Report on the possible revision of Geology 1
27th February, 2003.
Committee: John Dixon, Godfrey Fitton, Sue Rigby (Chair).
Method of working
The above team was given the remit to consider a revision of Geology 1. Following a
consultation period where contributions were invited from all members of the
Department who teach on degree programmes, the following guidelines were
identified:
a. The course needs to address the needs of five constituent groups; students in the
first years of the four degrees offered within the department and external students
taking this as an ‘interest’ course.
b. Material needs to be presented in such a way that core elements of knowledge and
skill are retained, especially between G1 and G2.
John Dixon prepared a critique of the Geology 1 course as it stands at present
(Paper1). We have used these observations to inform our decisions.
We identified the following aims for our work:
a. To integrate lectures, practicals and fieldwork.
b. To consider the possibility of dividing the course into two half courses.
c. To define the practical skills and knowledge base at the core of G1
We have met on six different occasions to discuss how a timetable might be generated
that would address the points above. In addition the Chair has held consultative
meetings with Kathy Whaler, representing the interests of the Geophysics Degree
Programme, and Sandy Tudhope, representing the interests of the Environmental
Geoscience Degree Programme.
The outline below is the outcome of these meetings and consultation.
Proposed revisions to Geology 1
1. We propose to divide the course into two, independent, self-standing, short, fat
half courses, after a trial period of two years when the course runs as one, long, 40
point course. A suggested new calender entry is attached (Paper 2).
2. We have attempted to consider the balance of Geology 1 as it stands at present,
against the perceived need for it to stand as a complete introduction to the subject.
We feel that at the moment the balance of lectures is approximately right, but that
the practicals emphasise skills such as mineralogy and map interpretation, that are
not required at first year level, but prepare the student for Geology 2. We
consider that some of this material should be moved to later years of study, so that
it is undertaken only by students for whom it is relevant. John Dixon has
considered the consequences of this, especially for G2Bh and is happy for this
pattern to be adopted (Paper 3).
3. Following on from this point, we have attempted to devise a course outline that
comprises a self-standing introduction to Geology for students who may, or may
not, pursue it further. This outline is attached (Paper 4). The timetable template
follows the proposed two-semester system for the University.
4. The main changes we propose are in the balance of the course, in the composition
of the practicals and in the integration of fieldwork into the main body of the
taught course. More detail on these is given below.
Balance of the course and key content
We suggest that the course divide into two halves, which mirror the current pattern of
the Geology 1 course. Practical lectures will cease to be taught and the course will
integrate practical and theoretical information as required. The first half course will
tackle internal processes and have a plate tectonic basis. This half course is
provisionally called ‘Earth Dynamics’. The second half course will tackle external
and secular processes and is provisionally called ‘Evolution of Earth’s Environments’.
Economic geology will be introduced into both halves of the course.
The key content for Earth Dynamics is as follows:
1. Students should be familiar with the processes by which the Earth formed and
partitioned with depth.
2. Students should be able to explain plate tectonics and understand how tectonic
processes operate.
3. Students should be able to relate patterns of surface features, such as the
distribution of volcanoes or mountain ranges, to plate tectonic processes.
4. Students should be familiar with a range of techniques for measuring internal
processes including methods dependent on gravity and seismology.
5. Students should understand that igneous rocks are a product of evolving magmas
crystallizing at a variety of rates and depths. They should be familiar with granite,
rhyolite, basalt, gabbro, andesite and diorite.
6. Students should know which silicate minerals comprise the rocks above, and
should know their chemical formulae and crystal structure as well as being able to
identify them in thin section or hand specimen. A list of minerals for which this
will be required is as follows – quartz, olivine, plagioclase feldspar, orthoclase
feldspar, biotite, augite, hornblende.
7. Students should understand that metamorphic rocks are formed by a variety of
PTT paths through the crust, broadly grouped into regional and contact
metamorphic events. They should be able to link particular PTT paths to plate
tectonic settings. They should be able to identify metamorphic rocks in thin
section and hand specimen, specifically gneiss, schist (greenschist, blueschist),
slate, marble.
8. Students should know the following minerals in the same detail as those described
in point 6 – garnet, kyanite, calcite.
9. Students should understand that rocks deform or break depending on depth and
confining pressure. They should understand how faults form and move, the
geometry of folds.
10. Students should understand the genesis and economic significance of
metalliferous and gem deposits. They should be familiar with the appearance of
common non-silicate minerals in hand specimen and thin section where
appropriate.
The key content for Evolution of Earth’s Environments is as follows1. Students should be familiar with the geological timescale.
2. Students should understand that the earth is a dynamic system which has behaved
in a substantially different way at certain times in the past.
3. Students should understand how heat is retained in the atmosphere and distributed
from equator to poles.
4. Students should be able to explain how clastic particles are generated, transported
and deposited.
5. Students should be able to identify aeolian and aqueous sandstones, shales,
conglomerates, breccias.
6. Students should be familiar with the facies concept and with facies models of
deserts, river systems, deltas and deep oceans.
