Quarry Beach -
Mallacoota
Hello and welcome to my 36th cache hide,
and my 2nd Earthcache.
Why have i put this cache here....?? Well, i came down here and
visited the area for the first time in November 2010 and thought,
what a fantastic place. Very rugged and seemingly untouched. I did
a few of the other caches in the area, and then chanced upon this
sensational site... The rock formations in the carpark of the beach
were inspiring. So, i thought, what the heck, I will list an earth
cache here. Now, i have made this one pretty easy, much like my
previous one. There is no climbing involved, just some observation
and a little research. THIS EARTHCACHE IS SUITABLE FOR CHILDREN
UNDER PARENTAL SUPERVISION. IT WILL BE QUITE EDUCATIONAL FOR THEM.
AS ALWAYS, BE CAREFUL FOR SNAKES, IT IS AUSTRALIA AFTER ALL....
The Significance Of Geography Of The Area
The Mallacoota Area is part of the Narooma Accretionary Complex
or Narooma Terrane. It is a geological structural region on the
south coast of New South Wales, Australia extending down to
Mallacoota. It is the remains of a subduction zone.
What Is a Subduction Zone?
A subduction zone is an area involving an oceanic plate sliding
beneath either a continental plate or another oceanic plate (that
is, the subducted plate is always oceanic while the sub-ducting
plate may or may not be oceanic). These zones are usually high in
volcanic activity, earthquakes and mountain production. As this
area is the remains of a subduction zone, there are many folds and
uplifts, but currently none or little earthquake or volcanic
activity.
Lachlin Fold Belt
The Lachlin Fold Belt is a larger geological structure which
included the Narooma Accretionary Complex. The area is huge
covering most of Victoria and NSW. It extends also in the
Australian Capital Territory, Tasmania and Queensland. It was
formed in the Middle Paleozoic from 450 to 340 Mya. It covers an
area of 200,000 km2.
The rocks are sedimentary, below is an example of some of the
rock layers in the quarry wall
Check out these links for more information
Wikipedia
- Subduction Zone
Wikipedia
- Narooma Terrane
Wikipedia -
Lachlan Fold Belt
Wikipedia - Middle
Paleozoic
Wikipedia
- Fold (Geology)
What Is There To Learn Here.....
well after a little bit of research, and observation you will be
able to answer the questions below.
Questions To
Answer....
Take a look at the vertical rock walls as indicated in the
photo. What do you notice? Firstly you should notice a wave like
structure in the rocks.
Question 1. What is the dominant feature in the wave like
structure? Is it up or down? Hint - It is darker in colour than the
surrounding rock and approximately in the middle of the wall, and
continues up to the right becoming lighter.
Question 2. What is this feature called? - See the link
on Fold's.
The rocks in this area apparently formed (as far as i can tell
from my research) in the Paleozoic Era, particularly in the
Ordovician Period, around 445 million years ago. Following the
Wikipedia link above to the Middle Paleozoic Era, the question
is:
Question 3. Research and complete this sentence "The
Ordovician came to a close in a series of........." It doesn't have
to be exact wording, just tell me what happened.
Question 4. Well sort of a question, while not required,
a photo of you or your group in front of the quarry wall would be
great.
Hope you all had fun here. I am no geologist, so if someone
visits the site, and can find "fault" in my information (pardon the
pun) please let me know. I have done several hours research just to
understand what is going on in the geology of the area, but would
love to know more if the info is incorrect.
YOU CAN LOG YOUR VISIT IN ADVANCE OF CONFIRMATION, BUT
PLEASE EMAIL YOUR ANSWERS OR THE LOG WILL BE DELETED
EVENTUALLY.
Cheers, Adam
(Blacklegend)
| I am a proud |
 |