounding areas (100 to 500 meters). They are categorized as:

• Absolute Depressions: Located below sea level.

• Relative Depressions: Lower than adjacent landforms but generally above sea level.

Detailed Examination of Brazilian Plateaus

• Brazil's landscape is predominantly composed of plateaus featuring various formations such as peaks, hills, and chapadas. Key regions include:

• Central Plateau: Spanning states like Minas Gerais and Goiás; home to rivers like São Francisco.

• Guianas Plateau: One of the oldest geological formations with tropical vegetation; includes Pico da Neblina (3,000m).

• Other notable plateaus include the Brazilian Plateau (Pico da Bandeira at ~2,900m), Meridional Plateau, Northeastern Plateau, among others.

Insights into Brazilian Plains and Depressions

• Significant plains include:

• Amazonian Plain: Found in states like Acre and Amazonas; features floodplains and terraces.

• Pantanal Plain: Located in Mato Grosso; known for being the world's largest floodplain.

• Coastal Plain: Extends approximately 600 km along Brazil's coastline.

• Major depressions consist mainly of:

• Northern/Southern Amazonian Depressions, often seen as part of the Amazon River plain.