7. Students should be able to describe carbon and silicate cycles, and the formation
of carbonates, evaporites and Fe-Mn nodules. They should be able to identify
limestone, rock salt and gypsum.
8. Students should understand how landscape and rock layers interact in three
dimensions. They should know how to take strike and dip measurements and
produce a simple geological map and cross section.
9. Students should be familiar with a simple narrative of crustal evolution for the UK
region, and with a simple narrative of biological evolution.
10. Students should be able to recognise ammonites, corals, graptolites, brachiopods,
echinoids, bivalves and be familiar with their stratigraphic ranges.
These elements of the course will be examined in a different manner to the rest of the
material, to ensure that all students will need to achieve this level of understanding in
order to pass the courses.
Practicals and pure science add-ons
We have considered a possible template for each practical to follow, and this is
outlined below.
a. Each practical should include questions that require the student to think
mathematically or with an awareness of basic chemistry. Box inserts, possibly
supported by supplementary (?web based) material, will explain the techniques
being applied and their basis in the pure sciences. This will level the playing field
of our students, who have widely divergent standards of science comprehension
on entry. It will follow the models devised by Patience Cowie under her remit to
introduce maths and chemistry to the current version of Geology 1.
b. Some practicals will need to introduce laboratory skills, for example descriptive
mineralogy, and will need three hours at a stretch for this. Other practicals should
aim to integrate geological data from a range of disciplines, focussed on a major
geological problem. For example, after the Barns Ness field trip we suggest a
practical should be developed that explores sedimentary architecture and
responses to changing sea levels. A log compiled in the field could be integrated
with data on compaction of the main sedimentary types, timescales of processes
that might be responsible for cyclical deposition, an analysis of the distribution of
fault systems in the Midland Valley during the Carboniferous, data on
Carboniferous climate (icehouse/greenhouse concepts), biological information on
timescale and environment and so on.
c. A bid should be considered to provide funding for the production of high quality
teaching materials for the Geology 1 practicals. This might include web-based
follow-up material, video clips for use in practicals, scale models, new thin
sections or specimens if needed.
Integration of fieldwork
Fieldwork is seen as critical to the successful training of geoscientists. A series of day
trips is conducted within Geology 1. These will continue to run and will be integrated
more thoroughly into the taught part of the course.
Each practical will be preceded by a lecture, in addition to the ‘virtual fieldtrips’
already available. Data will be collected in the field and used in the following
practical. An outline of what is intended is given below.
Field location
Lecture outline
Data collected in
field
Practical followup
Arthur’s Seat
?and Our Dynamic
Earth
Field sketches and basic
notebook skills
HS descriptions of rock
types
Baldred’s Cradle
and Siccar Point
Regional setting, role in
development of
geological thought,
lithologies and their
genesis.
Time and rock geometry,
Hutton, regional setting,
rock types
Barns Ness and
Cove
Lithologies, Upper
Palaeozoic setting, facies
encountered.
TS of main rock types,
with opportunity to relate
this to hand specimen and
outcrop-scale
observations.
Produce neat copy
geological map and cross
section. Relate
topography to outcrop
patterns using both
localities as examples.
Mulit-element analysis of
possible causes of
lithological repetition in
logs and assumed changes
in sea leve.
1.
Simple geological
map of BC
2. Rock relation
diagram of Hutton’s
Unconformity
Field notebook skills
Detailed sedimentary log
of parts of sections
Field notebook skills
PAPER 1:
AN ANALYSIS OF G1’S PRESENT STATE
1.1
We feel that the lecture course content in G1 is fundamentally sound, as it has been
subject to periodic review and up-dating, and generally sets out to communicate the
interest and enthusiasm for the Earth possessed by the Staff who deliver it. Even so, it
would benefit from much closer linking to the practical course and to the field
excursions, and if these change, so will it. The Practical Course, on the other hand,
has always been a separate entity, very much concerned with introducing the
materials of the Earth, and the various skills needed to recognise, describe and extract
information from them. It has been essentially detached from the exciting stuff about
volcanoes and colliding continents and also detached from the field excursions where
one would expect the greatest potential for cross-referencing and re-inforcement.
1.2
Looking at the practical course as a whole we identify three traditions that determine
its present sequence and content. These are:
 That G1 must, in part, look ahead to G2 and G3 and so will inevitably start what
it cannot finish, and will inevitably try to lay securer foundations than would be
appropriate for a one-year self-contained course.
 That to study rocks one must first become familiar with their constituent
minerals, for which, in turn, one must first understand the nature of crystals, and
along the way understand mineral optics at least in outline.
 That the essence of a first-year introduction to crystals, minerals, rocks and
fossils is to present students with a rich landscape to journey through, in which
travelling is more important than arriving, with the result that the amount of
material presented will always run well ahead of that which is used in assessment.
1.3
These traditions are, or were, based on firmly held views of the founding fathers of
present G1. The second tradition has been hallowed practice in geological education,
while the last one was very much Roy Gill’s personal belief and his inspirational
energy carried the students along despite the huge volumes of material he placed
before them. All three principles have been essentially adhered to in subsequent
revisions and improvements to the course over the years. Despite much pruning, the
Gill richness is still clearly there in the approach to the presentation of material if not
now in the sheer quantity.
