This Earthcache is meant to be kid friendly,
with easy access. My attempt is to introduce kids to the world of
geocaching and some Earth science, at the same time. The task to
claim a find has been kept simple so they can help in making the
final measurements. This area is named for the rocky outcroppings
that make up the river and surrounding landscape. But be careful
with small children and pets as the area could be dangerous as you
near the rivers edge.
The sea once covered this area, and as it slowly transgressed
into eastern Quebec during the Early Cambrian, it reached the
Ottawa area in the Late Cambrian period. The rocky landscape around
you had its beginnings during Ordovician time, some four hundred
and sixty million years ago. Lime-based mud and sand were deposited
here in an ancient marine basin. The mud and sand underwent the
natural process of compaction, upheaval, and erosion. Movements
within the Earth’s crust caused the sea to withdraw and disappear,
leaving behind a rugged landscape with outcrops of limestone,
sandstone and shale. Thus the formation of the Rideau River, and
giving life to the surrounding landscape. Fifteen thousand years
ago, continental glaciers covered the area where you are standing,
with a blanket of ice some 2 kilometers thick, and lasting some
4000 years. This too took it's toll on the area, helping to shape
and smooth the Earth's landscape. Nine thousand years ago the
Rideau River was much wider. Due to further adjustments in the
Earth’s crust, the surrounding area was changed, and so was the
shape of the river’s channel. Erosion over thousands of years has
also helped to modify the river channel, and the flow of the Rideau
River.
As the Earth’s strata were uplifted, it was folded and broken. A
large fault can be seen at low water just below the East end of the
bridge. One of the rocky ridges formed, and no longer visible, rose
high above the roaring waters, and looked like the back of a swine.
This was the cuesta or hogs back formation. Seeing this, early
loggers named this area, Hogs Back Falls. The Rideau Canal
construction began in 1826. This along with a retaining dam, helped
to destroy the natural shape of the falls. What was once 3 separate
rapids, were joined to form what you see today.
The word Rideau is French for
curtain. This was the appearance of the twin falls of the Rideau
River, where it meets the Ottawa River, to Samuel de Champlain who
traveled up the Ottawa River. The Rideau River stretches from
Kingston, on the shore of Lake Ontario to Ottawa the capital of
Canada. The oldest continuously operated canal in North America,
the locks work today much as they did when first opened in 1832.
Initial construction of the Rideau Canal started at the Ottawa
locks in the fall of 1826. Further construction on the rest of the
canal started in 1827. By November 1831 construction had
essentially been completed with 47 masonry locks and 52 dams
creating a 202 km (125 mile) waterway, one of the greatest
engineering feats of the 19th century.
Despite all of the numerous man-made
changes, Hogs Back Falls still remains a natural attraction that
draws people from all over to marvel at its wild rapids as they
flow through the gorge. I visited this area as a child in the 60’s,
and have recently returned to enjoy the falls, once again. I hope
you enjoy the area as much as I do.
The waypoint had brought you to a
level area beside the falls. From here you can watch the rapids run
through the mighty gorge. A visit here during spring’s high water
can be a spectacular site. Just behind you is one of the many
manual locks, still in use today to aid in the navigation of the
Rideau Canal. To log this Earthcache look across the gorge to the
other side and estimate the depth and width. Send this information
to me via my profile email at Geocaching.com. Please do not enter
the information into your log. Then post a picture of yourself and
your GPS with something in the area that you have found
interesting.
Some of the information for
this cache was taken from the placque and the map where you are
standing