Unconformity on the River
Welcome to the Napanee River Geocachers
How about a little Geology lesson on
Unconformities.
An
unconformity is a buried erosinal or non-depositional surface separating two rock
masses
of different ages, indicating that sediment deposition was not continuous.
Because this unconformity is on the edge of a river, it has become fully exposed
for your Geocaching pleasure.
Types of Unconformities
(taken from Wikipedia)
Disconformity
A disconformity is an unconformity between parallel layers of sedimentary rocks
which represents a period of erosion or non-deposition.[3]
Disconformities are marked by features of subaerial erosion.
This type of erosion can leave channels and paleosols in the rock record.[4]
A paraconformity is a type of disconformity in which the separation
is a simple bedding plane with no obvious buried erosional surface.[5]
Nonconformity
A nonconformity exists between sedimentary rocks and metamorphic or igneous rocks
when the sedimentary rock lies above and was deposited on the pre-existing
and eroded metamorphic or igneous rock. Namely, if the rock below the break is
igneous or has lost its bedding due to metamorphism,
the plane of juncture is a nonconformity.[6]
Angular unconformity
An angular unconformity is an unconformity where horizontally parallel strata
of sedimentary rock are deposited on tilted and eroded layers,
producing an angular discordance with the overlying horizontal layers.
The whole sequence may later be deformed and tilted by further orogenic activity.
A typical case history is presented by the paleotectonic evolution of the
Briançonnais realm (Swiss and French Prealps) during the Jurassic.[7]
Paraconformity
A paraconformity is a type of unconformity in which strata are parallel;
there is no apparent erosion and the unconformity surface resembles a
simple bedding plane.
It is also called nondepositional unconformity or pseudoconformity.[9][10]
Buttress unconformity
A buttress unconformity occurs when younger bedding is deposited
against older strata thus influencing its bedding structure.[11]
Blended unconformity
A blended unconformity is a type of disconformity or nonconformity
with no distinct separation plane or contact, sometimes consisting
of soils, paleosols, or beds of pebbles derived from the underlying rock.[12]
In order to log this Earth Cache. please send the answers
to the following 3 questions to me via my caching profile.
you may log the find once your answers are sent.
1) Describe the limestone above and below the Unconformity
2) Will the river or mother nature alter GZ, if so, How?
3) According to the above description, what type of Unconformity
is found at GZ
Remember, all my Earth Caches are meant to be fun and a little
educational, do your best and do not sweat trying to give perfect answers
**Non-spolier photo's are welcome but optional**
You must do this Earth cache by some type of boat,
attempting to walk to this Earth Cache will require you to trespass
If I find that this is happening I will archive it to keep the neighbors happy