1.4
However with the increasing focus on step-by-step instruction and explanation for
students unable to manage their own learning, the accompanying texts have got longer
and more detailed. Most of the subsequent development has been an honourable
attempt to create better, more accurate maps of the learning paths, but with the
underlying terrain largely unchanged. Most recently a single link between field and
practical has been introduced around the geology of Holyrood Park in Practical 1 but
it remains an isolated example and the traditional structure is resumed thereafter. In
essence we want to take this kind of development much, much further and to do that
we need to be radical, conservative, imaginative and realistic all at the same time.
1.5
In general there seem to be two interlinked problems associated with the present
practical course:
 its rationale is not self-evident to the students themselves and
 there is no clearly defined core body of skills or facts that has to be retained.
1.6
Anecdotal evidence suggests that at times the inspirational airborne traverse of the
whole landscape is becoming a slog through thick undergrowth. To quote an actual
exchange between a G1 student in CM&R and member of Staff running the practical;
“Why are we doing all this stuff? Answer: “ I don’t know. To pass exams.” At face
value this exchange suggests that the rationale is not even apparent to our colleagues.
Conversations with mature student members of the class also confirm that there is a
definite problem of perception and relevance: “They (fellow students) don’t see what
the connection is between the various practical skills they are acquiring and the
subject itself.”
1.7
On the question of what is to be retained, it is rarely clear in the course material
exactly what is examinable and there is clearly a huge amount of information
delivered in passing which is just that – background – and not structured to be
remembered and assessed. G2 experience makes it clear that not much is retained
even of key items flagged as essential. (This is a well known problem but when it
comes to only 60% recalling the formula for quartz one has some grounds for real
concern.)
2
OUTLINE OF A NEW APPROACH
2.1
If some parts of the course have become unwieldy and their objectives obscured, does
that mean that the whole structure has to change? By way of an answer we ask the
question:
 Are the basic guiding principles actually still appropriate in 2003 in the light of
changing student attitudes and capabilities, changes in the courses in later years and
the development of four increasingly differentiated Degree streams?
2.2
We conclude that all three traditions can be seriously questioned and that together
they have been a benign straitjacket within which it has been effectively impossible to
effect any major change to the content or the sequence. Our proposals effectively
abandon all three.
2.3
We conclude that a Geology 1 course which has a clear set of First Year objectives
will actually serve later years better – i.e. we move formal stuff that does not serve a
G1 objective to later years.
2.4
We conclude that it is more important to sustain interest by introducing rocks and
minerals in a minimum-formality form in parallel with the lecture material rather than
proceed with the classical sequence from crystallography onwards before they can be
made use of. In this way we can start the course with volcanic processes and tie this
to both a practical and a field excursion – i.e. take the most recent G1 change to its
logical extreme. (We have no intention of abandoning formality and rigour where it it
is appropriate.)
2.5
We propose to define clear learning and skill objectives for the course as a whole and
for each component part, which will then determine the practical content. There will
be optional strands for the enthusiasts to follow if they have achieved the stated aims.
2.6
The emphasis will be on empowerment rather than familiarisation by passive exposure
to variety – for example, equipping the student to identify a porphyritic volcanic rock
with a recognition kit for deducing what the rock is from first principles, rather than
matching the unknown to the memory of an andesite seen in a display. This skill
needs to be linked directly to its employment – deducing a crystallisation depth and
eruptive history.
2.7
Another guiding principle will be retainability – producing students who can all
confidently do some basic identification and interpretation tasks reasonably well and
who appreciate how and why the material they have learnt contributes to that process,
and take this knowledge into G2. This will be a “RISC” – reduced instruction set
course- with fewer names, less “stuff”, more very carefully chosen material, but not a
course that is “dumbed down”. We will in general do more with less rather than
expose students to unnecessary diversity in a laboratory environment. At the same
time we will try to make use of modern high quality visual material (video) to help
convey the dynamic parts of Earth processes and use more visual material to link to
practical work. The aim is to try to tie together all the strands of practical skills, the
vocabulary of rocks and minerals and the field and mapped relations so that, for
example, a G1 student can identify a basalt dyke in the field, know what is likely to be
in it, know what it would look like on a map and know how it relates to volcanic
activity generally. Some Glg4 students are not even confident about what basalts
have in them. To achieve this in G1 may seem ambitious but also seems to us to be
perfectly reasonable. We do not presume to have solved all the problems. The new
course will require a large investment of time and effort and much new material.
2.8
Dumbing Down: This term is so frightening that it merits a digression. JED has
wrestled for many tears with the twin problems of inculcating conceptually difficult
material with relatively few facts attached (optics) and at the same time conceptually
straightforward material (mineralogy) laden with facts but short on aids to link names
to structures to formulae. He is increasingly aware of the danger of measuring the
quality or standing of a course by content presented as distinct from content retained.
