CompuServe Thread

#Subduction & Ocean Basin

6 messages in this thread
#168124From: Jim YahrFeb 14, 1995 10:46 PM
Kamron, >>I agree! The pressure added caused the material to shift from solid to liquid very No shift from liquid to solid occurs. The deformation takes place at the atomic bond level. Also, this can't explain why rock can bend in tension also. Check out <Modern Structural Geology>, Ramsey and Huber, Academic Press, ISBN:0-12-576901-6 Jim
#168260From: Kamron KirkconnellFeb 15, 1995 7:46 PM
>> No shift from liquid to solid occurs. The deformation takes place at the atomic bond level. Also, this can't explain why rock can bend in tension also. << What happens on the atomic level. If the atomic bonds are changed how does the composition of the material stay the same or are you saying it unbonds and then rebonds back? Any crystalline structure would also be lost. All from just pressure and tension?
#168275From: Jim YahrFeb 15, 1995 8:16 PM
>>If the atomic bonds are changed how does the composition of the material stay the same or are you saying it unbonds and then rebonds back? The atomic lattice of the crystal becomes distorted. Usually by slippage between planes if that type of structure is available. It shows up in a petrographic microscope using cross polarized light. >>Any crystalline structure would also be lost. All from just pressure and tension? The structure is not lost, just distored. Enough small distortions can combine to form a visible effect in the rock. Jim
#168490From: Kamron KirkconnellFeb 16, 1995 8:18 PM
The structure of granites even the fine crystals types have such an interlocking matrix. LIke shifting a jigsaw puzzle it just wouldn't fit in a shift. This does not compute. Unless the crystals melted how can they shift arrangement when they are all interlocking crystal solids?
#169046From: Jim YahrFeb 19, 1995 2:41 PM
All crystals have planes of weakness in their crystaline structure. These are cleavage planes. When force is applied the crystals tend to deform along the clevage planes. There is a slippage in the atomic bonds, and the crystal lattice is distorted. Jim
#169344From: Kamron KirkconnellFeb 20, 1995 6:59 PM
Jim That is what Doug was saying. Still the planes run in all directions so it still is tough to see it sliding smoothly in any direction. The atomic bonds slipping is a real surprise also. Do you have a reference for that? It is obvious that the ocean basin faults in true lines straight and slight to moderate large curves. Some of the faults are thousands of miles long. So we know that it breaks like a brittle solid. If it deforms and reforms so well in some areas why would it break in the earths largest and truest fractures in other areas. Also why would both occurs together …it seams like one would unstress the area so the other process would not take place. Kamron