Last week there were a few comments that the Quiz on Structural Geology was not difficult enough – this week we have made it more of a challenge! Your challenge is to beat the GPTAPI that got 7/10 correct. Answers at the end.
Continue reading TEST YOUR ADVANCEDKNOWLEDGE ON: STRUCTURAL GEOLOGYSiem Reap has 98km of new roads and new sidewalks much of which has been paved with interesting felsic intrusive rocks from quarries in Shandong Province in China. The composition ranges from granodiorite to tonalite and is locally granophyric and pegmatitic. The intrusive consists dominantly of plagioclase, quartz, pyroxene and hornblende. Ovoid structures known as Miarolitic Cavities are evident in the sidewalks to the observant and indicates that the parental magma was hydrous.
Here we have attempted to reassemble a miarolitic cavity over ~1 metre of its length. Just bear in mind that this is dimension stone and its now the pavement. There are many places where there are a large number of slabs that are clearly related. Reassembling them is quite instructive and reveals much about the evolution of these structures.
We have previously published libraries of miarolitic cavities.
This post is a summary and review of Murphy, B., Hjuizenga, J. and Bedrosian, P., 2022. Graphite as an electrically conductive indicator of ancient crustal-scale fluid flow within mineral systems. Earth and Planetary Science Letters. https://doi.org/10.1016/j.epsl.2022.117700
Below is an exceptional article from the Queenslander of 1924. A remarkable record so soon after the discovery of Mt Isa and replete with the excitement of such a significant discovery. At the time of writing a mere 145 tons of ore had been shipped. The original has been transcribed from the Queenslander newspaper, where the ink has been absorbed by the newsprint making transcription locally difficult. Some editorial licence has been taken and minor alterations, including conversion into g/t, have been made and images added.
By RANDOLPH BEDFORD.
Saturday, January 26, 1924
In 1918 I travelled by Argylla and West Leichhardt to Lagoon Creek – 18 miles west of West Leichardt Telegraph Station returning to Cloncurry by a little east of the Sulieman Creek-Camooweal railway survey, via Bushy Park and Duchess. My journey was made to locate Mica deposits on Mica Creek, and returning from these I passed the Mount Isa field at a distance of a few miles, and on the wrong side of the range, as a hundred other men have done. For, as John Forrest said in explanation of failing to see gold although hw was on the Coolgardie field 23 years before their discovery: “A man gets what he’s looking for, and Forrest was looking for pastoral country.
Continue reading “The Most Important Mining Discovery of the Last Decade”