Even retention for exam purposes is an unsatisfactory measure, content understood
and used in context would be a far better, if tougher, standard to measure ones success
as an educator by. An equally seductive trap is to measure the course by the
achievements of the most able students. They will always massage one’s ego by
soaking up everything and chattering happily to you, however poorly presented it is.
The test of a first-year practical course should be “How much can the majority of the
students do and at the same time understand what they are doing and why?”. All that
matters is to get this quantity to increase. If this means cutting out material and
setting and clarifying more limited objects, it cannot be described as dumbing down.
The notion that the previous state of the course was superior by being fuller, will have
been an illusion. And keeping the high flyers stimulated is really not that difficult in
our subject, there is simply so much there to be pursued.
3
SOME SPECIFIC PROBLEMS OF CONTENT AND CONTINUITY IN THE PRESENT COURSE
3.1
We are sustained in our conviction that radical change is needed by a close look at
key components of the course.
3.2
In CRYSTALLOGRAPHY, IP’s carefully constructed formality in G1 continues in G2
with the minimum of duplication, and the fact that G2 can plot an orthorhombic
stereogram and represent P21/c etc. after only two sessions stems from the intensive
precursor course. However, the course across the G1-G2 boundary is critically
dependent for its success on clear assessment targets being set and met, and on careful
attention in the delivery to those targets. Gloss over plotting rules and the set
stereogram exercise in G2 nearly collapses. Good students do well but
crystallography has now usurped optics’s role as a prime slayer in the G2 exam (along
with metamorphic petrology). G2 students can do sophisticated exercises given the
rules, but many remain unsure what “perfect {110} cleavage” means in a monoclinic
crystal- i.e. they can’t interpret a simple DH&Z entry. The course is a beautifully
constructed ridge-walk but it is not clear that it all helps with the ascent of other
broader peaks.
3.3
Crystallography as a formal discipline is also not sticking well with those students
who don’t get exemption. This is particularly the case with GPG and EG students.
Again, part of the problem maybe that the crystallography and optics courses in G2
occur when the students simply don’t yet know very much about minerals and rocks.
It is not therefore obvious to them why they need to know all these fundamentals as
they don’t illuminate existing knowledge. The analogy would be learning an
extensive vocabulary and etymology of a foreign language before being allowed to
read any literature. Ian Parsons has said that as long as the formal structure of present
crystallographic instruction is in place prior to G3 mineralogy it is not actually that
important where it is occurs.
3.4
This is a case where the formality and continuity is carefully structured and very
evident from G1 to G2. The problem is not the formality itself but the length and
timing of the sessions and the relationship between the intermediate learning
objectives and the state of the students’ knowledge of related material at the time.
3.5
We conclude that the crystallographic end-point for G3 Mineralogy B students needs
to remain much the same and that the formalism on the way must be retained but that
the division of topics between years and the timing within any one year needs to be reappraised, along with the specific skills currently being taught, such as the plotting of
stereograms. some suggestions are presented in Section 4.
3.6
From a G2 perspective, in OPTICS AND MINERALOGY, it is difficult to detect, let
alone rely on, a G1 foundation. The G2 optics course could not run as fast as it does
with no prior exposure but once the indicatrix is introduced on Day 1 the whole
mental process for the students is clearly completely new and the points of reference
to what has gone before are minimal. Yet students cannot name or recognise even a
handful of minerals. This is an instance where the G1 course is taking a subject to a
particular level which in places is not very different from that in G2 (e.g. pleochroism
and extinction angles in hornblende) but by a different route and without G2’s
formality and theoretical framework. The two courses don’t join end to end as they
do in Crystallography. One solution (scary for optics) would be to adopt the intensive
IP crystallography model and have a formal G1 optics foundation lead directly to an
equally intense but related development in G2. This is not favoured.
3.7
The symmetry control of optical properties, which is the foundation of all extinction
angle principles, qualitative and quantitative, is not realistically teachable without the
indicatrix concept once the uniaxial systems are left behind. In G2 this is successfully
grasped by the majority and is still of net benefit to those going on to use the
microscope in G3. This is too much for G1 in terms of the first year yield. In the
writer’s view the present G1 approach attempts too much without this framework and
this leads to unrealistic implied targets for the students and some subtle but real
problems in that the instructions they have to follow are not comprehensive enough to
yield observations that they could actually interpret, as in hornblende pleochroism.
3.8
The origin of interference colours does not depend on the indicatrix concept but is not
simple. It involves two crucial concepts: the resolution at the analyser set at 90 and
the simultaneous presence of a range of wavelengths in white light. The origin of
first-order sensitive tint needs to be the goal of any serious attempt to teach the
principles. Again in G1, its half done – the diagrams are there but its not carried
through and its clearly not an assessment target. It is not clear if this approach
actually helps it’s eventual treatment in G2. It should either be done thoroughly as a
piece of very relevant science (with the calcite rhomb experiment relegated to a
demonstration of splitting and polarisation) or it should be done as a glossy
explanation in passing, with the colours treated entirely empirically as a sequence to
be recognised and used.
