Approximately 600 - 700 million years ago the North American
continent developed a rift (a tear in the earth’s crust that
continuously erupts magma and pushes the two sides apart) and began
splitting apart, each side moving in the opposite direction of the
other. As this occurred the area between the two land masses filled
with sediments and volcanic deposits (from the magma at the rift
zone). Over time sea level rose and much of New York was covered by
this ancient shallow sea known as the Iapetus Ocean.
In the marine environment that followed, different types of
sediment formation are associated with varying depths of ocean
water. Close to the beach, sand and course sediments are deposited.
Therefore, when these sediments are buried and lithified (hardened
into solid rock), sandstone typically results. In intermediate
depths, finer grained particles settle out and result in the
formation of shale (seen at this locale). In deeper oceanic
environments, organic material from shells and inorganic calcite
combine to form a finely grained rock known as limestone.
Once the rifting ended, the ancient sea began to close and our
continent collided with the island arc that had developed during
the rifting process. This event is called the Taconic Orogeny (or
mountain building event). During this event the sedimentary
deposits that made up the shorelines were scraped off and thrust
onto the continent as the rest of the mass was forced deep into the
earth. Following the Taconic Orogeny was the Acadian Orogeny which
occurred roughly 400 million years ago. These tectonic events
altered the landscape through active folding and faulting of the
entire area.
To picture what a fold would look like visualize a piece of
Play-doh. Roll the play dough out flat and then slowly push it up
against a solid object. During this process you would begin to see
the play dough fold into “S” shaped layers. Given
enough force your Play-doh would begin to split or break, this
would be similar to a fault.
As the layers of various types of bedrock were forcibly moved
they scraped past one another. Through various processes, minerals
would precipitate out in between these movement contact areas and
would harden to form mineral veins in the void space. The
precipitates would be various minerals such as calcite or
quartz.
Now, what do you need to do to earn a smiley?
- Walk along the structure near the IP. Take your time to follow
the layers of the rocks. Now, locate a fold in the rocks –
use the information above to help you find it. Once you find it,
take a picture of it.
- Now you have found a fold – what else do you see here? If
you look closely you will find an area where some fault movement
occurred and a mineral precipitate vein is present. Find this and
take a picture of this also – nice and close up so we can see
the precipitate. HINT – its whitish in color.
That’s it – TWO pictures and a little hunting on the
rocks and you’ve earned a smiley. Email these items before
you log the cache. As long as we can tell you read the info and
tried your best, AND TOOK 2 PHOTOS, we’re happy. Most of all,
BE SAFE AROUND THE ROCKS and have fun. There is NO NEED to go near
the falls. Please view them from a safe distance, the sandbar
offers a great view.