Locker Shale and Mungaroo formation (a bit of information on...

Locker Shale and Mungaroo formation (a bit of information on this).

The Locker Shale and Mungaroo formation are associated with the syn-rift and post-rift sequences of the Permian extension that occurred just prior to the late Triassic extension event across the northwestern margin of Australia. Lying atop unconformable unit of Paleozoic sediments, the Locker Shale is composed of marine sediments deposited in a transgressional environment during the Late Permian extension.

These marine sediments were deposited at the base of the Late Triassic and continued up until the end of Anisian age when it transitioned in the Mungaroo Formation. The Mungaroo Formation is an intricate fluvial environment of meandering and braided stream deposits laid down in the Ladinian (~241 Mya) to Norian ages (~209 Mya) during the pre-rift active margin of the Northwestern Australian Shelf.

It is one of the thickest formations in the region and becomes progressively thicker (approximately 3,000 m thick) in the distal portions of the Northern Carnarvon Basin furthest offshore.  One of the primary gas source for the Exmouth Plateau and Northern Carnarvon Basin, the Mungaroo Formation contains thick successions of siltstone, sandstone, and coal.