Glass House Mountains (Queensland)

Glass House Mountains
Aerial photo of Glass House Mountains township with the Glass House Mountains in the distance
Highest point
Peak	Mount Beerwah
Elevation	556 m (1,824 ft)
Geography
Country	Australia
State	queensland
Region	South East Queensland
Range coordinates	26°54′S 152°55′E / 26.900°S 152.917°E / -26.900; 152.917Coordinates: 26°54′S 152°55′E / 26.900°S 152.917°E / -26.900; 152.917
Geology
Formed by	Volcanic plugs
Age of rock	Tertiary

The Glass House Mountains are a group of eleven hills that rise abruptly from the coastal plain on the Sunshine Coast, Queensland, Australia. The highest hill is Mount Beerwah at 556 meters above sea level, but the most identifiable of all the hills is Mount Tibrogargan which from some directions appears to be a face staring out to sea. Mt Ngungun is a sub volcanic mountain. This means Mount Ngungun is a sub volcanic rock also known as a Hypabyssal Rock. It is an intrusive rock that is emplaced at medium to shallow depths within the crust, and has intermediate grain size and often Porphyritic texture between that of Volcanic and Plutonic rocks. Mount Ngungun and the Glass House Mountains are located near Beerburrum State Forest and Old Gympie Road. From Brisbane, follow the Bruce Highway north, take the Glass House Mountains tourist drive turn-off and follow the signs to the Glass House Mountains. The trip is about one hour and eleven minutes from Brisbane. The Volcanic peaks of the Glass House Mountains rise dramatically from the surrounding Sunshine Coast landscape. They were formed by intrusive plugs, remnants of volcanic activity that occurred 25-27 million years ago. Molten rock filled small vents or intruded as bodies beneath the surface and solidified into land rocks. Millions of years of erosion have removed the surrounding exteriors of volcanic cores and softer sandstone rocks.

Whilst the traditional names for the hills themselves are very old, the term 'Glasshouse Mountains' was given more recently by explorer Captain James Cook on 17 May 1770. The peaks reminded him of the glass furnaces in his home county of Yorkshire.Matthew Flinders explored the area and climbed Mount Beerburrum after sailing along Pumicestone Passage in 1799. The Glass House Mountains National Landscape was added to the Australian National Heritage List on 3 August 2006. In the land between the peaks, pineapple and poultry farming, as well as commercial forestry and quarrying are the main land uses.

The range was formed as molten lava cooled to form hard rock in the cores of volcanoes between 26-27 million years ago. The source of the lava was from the East Australia hotspot. The cores of the hills contain columns of comendite from lava which cools quickly into a hard rock. The surrounding softer rocks have been eroded in the subsequent time, forming the spectacular volcanic plugs that remain today. The peaks' location relative to each other exhibits an alignment that is believed to have occurred due to fracturing.