![](../../pictures/archives/compress/1999/108/jpeg/01t.jpg) Erosion forms of limestone in a rock shelter at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/24t.jpg) Erosion forms of limestone on a rock shelter at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/03t.jpg) Tree roots and erosion forms on a limestone rock at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/07t.jpg) Limestone erosion forms at Koomer Ridge Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/08t.jpg) Mushroom-like limestone erosion forms at Koomer Ridge Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/15t.jpg) Erosion of limestone near Gray s Arch. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/21t.jpg) Limestone rocks, view from Sheltowee Trail near Chimney Top Rock. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/13t.jpg) A.S. on Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/23t.jpg) View from Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/12t.jpg) Pine forest on Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/000t.jpg) Rough Trail to Gray s Arch. Red River Gorge, Kentucky, November 5, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/10t.jpg) A small maple on Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/00t.jpg) Rough Trail to Gray s Arch. Red River Gorge, Kentucky, November 5, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/16t.jpg) A tree with very big leaves on Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/12t.jpg) Blueberry and rhododendron bushes on Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/04t.jpg) Unknown dwarf berries on Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/07t.jpg) Multicolor maple leaves on Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/08t.jpg) Rhododendron in a canyon, view from Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/24t.jpg) Sheltowee Trail near Chimney Top Rock. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/23t.jpg) A fungus (?) on a birch, Sheltowee Trail near Chimney Top Rock. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/00t.jpg) View of canyon walls at evening from Sheltowee Trail near Chimney Top Rock. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/18t.jpg) Gray s Arch, view from rock shelters. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/11t.jpg) View of rock shelters from the top of Gray s Arch. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/17t.jpg) Gray s Arch, view from rock shelters. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/17t.jpg) Sheltowee Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/16t.jpg) A.S. on Buck Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/12t.jpg) Buck Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/15t.jpg) Forest near Buck Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/21t.jpg) View from Pinch Em Tight Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/19t.jpg) View from Pinch Em Tight Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/20t.jpg) View from Pinch Em Tight Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/18t.jpg) Oak forest near Pinch Em Tight Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/17t.jpg) View from Pinch Em Tight Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/13t.jpg) Flowers on a stone at Buck Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/14t.jpg) Mushrooms in moss at Buck Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/22t.jpg) View of a canyon from Pinch Em Tight Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/108/jpeg/18t.jpg) Bottom of a canyon, view from Sheltowee Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/03t.jpg) Bamboo brushes on the bottom of a canyon near Sheltowee Trail. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/109/jpeg/09t.jpg) Creeping fern among dry leaves and needles on Koomer Ridge Trail. Red River Gorge, Kentucky, November 7, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/20t.jpg) Forest below Gray s Arch. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/19t.jpg) Rhododendron, fir and maples near Gray s Arch. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/22t.jpg) Gray s Arch with rhododendron on foreground. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/08t.jpg) Forest near Gray s Arch at morning. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/10t.jpg) View from the top of Gray s Arch at morning. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/07t.jpg) Forest near Gray s Arch at morning. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/06t.jpg) Forest near Gray s Arch at morning. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/04t.jpg) Forest near Gray s Arch at morning. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/107/jpeg/09t.jpg) View from the top of Gray s Arch at morning. Red River Gorge, Kentucky, November 6, 1999.
![](../../pictures/archives/compress/1999/106/jpeg/23t.jpg) Tobacco farm near Slade, Kentucky, November 5, 1999.
