NR-1 Sinkhole interest, as sinkholes are generally believed to form only in environments which are subaerial, or exposed to the air. In contrast, the NR-1 Sinkhole is believed to be too deep underwater for the area to have been exposed to the air during formation in the Neogene. It was the first documented evidence suggesting that it is possible for karst sinkholes to form entirely underwater. NR-1 Sinkhole The NR-1 Sinkhole is a giant underwater sinkhole located in the Straits of Florida southwest of Key West, Florida. It is found at an approximate depth of of water at the foot of the
Pipe Creek Sinkhole Mammalian finds include an early rhinoceros ("Teleoceras", possibly from the Miocene epoch), canids, peccaries and short-faced bear. Backed by a grant from the National Science Foundation, researchers from the Indiana State Museum and several universities substantially completed field work at the sinkhole in the summer of 2004, but there was about one weeklong dig a year from 2005 to 2011. What probably was the last work at the site took place in 2014, with scientists and volunteers screening soil previously removed from the sinkhole. Pipe Creek Sinkhole Pipe Creek Sinkhole near Swayzee in Grant County, Indiana, is one of the