Wish I had seen this one years ago

Earlier this month I discovered that it is possible for me to download entire textbooks from the internet. Now, it may be that the reason I can do this is because I am on a university computer and they have an account with the publisher which makes it possible, but since a high percentage of readers who might be interested in the book I am about to talk to you about are likely to associated with a university in some capacity, there is a reasonable chance that you will have access to it as well, if not as a download, perhaps in paper at your uni library.

The book which I am enjoying reading just now is Phase Equilibria in Metamorphic Rocks, Thermodynamic Background and Petrological Applications, written by Thomas M. Will, published in 1998 by Springer, DOI: 10.1007/BFb0117723. This is volume #71 of a Lecture Notes in Earth Sciences series.

When I first started my PhD project in the field of metamorphic petrology I was coming into the field cold—it had been years since my last geology course of any sort, and I had had no background courses on topics like thermodynamics or the many calculations associated with phase equilibria. Consequently, when I started reading papers which included formulas that explained how the authors had arrived at their estimates for the pressure and temperatures at which their minerals formed I found myself skipping over the equations and looking for the sentences that explained what was done. Over time and after reading many papers which did this sort of thing I started to gain a partial understanding of the topic. Enough to apply the tools to my own samples and arrive at numbers that, hopefully, actually reflect the history of the samples.

However, while I could follow a recipe for calculating pressure and temperature of formation for metamorphic minerals, I choose which recipe to apply based on the fact that my samples were similar to those in the published papers, not because I had any real understanding of the models which underpinned the calculations. Terms like “ideal” vs “non-ideal” mixing painted pictures in my mind because I know what those words mean grammatically, not because I actually knew the difference between them as applied to the crystal structure of a mineral.

If you are in a similar boat, and would like to actually see good definitions of those terms, along with others like “entropy of mixing”, “activity-composition (or a - x)”, this may be the book for you. So far I have only managed to read the first 40 pages, but already I have a *much* better understanding of why it is that one gets such hugely different results in terms of pressure/temperature estimates depending on which model one uses for a given mineral, and a much better understanding why programs like Perple_X have so many models available to choose from. The author is kind enough to work through example calculations in a step-by-step basis, so that the reader can learn how it is done. Sure, when actually doing the geology you aren't going to do these calculations by hand—at the very least you will have a template full of formulas set up in a spread sheet, if not using a more complicated program to do the work for you, but it is always nice to understand *how* the program does the calculations—this makes it much easier to spot if a typo in the data-entry stage resulted in a geologically implausible answer being spit out by the program.

reading for fun and education

Sixty days ago I received the job offer to start my new job, and was given a small pile of literature for background reading before I started. As a result I started my “1000 words a day” challenge once again, after having had nearly a year off since last I had done that. The challenge is simple: do a little reading in the geologic literature every day, and keep track of how many days in a row you manage before you miss one. If you miss one re-start and begin the count from zero once again. How much is 1000 words? Well, today’s post is 691 words long. It doesn’t take much time to read that many words, but I have found that if I read that many I often keep reading the article until I either reach a natural breaking point or finish the article. Some days I read quite a bit more, others I just barely make the goal (do I actually count the words? No, not any more. And when I did at the beginning of the first time I undertook the challenge I didn’t count all the words, just how many words were in the first line of a paragraph, and how many lines long it was to calculate a rough word count for the paragraph, and then figured out how many paragraphs of that size it would take to reach at least 1000 words. It isn’t the precision that matters, but the consistency of actually reading (and thinking about what you read!) every day.

Since I started this time I have remembered to read every day. This has been easy during the week days since my job begun—the pile of literature I need to read and understand in order to get my knowledge base to where it needs to be for my research project is quite substantial, and growing all of the time as I find references to more and more articles I wish to read. Managing it on the weekends is a bit more of a challenge, but I have managed, so far.

So, what have I read over the past 60 days? I have completed reading six articles that relate directly to the ore deposits in the area near where my project is based (ok, one of those wasn’t a single article, but rather a PhD thesis which was comprised of five different papers, so really I have done 10 articles total on this subject), four articles on the concept of 3D modelling, and one article on geochemistry.

