Wildcat Falls EarthCache

View Wildcat Falls from River Drive. Do not venture any closer without permission from the landowner. If you are fortunate enough to meet him, be sure to thank him for this rare opportunity.

York County embraces part of the Blue Ridge and Piedmont province of the Appalachian Highlands and is composed of three geologically similar areas. They are the Southeastern Upland, comprising approximately two-thirds of the county, the Triassic Upland and the Hanover-York Valley combining to make up the remaining third. As subdivisions, the Hellam Hills and Pigeon Hills are part of the Southeastern Upland.

The existing underlying rock formations of Hellam Township consist largely of schists, inter-layered metabasalts and phyllites. Hellam Hills are primarily Cambrian quartzites. These formations are the result of volcanic flows that have arched up into anticlinal folds that trend southwestward.

The importance of these formations lies primarily in their use as aquifers for sources of water supply. The underlying rocks of the Southeastern Upland exhibit cracks and crevices through which water moves, rather than channel ways or pore spaces found in limestone and other nonporous rocks. This is very important for Hellam Township because of the dependence on groundwater.

A region's underlying geology has a powerful influence on a community. Rock formations influence the soils that were created; the minerals and materials that can be extracted; the amount of groundwater available and the buildings, roads and railroads that can be constructed. Rocks erode at different rates. This creates the local terrain, whether that is steep and rocky, gently or steeply rolling or flat. This is especially true in Hellam Township where the relatively flat limestone valley in the center of the Township lies between hill formations to the north and south.

The Township contains some of the oldest rock formations in the state, dating back to the late Precambrian times (over 600 million years ago.) These volcanic rocks are all found in the Hellam Hills. Also making up Hellam Hills is a slightly younger Cambrian-period Chickies Formation. Several outstanding scenic geologic features in the Township are part of the Chickies Formation. Included are Wildcat Run Cliffs and Gorge, Roundtop, Hellam Point and Schull's Rock. Chimney Rock, which consists of twin pinnacles of Hellam conglomerate, is a unique geological feature in the Township. The Chickies Formation also underlines the South Hills.

Although mineral resources such as limestone, dolomite and iron ore have been produced in the Township in past centuries, the only active mineral producer today is County Line Quarry. The quarry operates extensively in the South Hills in the southern part of the Township. They produce construction aggregates, fill, and agricultural products from dolomite, quartzite and phyllite.

In order to recieve credit for this Earthcache you must do the following:

1. Post a picture of you/your group holding your GPS in front of the waterfall with your log. Please, no pictures of your hand with a GPS. I need to be able to recognize that it was actually you at this earthcache. No exceptions.

2. Email the owner with answers to the following questions.

a)Describe what type of waterfall Wildcat Falls is--this may include more than one of the classifications.

b) Explain why you chose that classification

c) Estimate the height of Wildcat Falls. (needs to be within 10')

3. What is the underlying rock and how does that influence the Falls?

E-mail the answers to me and post the photo with your log within a few days. Failure to comply with these requirements will result in log deletion.

Almost every waterfall will first fall into one of two main categories. They can be considered either:

1) river waterfalls: called such because they are usually found on a river. They are wider than they are tall and usually handle a high volume of water. They hardly ever go dry in summer months with little rainfall and after a large rainfall they can resemble a large rapid.

2) stream waterfalls: usually found on a mountain stream and is high than it is wide; the flow volume will be either small or medium; in dry months some stream waterfalls go dry In the case of mountain streams, the water flowing becomes wider and more shallow just aboves waterfalls due to flowing over a rock shelf. There is usually a deep pool just below the waterfall because of the kinetic energy of the water hitting the bottom.

What is a Waterfall

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. 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.

This is a classification of waterfalls including the most common types :

Block: Water descends from a relatively wide stream or river. 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.