caravelair

i know very little about geology, so i need some help dealing with a creationist claim i have not heard before:

> They claim
> that the fossil record represents brief periods of
> catastrophe separated by long spans of time. But the
> geologic record itself shows that there are no
> worldwide time gaps from the earliest Cambrian rocks
> through the Tertiary period. Although sedimentation may
> have ceased momentarily in one place, it continued at a
> rapid rate in other places. Since it can be demostrated
> that each stratum formed quickly and that they all
> formed consecutively with no time lapses in between,
> then the sedimentary layers must have formed in a
> relatively short time, not over millions of years.

if someone can point me in the direction of a talkorigins article that deals with this claim, or anything like that, i would greatly appreciate it. feel free to throw in any useful comments too. thanks in advance.

KnightWhoSaysNi

Ask your creationist friend to explain how an angular uncomformity can develop with "no time lapse in between" strata in a "relatively short time."





The standard geological explanation is that there was deposition, then tilting (from tectonic forces), erosion, and then deposition again. Ask your creationist friend for a better explanation.

Edit: I'd also question his assumption that all strata must be "formed quickly."

Korihor (formerly, 'Nightshade')

Conchobar

The only strata that can form quickly are huge volcanic flows like the Columbia Plateau of North America. You can have such "LOCALISED" fast forming strata. But if you look at the layer below the lava bed you can identify a similar strata miles to the south that has the same dating and fossil representions, and it is covered by another layer of newer fossils and later dating. That layer is not found north in the Columbia Basin because it is covered by Lava.

Some fundies argue that the layers in one place may be the reverse of those in another. Such is found in the Alps of Southern Germany and Austria. There is a place where 5 layers of sediment show paradoxically that the newest fossils and latest dating is in the bottom layer and oldest on top. But if you drive several miles fruther south over the pass, you find the same 5 layers in correct order. You can also find the same layers in the correct order over in Raetia region of Switzerland. There are three places where the layers are reversed.

What happened is that as the African plate crunched up against Europe. The block-fault and fold formed the Alps. But continued crunching wrinkled the rising mountains so much that chucks fell back flipping over. Fundies site this, or attibute it to Noah's Magic Flood, but they offer no rational explanation as to why the 5 reversed layers are right side up all over the rest of the Alps.

Conchobar

Conchobar

> Although sedimentation may
> have ceased momentarily in one place, it continued at a
> rapid rate in other places. Since it can be demostrated
> that each stratum formed quickly and that they

Of course in some arid windless conditions sedimentation may temporarily cease but that is extremely rare. Much more common is that land is undergoing a battle between sedimentation, orogeny (mountain building), lava flows, on the one hand and erosion by wind and water on the other. Some sediments may be eroded away during erosional periods and no fossils preserved at all.

For some one to try to refute evolution but be ignorant of geology including orogeny, erosions, and crustal plate movements and continental drift. I have found fundies woefully ignorant of these sciences as they are in biogenetics and biological neurobehaviour. We are debating with modern people with Stone Age knowledge.

Conchobar

Coragyps

Purest excrement of a domestic male bovid. That can typically be demonstrated to be NOT the case - take the buried reefs 2 km beneath my butt, for instance.

Valentine Pontifex

Here is a diagram of the Grand Canyon, notice the most famous angular unconformity plus several other obvious unconformities:



Source

The Hutton unconformity from a two centuries old diagram:



And a photo of it:



Source

An unconformity from Texas:



Same source as last

ps418

What Coragyps said. There are many different types of evidence for long depositional hiatuses. Some of the examples I've studied are
paleosols (fossil soils) and weathering mantles, in situ fossil forests, bored and encrusted marine hardgrounds, and autochthonous (in-place) benthic marine fossils, particularly fossil reefs.

Patrick

SULPHUR

unconformity,non conformity,dis conformity how do they differ?

ps418

The differences are a bit fuzzy and used differently by different writers. unconformity - definitions:

MrDarwin

Try asking your friend how long it would take massive evaporite deposits to form, and whether they formed before, during, or after the Flood.