Natural Earth pump

In what is claimed to be the world's first, scientists have discovered a natural Earth pump which is involved in the formation of quakes and ore deposits.

An international team has found the natural pump -- in fact, the process called creep cavitation involves fluid being pumped through pores in deformed rock in mid-crustal shear zones, approximately 15 km below the Earth's surface. The fluid transfer through the middle crust also plays a major role in tectonic plate movement and mantle degassing, the Nature journal reported. 'We are seeing the direct evidence for one of the processes that got ore forming fluids moving up from the mantle to the shallow crust to form the ore deposits we mine today, it is also one of the mechanisms that can lead to earthquakes in the middle crust,' team member Rob Hough said.      In fact, the discovery was made by examining one millimetre sized cubes of exposed rock in Alice Springs, which was deformed around 320 million years ago during a period of natural mountain formation. According to team leader Dr Florian Fusseis of the University of Western Australia, the discovery could provide valuable information in understanding how quakes are formed.      'While we understand reasonably well why earthquakes happen in general, due to stress build-up caused by motions of tectonic plates, the triggering of earthquakes is much more complex.      'To understand the 'where' and 'when' of earthquakes, the 'how' needs to be understood first. We know earthquakes nucleate by failure on a small part of a shear zone,' he said.      While their sample did not record an earthquake, it gave the scientists an insight into the structures that can be very small and localised precursors of seismic failure planes.      The discovery was made possible through the use of high-resolution Synchrotron X-ray tomographic, scanning electron microscope observations at the nanoscale and advanced visualisation using iVEC in Western Australia.