Fossilized Ripples

| 24 Comments

Photograph by Paul Blake.

Photography contest, Honorable Mention.

Blake.Ladder.JPG

Fossilized Ladder Ripples, Torpedo Creek Quarzite near Mount Oxide in the Western Succession of the Mount Isa Inlier, Queensland, Australia. In environments such as tidally influenced areas, water currents often go in different directions, resulting in unusual ripple patterns (hard to explain tidally influenced areas in a global flood). Torpedo Creek Quartzite is about 1.69 billion years old.

24 Comments

Obviously, with a volume of water much greater than that of our current oceans, the Global Flood exerted such great pressure on the sediments that they were compressed into solid rock! And what happens when you compress a flat surface, like a towel? It wrinkles!

There you have it, a Bible-Based explanation for “fossilized” ripples. Same evidence, different world views! :)

Dear Wheels,

Thank you for your application to work in the science department of our museum. We are blessed by our Lord to inform you that your qualifications are perfect for the position we are offering and we’d like you to start work immediately. Please contact our office for details.

Sincerely,

Jeremiah Shem, Creation Museum

Wheels said:

Obviously, with a volume of water much greater than that of our current oceans, the Global Flood exerted such great pressure on the sediments that they were compressed into solid rock! And what happens when you compress a flat surface, like a towel? It wrinkles!

There you have it, a Bible-Based explanation for “fossilized” ripples. Same evidence, different world views! :)

Oh my, the Creation Museum is certainly doing business in odd places;)

There you have it, a Bible-Based explanation for “fossilized” ripples. Same evidence, different world views! :)

I think it’s one of those elusive “fingerprints of God” we’ve been looking for all these years.

Bible-based explanations are true “no-brainers”.

I’m not sure you’ve got this right, Matt.

I’ll have to consult my volume of Ripples Believe it or Not.

Wheels,

Congrats for getting a job offer where most DI fellows would be “expelled.” ;-)

Gimme a break!

How do you know these are ripples? Is it just because they look like ripples? Evolutionists merely see what their religion tells them to believe. Why can evolutionists “see” these ripples in rocks yet they will dismiss as crazy any Christian who might see Jesus or the Virgin Mary in similar rocks. You need more evidence than confirmation bias.

Because you can go to any beach or lakeshore and OBSERVE how ripples are formed, time and time again.

Got anything else besides the tired old “Were you there?” argument? Got a testable explanation of why the ripple pattern appears in those rocks?

Toidel Mahoney said:

Gimme a break!

How do you know these are ripples? Is it just because they look like ripples? Evolutionists merely see what their religion tells them to believe. Why can evolutionists “see” these ripples in rocks yet they will dismiss as crazy any Christian who might see Jesus or the Virgin Mary in similar rocks. You need more evidence than confirmation bias.

You don’t get out much, do you.

Toidel Mahoney said:

Gimme a break!

How do you know these are ripples? Is it just because they look like ripples? Evolutionists merely see what their religion tells them to believe. Why can evolutionists “see” these ripples in rocks yet they will dismiss as crazy any Christian who might see Jesus or the Virgin Mary in similar rocks. You need more evidence than confirmation bias.

Please do not feed the Mahoney troll.

What’s that odd formation next to the hammer? It looks like a Sheeposaurus fell into the mud and petrified along with it…

Reminds me of the ripples seen in the rocks on Mars as observed by the Opportunity rover. Mars is enough like Earth that similar geological processes operate. Creationists should be careful about ascribing everything on Earth to the Flood or they’ll have to figure out why the same things are on Mars. Or was the Flood solar system-wide?

The Conservapedia Bible shows that the word ‘raven’ is a mistranslation of the original word ‘hammer’. Or at least it will soon. So this picture PROVES babyjeebus!

USA! USA! USA!!111!!eleven!!

Or was the Flood solar system-wide?

That would explain where the water came from!!111!!one!!

I don’t know anything about digging fossils out of rock. I’m not an archeologist. But I’ve been curious for a long time how one can tell the difference between one hard substance (maybe a fossil) embedded in another hard substance. I assume it’s pretty easy if you have some kind of shale deposit, and the rock just splits on a fracture line and you have a wonderful spiral shell staring you in the face. But I’ve seen various science shows where people are chipping away at (what looks like) a pretty hard rock trying to extract a fossil, which looks like just another part of the hard rock.

