The photograph shows a showcase to preserve an active fault exposed on a cut slope.
This showcase is to preserve a part of an outcrop of the active fault appeared during the prefectural road improvement work at Shinomenakagou, Ato-town,Yamaguchi prefecture.It was installed in December 2005 by the procurer of the work, Yamaguchi prefecture Ato civil engineering office.The showcase preserves the fault in the area of 3m×3m.The showcase is designed to have three tempered glass doors that can move from side to side.The white gouge can clearly be observed to show the bedrock and sediment layer are in fault contact.The photograph of the fault taken before the cut slope was covered by protection layer is shown on the front cover of Journal of JSEG,vol.46,No.6(Feb.2006).

(Photographed by Tatsuya MORIOKA)



Osawa Collapse of Mt. Fuji




Rock mass failure caused by 2007 Noto Peninsula Earthquake




Mt. Damavand (EL. 5,610 m), the highest peak of Iran in the Alborz Mountain Range as much as 3000 meters high, is an impressive stratovolcano during the Quaternary (Picture at the top of the page). Lar Dam, a fill type dam, was constructed in foot of Mt Damavand in 1981 for the purpose of water supply for Teheran, the capital of Iran. However, water level of the reservoir is still below the intake facility because of remarkable water seepage from the dam reservoir. Andesitic lava of Damavand volcano covers the left bank of the dam site. The Jurassic to Cretaceous limestone is distributed from the reservoir area to the downstream of the dam site. Linearly-aligned old and new limestone sinkholes, maximum hole 20 m- 30 m in diameter, are found along the coast of the dam reservoir (Picture on the bottom-left corner). A large travertine deposit crops out in the Lar valley at the downstream of the dam site (Picture on the bottom-right corner). These limestone sinkholes might be created by erosion due to hot water infiltration through faults, and possibly cause the said water seepage from the dam reservoir.

(Photographed by Shuichi Hasegawa)



The picture at the top of the page presents an unusual landscape of carbonate chimneys at Dragon valley approximately seven kilometers to the west of Buddhist monuments at Bamiyan. The carbonate chimney grows upward in the direction opposite to stalactite, and forms a semi-logarithmic-curved surface shape. A river course behind the chimneys in this picture was changed its direction by continuous blowout of carbonate minerals from these chimneys. This is one of the few cases in land-forming process except for erosion. The picture at the bottom of the page is an anaglyph-image of the carbonate chimneys, which provides a stereoscopic effect of views, when viewed with two different color (red and cyan) glasses. Thanks to advancement in computer image processing technique, color photo-editing tool for a stereo effect image has been developed in addition to monochrome sstereoscopic imaging familiar to us.

(Photographed by Kaoru Shima)



This photograph shows a toppling failure occurred on a cut slope with the alternation of strata of mudstone-dominant sand-and-mud-stone in the Shimanto Belt. The deformation of the cut slope occurred when the cut at a ridge-like convex part reached to the planned plane. The cut slope is 44 meters high, with a gradient of 1:10, and 130 meters long. Regarding its geometrical relation to the geologic structure, it lays parallel to the strike, inclining 75 to 85 degrees to the strata of a system of fissures dipping backward. The sandstone formation consists of a geologic stratum with 10 centimeters thick, showing a discontinuous lenticular form, and the bedding planes partially interlace one centimeter or less thick clay layers. Many drops facing toward the mountain are found in the study area, and they are approximately one meter high at maximum, occurring at the layered crushing.

(Photographed by Masashi UENO)