Bedding in cave wall (Prairie du Chien Group, Ordovician; Crystal Cave, near Spring Valley, Wisconsin, USA) 3 : 無料・フリー素材/写真
Bedding in cave wall (Prairie du Chien Group, Ordovician; Crystal Cave, near Spring Valley, Wisconsin, USA) 3 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | Crystal Cave is a tourist cave just southwest of the town of Spring Valley in northeastern Pierce County, western Wisconsin, USA. This is an uncommon example of a dolostone network cave, developed in Ordovician-aged Prairie du Chien Group sedimentary rocks.The stratigraphic succession at Crystal Cave is:- Willow River Dolomite (1st & 2nd levels of the cave)- New Richmond Sandstone (a relatively thin interval here)- Oneota Formation (3rd level/bottom level)According to info. provided by Crystal Cave personnel, the travertine speleothem here is relatively young - <3000 years old, with most of it being <500 years old. Based on regrown broken speleothem from 1940s cave trail development, the speleothem growth rate here is estimated at about 1.5 inches per century.Chert nodules and drusy quartz-lined cavities occur in the dolostone in places at Crystal Cave. Solution pockets are moderately common, which produce a moth-eaten appearance to the dolostone cave walls and ceilings. Larger rooms and passage intersections have apparent break-out domes developed in the ceiling. Cave passages are frequently developed along subvertical joints (see map - people.uwec.edu/jolhm/Cave2007/TeamC/TeamC/CrystalCave/Cr...).Travertine speleothem occurs in some areas - principally dripstone (stalactites, stalagmites, columns) and flowstone. Some Crystal Cave travertine speleothem is fluorescent and even phosphorescent. |
| 撮影日 | 2015-06-04 12:41:32 |
| 撮影者 | James St. John |
| タグ | |
| 撮影地 |
