The work was carried out by researchers at the University of Australian School of Petroleum in which Santos sponsors and the University of Aberdeen's Natural Environment Research Council Centre for Doctoral Training in Oil and Gas. 

 

Despite the Cooper Basin currently being Australia's largest onshore oil and gas producing region, the ancient Jurassic volcanic underground landscape has largely gone unnoticed. 

 

The research team from the University of Adelaide and the University of Aberdeen used advanced subsurface imaging techniques, comparable to medical CT scanning, to identify the plethora of volcanic craters and lava flows and deeper magma chambers that fed them.

 

In a nod to the Australian cricket legend, they've called the volcanic region the Warnie Volcanic Province. 

 

While the Cooper is home to operations by Cooper Energy, Santos, and Beach Energy as well as a number of smaller players including recent entrant Oilex, researchers say in Jurassic times it would have been filled with craters and fissures, spewing hot ash and lava into the air and surrounded by networks of river channels, evolving into large lakes and coal-swamps. 

 

"While the majority of the Earth's volcanic activity occurs at the boundaries of tectonic plates, or under the Earth's oceans, this ancient Jurassic world developed deep within the interior of the Australian continent," University of Adelaide's Australian School of Petroleum's associate professor and co-author Simon Holford said. 

 

"Its discovery raises the prospect that more undiscovered volcanic worlds reside beneath the poorly explored surface of Australia." 

 

This latest discovery, published in the journal Gondwana Research, suggests a lot more volcanic activity in the Jurassic period than previously supposed. 

 

"The Cooper-Eromanga basins have been substantially explored since first gas discovery in 1963," University of Aberdeen associate professor and co-author Nick Schofield said.

 

"This has led to a massive amount of available data from underneath the ground but, despite this, the volcanics have never been properly understood in this region until now - it changes how we understand processes that have operated in Earth's past." 

 

The researchers named their discovery after one of the drill holes that penetrated Jurassic volcanic rocks, Warnie-East-1, itself named after a nearby waterhole. 

 

The well was spud in Queensland's share of the Cooper in 1985 by Delhi Petroleum. 

 

The research was carried out by Jonathon Hardman, then a PhD student at the University of Aberdeen, as part of the Natural Environment Research Council Centre for Doctoral Training in Oil and Gas.