The Town Creek locale of Jackson, Mississippi, USA: Charles Lyell (1797–1875), exemplary fossils and a subsurface volcano

Abstract

The Town Creek locale in Jackson, Mississippi exposes fossiliferous strata through stream erosion and provides evidence for stratal doming atop an extinct volcano. Charles Lyell (1797–1875) investigated the locale on his second visit to North America (1845–1846) and concluded that Town Creek fossils were older than Vicksburg fossils, and that strata dipped westward from Jackson. In the 1850s, Mississippi's state geologist Eugene Hilgard (1833–1916) recognized the first volcanic doming evidence and correctly concluded that a ‘local upheaval’ had elevated the Jackson area. Subsequent research revealed an extinct volcano as Jackson Dome's source, explaining the strata dip and Lyell's observation that Jackson's Eocene fossils were older than Vicksburg fossils, later identified as Oligocene. The Jackson fossiliferous strata, known today as the Moodys Branch Formation, exquisitely preserves fossils that have contributed to numerous scientific investigations. The Town Creek locale was threatened in 2003 when a proposed flood control project would have inundated it. Scientists rallied for the preservation of the geologically and historically important Town Creek, and today it remains as a geoheritage site available to scientists and the public, with a state historical marker noting its geological importance. Long-term preservation of the locale is needed but not guaranteed.