Phys.org has a post about a new way to date rocks.  Scientists at the University of Queensland have developed a way to date rocks by analyzing a silicate mineral known as garnet.  The method is detailed in a paper which appeared in the Journal GSA Bulletin.

A new way to date a common mineral could help pinpoint ore deposits and improve mineral exploration globally, according to University of Queensland scientists.

The researchers have identified a new reference material and used a state-of-the-art instrument to better date rock formations in central Asia.

UQ’s Professor Jian-xin Zhao said the team started by analyzing a silicate mineral known as garnet, which then helped understand the accumulation of precious minerals such as gold, copper, lead zinc, silver and uranium.

“Garnet, which looks a little like the seeds of a pomegranate, is a challenging mineral to date but very common in volcanic mineral systems,” Professor Zhao said.

“It forms when hot magma enters the subsurface of the Earth’s crust and it gives us clues about other magmatic formations in the same area.

“Magmatic activity is a key Earth process and leads to mineralization—many of the world’s major mineral districts including Australia’s Mt Isa and Olympic Dam were formed during a long history of magmatic activities.