What Is Karst Topography?
Definition: Karst topography is a landscape shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite. Limestone caves are created through the dissolving of limestone bedrock in the phreatic zone. Sink holes, land bridges, caves, and reappearing rivers all make their home here due to a series of world class Karst systems caused by the erosion of limestone.
The evergreen forests’ slightly acidic run-off has created many fantasy shapes. This happens when slightly acidic river water permeates the voids in the limestone and dissolves passageways through the rock. This weak acidity stems from ambient carbon dioxide (CO2) in the atmosphere that gets captured in rain drops. This geological process which occurs over many thousands of years, results in unusual surface and sub-surface features ranging from sink-holes, vertical shafts, disappearing streams to complex underground drainage systems. Rivers vanish and reappear, crystal clear waters spring from the earth only to disappear in the unknown.
Sometimes these passages are cavernous enough to walk through and sometimes they are even too small for a mouse. Some of the Benson river is made up of the water flowing from the large caves. Several underground air passages are located in the wet caves. The largest of the air passages is called Never Never Land, it's earned it's name from being nearly impossible to get to. As environmental conditions change, the river may dry up or be redirected, thus leaving passages. However, this river is still flowing strong and no hiker should go in at all.
Formation of Dolomite and Limestone:
Limestone and dolomite are formed by an accumulation of sediments.The best sources of dolomite formations are in magnesium rich ground waters with a high salinity; Limestone is formed of remains of tiny shells coral, algal, fecal debris and microskeletons, which are deposited on the seabed.
The shells and skeletons are compressed to form solid rock. Limestone is formed in layers and contains vertical cracks. The layers and the cracks make the rock permeable, allowing water to flow through. Water dripping from the roofs of limestone caves can leave behind particles and form icicle-shaped stalactites. Water that drips onto the floor of caves can lead to the formation of stalagmites. Characteristics Dolomite has a pearly luster. Colorless and white dolomite is common, but you can find yellow, gray, brown and black dolomite. Black dolomite indicates the presence of iron in the crystals. High manganese content gives dolomite crystals a pink color. Limestone is often light gray, and there are often streaks, fossils or shell formations in the stone. The shells and fossils mean that it has a high concentration of calcium. Uses Dolomite is often used in ornamental stone and to produce concrete and asphalt. Processed dolomite is used in the production of float glass, which is a sheet of glass. Dolomite can be added to soils and potting mixtures to lower the acidity and enrich the soil with magnesium, a component of dolomite. There are several different forms of lime, which varies in hardiness.
Chalk is a soft, fine limestone that is usually white or light gray. Lithographic limestone is a dense limestone that was used to make prints. Limestone can also be crushed and used as construction material, for example, road base. The North Island has a greater concentration of caves than any other area in Canada as well as some of the longest and deepest caves in Canada. Combine this with beautiful scenery, easy access via logging roads, and a year round caving season (thanks to our mild climate) and you will see why Vancouver Island is considered to have the best caving in Canada. Some of the most dramatic karsts features in our area include Devils Bath, Vanishing River, Eternal Fountain and rock arches at little Huson Cave Park. These can be viewed without going underground. There is currently NO cave tour operator in the North Island Area. There are a few self-guided caves in the area.
I suggest you stop by a local Info Centre and pick up a local free logging road map to help you find the locations listed above. Please take care as access to most caves are located on active logging roads. Trailhead starts at N50 18.184 W127 10.131
This is a very nice walk on a good boardwalk and stairs system, but can be slippery if wet. Please do not damage any ecosystems. To log this cache please email me the answers to the following questions which you will find at the site on the signboard and from your own observations:
UPDATE: If the signboard is no longer there, until it is replaced please log as found and post a pic of you in the area or a pic of the river!!
1. How far does the river flow underground before reappearing?
2. How far does the stream plunge into the cave?
3. What kind of stream is this?
4. The small stream that flows near the sign board is discolored. What color is it? And why do you think it is discolored?
5. How many people are in your caching party?
6. Post a pic of the area or yourself at the cache site if you wish.
For the First to Discover: When I recieve an email with the correct info, I will email you for your address, and I will send you an unactivated geocoin!!!
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