3.9
The time spent on PROBLEM MAPS likewise does not seem to translate into a lasting
ability to visualise and connect subsurface geometries and outcrop patterns, nor does
this effort translate into a confident ease with stratum contours in Arran. Maps, like
crystallography or palaeontology, is a sub-discipline of the subject with a life of its
own and the temptation is always to let the sub-discipline dictate the content in
isolation from the wider aims of the course. The questions to ask are: is the skill
being developed in this practical appropriate for the student’s current level of
knowledge of the context in which this skill could be employed? Is it reinforcing, or
will it be reinforced by active use at G1 level? We suspect that some of the wellknown 2D-to-3D problems that beset the Honours mappers could be due to a
continual mismatch between maps and cross-sections as theoretical exercises, and
maps and sections as practical solutions to simple real problems. The bits that seem
to work really well occur when the field experience is backed up on the spot with the
graphical treatment, as at Inchnadamph.
3.10
The G1 map course once led directly on to a G2 unit of lithostratigraphic exercises
which probably originated in a need to train geologists to predict the subsurface extent
of coal seams. TPS used it as a vehicle for developing 2D and 3D awareness of
lateral and vertical facies variations and unconformities which his lecture course was
concerned with. The residue of this is now in G3 hydrocarbons but the G2 links have
largely gone.
3.11
The six week G1 maps course is designed “to introduce you to the interpretation of
geological structures and history from the information contained on geological maps.”
The fact that the maps that follow are mostly simple stylised maps is explained by the
fact that they are easy to produce and draw on. There is no further written explanation
of the rationale behind the quantitative or the qualitative aspects of the exercises or
the avoidance of real maps, which came and went with the Edinburgh sheet in Week
1. It is presumably thought to be axiomatic and self-evident that this is the stuff of
geology and needs no further explanation. Reading through the now very well-crafted
exercises cold, one is struck by the vision of the Earth’s structures as static and
detached from their past, and that the main objective is to describe and quantify what
is there now. By default it appears to be more important to contour a fault surface or
fold limbs and calculate displacements than explore what it all might mean. Restoring
structures is simply not mentioned, yet is the essence of understanding history. That
the quantitative aspects might be a relic of coal-mining imperatives is not in sight.
One really has to reach across a conceptual chasm to connect these dry symbolic
diagrams with real geological events and one’s anchors are memories of one’s own
education rather than the geology of areas one knows well. Obviously the connection
between 3-D geometry and 2-D representation is important but there surely has to be a
better way to make it self-evidently useful and relevant for the students.
3.12
Why not explore the Midland Valley as a rift with oblique folding and use the
Edinburgh sheet to explore the link between the surface observations, the real
structure and the actual history? The basic visualisation rules which allow one to
recognise normal and reverse faults, vee-ing up and down valleys, cross-cutting
relationships etc. need to be absorbed, but models and graphics are surely the way to
do that.
3.13
This is a case where the G1 course was once part of a coherent G1-2-3 progression,
now largely dismantled, which also had a straightforward rationale: Geology
graduates should be able to carry out graphical analysis of maps, sections and
borehole data. As part of this progression, first year students needed to master the
principles thoroughly. Questions of cross-referencing of map principles to other parts
of G1, or the value of this discipline to outside students never really arose.
3.14
We are not aware that serious attention has been given to the newer question: to what
level should each of our Degree courses train their graduates to carry out graphical
analysis of surface and subsurface data? There is a working consensus on the
interpretation of seismic reflection data but is there a coherent philosophy
underpinning map interpretation? We think this an area which needs a proper
review, urgently. The results of that review will inevitably contribute to a new G1
approach and until this is thought through we can’t yet propose a vertical progression
of concept and skill development in maps beyond first year, in contrast to the
crystallography optics and mineralogy progressions which are considered below.
3.15
In the meantime:
We consider that once the basic principles of map construction are dealt with,
using as many CEF-style visualisation aids as possible, the G1 map course should be
tied in with the Holyrood Park and other trips, it should be as far as possible
synchronised with the courses in structure and sediments, it should focus on the
capacity of maps to reveal geological history through restoration and it should
prepare the ground for the Arran excursion, cross-linking and relevance being the
key. (It may not be appropriate to treat “maps” as a course in its own right but as a
means to various ends, integrated appropriately, once the principles are in place.)
Paper 2: Geology 1 revised calender entry
Geology 1 (40)
GY00xx
This course comprises Earth Dynamis 1h and Evolution of Earth’s Environments 1h. It is designed for
intending Honours students in Geology, Environmental Geosciences, Geology and Physical
Geography, and Geophysics. Such students must take both half courses.
A candidate who fails in the examination for Geology 1, which comprises the two separate
examinations for ED1h and EEE1h, may be awarded a pass in one of these half courses. Passes in both
are required for entry into Geology 2.
Exemption from the degree examination will be given to candidates obtaining first or second class
Merit Certificates.