That last one (MacLean 1990)* explains how one can use ratios of immobile elements to calculate what the unaltered composition of a suit of altered rocks must have been. I am gathering from my reading (many of those local papers cite this technique paper) that this is a very useful way to determine what types of rocks were present before the hydrothermal alteration associated with the formation of ore deposits. It works especially well when the precursor rocks are volcanic and changed in composition due to fractionation of the magma. When this is the case one can plot the current compositions on the same diagram as the curve which shows the expected changes in composition due to fractionation, and extrapolate from the trends in the current compositions back to the likely original compositions when the rocks cooled from their magma. The paper mentions that these sorts of calculations are easy to set up in a template in a spreadsheet, and that they will give away such templates upon request. I wonder if that offer is still open two decades after the paper was published, or if people use a different technique to accomplish the same sort of task today. I will have to do a search for papers which cite this one to work my way forward to the modern techniques, if they have changed. What did people do for research before it was possible to easily look up who had cited a particular paper?

*MacLean, W. H. (1990). "Mass change calculations in altered rock series." Mineralium Deposita 25(1): 44-49.

The next adventure has been revealed

As of 1 November I shall be employed again. True to my pattern thus far it will be for something I have never done before. My Master's research was a structural geology project focusing on the deformation style and timing of a specific fault in the Brooks Range, Alaska. My PhD research focused on the metamorphic history of all of Tasmania, my first post-doc position introduced me to experimental petrology as a tool for understanding subduction zone processes. Now I am about to start a research position focusing on 3D (and 4D) geochemical modelling of VHMS ore deposit systems in northern Sweden.

This will be a project with a steep learning curve for me since the last two projects focused on metapelitic rocks and now I will need to learn the intimate details of volcanic rocks and what happens when they not only contain ore deposits but also have been subjected to greenschist facies metamorphism.

Needless to say, I left the meeting where I accepted the job offer with a bit of light reading in hand—one textbook: Introduction to Ore-Forming Processes and one PhD thesis: Volcanic Stratigraphy and Hydrothermal Alteration of the Petiknäs South Zn-Pb-Cu-Au-Ag Volcanic-hosted Massive Sulfide Deposit, Sweden. This thesis contains cross sections of one of the important deposits in this area—my project will be to take this sort of research to the next step—modelling the actual volumes involved in 3D.

I will look forward to reading these during the next couple of weeks before the job actually starts—in theory I will be in a much better place to hit the ground running by doing so. If any of you have suggestions for things in the literature that I really should read if I hope to do well with this research feel free to share them here. It is time to start reading 1000 words a day from the geologic literature again. I stopped at the end of last year when my job ended and haven't picked it back up during my extended vacation between jobs. I have enjoyed the holiday, but it is time to refocus on science and learning.

motivation, 1000 a day, and winter holidays

A year and a half ago I was finishing up my PhD thesis, working really, really long hours and totally focused on the one goal: finish up before boarding that plane on my way to my first post-doc position. Many of my friends commented at how motivated I was, and I replied that plane tickets are a huge motivator.

Jump ahead to the present and I once again have plane tickets waiting for me at the end of the month, but this time they are taking me to visit friends in Scandinavia and enjoy some real winter weather while I keep applying for jobs. Since my friends will have jobs to go to during the days the prospect of not being quite finished with my current research isn't as worrisome as the prospect of not completing that thesis before boarding the plane to head to a job—I know that it will be possible to keep working, even once funding ends. As a result I have not been putting fort the same sort of concentrated effort I did a year and a half ago, but am instead permitting myself some distractions.

One of the biggest distractions, of course, is the need to continue to apply for all of those positions which sound interesting and related to any of the research I've done to date. Each of these applications takes time, and each has a deadline by which if I have not yet applied they will not consider me for the position. One of the other distractions has been my social life. I flew to Scandinavia on the last weekend of November, and to the UK on the first weekend of December. Both trips were to attend events focused on Medieval Dancing. I very much enjoyed both trips and got to renew some old friendships and make some new friends.

Prior to the first of those trips I had been wondering what to do about my 1000 a day—I had chosen to fly carry-on only, and wouldn't be bringing my computer—this means that I'd need to actually print out a pdf or bring a text book so that I'd have something with me to read from the geologic literature. Sadly, a couple of days before my trip I forgot to read my 1000, thus ending a streak of 321 days in a row. My record, by far, and I am pleased to have achieved it. But oh, wouldn't it have been nice to manage an entire year in a row of reading 1000 or more words from the geological literature?

