From source to basin of deposition: influence of transportation and digenesis on geophagic properties of soil

Abstract

Geophagia – the deliberate consumption of soil – has been practised for many centuries by a range of ethnic, religious and social groups in the world for a number of reasons. They include, but are not exclusive to, the following: nutrient supplementation; detoxification; alleviation of gastrointestinal disorders such as diarrhoea, craving and relief from morning sickness; or as part of a cultural belief system. The ability of geophagic soils to fulfil their desired objectives in humans is determined to a large extent by provenance and the pedogenetic development of the soil. This paper presents an overview of the impacts of distance and mechanism of transportation of sediments from source area to basin of deposition; the depositional setting and processes responsible for sedimentation; and the physical and chemical conditions during burial and digenesis on the positive and negative attributes of geophagic clayey soils.

Keywords:

• digenesis
• clay mineralogy
• soil morphometry
• sediment entrainment
• health implications
• geophagic clays