Joe Meert

http://www.sciencemag.org/cgi/reprint/300/5624/1379.pdf

Don't know if this is free access or not. The paper discusses supercontinents before Pangea and the assembly of Pangea. One of the creationist arguments is that Pangea is discussed in the bible, but they fail to point out that the evidence used to reconstruct Pangea is fully supportive of old earth chronology and evolutionary paleontology. Nor do they acknowledge that the same tools were used to detail the existence of Pangea were also used to document the assembly of Pangea and the breakup of the older supercontinents. No doubt, the one quote that will be picked up by creationists (if they bother to read the article) will be the conclusion:

Cheers

Joe Meert

ps418

I never quite understood how YECs could argue against pre-Pangea supercontinents or pre-flood plate tectonics, since the continents that made up Pangea are themselves agglomerations of discrete cratons or terranes or whatever that obviously had an extensive, prior tectonic history of collisions, as evidenced by metamorphism, foldbelts, ophiolites and so on. For instance, I wonder how a YEC geologist would explain the geology of the Canadian Shield, on the assumption that before Pangea the earth was tectonically relatively inactive? And even though it may be extremely difficult to reconstruct pre-Pangea supercontinents, the paleomagnetic data clearly does shows that precambrian continents were in fact moving relative to the geomagnetic pole.

Patrick

roxrkool

Can't read the paper

Just something that popped in my head. Hope I don't totally make a mess of it since I don't know much about the YEC stance on continental drift, nor am I an expert on plate tectonics...

I believe YECs are no longer denying continental drift because of overwhelming evidence, and their claim is that the plates moved up to several miles per day, which would be necessary to get them from ~Pangea to today's arrangement in 6,000 years. (I wonder, is that rate based on constant movement?) I wouldn't mind seeing a modeling study of what would happen to the crust, and what surface expressions you would observe, with plates moving at that velocity. You'd think SOMEONE would have noticed all hell breaking loose and written about it.

Anyway...

Okay, is there evidence indicating that some of the plates were ever motionless, or practically motionless - especially during continent-continent collisions - relative to other plates? And if so, wouldn't you be able to use, say paleomagnetic or climatic data, to give an indication of the amount of time the [super?] continents were in a particular position? Suggesting *resting* periods before continental break up.


I'm thinking this research has already been conducted, but I'm just curious.

Kevbo

Well, roxrkool, the creationist models require the existence of one Pangea, and one Pangea only, which existed as a whole up until the time of Noah's flood. Think about it, how else could every animal get to one place in the world if there were more than one landmass? Then, it requires some sort of supernatural act to somehow release flooding, which they usually attribute mostly to huge underground aquifers. And after that, they require all the continents to split up very rapidly in order to form the sea basins and get land looking like it does today.

That leaves them with some pretty sticky problems:

- As Joe's article points out, evidence indicates that there was more than one supercontinent.
- There is no mechanism to store a vast quantity of water in the earth and then release it without causing an incredible amount of heat. The earth heats up significantly as one travels even a mile below the crust. Any significant quantity of water stored in the crust had to have emerged as jets of superheated steam, ash, and magma, similar to a Mt. St. Helens explosion that happened all over the world.
- Most climatologists agree that even a small change in temperature is deadly to a vast number of species. In fact, I just watched a Discovery special the other day where an almost complete extinction on the earth was attributed to a mere 10 degree (F) change in temperature. The creationist model would likely have the earth's atmosphere heated up to a few hundred degrees minimum, after all the energy is released from the superheated steam condensing into water.
- Creationists then assume that this emergence of superheated H2O from the earth's crust coincides with Pangea splitting up. This requires the continents to travel tens, if not hundreds, of miles in a day, and no mechanism that would cause this rapid rate of tectonic change can be accounted for. They require Pangea to transform into today's arrangement of continents in less than a year in order to coincide with the biblical account. Such a rapid shift in continents also predicts oceans much more shallow that what we have today, which I'm sure Joe Meert can expound upon.
- Such a rapid change in the makeup of the continents would release even more energy than the superheated steam. The atmospheric temperature would raise several hundred more degrees and earthquakes/volcanic eruptions would be tearing the world apart. Continents would buckle and shred apart under the incredible stresses.

