Raman spectra of carbonaceous material in the Paleozoic strata around the Hikami and the Kesengawa granites in the Southern Kitakami Mountains have been investigated. Two spectral lines, one occurring near 1350cm^-1, and another at about 1620cm^-1, indicate the degree of graphitization in terms of the I₁₃₅₀/I₁₆₂₀ intensity ratio. The I₁₃₅₀/I₁₆₂₀ intensity ratio decreases with advancing coalification and graphitization, and becomes zero above about 190Å in crystallite thickness L_c (002) determined by the X-ray diffraction techniques. X-ray parameters which indicate the degree of graphitization could not be obtained because of fluorides formation during chemical treatment for isolation of carbonaceous material. However, the I₁₃₅₀/I₁₆₂₀ value of the Raman spectra could determine the degree of graphitization even where other compounds coexist.
The Raman spectra of graphites collected from along the western edge of the Kesengawa granite show a single line at 1620cm^-1 rather than the 1580cm^-1 line of the theoretical E_2g2 mode in pristine graphite. The spectral line shift to higher frequency side suggests that these graphites might be graphite intercalation compounds.
I₁₃₅₀/I₁₆₂₀ values of the Siluro-Devonian Formations around the Hikami granite are above 0.2. These data indicate that the Silurian stratum was not thermally affected by the Hikami granite.
Laser Raman spectra of carbonaceous material in sedimentary and metamorphic rocks could be applied to evaluate the degree of graphitization, and to estimate thermal effects from granite plutons.