Students proceeding to Geology 2 are required to attend and perform satisfactorily at a residential field
course in the Summer vacation.
None
Earth Dynamics 1h (20)
GY00xx
M, W, F 10 Laboratory M 2-5 or Tu 9-12 or Th 2-5 or F 2-5 (autumn and part-spring)
Volcanoes, earthquakes, mountain chains and the diversity of the Earth’s rocks tell us that the Earth has
been a dynamic planet since its formation 4.6 billion years ago. This course has two main aims: to
impart an understanding of the processes which shape the Earth, and to develop practical skills in
recognising the evidence of these processes in rocks, both in the field and in the laboratory. The course
will have a primary focus on the materials of which the Earth is made, how the major constituents are
distributed between core, mantle and crust and how this changes with time through the agencies of
plate tectonics and volcanism. From this viewpoint of underlying process, the course will also consider
the inherent availability of natural resources and the potential for predicting natural hazards.
None
Evolution of Earth’s Environments 1h (20)
GY00xx
M, W, F 10 Laboratory M 2-5 or Tu 9-12 or Th 2-5 or F 2-5 (part-spring and summer)
The Earth’s internal heat is the fundamental driving force responsible for the cycles of birth, growth
and death of ocean basins and the rifting and collision of continents. Plate Tectonics describes the
process. But the history of the Earth as a habitable planet has also depended critically on the
irreversible changes that have occurred to the oceans, the atmosphere and to the nature of the surface
processes which have created and modified the Earth’s surface environments through time. Periodic
catastrophic events, whether meteorite impacts or massive volcanic episodes, are increasingly
recognised as crucial influences on the evolution of life, and the emergence of life itself played a
fundamental role in modifying the Earth’s atmosphere through time. This course will explain how
surface processes operate and study their effects. It will explore the geological history of the planet
and the evolution of life as revealed in the fossil record. It will show how the geosphere, biosphere,
hydrosphere and atmosphere have interacted through time, using the geology of Britain as a case
study. It will develop practical skills in the recognition of present day environments and surface
processes of erosion and deposition, the record they leave in rocks, and in the identification of the
major fossil groups.
None
PAPER 3: POSSIBLE NEW VERTICAL SEQUENCES IN CRYSTALLOGRAPHY, OPTICS AND
MINERALOGY.
4.1
Crystallography, Optics and Mineralogy are the courses where changes impact
directly on the vertical progression from G1 to G3. Here we suggest how content
might be redistributed or even eliminated over three years.
4.2
Crystallography
4.2.1
Formality is essential in the teaching of any crystallography because crystallography
is the recognition of underlying order and form in the natural world. We can now
potentially distinguish three different target levels of crystallographic awareness: a
strictly G1 level which will allow the student to appreciate what makes minerals
different and identifiable and can be tied to a specific but limited set of skills to be
mastered; a G2 level which will support a G2 course in optics and mineralogy
common to all Degree streams and a third level appropriate to hard-rock petrology
and G3 Mineralogy A and B. All three would be taught formally, rather than in
disconnected factoids, but the practical skill hurdles will be judged against a strict
criterion of direct relevance to the level in question.
4.2.2
At G1 level the main objectives are the recognition of crystalline material as based on
a regular lattice and the recognition of different kinds of symmetry, principally as an
aid to differentiating minerals by their shapes and simple optical properties. Although
to appreciate the chemistry and occurrence of different minerals, and even to be able
to recognise olivine, pyroxene, hornblende and plagioclase one does not strictly need
to know about the seven crystal systems, this does seem an instance where the
organisation of crystalline material into seven systems is probably useful as a
framework for learning. Is there a case for learning the Miller system as a G1
objective? Only if it is used in the mineral familiarisation process in labelling
cleavages and describing crystal forms that will be seen and recognised. The result
will be a stripped down crystallographic introduction which will be formal but will
only contain concepts and procedures that are used in reinforcing and illuminating
other parts of the G1 course or which are introduced because they are the most
efficient device for learning. On balance we keep Miller Indices in G1.
4.2.3
At G2 level we face a potential dilemma. If we have a significant fraction of G3 (e.g.
Gp3) moving out of Igneous A and Metamorphic A there is a possible case for
dividing optics into basic in G2 and advanced in G3 for those doing petrology.
However there is also a strong case for Geophysics students knowing about rocks and
minerals as they do play a rather significant role in moderating the signals received by
geophysical equipment. Geophysics students also tend to master the theory of optics
better than any other cohort. For those going on to G3 Petrology and needing the G2
grounding in mineralogy there is no case for delaying full familiarisation with the
symmetry concepts needed to back up optics, but this does not mean that all present
G2 crystallography should be in the second-year core.
4.2.4
We suggest that it is an important G2 target to appreciate the symmetry of
orthorhombic lattices and crystals at Point Group and Bravais Lattice level, because it
enables the student to make more sense of minerals and rocks. It is not at all obvious
that plotting an orthorhombic stereogram and mastering the Addition Rule, helps at all
in this, nor does knowing what Pbca means, at that stage. So: leave out formal
stereogram plotting, possibly altogether, but use sketch stereograms to the full (the
stereographic projection is essential at G2 level and in crystallography is still the most
effective device for representing symmetry, but it needs active use rather than the
formality of face plotting).
