Dating of volcanic rocks nsw
Mount Beerwah is the highest of ten volcanic plugs in the Glass Houses. The original mountain is thought to be up to three times higher than the higher of two peaks of Beerwah’s 556 m. There are two volcanic formations in the southern Main Range, the Governors Chair Volcanics and the Superbus Basalt.Remaining plugs, domes, sills and dikes are generally trachytes. And there are rhyolites in the region, though no recognized pyroclastics. Maximum total thickness near 900 m of lavas with some pyroclastics.It thins to the east and underlies early basalts of the Tweed volcano. Note eroded plug Mount Warning in the center, drainage to the south and east, and the heavily eroded central caldera. https://gov/topics/earth/features/srtm/pia06664Tweed The Tweed volcano is a 100 km diameter shield volcano, heavily eroded, centered on Mount Warning, the remaining volcanic plug. There is a 30 km diameter heavily eroded caldera that separates the central core of the volcano from its surrounding flanks. Original coverage may have been as extensive as 7,000 km2. They flowed all the way east into the Pacific Ocean.There are rhyolitic lavas in the Hillview and Mount Lindesay areas. There is a suggested caldera centered on Focal Peak similar in shape to Hawaiian calderas based on slope of underlying rocks centered on a 6.5 km diameter central plug. The original height of the shield is estimated at 1,900 m.There are numerous forests in NSW and mining mainly west of the range.Agriculture is spread generally in the eastern two thirds of the state. Finally there over 780 national parks and reserves in the state. https://bellsinequality.wordpress.com/tag/bargara/ Southern Queensland Volcanics Bundaberg and Boyne There are several smaller volcanic fields along the Burnett River in southern Queensland.
Much of it positively ancient, though with the caveat that activity is generally younger the farther south you go in NSW.The Superbus basalts overlie the remains of the Governors Chair and cover 1,600 km2. Maximum total thickness of the lava pile exceeded 600 m. Brisbane There are basalt lava flows dating 55 Ma and 47 Ma. Focal Peak Focal Peak is a recently identified eroded shield volcano 60 km WNW of the Tweed / Mount Warning volcano.Its presence was inferred from the presence of eruptive rocks in the Lamington Group, the Albert Basalt and the Mount Gillies Volcanics.Welcome to the third in our series on volcanic activity in Australia.This post will clean up the remaining volcanic fields and provinces in southern Queensland and then work our way south through New South Wales (NSW).