I know how it happened that I forgot, too. Much the same way as the last time I broke a record-breaking streak. Step one: get into the habit of reading your 1000 right before bed for many weeks running. Step two, switch to reading during lunch for a week or three. Step three: encounter a particularly busy day, with no time to read your 1000 during lunch. Think about it a couple of times during the day that it still needs doing, but only while actively in the middle of another, important task. Finish up everything else for the day, do yoga, brush teeth, crawl into bed, and pick up some fiction. Read till you sleep, and don’t remember that the 1000 hadn't been done till you wake.

Having forgotten I then made a decision to take a hiatus from reading my 1000. I will start back up after the first of the year, but I am taking December off (I wound up taking off much of last December, too, as I traveled and visited friends and family after attending AGU). It is strangely freeing to have one fewer "must do" on my list each day. However, I strongly suspect that I will be very happy to start that task back up again with the New Year.

timing is everything

I really should sit down and ready my 1000 words a day of geologic literature earlier in the day. Often what I read is inspiring and makes me want to go and do things for my own research. But, when I read it late at night, like tonight (and, I confess, many other nights as well), I’m too tired to follow through with the inspiration. Sadly, by the time I’ve slept and started a new day I’ve often forgotten the feeling of inspiration and nothing comes of it. Perhaps by stating this publicly I’ll revise my habit accordingly and gain the benefit thereby.

today’s vocabulary lesson

While reading my 1000 words of geologic literature today I encountered the sentence “However, these data may be the result of sampling mixtures of discrete fabric elements. Thus, the age of the older event is equivocal”. Since I was doing “active reading” (typing up a summary of each paragraph in my own words), I decided that I’d best actually look up “equivocal”, since while I *thought* I knew what it meant, I wasn’t willing to swear to it. So I checked the on-line Oxford English dictionary:

equivocal, a. and n.

A. adj.

1. Equal or the same in name (with something else) but not in reality; having a name, without the qualities it implies; nominal. Obs. (dates back to 1643)

2. Of words, phrases, etc.: Having different significations equally appropriate or plausible; capable of double interpretation; ambiguous. (dates back to 1601)

b. Of evidence, manifestations, etc.: Of uncertain bearing or significance. (dates back to 1969)

c. nonce-use. Of a person: Expressing himself in equivocal terms. (dates back to 1601)

3. Of uncertain nature; not admitting of being classified, ‘nondescript’. equivocal generation: the (supposed) production of plants or animals without parents; spontaneous generation. (dates back to 1658)

b. Of sentiments, etc.: Undecided, not determined to either side. Chiefly in negative sentences. (dates back to 1791)

c. Music. equivocal chord: one which may be resolved into different keys without changing any of its tones. (no date given)

4. Of advantages, merits, etc.: Dubiously genuine, questionable. (dates back to 1797)

5. Of persons, callings, tendencies, etc.: Doubtful in character or reputation; liable to unfavourable comment or description; questionable; suspicious. (dates back to 1790)

B. n. An equivocal word or term; a homonym. (dates back to 1653)

I find it fascinating that a word which comes to us from “equal” means “uncertain” (which, from the context, is the best match in this case).

New, improved list of mineral abbreviations

I just found out about a newly published list of mineral names. A fairly high percentage of the geologic papers I’ve read have cited the 1983 paper by Kretz, Symbols For Rock-Forming Minerals, as a quick and easy way to state what they mean by the various abbreviations they used for mineral names, rather than wasting words in the paper stating that garnet is “Grt”, etc. However, 1983 is a rather long time ago, as far as papers are concerned, and that article listed only 193 minerals. Therefore I was delighted to hear about the newly published Abbreviations For Names of Rock-Forming Minerals by Whitney & Evans 2010. Their list expands on the 1983 list, giving us 371 mineral names to choose from (still only a drop in the bucket compared to the over 5,000 which are known, but this list includes the major rock-forming minerals). Like Kretz before them, they chose a format wherein all abbreviations consist of two or three letters (or rarely four if truly necessary to distinguish it from another). Unlike Kretz they also required that none of the mineral names conflict with the abbreviations used for elements of the periodic table (therefore, while they mostly keep the forms suggested in 1983, occasionally they changed them).
This expanded list will be very handy, and I’ve already copied it into an Excel spreadsheet and adjusted the formatting such that I can see the complete list on a single page.

