London: New insights gleaned from volcanic rock have helped scientists unlock the mystery of how our planet evolved 4.5 billion years ago.
Studies of basalt, the material that forms from cooling lava, are being used to develop a time-line of how the planet and its atmosphere were formed.
Scientists examined liquid basalt - or magma - at record high pressures and temperatures.
Their findings suggest molten magma once formed an ocean within the Earth`s mantle, comprising two layers of fluid separated by a crystalline layer.
Scientists agree that Earth formed around 4.5 billion years ago, at which time much of the planet was molten. As it cooled, Earth`s crust was formed.
Researchers are keen to pin down how the planet`s core and crust took shape and how its volcanic activity developed.
The discovery by a European team of scientists involving the University of Edinburgh, using hi-tech laboratories, supports current theories of how and when our planet evolved.
To recreate conditions at the Earth`s core, scientists placed basalt under pressures equivalent to almost one billion times that of Earth`s atmosphere and temperatures above 2000 degrees Celsius.
They found that at high pressure, silicon atoms in the basalt change the way in which they form bonds, which results in a denser magma.
Their discovery helps pinpoint how magma behaves deep in the Earth and is a missing piece in the puzzle of how Earth`s core formed.
The study was published in the journal Nature.