Trans-Amazonian cycle

The Trans-Amazonian cycle was a significant geological event in South America's Precambrian history, occurring approximately 2.2 to 1.8 billion years ago. This cycle involved the formation of mountain chains, known as orogenic belts, along continental margins or through collisions between continental blocks. These collisions are thought to have contributed to the formation of an early supercontinent around 1.8 billion years ago.1

The Trans-Amazonian cycle's rocks are categorized into three groups: orogenic belts, stable cover rocks, and extensive dike swarms. Orogenic belts represent ancient mountain ranges, while stable cover rocks are sedimentary layers. Dike swarms are groups of igneous rock intrusions. This cycle is crucial for understanding the Precambrian core of South America, including cratons like Amazonia and São Francisco.1