Now, if Noah wasn't killed by the eruption of superheated steam, the heat released when the continents shifted rapidly would have finished him off. If he managed to escape that, earthquakes and volcanic eruptions would be occurring right under him. Funny, I don't remember that mentioned in Genesis.

By the time all this heat is released, there wouldn't be any water around for an ark to float on, let alone anything remaining alive.

This doesn't even begin to scratch the surface of problems that the ark itself would encounter, such as the care/feeding of tens of thousands of animals and the inability of a wooden vessel the size and shape of the ark to remain intact on relatively calm waters. Noah's ark is purported to be a 450 foot long vessel built entirely out of wood. The longest wooden ship ever built by relatively modern people was approximately 300 feet long, and had extreme leakage problems. A wooden vessel the size of Noah's ark wouldn't even survive a launching.

This begs another question. Wooden boats much smaller that Noah's ark would be much more suited to survive rough waters. Why wouldn't any smaller boats survive if a much more unstable vessel managed to?

Even if all the above are accounted for, the creationists still encounter problems concerning biogeography (the distribution of organic creatures relative to geographic locations) and variation. The "little details" that falsify a global flood are legion.

roxrkool

And THAT Kevbo, is the reason Creationism has the foothold that it does in this country. The average person cannot begin to understand the myriad of complexities involved in the natural world. Thanks.

Imagine, all that devestation by simply raising the temperature of the Earth a measely 10 degrees. <sigh...>

ps418

Yes. When two plates are moving together as a unit relative to the geomagnetic pole, they will trace similar apparent polar wander (APW) paths over time. For instance, the APW paths of the pangean continents are similar prior to the breakup, and diverge afterwards. And yes, the APWs can be dated, which allows estimates of plate velocity over time to be estimated. Condie states for instance states that "rates of Proterozoic plate motions can be obtained from APW paths . . . results indicate that Proterozoic continental plate velocities (3-10cm/y) often exceeded those of present-day continental plates (which average about 5cm/y) and were equivalent to those of present day oceanic plates" (p. 219). Precambrian APWs also show "loops," which are interpreted as evidence of major collisions (ie, stuff that should only be happening during the flood). Several loops in Proterozoic APW paths also appear to be correlated with major orogenic episodes (1150, 1750, and 1850 in North America; 1100 and 2150 in Africa; Condie, 1989, p. 333).

It would take more than a post to answer your question in detail, but you can find lots of info by google searching for "apparent polar wander," or consulting a book such as Condie's Plate Tetonics and Crustal Evolution.

Patrick

Joe Meert

Yes, Condie's book is a good start. For a link on the effects of rapid drift on the depth of the oceans you can go http://gondwanaresearch.com/oceans.htm . I post many of my papers on the web. If you go to http://www.clas.ufl.edu/users/jmeert/pubs.htm you can download some papers on Precambrian plate tectonics. I would reccommend the in press paper by myself and Trond Torsvik. The Science paper (listed above) uses much of the information contained in our long manuscript. One of the more intriguing ideas regarding Proterozoic plate motions is that it is difficult to escape the conclusion that they were faster in the past. I'm not trying to push my articles, but I know they are accessible and a paper called the "HOG hypothesis" (HOG=Hand O God) is also available for download. Anyway, creationists do not acknowledge pre-Pangea supercontinents. Furthermore, I suggest you ask them what THEIR Pangea looked like. "Our" Pangea was constructed based on magnetic studies, geochronology, faunal evolution and many other geologic tools that are anathema to ye-creationism. I can tell you that ye-creationists are quite reluctant to provide details.

Cheers

Joe Meert

roxrkool

Thanks, Joe and Patrick. I'll go check out your papers, Joe. Condie's book sounds interesting, too.