Word of the day

While reading my 1000 words of Geologic Literature today I encountered a word with which I was unfamiliar: palimpsest.
According to the on-line Oxford English Dictionary the orginal sense of the word (when used as a noun) is as "Paper, parchment, or other writing material designed to be reusable after any writing on it has been erased. Obs."—this form dates back to 1616. By 1825 the word had evolved to mean "A parchment or other writing surface on which the original text has been effaced or partially erased, and then overwritten by another; a manuscript in which later writing has been superimposed on earlier (effaced) writing." By 1845 the word had also expanded to apply to "a thing likened to such a writing surface, esp. in having been reused or altered while still retaining traces of its earlier form; a multilayered record."
It has also been used (as early as 1876) specifically to refer to "A monumental brass plate turned and re-engraved on the reverse side. Cf. A. 2. Obs.". However, the most interesting uses to my mind are the geological senses of the word: "A structure characterized by superimposed features produced at two or more distinct periods." (1914) and "Of a rock structure: partially preserving the texture that existed prior to metamorphism." (1912). There are also geographical senses of the word: "Of a landscape or landform, esp. a glaciated topography or a drainage pattern: exhibiting superimposed features produced at two or more distinct periods."(1922).
It isn’t often that I encounter a word I don’t already know, and I find I rather enjoy it. There is something nice about being able to open a good on-line dictionary, paste in the new word, and be given not only the meanings, but dates for the earliest use of the word in that context that they could find. In this case I particularly like the development of the word over time first being limited to something humans make/use and re-use and then expanding to other categories. The rock record is full of instances where information is written upon pre-existing information to a greater or lesser degree. Our challenge, as geologists, is to correctly interpret each layer of information and take care not to confuse different layers of information with one another. Particularly when the layers of information may be recorded in so many varied manners.

Active reading can even overcome sleepiness and result in comprehension

I know better than to put off reading my 1000 words a day from the geological literature until late I the day, yet I chose to do so anyway. Today the impulse to do so was triggered by Spring. There were very few people in our geology department today, as most people chose to leave for their Easter long weekend as early as they could. Some of the general staff were here, but were only scheduled to be here till about 2:00 pm. Around the time that they were leaving I noticed that it was a beautiful day, nice and sunny, yet not hot at all, and I felt restless. Therefore I decided to head out on an adventure, and went into the city center to admire the street artists and musicians who perform for the crowds there. I also stopped in the American Book store and picked up a new book in a favourite series.

After these adventures I managed to limit myself to only an hour of reading in the new book before crossing the street to my office again around quarter to nine, intending to finish the work I’d interrupted hours before. Instead I procrastinated by catching up on reading blogs/e-mail/etc, updated my financial records to show today’s spending, and chatted with a friend on line. As a result I didn’t start reading my 1000 till 11:30 pm, and it was difficult to find the discipline I needed to actually complete the process.

However, hard as it was to make myself do, I am now a total convert to this “active reading” thing. The need to type the below notes meant that I had to actually pay attention to what I was reading, and not just sleepily skim over the words catching one in ten. I am positive that focusing on each paragraph one at a time and typing the notes as I go is the only thing that made it possible to understand what I was reading tonight. Perhaps I can understand and retain what I read the “normal” way when I’m high in energy, but this late in the day “active” reading is required. So, without further adieu, I give you the second-to-last installment of my paragraph-by-paragraph summary of the paper I’ve been reading (see a few days back for the citation and the link to the article itself).

The next section of the paper is on the 40Ar/39Ar results.

Paragraph 63 introduces the two pegmatites from which muscovite was obtained for the dating, describes the location of the pegmatites, gives the age results (~47.1 Ma for one and ~46.9 for the other). They state that the samples were obtained from above and below the contact, and are within error of one another. They state that this means that these numbers represent the time of cooling, rather than crystallization. This ends the section on the dating, and also concludes the section on their results. The next section is the Discussion.

Paragraph 64 points out that previous studies described a fault in this area and described the rocks on either side as high-grade on the west and low-grade the east, but this study indicates that what had been called “low grade” has actually undergone sufficient burial to achieve >650 C at 8-10 kbars, or largely the same as the “high grade” Gneiss. They go on to mention that the microstructures near the contact between the two units reveal progressive deformation & a high-T constrictional shear zone between the units, & subsequent overprinting by low-T deformation. They say that therefore this area is complex & important in context with the entire Cascades region, and for strike-slip dynamics in orogeny.

This concludes the lead-in portion of the discussion; the next section is on the Previous interpretations of Ruby Mt-Elijah Ridge tectonic history.

