Geology and Minerals
East of the Vanuatu island of Epi can be found a series of active underwater volcanic cones and a caldera which last erupted in 2023. These series of submarine volcanoes are generally referred as East Epi, and the 3 bigger cones have specific names, from west to east, Epi-A, Epi-B and Epi-C. All of these cones have had intermittent activity in this and the last century.
History of the petroleum industry in the United States.
Gunflint chert.
Text from Wikipedia; plate via Wikimedia Commons. Text CC BY-SA 4.0; plate freely licensed (see Commons). Source record. Images and catalogue data are reproduced from open-access collections.