Creationists: Where Are The Pillows?

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Actually, from runaway subduction, we *would* expect pillowing, because it would be pretty hard for runaway subduction to occur without exposure of the basaltic magma to water.

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--Right, and pillowed lava is found in the first several km of ocean crust all over the world. Do you dispute this? At least that is what I would say if you were referring to any basaltic magma. But if you are referring to terrestrial extrusive flows, than no, we would not expect pillowing of any and all lavas because it is clear from the geologic record that water was not always covering the earth.

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And lava erupting from undersea dikes forms... pillows! The question is why, if the entire earth was flooded when the basalts were formed, are there not pillows?

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--There are pillows! Pillowed basalts is what characterizes a large portion of oceanic crust where it is most prone to hydrothermal alteration. The REAL potential problem is that pillowed lavas grade down into gabbro with their characteristic large crystal sizes, which in the current geological literature is indicative of large intervals of cooling.

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If it's flowing above the surface, it's exposed to water, and thus going to form pillow lava at the periphery.

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--At spreading ridges, yes. On the continents, not always.Cheers,
-Chris Grose[This message has been edited by TrueCreation, 01-06-2004]

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Heh, now you're going beyond the realm of my knowledge on the subject. I was just giving a basic definition. Certainly you'll get different effects between the part that is above the surface and the part that is below, but the role that water pressure plays when it's fully submerged, I can't really say. (it's, what, 1 atmosphere pressure for every 33 feet?).

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Where's Bill when you need him?

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--I should have ordered AGU's geophysical monograph #128 when I had the chance.. Cheers,
-Chris Grose

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I don't have significant data yet on the structure of the lavas at such traps, though I think that in order for a CPT view of earth history to be correct, there should be extensive evidence for either pillowing and/or glassy flows for the latest extrusive events.

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My point exactly.

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--It wouldn't be expected for the same reason dessication cracks are found all throughout the geologic record.

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I.e., that we're dealing with a subaerial environment here? That's another good question for YECs... to explain desiccation cracks. I should add that to the yet-to-be-explained list.- Karen

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"Illuminant light,
illuminate me."

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That's another good question for YECs... to explain desiccation cracks. I should add that to the yet-to-be-explained list.

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--The mere fact that dessication cracks exist in significant amounts in the geologic record isn't difficult to explain, just understand that if there ever was a 'flood event', the earth either was never fully covered with water, or it was fully covered with water for a very short nearly insignificant time. And some argue that there is too much heat.. hm...--I will also say that there is the potential for falsification of the YECist catastrophic view of earth history. Dessication cracks, while they don't need a very significant time to form, they do take time to form. If we have a sample lithofacies characterized by dessication cracks, the directly superposing lithofacies should nearly always be significantly older relative to the underlying one if the YECist view is correct. This comes from the reasoning that if the YECist view is correct, radioisotopic decay must have been significantly faster (on the order of 1.37 My of decay per day for a year long time scale), and from the fact that the rate of many other processes such as the formation of dessication cracks, given certain constraints (eg. the area wasn't 200 deg/C or something, which could be varified by various ichnofossil data or some other method) shouldn't be accelerated as well. Therefore, if it takes, lets say, 4 days in livable to semi-livable conditions the directly superposing lithofacies should be about 5.48 My older by radioisotopic analysis. Similar expectations can readily be applied to other formations such as allochthonous fossil forests, coprolites (especially those exhibiting dessication cracks),and ichnofossils such as the ichnogeneras archaeoentomonichnus, attaichnus, coperinisphaera, pallichnus, etc.Cheers,
-Chris Grose[This message has been edited by TrueCreation, 01-06-2004]

Rei,I'm not positive, of course, but the picture you show is not a pillow lava. What you are looking at there is probably a vent area for a basalt flow. Here is an actual pillow lava in outcrop.Volcano Hazards Program

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Oh yes, I forgot that I read pillows can form in lakes and water-saturated seds (I think from Bill), but I don't know how or why. I was always told you needed pressure to keep them from 'exploding' (like what happens in Hawaii when the lava reaches the ocean).
The seds would qualify, but not sure about the lakes. How deep did the pillows form in the lakes, I wonder?

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They can form under quite shallow conditions. I think there are plenty of videos showing them form in natural light in the ocean. Can't be too deep. I think some of the sediments are actually palagonite which would be altered basaltic glass shards that look like shaley sediments. The textures do vary, but I'm not sure if depth has much to do with it, though one would expect to have a violent reactions at or near the surface of the water that would result in the formation of more palagonite.

