Laboratory Measurement of Curie’s Temperature for Sandstone from Ewekoro, Nigeria

One of the factors affecting attenuation of seismic waves is an elasticity-the departure from ideal elastic behavior in the interior of the Earth. Studies of the an elasticity of the Earth had begun in Nigeria by seismologists using various techniques at room temperature, to investigate what could be responsible for the mechanism. Continuous-wave transmission and spectral amplitude wave-ratio techniques were employed in this study to investigate the effects of temperature on sandstone from the upper crust. The frequency range 10HZ to 1000Hz were investigated. The aim is to obtain Curie’s Temperature of Ewekoro sandstone which can serve as a parameter for mineral identification. A special kiln was constructed to heat the rock sample from 344K to 774k. Results obtained show that attenuation is affected by many mechanisms including presence of organic matter, seashells and presence of impurities or hydrocarbons in the rock matrix. There is a general increase in the attenuation of the rock sample when heated this is attributable to the thermal agitation of the internal constituents in the rock matrix, causing annealing in it. The Attenuation versus temperature curve of sandstone has a peak at 630 K, which is the observed Curie’s temperature for sandstone