The formation of a talus slope results from the talus accumulation. The recognition and characterization of talus slopes is often important in determining the potential for mass movements (landslides, etc.). Movements occur whenever the talus slope exceeds the critical angle. The exact angle at which failure takes place depends upon the materials (e.g., rock type), rock size, moisture content, but dry homogenous materials in a pile generally experience slope failure when the angle of repose (the resting slope angle) exceeds 33–37°. The critical angle lowers as materials become less intrinsically cohesive or when friction between particles is reduced by rain or other forms of moisture. Moisture also adds to the overall mass of the slope and thus increases the gravitational force on the slope. For example, if a cliff or rock formation is composed of shale, the processes of weathering and the force of gravity (a shear stress) allow the downslope accumulation of shale rock fragments and debris at the base of the formation. The talus slope is triangular, with the internal angles of the sides of the triangle (the slope's angle of repose) limited by the critical angle. The degree of sameness in size, layering, and homogeny of the talus is referred to as sorting. As a general rule, talus accumulated from rock falls is better sorted than talus created by glacial deposits but far less sorted than piles constructed by sedimentation. Contributing rock that is irregularly fractured does not weather evenly and because it breaks off in large irregular pieces, contributes to a poorly sorted talus slope.(2)
At Clifton Gorge State Nature Preserve you will see almost the entire Silurian system in Ohio from the Brassfield in the river bottom to the middle to upper Massie Shale at the trail, and on up through the end-of-Silurian dolomites at the top of the gorge. While climbing or descending the gorge, one can see the differences in the formations by the thicknesses and evenness of the bedding, and by the way they differentially weather. (3)
An undifferentiated group of very steep soils lie on the side slopes of deeply entrenched valleys along the Little Miami River. Areas normally are less than a quarter of a mile wide, but they may be a mile or more long. Slopes are irregular, and erosion varies within short distances. Most slopes are greater than 35 percent. The surface of these soils is covered by numerous limestone channers. The lower slopes commonly have an accumulation of Talus. Tree roots penetrate this soil to bedrock and into fractures of the bedrock. Included with these soils are a few areas of soils that have short slopes of more than 60 percent. Also included are a few areas that have limestone ledges exposed on the surface. The very steep slopes limit the farm and nonfarm uses of these soils . These soils are suited to woodland or wildlife. The steep and very steep soils along the Little Miami River at Clifton Gorge are used mainly for recreation, nature study, and scenic value. (4)
You can approach the Earthcache from several directions. We recommend beginning your hike from one of two parking areas; Jackson Street parking lot in the Village of Clifton or Bear’s Den Parking Lot off State Route 343. The Jackson street parking lot can be found by taking the first right after entering the Village of Clifton on State Route 343. See waypoints.
This Earthcache is as much about the journey as it is about reaching the destination. Talus slopes begin the moment you descent the stairs at Bear’s Den. Along the trail, you will see talus in various shapes and sizes, including many large slump blocks. The talus slopes vary in shape, size, and density. The final coordinates are for an educational marker located alongside the trail.
The John Rich Trail begins as a gravel path exiting the rear of the nature preserve parking lot on Jackson Street in the Village of Clifton. The trail is named for a professor who played a big role in establishing the preserve. Almost immediately you'll come to the first of several overlooks of the gorge. The first one provides a nice view of a rapid in the river some 40 feet below you amid the dolomite walls. The trail continues through a thin strip of mixed maple-oak forest with the gorge on your left and some houses on the right. (6)
The next overlook, the Patterson Mill Overlook, is worth noting for its location. The mill that once stood here was wiped out by a flood over 100 years ago, but a square hole in the rock where the pier supporting the mill once stood is visible in the gorge just right of the overlook.(7)
The trail crosses a couple of newly constructed wooden bridges before arriving at an overlook of the narrowest portion of the gorge. Also visible are the Falls of the Little Miami, a large, powerful waterfall located deep in the gorge. This is the location where the frontiersman, Cornelius Darnell, a compatriot of Daniel Boone and Simon Kenton is said to have leaped the Little Miami while escaping the Indians who in fact captured Boone. The leap is around 18 feet and occasionally has been attempted by those who shouldn’t. When faced with the decision of jumping the gorge or sure death by torture, Darnell chose the first option. He successfully escaped and proceeded to Boonesborough, Kentucky to warn settlers of an impending Indian attack. (8)
The trail next crosses two streams near noisy State Route 343 before coming to Bear's Den, a trail intersection and meeting place for hikers. The Bear’s Den Parking Lot is accessible via a paved walking path. You may also choose to begin your hike to the Earthcache from this location.(9)
Look on the left side of this area for a set of stairs leading into the gorge. Descend these stairs, a combination of wooden and stone steps, to the north bank of the Little Miami River. There are only about 25 yards separating the sheer cliff on the right and the river on the left. The slopes of the gorge are littered with talus that has broken away from the cliff. One large piece of talus fell into the river and is called Steamboat Rock for its appearance. Another point of interest is Blue Hole, a wide, calm section of the river that has inspired many artists in its time. (10)
Steamboat Rock and the Blue Hole are featured in the Clifton Gorge Earthcache (GC10GTD).
