Fossilized palm fronds

| 21 Comments
IMG_1092_FossilPalmFronds_600.jpg

Fossilized palm fronds, Triceratops Trail, Dinosaur Ridge, Golden, Colorado.

21 Comments

Dinosaur Ridge in Golden, CO, also has fossilized dinosaur footprints (but no human footprints with them).

Yabba dabba doo!

There are some triceratops tracks along Triceratops Trail, but they do not make particularly interesting pictures. As you say, though, no human footprints.

:-)

One can already hear the ID/creationist objection:

“How did those plant impressions manage to cut across so many layers of sediment?”

It could normally be a teachable moment with students who retain the ability to observe and think.

I was wondering if there were any marine fossils there. But I guess with fronds like these, you don’t need anemones.

Any information on how and when these were formed?

fnxtr, thank you for that.

Mike Elzinga said:

:-)

One can already hear the ID/creationist objection:

“How did those plant impressions manage to cut across so many layers of sediment?”

Only the ID/Creationists who can’t tell the difference between bedding and tectonic joints/fractures. The fronds are on a single bedding plane.

Tree trunks, on the other hand, can penetrate through several layers of sediment, because they are preserved in beds laid down in individual floods, which might deposit 2 to 3 meters of sediment in a single day. Then nothing happens for the next century or so, until the next big flood occurs.

I once logged a borehole that consisted of 3 meters of coarse sand and gravel, and then about 5 meters of variably bedded materials, only to find a lead-foil milk bottle lid at a depth of about 4 meters in the variably-bedded unit. The upper 3 meters was laid down in the year or so since the last time the city mined out the gravel. The gravel bar then rebuilds. The variably-bedded unit was laid down in the waning stages of a flood in 1913. Flood-control efforts have prevented a similar magnitude of flood since that time. The next unit down was 15,000 year old glacial outwash, which suggests that the 1913 flood was the biggest that occurred during the Holocene.

So the lesson is that the depositional rate at this river could be calculated as 5 meters per month (for the flood deposit alone), 8 meters per century (for the upper two units together) or 8 meters per 15,000 years (for all of the postglacial sediments).

Mike Clinch said:

Mike Elzinga said:

:-)

One can already hear the ID/creationist objection:

“How did those plant impressions manage to cut across so many layers of sediment?”

Only the ID/Creationists who can’t tell the difference between bedding and tectonic joints/fractures. The fronds are on a single bedding plane.

.…

To be honest that was my thought on seeing the picture.

MichaelJ said:

To be honest that was my thought on seeing the picture.

Googling up the “Triceratops Trail” and looking at the images helps. The beds are tilted to vertical, and consist of alternating layers of sandstone and claystone. The clays were excavated out for use as raw materials for bricks, exposing both the top and bottom of the sandstone layers as cliffs. The footprints are in the “bottom” of the sand layers, and are the negative casts of the footprints. The palm fronds are in the top surface. The horizontal cracks seen in the photo at the top of this page are probably unlading fractures.

This comment has been moved to The Bathroom Wall.

Robert Byers said:

So moving water is involved. it follows that if its a great powerful moving water event the whole thing could be deposited under such pressure that instantly is fossilized. On e doesn’t need ages of further loads on top or squeezing out water/moisture.

This is almost as funny as the “fronds” and “anemones” above! The best part is “it follows”! Great parody imitation of actual logic… oh wait, you were trying to be serious? That’s even funnier.

Robert Byers said:

it would be said for tree trunks in some cases. i think a poster here admitted that.

You don’t listen well, do you. That seems typical of ID/creationists.

I pointed out that there was a 15,000 year old glacial outwash deposit, overlain by a 5 meter flood deposit, with anthropogenic material in it, overlain by a 3 meter gravel layer. While the 5 meter flood deposit was laid down in a short period of tims (about two weeks during the waning stages of the flood) the peak flow of the flood scoured out all of the materials laid down in the previous 15,000 years. The resulting channel was about 5 to 6 meters deep, and the resedimentation stopped when the scoured channel was filled.

Later, after the levees were built on the river and a bridge was built upstream, a gravel bar was developed in the lee of the bridge. It was never more than 3 meters thick. The city mines out the gravel and the bar gets rebuilt during the next spring, but to no more than 3 meters, the depth of the hole that got mined out.

So yes, there are occasional short-term rapid depositional events, where sedimentation rates may be as much as a foot a day, but there are natural limits on how long such rates can be sustained - until the sediments reach near the water surface. You also have to factor in the sediments that were removed to make the deepened channel. The long-term average sedimentation rate (8 meters/15,000 years) is the average of a few short-term rapid sedimentation events, long periods with nothing happening and the occasional erosional event.

To use the short-term sedimentation rates estimated from my example, or from “polystrate trees” to use your language, and to extrapolate that the sediments in the Grand Canyon could be deposited in a single Biblical Flood is asinine extreme extrapolation, never justified by real life.

And later, let me tell you about glacial varves, formed one per year in deglaciated areas in new England and Scandinavia (and still formed in ice-contact lakes today). In places like Glacial Lake Hitchcock (Connecticut and Msssachusetts) there are 7,000 to 8,000 annual varves - and they sit on top of older glacial deposits, the Connecticut Valley redbeds that contain clasts of older igneous and metamorphic rocks, and those older rocks on either side of the valley. The varves alone disprove any “young Earth” chronology.

So until you are willing to learn the FACTS about geology, biology and evolution, please shut up.

This comment has been moved to The Bathroom Wall.

The big point is that you are an idiot, Robert Byers.

You can’t even spell the old discredited canard about tree trunks, let alone quote it.

I still would appreciate a more detailed description of the generally accepted geological account of how these fossils came about.

JH said:

I still would appreciate a more detailed description of the generally accepted geological account of how these fossils came about.

68 million years ago, the whole region was a swamp infested with palmtrees: dinosaurs left many footprints in the mud, as well as many organisms and palm fronds fell into said mud. They would be buried with more sediment, dry out and petrify, and over the course of 68 million years, geological activity moved the entire bed of the former swamp to a perpendicular angle.

This link might help explain better.

Well, why does anybody accept the evidence that these are fossilized palm fronds based on recognition of a pattern with very low probability of occurring by random chance but not the evidence for intelligent design based on the same reasoning.

The palm frond patterns have very few microstates that correspond to that macrostate making random chance an unlikely cause of their formation. Why is intelligent design different?

darwinism.dogBarf() said:

Well, why does anybody accept the evidence that these are fossilized palm fronds based on recognition of a pattern with very low probability of occurring by random chance but not the evidence for intelligent design based on the same reasoning.

The palm frond patterns have very few microstates that correspond to that macrostate making random chance an unlikely cause of their formation. Why is intelligent design different?

Is this some sort of a gag, or are sincerely crazy?

Isn’t that the definition of a “Poe”? Statements so crazy that they have to be a gag–but somewhere there’s a fundie that really says things like that. So you can never be sure.

Fundies say things that are indistinguishable from over-the-top comedy.

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This page contains a single entry by Matt Young published on May 23, 2011 12:00 PM.

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