<p>The young Earth's mantle harboured two magma oceans which were layered like a pudding cake, scientists say.<br /><br /></p>.<p>Using the world's most brilliant X-ray source, scientists have for the first time peered into molten magma at conditions of the deep Earth mantle.<br /><br />The analysis at Deutsches Elektronen-Synchrotron (DESY)'s light source PETRA III revealed that molten basalt changes its structure when exposed to pressure of up to 60 gigapascals (GPa), corresponding to a depth of about 1400 kilometres below the surface. <br /><br />At such extreme conditions, the magma changes into a stiffer and denser form, the team led by first author Chrystele Sanloup from the University of Edinburgh said.<br /><br />The findings support the concept that the early Earth's mantle harboured two magma oceans, separated by a crystalline layer.<br /><br />Today, these presumed oceans have crystallised, but molten magma still exists in local patches and maybe thin layers in the mantle.<br /><br />"Silicate liquids like basaltic magma play a key role at all stages of deep Earth evolution, ranging from core and crust formation billions of years ago to volcanic activity today," Sanloup said.<br /><br />To investigate the behaviour of magma in the deep mantle, the researchers squeezed small pieces of basalt within a diamond anvil cell and applied up to roughly 600,000 times the standard atmospheric pressure.<br /><br />The team used two strong infrared lasers that each concentrated a power of up to 40 Watts onto an area just 20 micrometres (millionths of a metre) across - that is about 2000 times the power density at the surface of the Sun.<br /><br />"For the first time, we could study structural changes in molten magma over such a wide range of pressure," said co-author Zuzana Konopkova from DESY.<br /><br />The study was published in the journal Nature. </p>
<p>The young Earth's mantle harboured two magma oceans which were layered like a pudding cake, scientists say.<br /><br /></p>.<p>Using the world's most brilliant X-ray source, scientists have for the first time peered into molten magma at conditions of the deep Earth mantle.<br /><br />The analysis at Deutsches Elektronen-Synchrotron (DESY)'s light source PETRA III revealed that molten basalt changes its structure when exposed to pressure of up to 60 gigapascals (GPa), corresponding to a depth of about 1400 kilometres below the surface. <br /><br />At such extreme conditions, the magma changes into a stiffer and denser form, the team led by first author Chrystele Sanloup from the University of Edinburgh said.<br /><br />The findings support the concept that the early Earth's mantle harboured two magma oceans, separated by a crystalline layer.<br /><br />Today, these presumed oceans have crystallised, but molten magma still exists in local patches and maybe thin layers in the mantle.<br /><br />"Silicate liquids like basaltic magma play a key role at all stages of deep Earth evolution, ranging from core and crust formation billions of years ago to volcanic activity today," Sanloup said.<br /><br />To investigate the behaviour of magma in the deep mantle, the researchers squeezed small pieces of basalt within a diamond anvil cell and applied up to roughly 600,000 times the standard atmospheric pressure.<br /><br />The team used two strong infrared lasers that each concentrated a power of up to 40 Watts onto an area just 20 micrometres (millionths of a metre) across - that is about 2000 times the power density at the surface of the Sun.<br /><br />"For the first time, we could study structural changes in molten magma over such a wide range of pressure," said co-author Zuzana Konopkova from DESY.<br /><br />The study was published in the journal Nature. </p>