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Laboratory measurements were conducted to evaluate physical and mechanical properties of sandstone and calcareous concretions which were collected from the wave-cut bench in Iwami-tatamigaura, a natural monument in Shimane, with permission of Agency of Cultural Affairs, Government of Japan. Physical properties such as density, porosity and p-wave velocity of sandstone(concretions)were 2.16～2.21Mg/m 3 (2.50～2.58Mg/m 3), 10.6～14.9%(2.40 ～4.82%)and 2.30～2.99 km/s(3.69～4.63 km/s), respectively. Mechanical properties such as uniaxial compressive strengthandtensilestrengthbyBraziliantestofsandstone(concretions)were18.1～26.7MPa(56.9～128MPa)and1.52 ～6.04MPa(4.03～10.9MPa), respectively. Weathering susceptibility index, which is defined as the ratio of porosity to tensile strength, was calculated to be 2.1～7.6×10-2 MPa-1 for sandstone and 2.4～6.7×10-3 MPa-1 for concretions. Observations of thin sections revealed that carbonate occurs as a matrix in the concretions whereas less carbonate in sandstoneswithsmallerstrength.Therefore,theconcretionshavelowerporosity,lowersusceptibilityofweatheringand largerstrengththanthoseofthesandstonebecauseofbondingeffectbythecarbonate.

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