Roger,
With your humble question, you triggered an interesting discussion.
I think the main point is that students get proper guidance in the
field with respect to the goals of the exercise. I would suspect that
each geologist approaches an outcrop in different way, depending on what
his/her main field of interests are, and we tend to teach that approach
to students, perhaps unconsciously.
I remember being send into outcrops as a student to observe things
without actually being told what to look for. This can be quite
frustrating for a student as it will only demonstrate his/her inability
to observe what is bloody obvious from the lecturer's point of view.
What nonsense.
A petrologist will view an outcrop with different eyes than a
structural geologist or an engineering geologist. The petrologist will
emphasize rock types, minerals etc, but will not pay any attention to
joints (unless he/she makes a conscious effort). I don't want to make
inferences here, but the engineering geologist may not even know that
there are criteria for telling the top of a lava flow from the bottom.
We are all pre-conditioned in one way or another. I remember an
interesting quote (was it Klaus Weber who said that?): "You only see
what you know." There is some truth in that.
Take a sedimentologist, an igneous petrologist and a metamorphic
petrologist into a very-low grade metamorphic terrain where you have
(meta-) sediments, (meta-) volcanics, a little bit of deformation, and
just enough evidence for metamorphism that it can't be denied. Then let
them teach mapping to students. You'll see what I mean. We go through
this exercise every year. Quite amusing.
The point I am trying to make: there are a hundred thousand things one
can do and observe in an outcrop. So, the students need guidance on what
to concentrate. ("Go to the outcrop and tell us what you see" is just
not enough). Every time I come back from a field trip, I have this urge
to design a list for the students how to proceed. Now I read with great
interest what other colleagues experience with such lists. Anyway, going
through a basic routine is not such a bad thing. Wandering around
aimlessly is.
Cheers,
Jürgen
J. Reinhardt
Dept. of Geology
University of Natal
Durban, 4041
South Africa
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