Then we get to things like fossilized footprints, or impressions, or in this case fossilized deformations of some kind. Now, there isn’t even a fossil “thingy”. There’s just a “fossil” of an impression of something. There is a pick axe (or whatever you call it) shown in the picture, so presumably this formation had to be dug out of some larger matrix.

How does one dig out something like this? How does the archeologist know where to stop digging? Could one expect that the top layer(s) would have flaked off relatively “cleanly” on the observed plane? I have handled sedimentary rocks that break easily on relatively clean planes. Would this likely have been something similar?

I’m also not a geologist. Given the patterns shown, it certainly looks like the sand ripples I’ve seen on the bottom of ponds. But could such patterns also have developed after the rock was formed? Could water incursions have introduced similar fracture patterns? Or would the apparent cross hatching rule that out? Is this one of those cases where a trained geologist can just look at the rock and easily eliminate other possibilities? Perhaps one gains insight into what one is looking at by knowing what one has dug through to get there, and is not shown in the picture?

I really am curious how archeologists do what they do with their picks and chisels. If anyone has any personal insights, or recommended light reading for the curious amateur, I would appreciate it.

Thanks.

IANAG, but I can tell you they usually leave a tool in the photograph to give a sense of scale.

Fossils can also have a different texture and/or colour than the surrounding matrix.

A real geologist will probably tell you more soon…

I would expect that fossilized bone would have different composition and texture than the rock around it. As for footprints - I’ll speculate that the indentation got filled with a different material than what the indentation was made in, so there too the different in composition and texture would be a guide to somebody with experience in that area.

Henry

Hi Scott,

My comments can only deal with Australia where I work, however, all fossils are surrounded by material different than the fossil themselves. The differences may be in grain size, chemical composition, or structural competence. Therefore, when you break a rock, often it cracks around the fossil. Not always (I have broken lots of potentially good fossils), but generally this is true. Experienced fossil removers know how to use the difference between the fossil and the matrix to extract it.

With fossilised footprints you usually have the footprint going down into silt or mud and then filled with sand, so once again you have a difference between materials.

The geopick in my picture is a standard geological reference to show the scale of the features. For really small scale objects we use coins or lense caps, outcrop features like ripples, crossbedding, mudcracks,fossils etc we use hammers.…for larger scale features we use people etc.

In the case of this picture, what you see is what I found. Nature extracted it for me. The pattern could not have formed after the sediment solidified. Ripples are like small sand dunes, material moves up and over the shallow side of the ripple and cascades down the other side. That means that the ripples have internal laminations that display a shallow dip on one side of the ripple and a steep dip on the other side of the ripple.….so sorry wheels, your wrinkle explaination is crap!! :-P

This is true for current ripples. Ripples produced by wave action are more complicated, but don’t need to be addressed here.

I have seen plenty of ripples in cross-section and if I wanted to excavate them I could (and usually you get silt horizons that help with defining the ripple), but it would not be worth it. In the case of this picture, nature fortunately did all the work for me.

I have tried to explain this as simply as I could, but if there are still parts that you want explained please comment and I will try to answer as best I can.

Dear Paul,

So, with fossilized impressions, the presumption is that the underlying matrix dried and hardened after the impression was made, then something in the environment changed so that the impression later filled with a material different enough that you can distinguish? How rare are such fossil impressions? It sounds like they must be pretty rare.

Internal laminations in the ripples? Now that is really cool. It’s hard to see in the photo shown, but perhaps the asymmetry you mention shows best in the upper center-left portion of the picture, near the whiter edge of the layer? Such internal structure would certainly argue against later water incursions, as I presume (if such were possible) that those would be more symmetrical and less regular.

If you don’t mind an off-topic question about fossils, what exactly is the fossil “bone” that one digs up made of? I’ve handled real “petrified wood”, and there clearly wasn’t any cellulose left. It was all minerals. Is that true also of fossil bones? (I’ve only seen “copies” of those.) That may be harder to answer, as the bone started out as a calcium matrix. Yet, I’ve read about finding growth rings in cross sections of dinosaur bones. That would have to be some very fine-grained re-mineralization to leave evidence of growth rings.

Thanks for your patience and fine explanations.

The ripples do not have to be hardened before burial. If they are buried by a thin layer of siltstone then that would separate them from any overlying sandstones. When the whole sedimentary pile is lithified the different grain-sizes would give the different layers different physical properties and can be split along them to uncover the ripples.

