Looking at some of the large Quartz Monzonite rocks around you email me the answers to the following questions. This should be at the end of a little trail by an ampither, here is another set of coordinates as a few readings had different settings. N 40° 34.294 W 111° 46.433
- Looking at the crystals in the rocks, are they fairly uniform in size?
- Were they large crystals (1/4") That cooled slowly? or smaller that cooled rapidly or something in between?
- Are the crystals spread evenly through the rocks? Explain what you see with the different crystals (darker/lighter bands, pegmatic dikes, and/or pegmitites).
- Add a photo of you from the location or of an identifiable item (paper with trackable name). Posting a photo pulled from the internet, or photoshopped will result in instant deletion.
Granite is a rock that is made deep in the earth. Magma will push its way up from underground and fill cracks or form a bubble underground. These are commonly referred to as Plutonic rocks. Typically these rocks contain grains that are 1mm-5mm in size (.040-.200"). The cooling of these rocks tend to be 10,000 years or longer. The larger the crystals the longer the cooling time. Some of those crystals can be so fine you cannot tell the difference, and in other locations they may be inches across.
However the rock here is not technically granite. People refer to it as granite, but the composition of the rock is not correct.
The only real difference between the two kinds of rock is the amount of quartz crystals in them. If there is more than 20% quartz, then it is considered granite, if it is less than 20% then it is considered quartz monzonite.
The stone at this location has been used for a number of purposes. It was quarried for the Utah Capital, Salt Lake LDS temple, and the LDS conference center. They also dug caverns in the stone east of here to store many genealogical records from around the world.
As this material flowed in magma form, slowly and in some cases it was very thick, the different crystals may not form evenly. Some may form flows, or bubbles that have one type of crystal over another. The actual makeup of the Hornblend (dark material) and other materials that make up the stones are not always spread evenly through the stone. They may just be a darker flow, form larger crystals, or even have a higher percentage that looks like a darker/lighter band through the stone.
Those crystals may also form solid crystals of one type. This may form a pegmitite (what looks like another rock got stuck in the magma, but is just a large crystal). Or it may form a large pegmatic dike. splitting the rock completely towards the end of its cooling and forming a vein of crystal inside it. >/P>
These rocks, were laid down during the Cretaceous period and are many thousands of feet thick.