CLUES to major environmental events throughout Earth's long history are contained in the rocks deep below our planet's crust – a record that could help scientists deal with modern events like climate change and global warming.
An expert at unearthing these historical secrets is Professor David Bell, incumbent of Nelson Mandela Metropolitan University's (NMMU) new Research Chair in Earth Systems Science.
This is a new field of science that attempts to look at the way Earth functions holistically.
"There is a close interdependence between biology and the physical Earth – geology, physics and chemistry," Bell said.
A geochemist whose research background has been in the area of deep Earth studies, Bell, 54, said Earth's history was recorded not only in the rocks of the crust, but also in parts of the underlying mantle (between the crust and the core of the Earth).
"This rock record bears witness to Earth's past events ... it shows the way Earth has evolved as a system over more than three billion years."
He said the challenge for scientists was determining where modern events like global warming and climate change fitted in.
South Africa had a "fantastic wealth of mantle samples", Bell said. "It is probably the best place in the world to study ancient mantle."
These fragments are usually pushed up from deep Earth through volcanic activity, and are then uncovered by diamond mining operations. "We have many samples from depths up to 200km below [the] surface."
The born-and-raised Capetonian majored in chemistry, zoology and geology for his BSc at the University of Cape Town (UCT). He went on to complete his honours in geology at UCT and later his PhD in geochemistry at the California Institute of Technology (Caltech).
While studying deep Earth samples at Caltech he made his best-known research discovery. "I found traces of water in minerals at great depth ... there's a reservoir of water, at least as much as an ocean, bound in the minerals of the solid Earth."