Help identifying a rock.

I wasn't sure where to post this, but I figured this was the best place to ask for help.

I took a trip to Hell's Half Acre here in town yesterday, overall it was pretty uneventful and I didn't experience anything like what others claim to have.

But the site itself is weird in a geological or historical sence. I'm curious as to what may have happened there but I don't have any idea where to begin.

The area is covered in rock, millions even. All of them are generally the same type and just looking around everything pretty much looks the same. Here are a few pics, one has an interesting, seemingly natural wall built under some of the layers.

[atsimg]http://files.abovetopsecret.com/images/member/7540b57d0ccf.jpg[/atsimg]
files.abovetopsecret.com...

[atsimg]http://files.abovetopsecret.com/images/member/ceb35c9f8ce9.jpg[/atsimg]
files.abovetopsecret.com...

All of the rocks are the same as whats seen in the pics, and those are common type of rock in the area, I'm also unsure of what type of rock it is exactly.

But as we were leaving I noticed one rock that was remarkably different from any of the millions of other rocks out there, so I decided to take it and see if I could figure out what it is.

Its a dark red with some black and some light tan/orange and it has a large of amount of crystal/quartz within it. I believe its a type of volcanic rock, but I'm not certain.

Here are some pics of the rock, I can take better ones if needed. Anyone out there that can help identify it for me?

[atsimg]http://files.abovetopsecret.com/images/member/3dcc4a4e7cbf.jpg[/atsimg]
files.abovetopsecret.com...

[atsimg]http://files.abovetopsecret.com/images/member/cfedbd683f46.jpg[/atsimg]
files.abovetopsecret.com...

[atsimg]http://files.abovetopsecret.com/images/member/5b1237abc327.jpg[/atsimg]
files.abovetopsecret.com...

[atsimg]http://files.abovetopsecret.com/images/member/0f2c6391cace.jpg[/atsimg]
files.abovetopsecret.com...

My housemates know a bit about geology (one of them is studying it at uni ) and they think it looks like a Chondrite - a type of meteorite.

"The reddish colour suggests it is largely composed of Iron and it appears to have rusted somewhat. The uneven surface could be a result of chips as it hit and then bounced along the ground and are a result of weathering over time." - Fazza's housemates

Another example of a chondrite:

Interesting! I have no idea but I have posted a little post at the Earthquake Swarm in Arkansas thread to direct people here.

Shale

reply to post by ThaLoccster
Without actually seeing it my hands, I'm going with shale. I have seen large shale deposits and it looks like this exactly. IMO

They contain the mineral hematite, which is an iron oxide that is similar to rust. Should be an eclogite.

If it has quartz in it, it is not a meteorite.
2nd line.

Originally posted by Fazza!
My housemates know a bit about geology (one of them is studying it at uni

) and they think it looks like Chondrite - a type of meteorite.

"The reddish colour suggests it is largely composed of Iron and it appears to have rusted somewhat. The uneven surface could be a result of chips as it hit and then bounced along the ground and are a result of weathering over time." - Fazza's housemates

edit on 23/3/2011 by Fazza! because: (no reason given)

I'm quite interested in meteorites and that lightly crossed my mind. But I don't think the high amount of crystal/quartz would be present in a meteorite.

Originally posted by jude11
reply to post by ThaLoccster

 

Without actually seeing it my hands, I'm going with shale. I have seen large shale deposits and it looks like this exactly. IMO

It's definately not shale. Shale is also real common around here and I'm pretty familiar with that. The rocks in the pictures do resemble shale, but they have a very different size and structure than shale. The rocks that are out there are very hard and are nothng like shale.

The red rock is also not shale, unless it's a type of shale I'm unfamiliar with. I don't believe it is though.

HELLO WILL SOMEBODY NOT CLICK ON THE IMAGE I LINKED TO, ECLOGITE!!!!! damn I hate it when people on ATS ignore my posts.

[atsimg]http://files.abovetopsecret.com/images/member/ef63110136e5.jpg[/atsimg]

Originally posted by Serizawa
They contain the mineral hematite, which is an iron oxide that is similar to rust. Should be an eclogite.

edit on 23-3-2011 by Serizawa because: (no reason given)

I actually read about eclogite last night, most of what I read or the other samples I saw also had green in it and the only green on this is some moss that grew on it.

In my opinion, the majority of that grayish rock is chert. The dark reddish individual rock is some sort of quartz.

The main outdoor pics look like quartzite to me.
This is a metamorphic rock, starting out as sandstone it is changed by volcanic heat and pressure
into quartzite.
Limestone that undergoes metamorphic action ends up as marble.

The pic of the isolated rock looks like pyroclastic rock, which is where various ingredients, including quartz, get fused together during eruptions.

Quartz enclosed in a rock that was sourced in an Iron-rich soil maybe? Image and discussion halfway down this page.

Originally posted by Aggie Man
In my opinion, the majority of that grayish rock is chert. The dark reddish individual rock is some sort of quartz.

That may be right on there.

According to Wiki, chert is prevalent in novaculite here in the Ouachita Mountains. Following novaculite on Wiki, it says that the Arkansas novaculite, known as tripoli is mined just east of the city here. I did find this in the eastern part of the city.

Still can't find any pictures that resemble what I have. I may just go to the mining company here that mines the tripoli, and see if I can find an opinion there.

reply to post by ThaLoccster


Another option would be to e-mail a college Geology professor from a local university, with the picture, and asking for an opinion?

The Ouachita Mountains are composed of sandstones, siltstones, shales, cherts, novaculites, and a few limestones. These sedimentary rocks were deposited in a deep ocean basin under thousands of feet of water. Novaculite is somewhat unique to the Ouachitas. It is a very dense, even-textured cryptocrystalline rock composed of microcrystalline quartz bound together. Novaculite is the rock that makes the very best whetstones (knife-sharpening stones).

Novaculite


www.encyclopediaofarkansas.net...#

Originally posted by JBA2848
The Ouachita Mountains are composed of sandstones, siltstones, shales, cherts, novaculites, and a few limestones. These sedimentary rocks were deposited in a deep ocean basin under thousands of feet of water. Novaculite is somewhat unique to the Ouachitas. It is a very dense, even-textured cryptocrystalline rock composed of microcrystalline quartz bound together. Novaculite is the rock that makes the very best whetstones (knife-sharpening stones).

Novaculite


www.encyclopediaofarkansas.net...#

edit on 23-3-2011 by JBA2848 because: (no reason given)

The look of that rock seems to eliminate it as a possibility.