![](../../pictures/archives/compress/2018/2421/jpeg/10t.jpg) Erosion of the dome of Enchanted Rock, view from Freshman Mountain. Enchanted Rock State Natural Area, Fredericksburg, Texas, December 25, 2018
![](../../pictures/archives/compress/2002/246/jpeg/19t.jpg) View of limestone erosion from a trail along a western slope of Mount Yoash, 4 miles north-west from Eilat. The Middle East, January 17, 2002
![](../../pictures/archives/compress/2019/2428/jpeg/25t.jpg) Some whitish lichen on a limestone rock near the river in Pedernales Falls State Park. Johnson City, Texas, January 11, 2019
![](../../pictures/archives/compress/2019/2429/jpeg/03t.jpg) Button lichen (Buellia) on limestone rock near the river in Pedernales Falls State Park. Johnson City, Texas, January 11, 2019
![](../../pictures/archives/compress/2019/2429/jpeg/15t.jpg) Some dark-green crustose lichen on a limestone rock near the river in Pedernales Falls State Park. Johnson City, Texas, January 11, 2019
![](../../pictures/archives/compress/2015/1567/jpeg/19t.jpg) Limestone erosion in Harrarah (Al Kharrarah). Southern Qatar, March 27, 2015
![](../../pictures/archives/compress/2015/1568/jpeg/03t.jpg) Erosion of soft limestone in Harrarah (Al Kharrarah). Southern Qatar, March 27, 2015
![](../../pictures/archives/compress/2015/1568/jpeg/27t.jpg) Erosion of limestone slabs in Harrarah (Al Kharrarah). Southern Qatar, March 27, 2015
![](../../pictures/archives/compress/2015/1568/jpeg/01t.jpg) Erosion of limestone rocks in Harrarah (Al Kharrarah). Southern Qatar, March 27, 2015
![](../../pictures/archives/compress/2019/2428/jpeg/21t.jpg) Bordered scale lichen (Psora pseudorussellii) on a limestone conglomerate rock near the river in Pedernales Falls State Park. Johnson City, Texas, January 11, 2019
![](../../pictures/archives/compress/2015/1577/jpeg/23t.jpg) Erosion of limestone near Salwa Road in area of Rawdat Ekdaim. Southern Qatar, April 11, 2015
![](../../pictures/archives/compress/2016/1830/jpeg/18t.jpg) Wind erosion of limestone cliffs in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, May 20, 2016
![](../../pictures/archives/compress/2016/1793/jpeg/03t.jpg) Erosion of limestone cliffs in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, April 1, 2016
![](../../pictures/archives/compress/2015/1546/jpeg/09t.jpg) Erosion of beach limestone in Purple Island (Jazirat Bin Ghanim). Al Khor, Qatar, February 14, 2015
![](../../pictures/archives/compress/1999/110/jpeg/03t.jpg) View of Wabash River from a trail to Fort Ouiatenon. Indiana, November 13, 1999
![](../../pictures/archives/compress/2016/1843/jpeg/01t.jpg) Wind erosion of limestone cliffs in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, June 25, 2016
![](../../pictures/archives/compress/2016/1796/jpeg/20t.jpg) Erosion of an orange limestone formation in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, April 1, 2016
![](../../pictures/archives/compress/2016/1794/jpeg/14t.jpg) Erosion of the edge of limestone cliffs in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, April 1, 2016
![](../../pictures/archives/compress/2016/1817/jpeg/24t.jpg) Limestone wind erosion on the tabletop hill in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, April 29, 2016
![](../../pictures/archives/compress/2019/2429/jpeg/30t.jpg) Rock shield lichen (Xanthoparmelia)(?) on a limestone rock in a forest in Pedernales Falls State Park. Johnson City, Texas, January 11, 2019
![](../../pictures/archives/compress/2019/2429/jpeg/24t.jpg) Rock shield lichen (Xanthoparmelia) on a mossy limestone rock in Pedernales Falls State Park. Johnson City, Texas, January 11, 2019
![](../../pictures/archives/compress/1999/104/jpeg/12t.jpg) Soil erosion in Happy Hollow Park. West Lafayette, Indiana, October 27, 1999.
![](../../pictures/archives/compress/2016/1796/jpeg/10t.jpg) Erosion of a limestone formation on a plateau of a tabletop mountain in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, April 1, 2016
![](../../pictures/archives/compress/2016/1802/jpeg/10t.jpg) Erosion of a rock formation on a tabletop hill in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, April 8, 2016
![](../../pictures/archives/compress/2004/424/jpeg/09t.jpg) Early snowfall on Rock Street near Museum of Fall River Historical Society in historic Highlands District. Fall River, Massachusetts, November 13, 2004
![](../../pictures/archives/compress/2015/1568/jpeg/26t.jpg) Rough eroded limestone rocks in Harrarah (Al Kharrarah). Southern Qatar, March 27, 2015
![](../../pictures/archives/compress/2015/1568/jpeg/25t.jpg) Rough weathered limestone rocks in Harrarah (Al Kharrarah). Southern Qatar, March 27, 2015
![](../../pictures/archives/compress/2019/2605/jpeg/04t.jpg) Limestone with fossils near Whiskey Bridge of Brazos River, on Highway 21 west from Bryan. Texas, November 29, 2019
![](../../pictures/archives/compress/2004/423/jpeg/26t.jpg) Rock Street in historic Highlands District. Fall River, Massachusetts, November 13, 2004
![](../../pictures/archives/compress/2003/355/jpeg/14t.jpg) A rock in the middle of Bell Rock Road in Freetown - Fall River State Forest. Massachusetts, August 24, 2003
![](../../pictures/archives/compress/1999/90/jpeg/13t.jpg) Potholes Park, Fall Creek Gorge. The trip was organized by Purdue University International Center. Near Pine Village, Indiana, June 5, 1999.
