Anyone out there into rock collecting, geology?

[WaterWitchin]

I have a cousin who's an archeologist. When he has free time, we go hang down by our home town, in an area along a creek on the Humboldt Fault.

There are a lot of artifacts, and also quite a few weird geological formations. Neither of us know what these are. Anyone out there who might know? I have these pics on a geology/rockhound board, but haven't gotten anything other than a guess.

They're round balls in a harder than tar type substance. but reminiscent of tar. Full of pyrite crystals. The other picture is of several similar still embedded in rock. The other picture showing the ones that easily come loose as little balls I can't find at the moment, but if anyone has knowledge, I'll try to find it. Thanks in advance to anyone out there who might be able to assist. PS There's a few rocks at edge of pictures that aren't a part of it. Just other rocks on a too-full table.

[Mountaineer370]

I can't help with identification of the rocks, but to answer your question about anybody into rock collecting and geology, yes, I am. I've always been fascinated by geology and all of the earth sciences -- planetary science, I guess I should say, since my interest extends to other worlds, known and as-yet-unknown.

I hope you get an answer to your ID question soon, from somewhere.

[Orchid Whisperer]

I'm a geologist.

Many of those objects appear to be ironstone concretions or nodules.

Some of the objects I can't identify from a photo. (Keep in mind that a geologist often will break open one specimen to examine it, and do physical tests, to identify the "keepers", so there are some limits to what I can do over the internet). The concretions probably weathered out of local sedimentary rocks.

Not all of those objects appear to be the same thing, though.

[Ray]

Originally Posted by Orchid Whisperer

I'm a geologist

Very cool!

My geologic collecting is very limited, and mostly happened while I was in school in Atlanta. Had to take a geology course as part of the ceramic engineering curriculum.

When they cut the earth to build I-75 between Atlanta and Chattanooga, they exposed all kinds of good stuff, including some quartz fossils in the red rock. They looked something like giant crinoids, but the individual rocks they were in were about 4’ cubes that we weren’t carrying home!

I do have a nice chunk of amethyst in matrix that I got out of a cave (more like a giant geode) somewhere north of Cartersville. The land belonged to a friend’s grandfather, and he had sold the commercial rights to the cave, and gave us a weekend to get some samples. I used to have a 40# lump of quartz that came out of the Dahlonega gold vein. It stayed in PA when we moved.

[Orchid Whisperer]

Ray, I've done some collecting along I-75 road cuts myself. At one, near Ringgold, Georgia, as a student on a class trip, we were looking at fossils and various other structures in the Ordovician and Silurian age rocks there. A half dozen of us were looking at a rock with "trace fossils" (tracks, trails, burrows) in it, I saw something poking out from under that rock, flipped it over - perfect spear point lying under it (other students claimed I'd planted it).

The red rock you described could have been Silurian. Thick deposits of that red Silurian rock were used as iron ore at one time. That same rock is in Alabama, it's the reason that Birmingham, AL had a steel industry.

One of those big boulders at Ringgold had a whole bunch of trace fossils on it, made by starfish resting and feeding on a sandy sea floor, millions of years ago. I came back years later with a different class, all the starfish traces had been removed, either by collectors or by weathering.

[WaterWitchin]

Yup, I-75 runs right through the place I live. Good times. My cousin found a spearhead last summer when we were out (the other place where rocks came from). I will try to find that picture OWhisperer... you'll get a hoot out of it.

I agree with Ray... way cool to have a geologist on board. I've been collecting since I was around five years old. I have another story about this place I'll try to put up in the next week or so. You'll enjoy it.



---------- Post added at 03:11 PM ---------- Previous post was at 03:09 PM ----------

PS All those nodules in the little rock "bowl" I dug out from a super big chunk of stuff. The others around it are just larger, or embedded in rock that's really hard. I'll take a picture of the "stuff" I took it from.

[Paphluvr]

Heck yea, who can collect just one thing. Here in MI the lower peninsula is great for fossils (Petoski stone is the state stone, a fossilized coral). The Upper Peninsula has a wealth of minerals including gold, silver and copper, and we have agates on Lake Superior. It's a rock-hounders paradise.

[WaterWitchin]

I just LOVE Petoskey stones! A dear friend of mine's husband grew up on Grand Island. We used to go back and visit, and I'd spend all day with my head down scouring the beaches. Good times!

[WaterWitchin]

Here's a piece of the stuff we find in the riverbed, usually in sand. Sometimes the surrounding black part can be crumbled away, leaving the little round pyrite nodules shown in the rock bowl. Sometimes not all of the black parts can be crumbled away and that's where you see the little balls (from first set of pictures or this one) sticking in the other "stuff" but unable to be removed by hand.

Wouldn't these be attracted by a magnet if they're ironstone? I know some of the different looking rocks off to the right side are ironstone concretions. But these don't seem the same. The only way when googling I can find anything that looks like them is when I input "pyrite nodules" and I still can't find the same thing.



---------- Post added at 11:11 AM ---------- Previous post was at 11:00 AM ----------

And as promised, the similar spearhead story. One of my cousin's main jobs is surveying clearance for power lines, roads, etc, etc. He walks and does readings every X number of feet. Or he's called in often to excavate old burial sites. So he finds lots of interesting stuff, and people often believe he's BS'ing about his finds. He's been attempting to teach me for decades how to "see" arrowheads, etc, just by looking around. I end up walking right over them, but I do find a lot of petrified wood. Seems to be my specialty.

So we're out on our creek, exploring last July. There had been high flooding in the area, plus a few recent earthquakes, as the area is directly on the Humboldt Fault. If I hadn't seen it happen, I would SWEAR he planted this. I walk over a spot. He's behind me, stops and takes a couple of pictures. I'm watching him take the pictures and say did I miss something? First picture is exactly how this spearhead was laying that I walked right over. Second picture is his size 14 foot (he's a big guy) for perspective.





Really? I was stepping on that same rock his foot is on. But I did find some cool petrified wood.

I'm pretty fond of him, but sometimes he really irks me. He makes up for it by doing all the paddling.

[Ray]

Aw, c'mon. That arrowhead looks too well preserved and "planted" to me.