Dating an orogeny

It is also likely that granite mountains were uplifted when the granite was already solid (pp. Do the authors, or anybody else, know the cause of such recent vertical tectonics?

Does the lack of a mechanism nullify the authors’ field deductions? They provide a list of 20 possible mechanisms for vertical tectonics, none of which can be demonstrated to be occurring today (p. One strong contender is isostasy after erosion, but the authors find much evidence against this suggested mechanism: One of their conclusions is quite controversial, namely that plate tectonics explains very few mountains. The authors attribute the formation of rifts, such as the East African rift (p. They even state that the East African rift can be traced to the Carlsberg Mid Ocean Ridge in the Indian Ocean: “As noted in a previous section, the formation of swells seems to initiate faulting, rifting and extension, and it is interesting that the rift valley system of Africa can be traced continuously to the Red Sea, and thence to the Carlsberg sub-oceanic ridge” (p. By this they are implying that vertical tectonics also produced the mid-ocean ridges in the last periods of geological time.

302), suggesting that it occurred “There is nothing very special about the climate in the Late Miocene-Early Pliocene period when there often occurred planation that suggests an increased erosion rate, and in any case the mountains discussed are in a wide range of latitudinal and climatic situations.

At present, the cause of the observed high rate of planation remains a mystery.” Of course, their concept of climate in the Late Miocene-Early Pliocene is based on uniformitarian assumptions, which ignores the effects of the Genesis Flood.

Ollier and Pain show that after all the continents were planed, they were uplifted and dissected.

The authors essentially conclude that the plains that were once near sea level in the Miocene were uplifted to form the mountains we see today.

They believe this is the origin of nearly all mountains and have an impressive amount of evidence to back up their conclusion.

Many geologists and geophysicists assume that the mountain building process of horizontal compression caused the folds we see in the mountains today.The surfaces were planed down to what is called base level, which is usually considered to have been sea level (p. It is interesting that one planed area, the area that is now occupied by the Apennines Mountains of Italy, was planed sea level (p. In some areas the planation surfaces are very flat, such as the plains of Australia and Africa (p. Below these plains the sedimentary rocks are generally folded.Ollier and Pain marvel how such planation could have occurred at all and that is was so widespread: “The remarkable thing is that plains of great perfection are ever made, despite all the obvious possibilities of complications.Tensional and compressional structures, similar to those found in mountains, have formed in these areas during downslope mass movement.Seismic sections of ancient folded sediments from all over the world, especially along convergent plate margins, look similar to these modern marine sediments found along the continental margins.

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