![](../../pictures/archives/compress/2003/366/jpeg/23t.jpg) A dam in Russells Mills village, on Paskamansett River, view from Rock O Dundee Road. Dartmouth, Massachusetts, November 28, 2003
![](../../pictures/archives/compress/2003/366/jpeg/10t.jpg) A dam in Russells Mills village, on Paskamansett/Slocums River, view from Rock O Dundee Road. Dartmouth, Massachusetts, November 23, 2003
![](../../pictures/archives/compress/2003/366/jpeg/22t.jpg) A dam in Russells Mills village, on Paskamansett/Slocums River, view from Rock O Dundee Road. Dartmouth, Massachusetts, November 28, 2003
![](../../pictures/archives/compress/2003/365/jpeg/10t.jpg) A dam in Russells Mills village, on Paskamansett/Slocums River, view from Rock O Dundee Road. Dartmouth, Massachusetts, November 13, 2003
![](../../pictures/archives/compress/2004/425/jpeg/21t.jpg) A dam in Russells Mills village, on Paskamansett/Slocums River, view from Rock O Dundee Road. Dartmouth, Massachusetts, November 25, 2004
![](../../pictures/archives/compress/2019/2512/jpeg/25t.jpg) Rock foam lichen (Stereocaulon saxatile)(?) on a rough surface of a granite stone in Kannelyarvi, 45 miles north from Saint Petersburg. Russia, May 25, 2019
![](../../pictures/archives/compress/1999/90/jpeg/16t.jpg) Overcoming a tub in a creek in Potholes Park (Fall Creek Gorge) by an international student of Purdue University. Near Pine Village, Indiana, June 5, 1999.
![](../../pictures/archives/compress/1999/90/jpeg/14t.jpg) Inspecting a creek in Potholes Park (Fall Creek Gorge) by international students of Purdue University. Near Pine Village, Indiana, June 5, 1999.
![](../../pictures/archives/compress/2005/473/jpeg/09t.jpg) Forest of Enfield gorge, from Rim Trail, in Robert H. Treman State Park. Ithaca, New York, November 2, 2005
![](../../pictures/archives/compress/1999/90/jpeg/18t.jpg) International students of Purdue University walking over rapids and tubs of a creek in Potholes Park (Fall Creek Gorge) near Pine Village. Indiana, June 5, 1999.
![](../../pictures/archives/compress/2005/476/jpeg/21t.jpg) Fallen sycamore tree in snow near Gorge Trail in Taughannock Falls State Park. New York, November 23, 2005
![](../../pictures/archives/compress/2015/1683/jpeg/04t.jpg) Fossilized oyster sea shells Ostrea latimarginata(?) in a limestone layer (Dukhan Limestone Member) of Dammam Formation in Jaow Al Hamar depression south from Trainah. Southern Qatar, November 6, 2015
![](../../pictures/archives/compress/2004/376/jpeg/14t.jpg) View in direction to Rough Point from Cliff Walk at Sheep Point, behind Gull Rock tunnel. Newport, Rhode Island, February 5, 2004.
![](../../pictures/archives/compress/2005/473/jpeg/08t.jpg) Fall colors of Enfield gorge, view from Rim Trail, in Robert H. Treman State Park. Ithaca, New York, November 2, 2005
![](../../pictures/archives/compress/2016/1796/jpeg/22t.jpg) Limestone rock formation in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, April 1, 2016
![](../../pictures/archives/compress/2016/1793/jpeg/05t.jpg) Limestone rock layers in Maszhabiya (Al Mashabiya) Reserve near Abu Samra. Southern Qatar, April 1, 2016
![](../../pictures/archives/compress/2001/170/jpeg/31t.jpg) Entrance to Nahal Tseelim River Gorge, 2 miles north from Masada. The Middle East, January 20, 2001
![](../../pictures/archives/compress/2005/473/jpeg/11t.jpg) Fall colors of Enfield gorge, zoomed, view from Rim Trail, in Robert H. Treman State Park. Ithaca, New York, November 2, 2005
![](../../pictures/archives/compress/2003/354/jpeg/16t.jpg) Rough Point, New Lodge and Ocean View mansions from Cliff Walk at Sheep Point, behind Gull Rock tunnel. Newport, Rhode Island, August 24, 2003
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