Getting the Drift
Michael Creech (the Skeptic, Vol 14:4 p.22)
This paper is based on the talk I gave at the 1997 National Convention at Newcastle. It uses the theory of continental drift (CD) as a vehicle to delve into the geology of a 6000 year old planet and will use some of the overheads I used there to illustrate just how ludicrous the creationist world view really is. They make the point - if dinosaurs and man were created during Week 1 of this planet's history then our co-existence with dinosaurs should surely warrant extensive recognition. Yet there are no extant art-works from any ancient cultures that give any indication that any of our ancestors had the faintest notion of dinosaurs, many of which were animals of such magnitude that it is inconceivable that they could have overlooked them. It is also worth noting that Genesis utterly fails to mention the co-existence of man and dinosaurs.
I also present an image of a coal miner looking up at a fossil boat anchor in the roof of a mine (something I am always looking out for as I know I will be rich and famous after such a discovery!). The point - if all the sedimentary rocks including coal were laid down during Noah's Flood, surely in the 2000 years that mankind has been mining coal we would have found numerous examples of fossilised boat anchors, fence post, pieces of pottery, not to mention people, by now.
My talk was inspired, in part, by a lady and a young boy who tried to sell me their beliefs one Sunday morning. All was cordial until she stated that the shells found on top of the Himalayas are proof of Noah's Flood, for which, "scientists have no explanation!" It was such a nice morning that I assumed ignorance on her part (rather than a more sinister option) and tried to educate her, and the boy, about a well respected theory, which not only explained the shells, but also the reef limestones atop the Himalayas, which obviously had the difficult job of accumulating in 40 days in rather turbid waters. I still wonder whether she went on to the next household and used the same line again, which would then be "telling lies for her God".
Her ignorance of CD was understandable, as it fits very uncomfortably with a 6000-year-young planet. The scales of plate motion across the globe (1000's of km) and the very slow rates (cm/year - about as fast as your fingernails grow) imply a much older planet. Creationist literature will argue either; that it never happened; that it started during Noah's Flood or after the destruction of the Tower of Babel, and has slowed down since; and anyway the Bible does not speak for or against CD (so there!). All these arguments can be found in the one article, making for a rather convoluted approach, to the say the least, but a damned fine read!
An explanation of the theory of Continental Drift
CD is to Geology what evolution is to Biology. It provides the broad canvas onto which all other observations are placed into context. Like evolution, CD is a fact, though details of the mechanisms are still the subject of scientific papers.
CD involves the creation of new oceanic crust at the mid-ocean ridges, which bisect the world's oceans. At these localities, basalts rise and cool, and submarine vents spew out cocktails of chemicals. Such vents, in the geological past, have been the sites of extensive mineral deposits such as those found at Broken Hill and Mt Isa. The new crust is forced, like two conveyor belts, away from the submarine ridges. The crustal plates, along with their continental passengers, ride over the mantle. But, no, the Earth is not growing! Crustal material is also being consumed at the other end at deep ocean trenches where one plate rides over another and the lower one is consumed by the mantle. At these "subduction zones" there is considerable volcanic activity and earthquakes, one manifestation of which is the Pacific "ring of fire".
Other plate boundaries involve collisions where mountains are formed. The example of the Himalayas is apt, as they are still rising, as India continues to collide with China. Since the world is round and far from perfect, transform faults, perpendicular to the mid ocean ridges, occur, which contain these irregularities, creating large scars on the earth where one part of the crust moves laterally in relation to the other side. A well known transform fault is the San Andreas Fault in California, which is a rare land based example.
The mechanisms which drive these plate motions are considered to be large scale convection cells in the upper mantle, rising at mid ocean ridges. But as already stated, this premise is still the subject of scientific inquiry.
So the answer to the first creationist response that "it never happened" is seen in the direct evidence for CD, which includes:
jigsaw fit of many continents at their continental margins;
ability to correlate the geology of widely separated
continents across the distribution of fossils. One of the most
striking being the tree Glossopteris, once restricted
to Gondwana continent now spread across the globe, and
associated with extensive coal seams in these countries;
bathometric map of the ocean floor, resplendent with mid
ocean ridges, subduction trenches, and transform faults. Yes
the world isn't flat!;
island chains forming, as the plate rides over a
stationary hot spot in the mantle;
foci at subduction zones, tracing the subducting
plate to depths of 4-500 kilometres;
new mid ocean ridge system that is currently forming in the
Red Sea and along the African Rift Valley - the process is still
concentration of volcanic and earthquake activity at plate
margins - the process is obviously ongoing;
lows existing over subduction zones, where lighter
crustal material is being consumed in the more dense mantle;
dating of ocean floor basalts, clearly show the
spreading away from mid ocean ridges. The oldest ocean floor
is less than 200 myrs, the oldest sedimentary rocks are almost
of reversals of the earth's magnetic field in the ocean
basalts also testify to this spreading phenomenon, as ancient
magnetic fields are preserved by the inherent magnetic
wander paths for continents are calculated using magnetic
minerals which, when cooled, have recorded the inclination and
direction of the earth's magnetic field. For instance at the equator
the field is flat, at the poles it is vertical. So a global position can
be determined from rocks of various ages and a continental
wander path calculated.
