Leblon Quartzite Blocks

Leblon Quartzite, whose name refers to the famous beach of Rio de Janeiro, also has its formation directly linked to the sea and its level variations on the Brazilian coast.
Around 1.6 billion years ago, the increase in the planet's average temperature promoted a thermal expansion of the oceans, causing glaciers to melt and consequently increase the volume and rise in sea level. This advance of the coastline towards the continent caused the water to reach surfaces that previously did not suffer marine interference, starting to erode the pre-existing rocks and depositing new sediments.
There was also the contribution of colored pebbles, of larger sizes, carried by ephemeral (temporary) rivers originated from the flow of rainwater from the constant storms of the period. Therefore, seas and rivers contributed to the structuring of the forms found today in Leblon quartzites, and the low level of metamorphism that these rocks suffered contributed to their preservation.