Paragraph 65 names three different studies which have addressed the tectonic history of this area. The first called this area a suture of Insular and Intermontane belts since it puts ocean rocks structurally above continental arc rocks. The second calls it a tectonized intrusive contact without a through-going fault, saying tilting is enough to expose the largely intact Mid-Cretaceous section, and add in one more fault to account for the change in pressure across the area. The third described this area as a major tectonic boundary, since there are mylonites present in addition to the difference in metamorphic pressures.

Paragraph 66 gives one other possible interpretation (calling this area the uppermost part of the flowing orogenic crust with the Napeequea unit acting as a rigid lid of a layered crust. They describe this interpretation as analogous to migmatite-upper crust relationships observed in the hinterland of the orogen, and cite a source (but from the sentence itself it isn’t clear if the source proposes this interpretation or simply describes the relationships in the analogy). They then state that all four models can be considered in light of their new data. This concludes the section on previous interpretations. The next section is the Re-evaluation of Ruby Mt-Elijah Ridge tectonometamorphic history.

Paragraph 67 describes the units in this area (orthogneiss dominating, Napeequea over it on Ruby Mt. and part (west end) of Elihah ridge, and Methow rocks above it on the east part), the dip (35-45 to the east) of the planar fabrics of bother Napeequea rocks and orthogneiss on Elijah Ridge while the far east side of the ridge is folded (= different deformation style across the ridge).

Paragraph 68 specifics that the low-T fabric overprinting migmatite seen in the microstructural analysis occurs only in the structurally deepest part of the exposed orthogneiss at the base of Ruby Mt. the only other units to show such overprint is the tonalitic amphibolite at the Skagit Gneiss-Napeequea contact .

Paragraph 69 contains too much information for one paragraph. It states that the strain gradient near the summit of Ruby Mt. displays more constrictional fabrics near the contact between the Skagit orthogneiss and Napeequea units (both of which are L-tectonites). It mentions the pegmatite which intrudes both that was deformed and cooled at ~47 Ma. It lists the clues which lead them to conclude that the shear zone is a medium- to high-T feature. It acknowledges some lower T-overprinting in a few of the units. It suggests rheologic contrast as the cause of the shear zone, but doesn’t decide between shear zone formation during or after emplacement of the orthogneiss. It suggests that the shear zone is an old contact which preserves the early high-T deformation of both units, further suggesting that the deformation either developed along or transposed the intrusive contact.

Paragraph 70 mentions the contacts between these units in other areas, the fact that the quartzite and schist of the Napeequa unit is generally more deformed than is the orthogneiss, suggesting that the composition of each is likely responsible for that difference. It then states that the contact exposed on Ruby Mt. is the one showing the most intense high strain fabrics.

This is not a section break. However, there are no more section breaks in this paper, save for the one which precedes the final paragraph, and I’m at 1000 words read today, and 1000 more left before the end of the paper. Therefore I’m going to stop here and pick it up with the next paragraph tomorrow.

getting faster

I just read and took notes on the next section of the paper I’ve been “actively reading” for my 1000 words a day from the geologic literature, and am pleased to note that while I read well over 1000 (bringing yesterday’s and today’s combined total over 2000 words), it took just under 35 minutes to do so. I don’t know if this is because I’m becoming more comfortable with the process of active reading and typing up notes on each paragraph I read as I read them, or if these notes are less extensive than those for the earlier section, but I’m hopping it is just a matter of practice making me more efficient. I am willing to make 30 minutes a day, every day for this goal, but the over an hour I spent the first time I tried this technique might be asking a bit much.

I don’t know if anyone is actually reading the notes I’ve been posting, but I shall continue to post them till I reach the end of this article. If it should happen that someone tells me that the notes are interesting and/or helpful, I could easily be talked into continuing to post them for future articles I read, too. However, I suspect that for most people who are looking for interesting blogs to read one article summarized one paragraph at a time will be plenty. Feel free to let me know if I’m mistaken on that point.

