Download Weathering-on-Long-Island

Weathering: The Response of
Rocks to a New Environment
Caumsett State Park
How is this rock’s environment
different from where it formed?
Boulders in the woods at Caumsett.
Let’s take a closer look at these rocks. What beautiful cranberry
mineral is in this one?
What weathering processes might be going on in these rocks
knowing (and seeing here!) the climate of Long Island?
Water in what
state?
What is
happening
here?
What weathering process appears to be happening here?
Is it a physical or chemical process?
What weathering
process is
happening here?
A close-up view!
What weathering
Is this chemical or physical?
process is
happening here? EXFOLIATION PHYSICAL
MONTAUK POINT: Long Island, NY
What mineral is the cause of this beautiful purple/red sand?
Remember this one?
Where does sand come from? What processes formed the
sand we see here?
Sand is the remains of weathered and eroded rock!
Welcome to Huntington
Cemetery! Step inside to
another real-life weathering
laboratory!
Wow! We haven’t even stepped inside
and we have evidence of weathering in
the gate!
What process is this and is it physical
or chemical?
We are going to look at
cemetery rocks…
(tombstones!) and observe the
weathering that has occurred
in them.
Since tombstones are dated we can even
determine how long the weathering has
occurred!
Here is a typical marble
tombstone which used to be a
very popular rock for cemeteries.
What mineral largely composes
the rock marble?
What is the hardness of this
mineral? Why was it a good rock
for tombstones?
Here is another type of
tombstone. It is made up of
slate.
Compare the two tombstones in the next picture.
How do they differ in terms of the types of
weathering that has occurred to each?
How do they compare in appearance? Which
appears more weathered?
Marble
Slate
Which tombstone is older?
Marble
Slate
This means that rocks can weather at different rates!
Marble
Slate
This is called “Differential Weathering”
Rocks weather at different rates due to
differences in mineral composition.
Some minerals are more stable at the earth’s
surface than others! These take longer to
weather.
Calcite is very unstable at the earth’s surface in
certain climate types. Which type in particular?
CO2 CO
2
What weathering process causes the tombstones to “dissolve”?
Is this chemical or physical?
But even slate tombstones are
not immune to weathering!
What weathering process is
occurring here? Is it physical
or chemical?
More tombstones undergoing weathering! What process
might be happening here, knowing the climate of Long
Island?…
Another tombstone
weathering (for almost 200
years!)
Its distinct color indicates one
weathering process going on!
Which one?
What other
process is
occurring?
EXFOLIATION
Slatey
cleavage seen
due to
weathering!
Why does the climate of Long Island
contribute to exfoliation and frost
action of these tombstones?
Living organisms can also
weather rock!
Here are lichens, organisms that can make a living on bare
rock (in this case a tombstone…)
Lichens secrete acids that dissolve rock!
EXFOLIATION
REVIEW: What types of weathering processes can you see here?
Another view of the previous tombstone
The climate of L.I. (its fluctuating temperatures) is even causing
these tombstones to heave up out of the ground!
It’s time for us to leave, but
weathering processes continue
24-7!
What will this place look like in
another 50 years?