landslide fires

[Meager1]

I`m still in Idaho, should be home next week.
I just wanted to make note of the fact that I have just witnessed a small fire igniting, as the result of rocks rolling/sliding together down a steep hill. The forest service is always announcing new fires as lightning caused, but we just witnessed a small fire ignited by nothing but rock sliding/rubbing together in a short run downhill. Are there chemicals, or elements in the rocks themselves, that will ignite from friction, I don`t know? Does anyone here know about that, or have an explanation?

This "fire" occured as my son was coming down the mountain after collecting some rock samples, he created a small landslide, luckily there was very little tinder, and nothing to catch on fire only rock, so after maybe two minutes it extingushed itself, but it was easy to see how a deer or big horn sheep etc, might cause a small landslide that can ignite these fires if there is sage brush or other kinds of tinder in the path of it.

I don`t have an explanation for this as yet..I am only reporting what was witnessed.
I would never have expected, or even belieived something like this was possible.
Yet it seems that all these fires if not meteor related, and/or without other explanation, such as lightning caused, when there is no lightning reported, make much more sense to me now.
The prospect of fires starting themselves from landslides is a kinda scary thing, if you think about that, yet we saw it happen!
There is one other item I want to talk about, but will wait until I am back in MA.

 

[Nienna]

I do know that certain types of rock, when striking each other, can cause sparks. Could some sparks have ignited the dry tinder around there?

 

[Zadius Sky]

I do know that certain types of rock, when striking each other, can cause sparks. Could some sparks have ignited the dry tinder around there?

I remembered someone, on one of my hikes, having mentioned about certain types of rocks that can cause a fire. They are iron pyrite (two of them together) or any rock that has an iron element, and marcasite with flint. Of course, when you have so much of these around on a dry ground, there bound be a fire if there's sudden movements or quake that cause them to move against each other in the hard way.

My .02 cent.

 

[Meager1]

It seems that most of the rock that forms these rock slide areas is shale. I found the following which seems to explain it.


"Black organic shales are the source rock for many of the world's most important oil and natural gas deposits. These black shales obtain their black color from tiny particles of organic matter that were deposited with the mud from which the shale formed. As the mud was buried and warmed within the earth some of the organic material was transformed into oil and natural gas.

The oil and natural gas migrated out of the shale and upwards through the sediment mass because of their low density. The oil and gas were often trapped within the pore spaces of an overlying rock unit such as a sandstone (see illustration at right). These types of oil and gas deposits are known as "conventional reservoirs" because the fluids can easily flow through the pores of the rock and into the extraction well.

Although drilling can extract large amounts of oil and natural gas from the reservoir rock, much of it remains trapped within the shale. This oil and gas is very difficult to remove because it is trapped within tiny pore spaces or adsorbed onto clay mineral particles that make-up the shale."