Preprints  

We present a tribute to Georg Friedrich Karl Hartung (1821–1891), a German geologist, on his 200^th anniversary. Influenced by eminent 19^th century scientific personalities and performed pioneer geological observations and sampling in the Azores, Madeira, and Canaries volcanic archipelagos. Later in his life he travelled to the USA and explored the Scandinavian countries. His works on the macaronesian islands are deemed as classics, many enriched by his own detailed geological illustrations.