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Mudrock is a type of sedimentary rock whose original constituents are clays and muds. Mudrocks are fine grained siliciclastic which include mudstone and claystone depending on the grain size. The colour of mudstone is a function of its minerology content and geochemistry processes. One common sedimentary structure of mudrocks is lamination due to variations in grain size and composition changes. The importance of mudrocks is as a mixture for cement and to produce brick used for building structure. This research emphasizes on the resistivity value of mudrocks; claystone and mudstone which exist in northwestern of Peninsula Malaysia. Mudstone of Kubang Pasu Formation, red mudstone and grey mudstone of Chepor Member and claystone of Semanggol Formation were chose as the study area as each of the mudrock was formed in a different environmental condition. Electrical resistivity survey was conducted on top of the outcrops using Wenner -- Schlumberger array with 1.5 m and 1 m electrode spacing with respect to localities. The data was processed using Res2Dinv software to get the inversion model resistivity and the results were imported to Surfer10 software for labelling purposes. The mudstone resistivity value of Kubang Pasu Formation formed by depositional of calm water gives resistivity value from 20 - 120 Ωm. The red mudstone of Chepor Member formed at high oxidation environment gives resistivity value of 15 - 100 Ωm contrast to grey mudstone which formed under low oxidizing condition gives 120 - 500 Ωm resistivity value. The claystone of Semanggol Formation formed from shallow depositional environment gives resistivity value from 400 - 1000 Ωm. As a conclusion, electrical resistivity survey was successfully applied in differentiating the type of mudrocks. Also, mudrocks formed from different depositional environment gives different values of resistivity. [ABSTRACT FROM AUTHOR]

Rock is a naturally occurring substance. The study of rock properties and its mineral composition have many useful information and benefits, such as for building construction and aggregates. Understanding of how rock material was formed will reveal how it can be used in a building, its limitations and how it will weathered over time. The research objectives are to categorize the rock properties based from the methods of geophysics, geotechnical and petrography analysis, and to identify the possibility of the material used for construction purpose. The location of the study is at Bukit Chondong, Beseri, Perlis, Malaysia. The study was conducted using 2-D resistivity method, geotechnical test and thin section analysis. For 2-D resistivity method, the length of a single survey line is 40 m with minimum of 1 m electrode spacing and the array used was Pole-dipole. For geotechnical test, there are two test conducted on the core samples of mudstone and sandstone, which are permeability test and porosity test. Finally, the core samples was analysed from thin section to observe the shape and sorting of the grains. The result was tabulated, where mudstone has low resistivity compare with sandstone, which are less than 170 Ωm and 200 to 2000 Ωm respectively. The value of permeability for sandstone is high compare with mudstone, which is 4.48 and 0.883 (x10-22 m²) respectively. However, sandstone has low percentage of porosity (0.9 %) compare with mudstone (1.6 %). By comparing both types of rocks in this area, sandstone has high resistivity, high permeability and low porosity, while mudstone has low resistivity, low permeability and high porosity giving sandstone and mudstone are suitable material for construction and aggregates. The methods of geophysics, geotechnical and petrography analysis successfully identify the rock properties. [ABSTRACT FROM AUTHOR]