How to write a paper or organize a presentation
A research presentation framework
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Title, authors, affiliation
Abstract
Introduction
Previous work
Methods
Results
Discussion
Conclusions
Acknowledgements
Bibliography
Glossary
Most journal-style scientific papers are
subdivided into the following sections: Title,
Authors and Affiliation, Abstract, Introduction,
Previous Work, Methods, Results, Discussion,
Acknowledgments, and Literature Cited, and
maybe a glossary if technical terms are used.
Metamorphic Zones in the
Eastern Scottish Dalradian
George Barrow, BA
Kings College London
April 28, 2014
Title
What paper is about
where, when it form
Authors names
University affiliation
Date of presentation
Abstract
When, on what, where,
methods, results, why
• From 1884 to 1900 I conducted field work on
metamorphic rocks in the region south of Aberdeen.
Rock samples were collected and thin sections were
prepared for three SE to NW transects of thin outcrops
of metamorphic rock types. Based on these studies, I
recognized five metamorphic zones based on the first
appearance of five minerals: Chlorite (adjacent to the
Highland Boundary Fault) , Biotite, Garnet, Kyanite,
and Sillimanite. The chlorite zone was furthest from
granite and gabbro intrusions in the Dalradian, and the
grade increases in the above order to the Sillimanite
zone adjacent to the intrusions.
Introduction
• From 1884 to 1900 I conducted field work on
metamorphic rocks in the region south of
Aberdeen. Rock samples were collected and
thin sections were prepared for three SE to
NW transects of thin outcrops of metamorphic
rock types.
Use Cassi’s paper on additional laboratory tests of a Tonalite/Dacite origin for the Losee as a
model for the type of previous work papers you are looking for.
Previous Work
•
•
Barrow would write: In 1910, Grubenmann advanced the hypothesis of the threefold division of the
earth’s crust into depth zones distinguished by the nature of the metamorphic processes: the kata, meso,
and epi zones. These terms have been retained to the present but are used to designate not so much the
depths of rock occurrence as the grades of metamorphism.
Harker (1918) thought that crust pressure increases downward [along] with increasing temperature. He
further thought that the maximum shearing stress a rock can withstand decreases with increasing
temperature, so temperature is the only independent variable that controls regional [dynamothermal]
metamorphism (Miyashiro (1994)). He thought that my earlier papers on the Dalradian (Barrow (1910) )
were examples of this type of metamorphism. Harker further thought that strong shearing stress produces
such characteristic minerals as chlorite, almandine garnet, staurolite, and kyanite.
•
On the other hand, Harker thought that the absence of stress in contact metamorphism produced such
characteristic minerals as andalusite and cordierite.
•
YOU WOULD WRITE ABOUT Volkert and Drakes opinions, discussions on the Cranberry Lake
Map (“Stanhope Quadrangle”), the distribution of rocks and faults the mappers found, the
minerals they found, what they thought the parent rock was and why, and later tests of their
ideas, as well as any new ideas.
•
YOU would also display and explain any pertinent tables or graphs related to the origin of
your rock in the papers you found. For example, from Volkert and Drake
Field Area Previous Work
The field area is in the northeast portion of Scotland.
The Dalradian
Supergroup is a
complex of
metapelites
bounded by the
Highland Boundary
Fault to the
southeast, and by
the Great Glen Fault
to the Northwest.
