Geo-engineering evaluation of Harrat Irbid Basaltic Rocks, Irbid District-North Jordan

The basalt flow in Irbid district covers an area of about 300 km(2) and forms different shapes: elongated strips, sub-rounded spots, and arc-like outcrops. The basalt flow in the study area has thicknesses ranging from 1 to 30 m. This study is conducted to evaluate the basaltic rocks as a construction material in eight different places of Harrat Irbid. Thirty-six rock cores were prepared from the collected fresh basaltic rock samples to study the physical and mechanical properties. The basaltic rocks in the study area have desirable physical and mechanical properties; the rocks have high apparent specific gravity values (2.70-2.90), bulk specific gravity (2.60-2.84), absorption values (0.33-1.60 %) that indicates the texture is crystalline, porosity (0.22-2.15 %), void ratio (0.002-0.022), water content (0.35-1.08 %), degree of saturation (4168 %), rebound number of Schmidt hammer hardness test (average 44.10), point load strength(average 11.35 MPa), uni-axial strength (average 106.83 MPa) which is classified as medium strength, basalt uniformity of wear (0.206), and very high durability which is equal to 99.52 % in average, recorded after the second cycle of the test. Based on field observations and physical and mechanical tests, this study confirms that the genesis of basalt in the study area is strongly related to Harrat Al-Shaam basalt. Therefore, this study adds a new area of about 300 km(2) to the Harrat Al-Shaam area. Additionally, this study strongly recommends the use of the basaltic rocks that have been tested in this study for some industrial applications (e.g., in construction).