The Origin and Distribution of Hydrocarbons in an Upland Moorland Soil and Underlying Shale

Summary Investigations of plant and soil lipids at an upland moorland site revealed certain similarities in composition. In all lipid samples the polar compound fraction was the largest and the paraffinic the smallest. The range (C 16–36 ) and pattern of alkanes in the soil were also similar to those of the surface vegetation, both demonstrating a definite predominance of C odd components. A slight peak in the alkanes identified was seen in the region C 27– C 30 . The pattern of alkanes in the water running into the soil was quite different, and was not seen to influence the spectrum detected in the soil. Incubation of soil samples with and without added succinate, although causing a drop in lipid content, did not produce many significant changes in the soil alkanes. Plant‐derived alkanes in the soil appeared to be resistant to microbial alteration under the experimental conditions employed. The origin of alkanes in an ancient sediment, the underlying shale, was not so clear since the carbon preference index was around unity. It seemed possible that microbial activity might have altered the spectrum of alkanes in the sediment during ageing.