Geology of Guayana and Brasília Massif

Guayana Massif

• Covered with sedimentary layers rich in minerals, especially iron and bauxite (primary raw material for aluminum).

Brasilia Massif

• Located in eastern South America, consists of ancient crystalline rocks.
• Largest Precambrian core in South America with extensive outcropping.
• Fractured during the Mesozoic era, impacting mineral distribution and leading to the formation of red lateritic soils suitable for subtropical crops like coffee and bananas.
• Major rivers in the Plata and Amazon basins have waterfalls, such as Iguazú Falls, contributing to energy production.
• Erosion has shaped elevated ridges into mountainous sierra features and created dome-shaped geological structures known as morros.
• Western tip features lower plateaus termed Chapadas, with prominent plateaus found in the south and southeast region.
• Climate varies from equatorial in the north to temperate in the south; rainfall decreases inland, especially in winter.
• In the northeast region, known as Sertão, experiences scarce precipitation, leading to alternating wet and dry cycles.
• Rich in mineral resources (coal, iron, oil) aiding regional development; intensive fruit agriculture in river valleys; suitable conditions for extensive sheep farming in plateaus.

Andes Mountain Range

• Extends approximately 8,500 km along the Pacific coast from Venezuela to the southern tip of South America.
• Originated over multiple stages during Mesozoic and Cenozoic eras; ongoing processes include volcanism and seismic activity caused by the movement of tectonic plates.
• Contains numerous peaks over 6,000 m, with Aconcagua at 6,959 m as the highest.
• Other significant peaks include Ojos del Salado, Monte Pissis, and Nevado de Huascarán, among others.
• The Andes influence climatic variation from warm to cold, with significant implications for human settlement and economic activities.
• Acts as a crucial water divide for rivers flowing into the Atlantic and Pacific Oceans.
• Geological formation is complex, involving folding and fracturing, which has enriched the region with mineral deposits like copper, tin, and silver.

Coastal Environment of the Pacific

• Coastal ranges are close to the Pacific Ocean, creating diverse environments from north to south.
• Northern and southern extremes show glacial activity forming fjords and unique coastal structures.
• North American Pacific coast features cities like Anchorage, Vancouver, and San Francisco; while South America highlights ports such as Guayaquil, Callao, and Valparaíso.
• Cold ocean currents impact climate and economic activities; upwelling phenomenon nurtures marine life, enhancing fishing resources.
• El Niño phenomenon occurs every 7-12 years, characterized by warm water currents, leading to ecological disruptions and severe weather impacts.

Coastal Environment of the Atlantic

• Ancient massifs east of the continent slope toward the Atlantic Ocean, creating diverse coastal types and plains.
• Atlantic coast served as a major entry point for European settlement; currently hosts significant urban agglomerations.
• From Newfoundland to the U.S. border, the coastline features harbors, bays, and peninsulas; significant economic areas include the Gulf of St. Lawrence and cities like Boston and New York.
• Southern coastlines feature warm climates, with resorts located in Florida.
• Central America has low coastal plains featuring mangroves, less suitable for population due to humidity.
• Important rivers such as Magdalena and Orinoco flow into the Atlantic; Lake Maracaibo is a notable oil-rich region.
• Brazilian Atlantic coastline is steep and narrow, hosting significant ports like Salvador, Rio de Janeiro, and Santos.