According to the USGS topo map, it calls the creek "Ketron
Branch" and it is between Ridgeway Hollow and Wright Hollow. The
road is US58 / US421. The roadside turnout is right next to the
falls, no walking required.
We just had to share this with everyone and felt it deserved to
be an Earthcache. We hope you enjoy it as much as we did for a nice
peaceful stop along the way. Certainly the amount of flow will
depend on the time of year.
Waterfalls
A waterfall is usually a geological formation resulting from
water, often in the form of a stream, flowing over an
erosion-resistant rock formation that forms a sudden break in
elevation or nickpoint.
Some waterfalls form in mountain environments where the erosive
water force is high and stream courses may be subject to sudden and
catastrophic change. In such cases, the waterfall may not be the
end product of many years of water action over a region, but rather
the result of relatively sudden geological processes such as
landslides, faults or volcanic action.
Why here?
This area is part of the Appalachian Valley of Virginia which is
part of the Great Appalachian Valley and is one of the major
landform features of eastern North America. It is a gigantic trough
— a chain of valley lowlands — and the central feature of the
Appalachian Mountain system. The trough stretches about 700 miles
from Canada to Alabama and has been an important north-south route
of travel since prehistoric times.
These mountains are characterized by long, even ridges, with
long, continuous valleys in between. From a great enough altitude,
they look almost like corduroy, except that the widths of the
valleys are somewhat variable and ridges sometimes meet in a
vee.
These curious formations are the remnants of an ancient
fold-and-thrust belt, west of the mountain core that formed in the
Alleghenian orogeny (Stanley, 421-2). Here, strata have been folded
westward, and forced over massive thrust faults; there is little
metamorphism, and no igneous intrusion.(Stanley, 421-2) The ridges
represent the edges of the erosion-resistant strata, and the
valleys portray the absence of the more erodible strata. Smaller
streams have developed their valleys following the lines of the
more easily eroded strata. The streams can develop waterfalls along
the way by eroding the softer rock quicker such as in this
case.
Formation
Formation of a waterfall typically, a river flows over a large step
in the rocks which may have been formed by a fault line. Over a
period of years, the edges of this shelf will gradually break away
and the waterfall will steadily retreat upstream, creating a gorge
of recession. Often, the rock stratum just below the more resistant
shelf will be of a softer type, meaning undercutting, due to
splashback, will occur here to form a shallow cave-like formation
known as a rock shelter or plunge pool under and behind the
waterfall. Eventually, the outcropping, more resistant cap rock
will collapse under pressure to add blocks of rock to the base of
the waterfall. These blocks of rock are then broken down into
smaller boulders by attrition as they collide with each other, and
they also erode the base of the waterfall by abrasion, creating a
deep plunge pool.
Streams become wider and more shallow just above waterfalls due
to flowing over the rock shelf, and there is usually a deep pool
just below the waterfall because of the kinetic energy of the water
hitting the bottom.
Waterfalls can occur along the edge of glacial trough, whereby a
stream or river flowing into a glacier continues to flow into a
valley after the glacier has receded or melted. The large
waterfalls in Yosemite Valley are examples of this phenomenon. The
rivers are flowing from hanging valleys.
Some types of waterfalls:
- Block: Water descends from a relatively wide stream or
river.
- Cascade: Water descends a series of rock steps.
- Cataract: A large waterfall.
- Fan: Water spreads horizontally as it descends while
remaining in contact with bedrock.
- Horsetail: Descending water maintains some contact with
bedrock.
- Plunge: Water descends vertically, losing contact with
the bedrock surface.
- Punchbowl: Water descends in a constricted form, then
spreads out in a wider pool.
- Segmented: Distinctly separate flows of water form as it
descends.
- Tiered: Water drops in a series of distinct steps or
falls.
- Multi-step: A series of waterfalls one after another of
roughly the same size each with its own sunken plunge
pool.
To log this this Earthcache please answer the
following questions:
- Based on the above list of types of waterfalls, what kind of
waterfall do you think this is?
- What direction is it flowing?
Also post a photo of yourself with your GPSr in hand at the
waterfall. A photo of your hand holding your GPSr would be
sufficient as well, though not as good. Please do not post your
answers within your log. |