You have much better previous work maps
Keep the
symbol box,
but type out
the
description
These need to be labeled and cited in biblio, one is Stanhope Quad, other is NNJ Geologic
Previous work Losee Ylo
• Volkert and Drake (1999) plotted mineral modal analyses for
three types of Losee Orthogneisses. Potassium Feldspars were
uncommon. Plagioclases were abundant and plotted nearer to the Albite
end member. All Losee samples plotted in the Tonalite to Trondhjemite
fields. ADD other papers results after this
Bibliography entry looks like this
Puffer, J. H.; Volkert, R. A. (1991) Generation of trondhjemite from partial melting of dacite
under granulite facies conditions: an example from the New Jersey Highlands, USA
Precambrian Research, 51: 115 – 125
http://pubs.er.usgs.gov/publication/70016646
Their discussion went like this: “New field and geochemical data place the Losee Metamorphic
Suite (a tonalite/trondhjemite complex) of northern New Jersey into the context of a major
Proterozoic Continental Arc represented by a discontinuous belt of northern Appalachian
metadacite. Samples of Losee rock range from extremely leucocratic trondhjemite locally
associated with amphibolite, to banded biotite, hornblende, pyroxene, and garnet-bearing
tonalites. The major element and REE composition of the tonalite closely resembles dacite from
continental are settings and model melts extracted from an eclogite residue by partial melting at
15 kbar. The REE composition of most Losee trondhjemite is enriched in REE, particularly HREE,
compared with Losee tonalite, and is interpreted as the product of local anatectic melting of
Losee tonalite (metadacite) that occurred in a granulite facies environment during the Grenville
orogeny.”
USUALLY YOU WOULD SUMMARIZE ON A POWERPOINT SLIDE, with cues to remind you what to
say.
Previous work Ymp
• Ymp metasediment
• Volkert and Drake C13-C15 Fig. 12 and Table 8 .
“Clinopyroxene-quartz-feldspar gneiss [author: Ymp]
typically contains 60 to 75 weight percent SiO , 10 to 14
weight percent Al2O3, 1 to 6 weight percent CaO and
appreciable Na2Oand K2O (table 8). This gneiss is slightly
higher in CaO than hornblende-quartz-feldspar gneiss (table
7), but their major- oxide contents are otherwise similar. In
figure 12, clinopyroxene-quartz-feldspar gneiss [Ymp]
spans the fields of arkose, lithic arenite, and graywacke,
reflecting variability in the sedimentary protoliths.” In other
words, mixed sandstones
2
,
Previous work Ymp
Methods
• Large hand samples were collected and thin sections prepared for
localities from (choose: A leucocratic Granulite “Losee Gneiss Ylo”; A
Microcline-Clinopyroxene-Quartz Gneiss” metapsammite Ymp).
• Rock samples were cut in half on the _____ diamond saw. Half was
relabeled and retained as a reference specimen and for photography, the
other half cut into a 1 cm slab for thin sections. The slab was divided,
relabeled, and marked for oriented thin sections. One specimen was sent
to National Petrographic Services, Houston, for thin section preparation.
The other half was prepared as a thin section in our lab using the Ingram
thin section machines.
• Thin sections were examined on the Leitz and Olympus petrographic
microscopes, then photographed and videographed under plane
polarized and cross polarized light. Linear counts were made in 10 regions
of each slide or photograph for Quartz, Plagioclase, Potassium Feldspars,
Orthopyroxenes and Clinopyroxenes, Amphiboles , Micas, and Garnets.
• The counts were then converted to percent volumes.
• Plagioclase compositions were calculated using the method of MichelLevy Extinction plots.
• Based on these and plots of laboratory data from similar rocks, possible
parent rock types were determined
RESULTS
Both granitic and
gabbroic
intrusions caused
the
metamorphism
discussed in this
report.
The Chlorite zone
is furthest away,
followed by the
biotite, garnet,
kyanite and
sillimanite zones.
RESULTS
Sequence of zones, typical mineral assemblage
 Chlorite zone. The metapelitic rocks are slates or phyllites and
typically contain chlorite, muscovite, quartz and albite
 Biotite zone. Slates give way to phyllites and schists, with biotite,
chlorite, muscovite, quartz, and albite
 Garnet zone. Schists with conspicuous red almandine garnet,
usually with Biotite, chlorite, muscovite, quartz, and Albite or
Oligoclase
 Kyanite zone. Schists with Kyanite, Biotite, Muscovite, Quartz,
plagioclase, and usually garnet and Staurolite
 Sillimanite zone. Schists and gneisses with Sillimanite, Biotite,
Muscovite, Quartz, plagioclase, garnet, and perhaps Staurolite.