Introduce space group symmetry elements because they are used in G2 mineralogy to
explain real structures but
consider leaving the formality of the depiction and equivalence of space groups until
G3, if at all.
4.2.5
By G3 Mineralogy B or even EG3 it may be important for students to understand
even more about crystallography than they do at the moment so that they can interpret
X-ray diffraction patterns. So consider a shift in G3 Mineralogy B from feldspars
towards more general aspects of using X-ray or even electron diffraction in the
understanding and characterisation of minerals.
4.2.6
In general prune out and/or delay the systematic coverage of classes and forms unless
this serves the goal of practical utility. Resist the temptation to deliver the course
material in 7-, 32- and 240-fold units simply because the world is organised that way.
4.2.7
Crystallography is a litmus test of the present strategy of formality and completeness
within sub-disciplines. The formality must be there because it is a reflection of the
underlying organisation of matter and it also must be there because students need the
formal structure to assist retention and to hang subsequent knowledge on. What they
don’t need is the taxonomic approach which still lingers on in crystallography and
mineralogy just as it does in palaeontology. What if there were fourteen crystal
systems and sixty-four point groups?
4.3
Optics
4.3.1
In OPTICS, it follows from the earlier analysis that the G1 optics treatment is
considered mostly too ambitious, given its self-imposed restrictions on both time and
allowable concepts. Colour, pleochroism and relief, maximum birefringence colour
through recognition of Newton’s scale, cleavages and shape will get everyone a long
way. We are not convinced that extinction type is useful beyond well-formed
prismatic uniaxial cases. There are simply too many exceptions that can only be
negotiated with the aid of a deeper understanding of principles. Virtually all
observations that rely on grain selection should be postponed in favour of simple
familiarisation and more exposure. It really would be a major advance if students
going into G2 could all actually distinguish and put the right name to olivine,
pyroxene, hornblende, biotite, plagioclase, microcline and quartz and more to the
point, could do it because they knew it gave them the power to make deductions about
the nature and origin of the rocks in question.
4.3.2
Our deduction from this is to spend the time in G1 on familiarising students with the
appearance, names and formulae of a very reduced set of minerals, using rule-ofthumb optics with reinforcement coming from colour photographs. Interference
colours could be done rigorously as a specific target much as in G2 but this is open to
debate. Otherwise the explanations and the systematics should be left until they can
be done thoroughly. There should also be a very clear delineation of what is
examinable and what is optional background.
4.3.3
This revised set of objectives would have little or no impact on the G2 Optics
curriculum. Increasing familiarity should make microscope usage less unfamiliar and
could make more advanced treatments more of a natural progression. At present,
dealing with extinction angle theory in monoclinic amphiboles suffers from several
drawbacks: they don’t have much feel for monoclinic-ness, it is just one concept in
the welter of crystallography; they don’t easily relate {110} to a pair of cleavages;
they don’t know what amphiboles are for sure or what they occur in, having seen
them on only a couple of occasions months before; they don’t as a result have much
feel for why it might be useful to measure an extinction angle. They might remember
G1 Practical 8 but it had no indicatrix foundation. (Even after the G2 Minerals and
Optics courses less than half the class could identify a colour photo with brownyellow pleochroic crystals and 124 cleavages as hornblende – there is plenty of scope
for increasing familiarity by repeated exposure!)
4.3.4
At G2 level the issue is: should we continue to teach an Optics course founded on the
indicatrix concept to students who may not go on to do Petrology in G3. I remain
convinced that it is still the best foundation for those students who do use the
microscope, not so much because they use it daily to solve identification problems but
because it gives structure to their procedures. They know why they are going for the
maximum birefringence section, even if it would take some dredging up. They can
use DH&Z to identify an unknown or a forgotten mineral because they know what the
optical properties mean and how to confirm them. This seems to be a crucial and
legitimate teaching objective for geology graduates and one that is only properly
realisable with a theoretical foundation. JED has first hand experience of the products
(some with Firsts) of undergraduate courses that have abandoned the formal discipline
of Optics. They have admitted to being at sea with a microscope and to rely on
picture matching. He is encouraged this year by a significant jump in performance in
Optics by this year’s G2 following his move to printed-up and re-organised notes. He
is more convinced that different teaching and assessment strategies can make a
difference.
4.3.5
With students leaving petrology after G2 the rationale is less clear. If G3 petrology
courses were to remain optional even for cohorts directed away from them, we would
not wish to inhibit students from taking them by simultaneously removing the option
to study the requisite theory. This alone suggests that Optics is best left in G2. If
petrology is forcibly removed from some G3 groups then Alternative A would be to
split Optics into elementary (G2) and advanced (G3). There would be two obvious
problems. The conceptual division is between uniaxial and biaxial but rocks don’t
organise their minerals to match. The second problem would be an increase in the
ever-present tendency for students to stop off mentally at uniaxial and try to use e and
o in biaxials. A year gap would be fatal. Alternative B would be to postpone the
indicatrix to G3 for the petrologists. This would mean a further year of rule of thumb
optics and would probably ingrain bad habits. Interference figures could not be left
out, nor could sign determination because of the need to identify key minerals but the
theory would have to be left in limbo. Extinction angle composition determinations in
pyroxenes and plagioclases could not be postponed but the rationale for grain
selection would remain magical. It would be a mess.
