Complex sentence: He continued publishing research papers for the Geological Survey into the 1950s and, after 23 years of geological survey in Rajasthan he published his "magnum opus", "The Geology of Central Rajasthan", in 1953.
Split into simpler sentences: He continued publishing research papers for the Geological Survey into the 1950s. After 23 years of geological survey in Rajasthan he published his "magnum opus", "The Geology of Central Rajasthan", in 1953.