Some Kyanite may also be present. Kyanite and Sillimanite are
both polymorphs of Al2SiO5)
Chlorite Zone
Chlorite Zone along the Glen Esk River
http://www.esci.umn.edu/orgs/whitney/Barrovian_sequence.htm
Field Photographs
• Barrow had many more areas than you have
Biotite Zone
Biotite Zone along the Glen Esk River
http://www.esci.umn.edu/orgs/whitney/Barrovian_sequence.htm
Garnet Zone
Garnet Zone along the Glen Esk River
http://www.esci.umn.edu/orgs/whitney/Barrovian_sequence.htm
Kyanite Zone
Kyanite in the Kyanite Zone
http://www.esci.umn.edu/orgs/whitney/Barrovian_sequence.htm
Sillimanite Zone
In the Sillimanite Zone
http://www.esci.umn.edu/orgs/whitney/Barrovian_sequence.htm
Thin Section Studies
• Barrow had multiple thin sections for each
zone.
• You provide multiple views in one section
• These will be the basis for your modal
analyses.
Chlorite Zone
The Chlorite zone metapelites typically contained chlorite, muscovite, quartz and albite
Biotite Zone
phyllites and schists, with biotite, chlorite, muscovite, quartz, and albite
Biotite Muscovite and Quartz
Garnet Zone
Schists with conspicuous red almandine garnet, usually with Biotite, chlorite, muscovite,
quartz, and Albite or Oligoclase
Garnet-Mica Schist
Kyanite Zone
Schists with Kyanite, Biotite, Muscovite, Quartz, plagioclase, and usually garnet and Staurolite
Sillimanite Zone
 Schists and gneisses with Sillimanite, Biotite, Muscovite, Quartz,
plagioclase, garnet, and perhaps Staurolite. Some Kyanite may also
be present.
Modal Analysis Methods
• In as many microscope fields of view as you can manage
(magnification is Objective x eyepiece power) count the
common mineral phases visible, calculate a multiplier, and get a
% for each.
• For the Losee count quartz, plagioclase, garnet etc in the
commercial slide. Determine and also count mafics for the slide
we made.
• For Ymp count Microcline (tartans) , clinopyroxenes (higher int
colors), Quartz (und .ext.) and Oligoclase (near Albite)
plagioclases.
Ymp Published Lab Results
• 2. Ymp metasediments
Sample “692—Titanite [aka Sphene]-clinopyroxenequartz-feldspar gneiss. [the remark “Interlayered with
clinopyroxene-hornblende-plagioclase amphibolite” –
THIS IS NOT IN YOUR SAMPLE]. North side of draw
between ridge crests, Allamuchy State Park, 0.50 mi
south of Strawberry Point, Cranberry Lake; Stanhope 7.5min quadrangle.” This is the place we went to just south
of your collection locality. We decided it looked exactly
the same.
Compare your mineral findings to this sample
Plot sample 692 on this. Use the oxides.
Conclusions: Parent Rock
• Discuss possible protolith sources for your
respective rock.
Acknowledgements
• I thank my fellow
geologists, J.B Hill,
L.W.Hinxman, J.
Horne, J.Linn, B.N
Peach, H.Mitter,
and W. Gunn. for
helpful comments
and help in the
field and
laboratory.
Literature Cited
•
George Barrow didn’t have much of a literature or geologic maps to refer to.
•
•
Grubenmann, Ulrich (1910) Die kristallinen Schiefer, 2nd ed., parts 1–2. Berne.
Harker, Alfred (1910) Geology for Students
•
You have a vast literature at your disposal. An example citation:
•
1. Puffer, J. H.; Volkert, R. A. (1991) Generation of trondhjemite from partial melting of
dacite under granulite facies conditions: an example from the New Jersey Highlands,
USA
Precambrian Research, 51: 115 – 125
http://pubs.er.usgs.gov/publication/70016646
2. Volkert, Richard A. and Drake, Avery (1999)
Geochemistry and Stratigraphic Relations of
Middle Proterozoic Rocks of the New Jersey Highlands
U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1565–C. 77 pages.
http://pubs.usgs.gov/pp/p1565c/p1565c.pdf
•
If you have too much, you may wish to limit your literature discussions to studies that
pertain to rocks most similar to your project rock and slide.