4.3.6
After much thought there seems no obvious alternative but to retain the present plan.
If interference colours really were dealt with formally in G1 a full session would be
liberated in G2 and the G2 mountain would be a bit less steep.
4.4
Mineralogy (and Rocks)
4.4.1
Given that G3 mineralogy is appropriate in level for the accompanying petrology
courses and the basic information about the major rock-forming mineral groups needs
to get transmitted at G2 level the challenge is to organise the information and
retention sequence into a natural progression from G1 on. Duplication is to be
avoided but revision and reinforcement is OK , preferably in the context of expanded
application of basics.
4.4.2
In essence a combined diagnosis and prescription would be that in G1 there is too
much mineralogical detail but it is not prioritised, there is too little progressive
accumulation of knowledge of a cut down set of the most abundant and important
rocks and their minerals, rather an overwhelming rush of information which is then
not revisited or cross-linked to field and lecture. In G2, when systematic mineralogy
is resumed, there is no context of need-to-know, the host rocks are distant memories
and mineral names inhabit a different planet from mineral formulae and yet another
planet is home to mineral structures.
4.4.3
Action: take a machete to the G1 thickets and replant as a garden with clear paths (!
sorry). Develop a prioritised strategy based around a cut-down set of minerals and
rocks. Get the students to know them well over the course by weaving them into the
fabric of teaching throughout. Then G2 can build from some sort of foundation.
Paper 4: Possible course outline
Earth Dynamics 1h
Week Lectures
1 Introduction to the Earth
Practicals
The earth in space
Measuring the earth
Planet earth dynamics and evolution
Geological time
2
Earth materials
Internal structure of the earth
Earth materials, common silicate minerals, mic
Gravity and how to measure it.
Seismicity
3
Earthquakes and how to measure them
Earthquakes, gravity
Earthquake prediction and hazards
Holyrood
4
Holyrood lecture
Core and mantle
Holyrood practical
Crust
Plate tectonics
5
PT1
PT2
Plate movements, characteristic rocks, micros
PT3
PT4
6 Igneous
Igneous rocks and volcanoes
Igneous rocks
Volcanic hazards and eruption prediction
Rock forming minerals
7
Silicates 1
Silicate minerals in more detail
Silicates 2
Mineralogy of igneous rocks
8
magma evolution and fractional crystallization
Fractional crystallization
?Hot spots and LIPS
Structural geology
9
Deformation of rocks, stress and strain
Big faults and fractures, smaller relatives
Folds and faults
Folds, thickening crust, mountains
PTT paths
10
Contact metamorphism
Metamorphic minerals
More silicate minerals
Regional metamorphism
11 Metamorphic
More silicate minerals
Metamorphic textures
Prograde and retrograde paths through crust
Tectonic settings and types of metamorphism
12 Metals and gems
Fluids inside the earth
Non-silicate minerals
Metalliferous deposits
Gems and gem gravels
13 exams
14 exams
Christmas
Christmas
exams
Evolution of Earth’s Environments 1h
15 Atmosphere, oceans, climate
Overview of plate tectonics and the solid earth
Assessing climate change
Formation of atmosphere/composition
process and rates
Atmosphere as heat engine
16
Climate now and in past
Water cycles/ landscape
Maps - landscape and subcrop
Liquid water on the surface
Water underground
17
Ice
Sedimentary cycles
Maps 2
Chemical weathering
Depositional and diagenetic processes
18 Baldred's Cradle lecture
Clastic sedimentology
Sedimentary rocks 1
Deposition by flowing water
Deposition by wind
19
Still waters and muds
Introduction to facies
Baldred's Cradle practical
Facies analysis
Example facies
20 Siccar point lecture
Chemical sediments
Sedimentary rocks 2
Evaporites
Carbonates
21
How old is the Earth?/measuring time
Feedback mechanisms and time
Archaean and Proterozoic world
Precambrian earth and life
Precambrian of Britain
22
Origin of life and complexity
Barns Ness cyclothem practical
Museum practical
Cambrian explosion and Phanerozoic diversity
The Palaeozoic
23
Palaeozoic fauna/ life on land
Palaeozoic history of UK
Cambrian faunas
Economic geology: coal
Modern faunas and the carnvore crisis
24 The Mesozoic
Mesozoic evolution of UK
Palaeozoic faunas
Economic geology: oil and gas
Mesozoic vertebrates
25
Cenozoic history of UK
The Cenozoic
Economic geology:gravels and aggregates
Cenozoic mammals and man
Easter
Easter
exams
Modern faunas