Reflectance anomalies in Pike River coals: Evidence of variability in vitrinite type, with implications for maturation studies and “Suggate rank”

Abstract

Trends in volatile matter content and vitrinite reflectance of Upper Cretaceous bituminous coals at Pike River Coalfield (South Island, New Zealand) indicate that vitrinite properties are strongly influenced by paleoenvironmental factors which controlled peat composition. Variation in vitrinite type can invalidate the use of vitrinite reflectance for assessment of thermal maturity, and R. P. Suggate’s rank scheme may be similarly affected. The consequent potential for underestimation of thermal maturity has important implications for petroleum exploration. In addition, isorank variations in vitrinite chemistry may have an important effect on the potential for oil and gas generation from vitrinite-rich coal measures. © 1982 Taylor and Francis Group, LLC.