With footprints you often have the print pressed into mud or silt which then gets filled by fine sand.

Preserved sedimentary structures are actually very common, particularly in the Precambrian before there were worms churning them up. At this same locality I also found several horizons of dessication mudcracks, synaeresis mudcracks, and wave-form ripples.

The internal lamininations in these ripples would be difficult to see since we are looking down onto the ripples. A side on shot would show the laminations within the ripples.

I don’t know much about bones (the only ones I have found are Middle Devonian Placoderm bones). However, from what I have read, most bones are still composed of the apatite they were made of in life, but the cavities in the bones get filled by minerals. Only in extreme cases do the original boney material get replaced. Maybe somebody else more familiar with fossilised bones could help.

I hope this has helped. Let me know if you need more info. I enjoy answering questions.

Well, that makes sense of it. I was wondering how the ripples could be preserved without cracking while drying out. They don’t dry out first. And it all comes down to grain size! (Well, not “all” of course.)

So the bones do fill. Fascinating. I guess they must be porous enough to admit dissolved minerals. I figured only tooth enamel was hard enough to be preserved intact.

I really appreciate the information, and the hints. Just having to look up the technical terms helps a lot. :-)

Thanks.

Scott said:

I don’t know anything about digging fossils out of rock. I’m not an archeologist. But I’ve been curious for a long time how one can tell the difference between one hard substance (maybe a fossil) embedded in another hard substance. I assume it’s pretty easy if you have some kind of shale deposit, and the rock just splits on a fracture line and you have a wonderful spiral shell staring you in the face. But I’ve seen various science shows where people are chipping away at (what looks like) a pretty hard rock trying to extract a fossil, which looks like just another part of the hard rock.

The bond between fossils and the substrate they’re found in is quite variable, and seems to me to be in part dependent on whether the sedimentary rock has the same composition as the fossil. Here in FL, most of the vertebrate fossils that I’ve found are found in lake or sinkhole fillings (clay) or limestone, and they seem to come out pretty easily. From what I’ve seen on TV, etc., the vertebrate fossils that are hardest to remove are silicified bone encased in quartz sandstone, so that the material in and outside of the bone are similar, and bond together well.

I’m a lot more familiar with marine fossils (mollusk, brachiopod, shells, coral and bryozoan colonies, echinoderm fossils, etc.) and there is a wide variation in how easy it is to remove the fossils. I’ve seen fossils literally separating themselves out of Ordovician limestone in and around Cincinnati, OH (still the best place I’ve EVER seen for finding Paleozoic fossils). I’ve easily dug out Belemnites from soft chalk in South Carolina. On the other hand, it’s almost a standing joke that as you’re trying to chip off the excess rock around a particularly interesting fossil, your last tap with a hammer will cause a crack right through the middle of your prize. And in many areas, fossils are preserved as molds around empty space, so there is no way to “separate” the fossil from the rock itself.

As to how you can tell the difference between the substrate and the fossil, even if the composition of the two are the same, there are just about always differences in hardness, crystal size or orientation, or color.

How does one dig out something like this? How does the archeologist know where to stop digging?

.…

I really am curious how archeologists do what they do with their picks and chisels. If anyone has any personal insights, or recommended light reading for the curious amateur, I would appreciate it.

Thanks.

By the way, a pet peeve of mine is that geologists are not the same as archeologists. Some of the tools used by them are the same or similar, but we study vastly different things. For that matter, strictly speaking it is paleontologists who study fossils, not geologists, although there is a lot of overlap.

Deklane said:

What’s that odd formation next to the hammer? It looks like a Sheeposaurus fell into the mud and petrified along with it…

Dangit, now I see that fossilized sheeposaurus EVERY TIME I look at the picture! Fluffy head pointing towards the bottom of the shot, smooth tail pointing up?

Dear GvlGeologist,

I really appreciate the insights. So, not just grain size, but chemical similarities between the fossil and the substrate as well. Cool.

And “hollow” fossils? The only thing like that I had heard about were the hollows in the ash at Pompeii. So it’s more common than that? Those must really be tough to recognize.

As to geologists vs. archeologists vs. paleontologists, don’t the latter two need to know quite a bit about geology if they’re going to understand the layers of rock they are digging through? Or would that more typically be something like a team effort, with (perhaps) a geologist along on the dig (or as a consultant) to make sense of the ground?

Thanks.

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This page contains a single entry by Matt Young published on October 19, 2009 12:00 PM.

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