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Gigapan Comments (1)

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  1. Keith patton

    Keith patton (November 30, 2009, 04:56AM )

    Brian: It is indeed limestone (test it with dilute acid if you can it will effervess or fizz as the acid dissolves the calcium carbonate in the limestone. The rock appears to be made up of interbedded limestone and silt stone with possible sandy layers. It has undergone compressional deformation resulting in the folds and fractures. It is difficult to tell if the deformation was great enough to be classified as metamorphism resulting in changes to the fabric of the rock other than the folding. The marked shaley fabric of the rock is also a result of the compressonal stress causing some realignment of the grains in the rock layers. Notice the small fractrues in the rock that exhibit 120 and 60 degree spacing. This is indicative of compressional stress due to tectonic movement along the plate boundary on which the Ryukyus lie. I would guess that this rock is apart of the Naha Limestone Formation or possibly the more highy deformed Shimajiri formation which also is found on the southern part of Okinawa. The formation if not identical is probably related by mode of formation and deposition. It is 7-20 meter thick and is coarse to medium lime sand and powdery non-porous limestone. The rock forms structures with one gentle slope and one steep face which forms an escarpment, typical of structures like the Maeda Escarpment of southern Okinawa sciencelinks.jp/j-east/article/200 004/000020000400A0051415.php Will open in
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