For almost a century, geochemists have been making minerals and rocks in high-pressure high-temperature laboratory experiments. Water fluxes melting rocks and increases melt viscosity. By changing the water content, measuring geothermal gradients and melting rocks at different temperatures and pressures, we get a pretty good idea of what happens deep down in the Earth and way back in time.

In the late 18th Century, Abraham Werner (1750-1817 AD) of the Bergakademie, Freiberg (Saxony) proposed that granite was originally an ocean sediment. European scientists agreed and the science was settled. The founder of modern geology, Scottish naturalist James Hutton (1726-1797 AD), argued that granite was once a molten rock that solidified at great depth. In Britain, Hutton’s ideas were the settled science. Consensus has never existed in science.

At Siccar Point in Scotland, Hutton observed sequences of sandstones that demonstrated deep time with long periods of no sedimentation. He concluded that modern processes are the same as past processes and that the planet is dynamic. Hutton was forced to abandon his belief in young Earth creationism because of his own scientific evidence.

With the ability to observe granite at different erosional levels all over the world and to make granite in the laboratory, our knowledge of granite has increased. Granite melts are an emulsion of liquid rock, gas and solids. They are buoyant mainly because of dissolved gases, principally water vapour. The solids are crystals, fragments of wall rocks ripped off as the molten rock ascended and fragments of the parental rocks that were partially melted to produce a granite melt.

Granite forms at depth from the partial melting of older sedimentary rocks, partial melting of igneous rocks or is the last melt fraction from the cooling of a large body of molten rock. The minerals of a granite can be used to calculate the depth of solidification and, by using granite radioactivity, the time of solidification of a granite can be calculated.

At Poolamacca Station on Campbells Creek 50 km north of Broken Hill, a two-mica granite solidified 1,590 million years ago at a depth of at least 20 kilometres. Draped over the granite outcrop is lithified ancient glacial debris called tillite. Magnetic minerals in the tillite show that debris left behind by glaciers was at the equator and magnetic studies of similar tillites all over the world show that at that time globe-covering ice sheets were kilometres thick at sea level.

The tillite at Poolamacca contains rounded fragments of the underlying two-mica granite showing that the granite must have been exposed to the surface 700 million years ago during glaciation to enable moving ice to pluck and round granite boulders from the substrate and dump these boulders at the surface as ice sheets retreated.

Experimental mineralogy shows that dolomite can only form as a shallow marine mud when there is an exceptionally high atmospheric carbon dioxide content. Because dolomite was a universal rock type at that time and common at Poolamacca, it is concluded that the atmosphere contained at least 20 per cent carbon dioxide during glaciation yet our climate activists claim that a very slight increase from the current 0.04 per cent atmospheric carbon dioxide will create a global warming climate catastrophe.

The chemistry of the granite at Poolamacca shows it formed from the compression and heating 1,590 million years ago of 1,660-million-year-old muddy rocks formed in a temperate to tropical climate. A Himalayan-type mountain range formed along the eastern boundary of the continent of Australia 1,590 million years ago. The mountain range has since been flattened by the removal of at least 20 kilometres of overlying rocks over a 900-million-year period and only the mountain range root remains. The mountain range rose by removal of material during erosion.

The same is happening today in the Himalayas. In my life, Mount Everest has risen 60 centimetres and one day it will not be the highest mountain on Earth. Others are rising faster. Gravity, erosion and weathering keep removing material from the mountains as they are rising. If you are ever asked in a quiz show ‘How high is Mount Everest?’, the only correct answer is ‘When?’

The land level goes up and down, as does sea level. It’s not possible to talk of sea-level change without discussing land-level change in the same breath. It’s not possible to observe a rock outcrop without seeing evidence of past climate change.

The East India Company undertook the Great Trigonometrical Survey of India between 1802 and 1832 to provide accurate maps of India. The survey covered 165,342 square miles. Surveyors found that close to the Himalayas, the plumb bob was not vertical and a correction for the gravitational pull of the mountains was applied. This correction created slightly greater accuracy. It was then concluded that mountains must have roots with a gravitational influence. When the gravitational pull of the roots of the Himalayas was also used in calculations, the survey then had a very high degree of accuracy.

The collision of the Eurasian and Indian plates 50 million years ago led to the rise of the Tibetan Plateau which created frequent massive earthquakes. Sedimentary rocks 200 million years old deep under the Plateau melted under high pressure and high temperature to form granites. They did not rise to the surface to erupt as volcanoes because the high dissolved water content. The same happened at Poolamacca aeons ago.

There is a theory that the weathering of the freshly-exposed rocks of the Tibetan Plateau withdrew carbon dioxide from the atmosphere which led to the present glaciation. This theory is rejected because atmospheric carbon dioxide has been declining since the appearance of complex life on Earth 520 million years ago and glaciation is cyclical with no relationship to mountain building.

In the 1860s, Poolamacca was one of the early sheep stations in the rough hilly Barrier Ranges. There was a false gold rush in the area in the 1860s, a tin rush at nearby Euriowie in the 1880s and Tarrawingee, a town of 400, was established in 1890 to provide limestone flux that was transported to the Broken Hill smelters along a tramway. Tarrawingee now has neither residents nor buildings. The tramlines were cut up for fence posts from 1932 for a regeneration area encircling Broken Hill. The regeneration area greened Broken Hill and reduced temperature extremes and dust storms. This first revegetation program in Australia was paid for and undertaken by the mining companies. There was not a greenie in sight.

I first stayed at Poolamacca in 1968. It was one of the grandest historical stations in far-western NSW. Previously it was in the heart of the Kidman empire. Since acquisition using taxpayer’s money by the Wilyakali Aboriginal Corporation in 2002, the historical fences, shearing shed, shearing quarters and homestead have gone to rack and ruin and are full of garbage. There has been no maintenance and Poolamacca will soon just be a pile of rubble like so many other outback stations.

Why do Aboriginal corporations want Aboriginal history preserved and yet allow settlement history to be destroyed?