So today we have come up north of Yilan
to an area called Lai Lai, an area of rocky
outcrops along the shoreline of the
coast . And so we're exploring this area
today because we want to develop a
geology field trip for school students
where they can not only just see what's
there and be told about it but actually
have some hands-on activities to help
them see what's here: make measurements,
make comparisons and investigate a
little bit themselves with a bit of
guidance, so that they can start thinking
about how to interpret their
observations and come to some insights
of their own rather than just being told
what everything is all about by an
expert or a teacher. This area is quite
extensive and you can see the layers
are dipping at an angle. Some of them
are sticking up and some of them are
more worn away so we have alternating
hard and soft layers of mud stone and
fine grained sandstone I think. So the
hard layers forming the these small
bluffs and cliffs, the soft layers more
broken and shaley underneath forming
the areas that have been scooped out and
eroded more easily.  So here we've got a
beautiful bit of coastal erosion with
some sea stacks some sea cliffs behind
us, some quite heavy jointing in the
rocks which means that when they break
apart they often break apart along the
joints which are lines of weakness. They were formed as these rocks
decompressed from being deep under the
earth to being gradually uplifted to the
surface due to erosion of the overlying
material.  And then this wide shore
platform which is crisscrossed with
some faults and then the beds that you
can see in some places form a beautiful
curve so these beds have not only been
tilted up but from their original
horizontal position, but they
have been folded slightly as well as
tilted.  So one thing we can do with
students here is firstly to get them to
do some drawing to
make observations about the general area,  the general features.  And then we
could challenge them to find some faults
and measure the offsets of the faults so
how much the faults have displaced the
rock on either side.  They can look for
fossils - we haven't found many but these
are sedimentary rocks and there's no
reason to think that there shouldn't be
fossils in them somewhere. Why does a
wave cut platform form like this? so that
would be a question for the students to
think about.  How do we get such a smooth surface out of rocks which are actually tilted?
We're looking for questions to ask our
students a bit like that.  We want them to
interpret what they see and try to think
about the processes that have created
this coastal landscape.
So we're just a little bit further north
on the Lailai coast and right here is a
beautiful dyke, an igneous intrusion
sticking up like a wall through the
surrounding sediments.  So this is a
classic example of a dyke and what's
great about it is you can see behind me
that it's offset by a fault .In fact
there are several faults cutting through
this dyke that's offset it.  This is a
really brilliant example for students
we've got sedimentary layers, we've got
faults, we've got a dike, there's lots of
geological features here to investigate. 
There's just lots to look at so I'm just
going to show you now what this dyke
looks like close up. Because it's
harder rock it's not been eroded
away as quickly as the surrounding
softer shaley stuff.  If you look at the
rock of the dyke you can see that it's
got crystals - quite large white
crystals near the middle, but as you go
to the edges they just kind of
disappear. So the material at the edges
is quite fine and then you can see that
lighter brown color where the dike was
chilled on the very edge of itself so
another example here. You've got coarse
material in the middle, some crystals, and
then as you go to the edge it cooled
more quickly, the crystals didn't have
time to form, and on the very edge is a
nice chilled area about four centimeters
thick - something like that. And then down
below if you look at the sedimentary
rock you can see that it's very dark
near to the dyke it's been baked, it's
more fractured compared to a
a few tens of centimeters away maybe
30, 40 centimeters to the side it's got
a different appearance
it's not quite so dark, so it's not been
baked so much.  So
there's some of that baked sedimentary
rock and the chilled margin of the dyke
and the more crystalline large crystals
in the center of the dyke. And over here
we can see the offset of the dyke and
you can actually see the fault that's
offset the dyke,  with Hsini checking it
out in the distance.  So that fault can be
traced through the sedimentary layers so
that does tell us that the dyke was in
placed before the faulting happened
rather than the dyke pushing up through
weaknesses in the crust than being
offset by finding slightly different
places to push up. There's one part of
the dyke coming down here and then it
stops - comes to a stop - and it continues
over there and along across the beach.
There are several of these offsets because of faults
So just a couple of things that you
could do here on this beach with class
of students that come to mind you could
get them to survey the dyke to measure
the largest offset, or even to measure
all of the offsets caused by faults and
then add them up and even average them.
They could also take a really close look
at the dyke without any information from
you initially so that they draw the
rock from across the dyke from one side
to the other to see if their observation
of the color changes and the crystal
changes in the rocks would be detailed
enough. I always think that drawings are
an excellent way to increase observation
of detail and a good drawing is
something you can refer to back in the
classroom or back at home when you're no longer at the outcrop. Of course we could
just take photographs and that's
valuable but it doesn't force you to
look. In fact taking photographs can be a
really good way not to bother looking. So
once a drawing has been made the
students should also label the drawing -
what it is,what the scale is, what the
date is, where they are so that the
information is complete for somebody
who has never been there when they see
the drawing they'll know what it's all
about. There's plenty to do here to keep
a class busy and then the important part
of it is to follow up back in a
classroom which is the opportunity to
make sure that everybody in the class
gets the maximum learning out of the
trip
