It helps to look up your underlying rock because it gives an idea of what minerals are available in your soil.
The Pennsylvanian Epoch lasted maybe 33 million years and was the latter part of the Carboniferous Period. The age that created vast coal deposits here in New Mexico. Within an hour of my house there are coal deposits and it is possible that I have coal beneath my feet. New Mexico coal is used to generate electricity and keeps our electrical prices low. A good thing for the people who are some of the poorest in the United States. In fact, my electrical usage is low and so inexpensive that buying solar panels is not cost effective at this point, but on the list. Not sure how long we will have coal due to new regulations.
The burying of large amounts of forest/coal happened in large part because trees developed a very thick coating of bark containing lignin. Animals and decomposing bacteria were unable to break it down so it accumulated and was buried. Oxygen levels rose all through this period, to about 35%. In the end, the fires burned the accumulating lignin and it was buried.
While I grump around about gardening on Calcium Carbonate, it isn’t the whole story even when it feels like it as I dig through a Calcium Carbonate layer for my cabin-in-dreaming. I have other rocks tumbling down the hillside, including fossil mudstones:
I have a lot of these loose stones, but have not climbed up to the place where there is a solid wall. There are huge boulders or bedrock that are exposed to daylight also. Fossils from this period are everywhere, and all fossils are numerous and tiny. At university I had access to a scanning electron microscope and one of my projects was looking at microscopic fossils from the Cretaceous period. Were I wealthy, I would buy a scanning electron microscope. Wouldn’t mind a standard microscope either! With a digital camera attached, of course. I’m dreamer.
The infamous Calcium Carbonate is usually mixed with other things, but some seem very pure and white.
Calcium Carbonate is handy stuff for building trades, and can be made into lime plaster, an old fashioned product. A cement plant in Tijeras is knocking down a substantial amount of mountain for concrete blocks to build Albuquerque and my raised beds. I do mean knocking down a mountain.
This is essentially chalk, and I use it like chalk for little household jobs. For example, my old tan suede jacket got oil stains over the years. As I contemplated turning it into leather slippers, I first tried a chalk rock powder on the stains. It removed the oil and soil and I brushed it up with a suede brush. Perfect. The rock chalk is good to clean oil stains on clothing by drawing the chalk rock over the stains, like on shirt collars, let sit 15 minutes or so, brush off, then wash. No Market Economy toxins and more effective. I could use Market Economy chalk for several things, or free to me chalk from uphill. I am setting aside some of the purest ones for a to be determined project. It is very soft. Chalk drawn discretely around windows and doors stops ants and roaches from coming in the house. I used Market Economy chalk this way for years in Texas and it kept horrible bugs out of my house with no toxin sprays. I would use my rock here, but no need so far.
I also have Greenstone and quartz in small amounts.
The color doesn’t come through well, but Greenstone is believed to have been formed during an even older period, formed by heat and pressure on lava rock and exposed by rift. The Gutierrez-Hubbell House Museum in South Albuquerque is a lovely example of local Greenstone ground into powder and used to color the walls. My dream color. At this time, you cannot take any of the Greenstone at Tijeras.
Besides finding interest in my geology, the combination of these plus sandstone indicates that I likely have a good amount of minerals in my soil, much coming from the fossil mudstone.
I once mentioned my Pennsylvanian Mudstone fossils to a coworker whose worked part time as a Docent at the Natural History Museum in Albuquerque. He went delirious about “his” find, “his” dig, and wanted to move “his” camp trailer to “his” extraction site. That would be MY house, bubba.
That old boy didn’t notice that I was both annoyed and uncomfortable. I stopped that line of thought (in a kind way of course). I never did get over to the Natural History Museum in Albuquerque and get advice on handling my fossils. I wish I could chat with my former geology professor, though. I enjoyed fossil hunting with my mom and dad when I was a kid (eastern Oregon), with my son when he was young, and with a Paleo group in Texas. One of these days… as I always say.