I was thinking the same thing, but I didn't see a scale in Rei's image and didn't want to guess poorly. It looks a lot like the CRB outcrops I saw in the Columbia River Gorge.[This message has been edited by roxrkool, 01-07-2004]

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REi: but the pressure from the flow continues to build up on the inside, forcing it to break; a new flow forms out of the break, which develops its own shell; etc. The end result is long successive chains of overlapping "pillows". The quenching of the surface additionally leaves clear lineations on the side.

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Moose: I think this is somewhere between misleading and flat-out wrong. Not that pillow don't sometimes break open, but I don't think it's from internal pressure. I believe what you are referring to as "lineations", are radiating joint patterns. This is the pillow Basalt counterpart to the columnar jointing that can be seen at Devils Tower, in Wyoming, USA.

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Sorry, Moose, but I'll have to go with Rei on this one. There are spreading cracks on some pillows that show perpendicular lineations or corrugations that formed as the pillow expanded. I have a picture in the Encyclopedia of Volcanoes that shows such lineations with perpendicular tension cracks. I haven't read this chapter yet, but it looks pretty informative.

In message 20, Edge wrote:"I'm not positive, of course, but the picture you
show is not a pillow lava. What you are looking
at there is probably a vent area for a basalt flow.
Here is an actual pillow lava in outcrop.Volcano Hazards Program "I agree with edge. What the picture shows is definitely not pillow lava. the picture shows columnar jointing with is, for some reason, not perpendicular to the top and bottom of the flow. Possibly it is a vent, valley fill, or some enclosed space within which the lava / magma cooled. This picture is from New Zealand in the "Gannets at Muriwai" web page at:http://www.scitec.auckland.ac.nz/~hafner/gannets/Some more pictures of pillow lava:1. Pillow Lava
404 Not Found 2. Pillow lava in the Bay of Islands ophiolite complex
http://www.esd.mun.ca/stjohns2001/photos/photo_14.jpg
http://www.esd.mun.ca/stjohns2001/photos1.html3.Pillow Lava
http://www.winona.msus.edu/geology/MRW/mrwimages/pillows.gif
http://www.winona.msus.edu/geology/MRW/minrx.htm4. IL VULCANISMO
Libero - Community - I siti personali
Libero - Community - I siti personaliModern Pillow Lava:1. http://vulcan.fis.uniroma3.it/...VULCANOLOGIA/gif/pillow.gif2. Pele Meets the Sea - Part II: Still Photographs of Active Lava
http://satftp.soest.hawaii.edu/...aii/vfts/pele/page.s2.html3. Pillow lava rocks on the slope off Hawaii form when magma oozes from below.
http://www.photolib.noaa.gov/nurp/nur05018.htm4. Types of lava seen at the mid-ocean ridge axis
GMRT5. Lava Flows Underwater
Eruptions on land at Kilauea Volcano
Lava Flows UnderwaterYours,Bill Birkeland

My apologies for the picture; I like to include a picture with new topics, and chose that one because it looked nice and showed a large scale formation as opposed to an individual pillow (or small group); I guess the author of the page was incorrect, since you're the expert here .Since you're here, Bill, would you care to help inform us as to what role pressure actually does play on pillow formation? And also as to whether extensive pillowing on most basaltic flows would be expected under the typical creationist view that basaltic flows that have fossil-bearing sediments underneath them are from undersea volcanic eruptions?

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"Illuminant light,
illuminate me."

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5. Lava Flows Underwater
Eruptions on land at Kilauea Volcano
Lava Flows Underwater

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This is an excellent picture of some of the corrugations that we discussed earlier. Note the mirror plane symmetry of some of the lobes. This is caused by expansion of the outer crust by internal pressure at a separation crack, and formation of corrugations perpendicular to the crack and parallel to the translation of the crust. Sort of like smearing butter with a serrated knife.

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I.e., that we're dealing with a subaerial environment here?

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That's another good question for YECs... to explain desiccation cracks. I should add that to the yet-to-be-explained list.

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- Karen

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Rei,I think that, once again, we are talking past each other with Chris. He may not have explained (which I find mildly annoying) to you that he is not a global flooder, but a temporary surger. Neglecting, for just a moment, that this hypothesis is only slightly more plausible than your basic biblical flood (which, of course, isn't saying very much). Consequently, he has no problem with dessication cracks, or with lavas that do not exhibit subaqueous structures. Every evidence for dry land is simply evidence for an ebb period of surging.

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he is not a global flooder, but a temporary surger

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*sigh*
We really need to have a mandatory "stance sheet" that you have to fill out in your profile before you can get on here and debate.

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"Illuminant light,
illuminate me."

good idea!

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*sigh*
We really need to have a mandatory "stance sheet" that you have to fill out in your profile before you can get on here and debate.

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--Well it is more than obvious that any hypothetical 'global flood' through which the geologic column was layed down while the earth was completely covered with water is falsified.Cheers,
-Chris Grose
OYSI