Geology of Brazil

Brazil Travel / Geology - Based on radiometric dating, it is nowadays believed that the Earth was formed about 4,5 billion years ago, from collisions among countless meteors that made up the early solar system. Its surface was an ocean of molten rock, with very high temperatures, similar to the conditions on the sun.

During Hadean times, Earth was slowly cooling down and its chemical and physical basic structure was formed. The heavier elements, such as iron and nickel, sank into the Earth's core (6.371 - 2.900 km) and the lighter elements, such as Oxygene, Silicon and Aluminium rose into the Earth's viscous mantle (2.900 km - 40 km).

After 1 billion years, the Earth's outer silicate solid volcanic crust (40 - 0 km) has been formed. Unfortunately, no rocks have survived from Hadean times.

The oldest rocks found on Earth, are from Archean times (< 3,5 Ga) and are all characterized by a unique, rounded pillow shape which is only formed when lava solidifies under deep water. Accordingly, it is believed that the Hadean Earth was almost entirely covered by a primeval, iron - rich, green - colored ocean. Geologists are divided about the origin of this hot and toxic water world but some believe that it was brought in in the water - rich asteroids and comets that collided with Earth in the beginning.