Complex sentence: He was among the first to study the mineralogy and geology of the Limousin region of France, paying particular attention to kaolin deposits, the key raw material in the manufacture of porcelain.
Split into simpler sentences: He was among the first to study the mineralogy and geology of the Limousin region of France. His interest in geology began by way of investigations of kaolin deposits, the key raw material in the manufacture of porcelain.