MrDarwin

Have any creationists attempted to explain the <a href="http://hawaii-pineapple.com/geology1.htm" target="_blank">Hawaiian Islands</a> within a YEC model? Biogeography aside (although that's another important point), the islands sure seem like they've been around for more than 6,000 years.

The string of islands stretches from the Big Island at its southeast to the northwest in nearly a straight line, becoming progressively smaller and finally petering out into atolls (submerged islands surrounded by coral reefs). The Big Island is the largest for two reasons: it is still active (i.e., volcanoes are still adding to its mass) and as the youngest it has also eroded the least. The islands to the northwest become progressively smaller, because although they are also volcanic in origin their volcanoes are extinct and, being older, erosion has worn them down. The islands the farthest to the northwest in this chain, in fact, are completely submerged and exist only as atolls.

Plate tectonics, with the Pacific plate slowly moving over a magma "hot spot", neatly accounts for this island formation. Volcanoes form over the hot spot, building islands, but as the plate moves northwest it carriest these islands with it, away from the hot spot, and their volcanic activity ceases and they begin to erode and shrink in size.

Consistent with this theory, a new island is evidently beginning to form to the south, although its volcano (Loihi) is still completely submerged. At its current rate of growth, this underwater volcano is not expected to break the surface for several thousand more years.

Moreover, I've completely omitted any discussion of radiometric dating, but would be comfortable predicting, based on this theory, that radiometric dating will be consistent with the hypothesized relative ages of the islands. I would also predict that radiometric dating will give absolute ages of far more than 6,000 years for all of these islands. Yet in a YEC framework, even the oldest and most eroded islands would have to be no more than 6,000 years old.

Radiometric dating aside for the moment, and taking into account the things we can measure or reasonably estimate, e.g., the movement of the Pacific Plate; the rate of growth of the islands with active volcanoes; the rate of erosion--can anybody possibly come up with an age of less than 6,000 years for the islands?

[ July 16, 2002: Message edited by: MrDarwin ]</p>

Dr.GH

RE: Radiometric dating.

There are different melt sources for Ocean Island Basalts as opposed to Mid-Ocean Ridge or subduction zone volcanics. This can complicate the radiometric dating of the resulting material. Additionally, rapid quenching under pressure of volcanic melts alteres the gas contents, and thus some types of radiometric results, K/Ar for example. Dickin is probably the best "one stop" source to read on this.

Dickin, Alan P.
1997 Radiogenic Isotope Geology Cambridge: Cambridge University Press

There was at least one creato attack on radiometric dating based on Hawaiian basalts, I seem to recall it was by Steve Austin.

MrDarwin

Thanks, Dr. GH. The point I was trying to make was that we can reach certain conclusions about the age of the Hawaiian island chain and the relatives ages of the islands, completely independently of radiometric dating.

Dr.GH

Right. There is no problem there. I seem to recall a comparison to the arc made by the Yellowstone plume and the Hawaiian arc. You might see if that offers any additional fodder for the mill.

ps418

K-Ar dates clearly confirm this prediction. The image below is linked from the <a href="http://www.soest.hawaii.edu/GG/hcv.html" target="_blank">Hawaii Center for Volcanology</a> website:




The relationship between age and distance (the slope of an imaginary best-fit line through the points) indicates an average rate of about 8.0 cm/yr northwest displacement of the Pacific plate, over an assumed stationary mantle plume. This is consistent with space geodetic measurements of the mortheast-ward movement of the Pacific plate.

Patrick

GeoTheo

I for one am willing to admit it creates a problem for the YEC viewpoint. Another problem to me is the fact that Australia is populated by so many marsupials found nowhere else on the planet. Also madagascar and it's endmic population od various types of Lemurs.
Is anyone here willing to be honest and admit that abiogenesis presents a big problem to anyone with common sense?

MrDarwin

Thanks, Patrick, for backing me up, and also for demonstrating why the overwhelming consensus in science is for an ancient earth: not only because it makes sense, and not because it explains something in one particular scientific discipline, but because completely different kinds of evidence, from completely different scientific disciplines, are consistent with an ancient earth. The true test comes when we make predictions about what to expect from one discipline, based on what we know from another.

So how do you grapple with that problem?

Unanswered question, maybe. But problem? Abiogenesis is not inconsistent with an old earth (nor with evolution, for that matter). Perhaps you'd like to start a separate discussion to elaborate on why you think we should regard abiogenesis as a problem, so we can keep this one on-topic?

Vorkosigan

Hi Geo,

I've started a new thread for this one, to keep this thread on topic.

Vorkosigan

scombrid

I'll make it easy for him so he has no excuse to miss the thread.

<a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=001096" target="_blank">thread</a>

mibby529

Hawaii IS a problem for creationists. And even if the Bible were entirely true, or even if one of the main Xian doctrines (exclusive salvation) were true, that would mean that Yahweh damns whole races. Vine Deloria Jr was the first I can name to equate exclusive salvation with racism, but many have probably thought of it. It's just un-PC to say so.