Identify This Rock ? - DPChallenge Forums

Canon EF 17-40mm f/4.0L USM

04/14/2007 11:00:12 PM · #26

Originally posted by David Ey:

What would vinegar do?

Made simple... Click Here to find out.

Read more Here On rocks...

Message edited by author 2007-04-14 23:02:32.

DrAchoo

Panasonic Lumix DMC-LX5

Canon EF 24-105mm f/4.0L IS

04/14/2007 11:04:15 PM · #27

Sulfur ball?

ButterflySis

Canon EOS-50D

Canon EF 50mm f/1.8 II

04/14/2007 11:04:43 PM · #28

They look like a pair of calcified walnuts...lol

Tamron AF 28-80mm f/3.5-5.6 Aspherical for Nikon

04/14/2007 11:11:56 PM · #29

This piece is 15 x 10 x 7 cm and weighs about 3 pounds.
( 5 3/4 x 4 x 3 inches)

vtruan

Nikon D5100

04/14/2007 11:14:28 PM · #30

It looks like a large iron concretion. It it where iron in soil is consentrated when ground water moved up and down an eventually forms these concretions or round balls (kind of like old civil war mini-balls.

Message edited by author 2007-04-14 23:16:23.

downtherabbithole

Canon EOS-30D

Canon EF 28-135mm f/3.5-5.6 IS USM

04/14/2007 11:24:36 PM · #31

keep us posted on what you do with it. I would love to see where this goes.

Dirt_Diver

Nikon D3s

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

04/14/2007 11:35:35 PM · #32

Looks like the bone of a knee or something. break it open and see what's inside.

scalvert

Canon EOS-5D Mark III

Canon EF 24-105mm f/4.0L IS

04/14/2007 11:59:00 PM · #33

That looks like a concretion to me.

Message edited by author 2007-04-15 00:00:34.

Nikon AF-S DX Zoom-Nikkor 18-55mm f/3.5-5.6G VR

04/15/2007 01:10:55 PM · #34

OK, It opened very easily with a screwdriver. I think it is a concretion as some have said. Here are some daylight shots. Thanks for your interest. David

RainMotorsports

Nikon D60

04/15/2007 01:15:24 PM · #35

Well i cant mention what it looks like, besides it has an STD. Just now noticed you split it open. Could always have someone at a university sample it. Most people wouldn't do it for free thought.

Nikon AF-S DX Zoom-Nikkor 18-55mm f/3.5-5.6G VR

04/15/2007 01:19:40 PM · #36

STD ?

RainMotorsports

Nikon D60

04/15/2007 01:23:36 PM · #37

Originally posted by David Ey:

STD ?

LMAO nothing as i said i could mention what it looks like, and in the fact of what it was shaped like.... yeah anyways should have kept my mouth shut.

Message edited by author 2007-04-15 13:24:00.

rox_rox

Canon EF-S 18-55mm f/3.5-5.6 USM

04/15/2007 01:26:01 PM · #38

Interesting thread. Thanks for sharing.

Strikeslip

Canon EOS-5D

Canon EF 100-400mm f/4.5-5.6L IS

04/15/2007 02:03:11 PM · #39

Hey, coolio. Oh, and in that other thread I wrote "hump" instead of "bump" and I'm not annoyed with anyone, hehe! :-D

I'll take my guess at this, though it's tough to tell without holding it in my hands.

scalvert has a pretty good guess with concretion, but he's got it backwards. Actually, youre guess that it's a geode is very good. I think you're right.

My guess is that this was formed within a void in limestone, which you mention is a common country rock in the area. Limestone is susceptible to chemical erosion and can have smooth voids form within them far below the surface. Groundwater, rich in chemicals, will then percolate through these voids and deposit layers of calcite, goethite, quartz, and large variety of 'whatever'. Quartz and calcite can be any colour, depending on what accesory minerals are in it. For example, iron will make quartz or calcite look reddish.

Limestone, a sedimentary rock, deposits in originally horizontal layers. My explanation for the seam in your hand specimen is that there was a discontinuity in the limestone's layering there. I'll also hazard a guess that the bumpy side of your specimen, below the seam, was originally the bottom of the void, where some pieces of junk were resting inside the void. The smooth side was the top of the void.

This is the same way geodes are formed, as layers of mineral are chemically deposited on the walls of voids, growing inwards. Concretions grow outwards from a nucleus of some junk. I remember collecting concretions in a shallow river bed with my dad. We found all sorts of really cool shapes, usually symetrical.

That's my guess!
:-)

Strikeslip

Canon EOS-5D

Canon EF 100-400mm f/4.5-5.6L IS

04/15/2007 02:07:47 PM · #40

FYI, fossilized poo is called coprolite. Ridiculous, eh? :-D

But also not a bad guess.

Message edited by author 2007-04-15 14:08:16.

GeneralE

Canon PowerShot S3 IS

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

04/15/2007 02:28:30 PM · #41

Coprolite -- the turd you can polish ...

04/15/2007 03:11:56 PM · #42

Thanks for the geology lesson Slippy. I'd bet your right.

rox_rox

Canon EF-S 18-55mm f/3.5-5.6 USM

04/15/2007 05:35:44 PM · #43

Yes, what an educational thread. Thanks for sharing your knowledge Slippy.

David, would you mind if I kept it going with one of my own?

This is a suspected coprolite that my brother has. Sorry for the quality of the images. He found it on top of the ground in the plains of Colorado. If my memory serves me, it's about 8" in diameter.

Anyone want to take a stab at it?

And to make up for the ugliness of these shots, here's a beautiful concretion that I'd love to have in my collection.

bigalpha

Sony DSC-S60

04/15/2007 06:31:46 PM · #44

I'll second what Slippy says. If it was an iron ball, it'd be really heavy. Like, really heavy. It has that color probably because of iron staining. I like geodes, I have a lot of them.

greatandsmall - If I were to venture a guess, I'd say probably not. It doesn't look like most coprolites. Google coprolite, and see what ya get. Nice picture. That's awesome.

Slippy - I can't remember off-hand, but what's the name of the "mudcrack ball?" I suppose that's the best way to describe it. *** nevermind, it's a septarian nodule.

For the record, I just graduated with my BS in geology. :D

Message edited by author 2007-04-15 18:39:58.

rox_rox

Canon EF-S 18-55mm f/3.5-5.6 USM

04/15/2007 07:06:36 PM · #45

Thanks bigalpha. I guess it was wishful thinking. It just looks like something that fell from a height and went "plop".

Congrats on your degree, BTW!