Not far past Blue Hole, you’ll begin to close-in on the Earthcache. An educational marker was located at the final coordinates.
LOGGING REQUIREMENTS:
In order to claim the find, you must perform the following tasks:
Task 1: Answer the following question.
Identify the type of rock that has formed layers on the steep slopes leading to the cliffs above.
Task 2: Send us an email via our profile providing the answer. Pretty simple, huh?
Suggestion only, not a requirement: Post two photos with your log; one of you standing next to the Talus Slopes sign located alongside the trail and one of any other geological feature in Clifton Gorge Nature Preserve that you discovered.
After completing your observations, you can return the parking area by using the same avenue of approach or follow the alternate directions below.
The trail continues about 0.2 miles past beyond the talus slopes marker to arrive at the edge of the preserve. Trails continue straight into adjacent John Bryan State Park. Turn right to climb out of the gorge using one switchback. At the top of the hill, the trail intersects the North Rim Trail, which goes right and left. Turn right on this trail, which follows the rim of the gorge.
Bonus: At the top of the hill, inside John Bryan State Park, as the trail makes a hard right turn, an outstanding display of the Cedarville and Springfield dolomite will be on your left.
A few nice views of the river and the opposite hillside are afforded, but based on the season, they may be limited due to the thick canopy of trees growing in the gorge. Whenever a side trail goes off to the right or left, stay on the gravel trail that continues to follow the rim. After 0.6 miles, the trail arrives back at Bear's Den. Continue straight for another 0.5 miles, retracing your steps on the John Rich Trail to your vehicle in the village of Clifton.
Rules to abide by while at Clifton Gorge Nature Preserve:
Public use areas are open from one-half hour before sunrise to one-half hour after sunset.
Use of this nature preserve or scenic river area is primarily intended for passive recreation, nature observation, research, and education.
1. Facilities for public use are open from one-half hour before sunrise to one-half hour after sunset.
2. Special events and meetings require a special permit. (Permits obtained by contacting the division.)
3. Visitors are required to stay on trails.
4. Picnicking is ONLY permitted in areas immediately adjacent to parking lots.
5. Vehicles, horses and bicycles are prohibited on trails and closed roadways.
6. Speed limit on area roadways is 20 m.p.h. unless otherwise posted.
Prohibited Activities
1. No alcoholic beverages permitted.
2. No littering or dumping of debris permitted.
3. No pets permitted (except assistance animals).
4. No collection of any plant, animal, or other substance permitted.
5. No defacing, injuring, disturbing, or destroying any property permitted.
6. No hunting and fishing on nature preserve and natural areas permitted (Fishing permitted on scenic river lands).
7. No firearms, dangerous ordinance, fireworks and air guns permitted.
8. No kindling of fires permitted.
9. No swimming or wading permitted.
10. No rock climbing or rappelling permitted
11. No camping permitted.
12. No roller blades, skate boards, street luges, in-line skates, sound amplifying devices, or model aircraft permitted.
Permission to create this Earthcache was obtained from Shannon Hoffer, Southwest District Preserve Manager, Yellow Springs, OH.
References:
1. Wikipedia, Skree, http://www.wikipedia.orgwiki/Scree, last modified 15 June 2011, retrieved 27 June 2011.
2. Talus Pile or Talus Slope." World of Earth Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. Gale Cengage, 2003. eNotes.com. 2006. 29 Jun, 2011
3. Indiana University - Perdue University Indianapolis, Course G119, Fundamentals of Earth History Laboratory, Fall 2008, http://www.geology.iupui.edu/Academics/CLASSES/G119/ThePlotandSetting.htm
4. Soil Survey of Greene County, United States Department of Agriculture Soil Conservation Service, In cooperation with Ohio Department of Natural Resources, Division of Lands and Soil, and the Ohio Agricultural Research and Development Center, 1973
5. Greater Dayton Hikes, Hike #16, Clifton Gorge State Nature Preserve, http://www.math.uga.edu/~pragerdj/Nature%20Hikes%20in%20Greater%20Dayton.doc
6. Ibid
7. Ibid
8. Ibid
9. Ibid
10. Ibid