It is worth noting that all
these various diverse forms of evidence reinforce each other, creating a powerful,
interconnecting, set of evidence to support the theory of CD. For example: where
radiometric dating and magnetism show spreading, a mid-ocean ridge exists, which bisects
an ocean basin between two continents, which contain fossils and rocks, which can be
correlated, indicating they were once one landmass.
The other creationist argument that must be addressed is that CD started only 3500 - 4000 years ago and then slowed down to present rates. The supporting nature of the diverse evidence listed previously, also provides proof of relatively constant slow rates of drift. However, all this evidence is ultimately based on radiometric dating, which creationists argue is unreliable. Except for one fresh piece of evidence. Recent attempts at using satellite assisted surveying, to measure plate motions, have shown remarkably good agreement between these measurements, and the predicted rates estimated, using evidence based on radiometric dating. This agreement also gives strong support that radiometric dating actually does work.
Now for the third argument, that the Bible speaks neither for nor against CD anyway. Well this is a clanger. What does this admission suggest, if the creationists' main source of evidence fails to mention CD at all. What can we make of a "scientifically accurate" document which fails to mention the main process driving so many aspects of our planet's surface? But let's humour these confused souls. Assume CD has occurred, but pretend to agree that radiometric dating is unreliable, and explore their "theory" of a 6000-year-young planet.
Variable speed CD
First some theory on theories. A theory must:
of these predictions must be able to prove the theory
false (a theory must be falsifiable);
be based on more than one source of evidence (not
just from one old book for instance).
So, to squeeze CD
into a young Earth it must have started at much
faster rates and have slowed down to present day rates.
Now, if all sedimentary rocks were laid down during Noah's Flood, and we have found these rocks can be correlated across vast basaltic oceanic crust, then we can conclude these oceanic basalts were formed after the Flood, or they, too, would be covered by thick sediments. Therefore CD was initiated some time after the Flood, possibly at the time of the Tower of Babel (see Genesis 10:25 "the world was divided" - their reference not mine!). We can now build a time chart (see Chart) and identify some predictions and implications of such a proposition.
Let's assume that CD was initiated around 2000BCE, 350 years after the flood, and at rates of many km/yr. There would have been considerable volcanic activity and mountain building, along with folding and faulting of the sediments previously laid down during the Flood. Maybe all this upheaval brought the demise of the dinosaurs (pure speculation on my part, that source of scientific information, Genesis, fails entirely to mention these animals).
Implications of CD, at such fast rates, only 4000 years ago, raises some interesting points. The Chinese have written records going back beyond 4000 years, and surely they would have noticed the bump as India hit? Yet they don't mention it. And from a geological perspective some other factual problems:
We would not expect to find a relatively flat sedimentary pile, kilometres thick (laid down during Noah's Flood), overlying folded strata deformed some 350 years later. (Oops! Try the Sydney Basin.) And this sedimentary pile includes dinosaur footprints, from an animal that was already extinct?
The Tigris and Euphrates are recorded as having their headwaters in the Garden of Eden. To have survived intact, the land through which these rivers flowed must be basement, having not had any thick sediments deposited over them, or had their riverbeds folded and faulted. (Oops again! They flow over a thick sedimentary pile which has been severely folded and faulted.)
I'm sure there are many more, but these "facts which don't fit" are a good start. Along with no boat anchors in coal, a lack of dinosaur hieroglyphics or cave paintings, the proposition is failing the first requirement of a theory, and yet they want this taught in schools! Their proposition also fails to make any predictions which are testable or falsifiable, resulting in it being entirely useless in regards to science and mankind in general.
Expanding on this point, in the final analysis, money talks. Multinational energy companies spend billions of exploration dollars on the basis of an ancient Earth, with slowly drifting plates and an evolving fauna and flora. I am unaware of any such company using "flood geology" as an exploration model. Since everyone has so far been looking in the wrong places, a unique business opportunity exists for the CSF and its followers to put their savings where their ideologies are. Float their company on the stock exchange, aboard the decks of their Ark (and all tax free no doubt).
A final point though. The little boy who accompanied this lady to my doorstep stood silently as she stated that the end of the world was nigh, and as she asked if I was ready. So what thoughts has this young boy for his future? Should he worry about education, or thoughts of being a grandfather one day? How does this nonsense affect the children? And on the monetary angle again, do the fundamentalist churches insure themselves beyond the end of the world, and have they lobbied Canberra about the pointless policy of compulsory superannuation? Have they calculated an age cut off, so that their younger members don't lose out by being unable to recoup their super entitlements, because the world has ended. Or is this end of world stuff just a ploy? I hope that little boy, for his sake, knows that it is just that and nothing more.