Today’s notes are from the section on microstructural analysis:
Paragraph 53 introduces the locations from which the samples were collected for microstructural analysis and gives the goals for this portion of the study (understand mechanisms and relative timing of juxtaposition of the units)
Paragraph 54 mentions which samples were chosen for electron back scatter diffraction, gives details of what was found and compares and contrasts the results from the leucosome and mesosome layers of the sample. They go on to offer a tentative (since there weren’t enough samples analyzed to be confidant) interpretation (possible late shear zone affected the structurally deepest exposed rocks)
Paragraph 55 names a sample chosen for EBSD, reiterates that it is from the Skagit Gneiss), gives published U/Pb zircon age for this sample (which is younger than for other Skagit Gneiss samples), and describes the areas in this sample for which they made EBSD maps.
Paragraph 56 lists the results of the EBSD analysis for this sample (including strong crystallographic preferred orientation, prism slip for quartz (both regions of sample), sub grain rotation and recrystallisation (in shear zone), different grain sizes in different regions.
Paragraph 57 describes an effect (some qtz not deformed adjacent to larg plg grain) which only shows up in EBSD map, not via traditional optical methods. It also points out that such variety in qtz textures could indicate qtz deformed at all T and may have preserved evidence for more than one condition.
Paragraph 58 gives EBSD results for a new sample, from a new location.
Paragraph 59 mentions that the above sample has overprinting which doesn’t show up in higher parts of Ruby Mt. (instead the higher parts preserve high-T fabric with not much qtz recrystalization).
Paragraph 60 discusses textures in the structurally highest regions of Skagit Gneiss, and interpret them to indicate that the shear zone is a high-T feature.
Paragraph 61 more EBSD results this time for another couple of samples, comparing and contrasting them with each other, and with the other samples in the area. Interprets the results to indicate that the quartzite may have taken up much of the low-T deformation in this area
Paragraph 62 gives the EBSD results for samples from the RLFZ because they feel that understanding deformation in the fault zone will help interpretation of the role of the fault in burial and exhumation. They point out the similarities between these samples and the above.
Here ends the microstructural analysis section. I found it slightly hard to follow in terms of understanding which samples/areas were being discussed when, but that was because I hadn’t made notes about the sample names/locations in my pre-reading familiarization session. Nonetheless, I think that sub headings might have helped.
The next section will cover the 40Ar/39Ar results.

Quality is better than quantity

The section of the paper I read today is just under 1000 words, but the next section of the paper is a long one—if I read on it will be over 2000 words of reading for the day. While that is not necessarily a bad thing in and of itself, I do have other things I need to do with my day, so I will choose to cut today’s total # of words a bit short, knowing that today and tomorrow will combine to meet the goal of reading “1000 words a day”. It is the sprit of the law which is more important than the letter in this case, and I feel that the “active reading” I’ve been doing, summarizing the contents of each paragraph as I read it, and before going on to the next paragraph is more than good enough in terms of quality of reading comprehension and retention to make it reasonable to break at a section break, rather than at an exact word count.
So, without further adieu, here follows my summary of the paper I’m reading. See the past few days for the earlier sections, and stay tuned tomorrow for the next section.
The next section covers Thermometry and Barometry. They present thermometry first.
Paragraph 44 lists the three techniques they used to calculate metamorphic temperatures. They specify that unzoned garnet and matrix biotite compositions were used for one set of calculations, that garnet core + green matrix hornblende and garnet rim + blue-green hornblende was used for the other, and they don’t specify here what minerals were used for the Thermocalc compositions.
Paragraph 45 reports temperatures of 700-800◦ C for the grt-bt schists of Ruby Mt. and 675-730◦ C for the grt-hbl in the amphibolites. They say that the amphibolites above and below the contact between the Skagit Gneiss and the Naeequea give results within error of one another.
Paragraph 46 reports for Elijah ridge 650-700◦ C for both ky-st & and-crd schist and 570-670◦ C for the amphibolite. They specify that Elijah Ridge gives lower temps than Ruby Mt., but point out that errors are ~50◦ C so it is hard to say if difference is real. They also point out that the andalusite is a late phase, so the T pre-dates that mineral’s growth.
That concludes the thermometry section, the next section is barometry
Paragraph 47 lists the three barometers used, and specifies that garnet core and matrix plag gave max P. They also state that they usually assumed that kyanite is the stable Al2SiO5 polymorph, and named the one exception to that.
Paragraph 48 states that most samples from this study yield pressure estimates of 8-10 kbar, which agrees with previous studies in the area. They state that while Elijah Ridge gave slightly lower results, they are still within error of the others.
Paragraph 49 addresses garnet zoning, pointing out that only along the eastern margin near the RLFZ can one find garnet that has discontinuous zoning in the grossular component (see pretty maps of fig 8)—they state that this pattern could relate to GASP reaction of coexisting grt and plg, in which case the increase in Ca towards garnet rims equals an increase in pressure as they grew. They go on to specify that structurally deeper samples have homogeneous garnet or only a thin retrograde rim zoning. They further state that the above mentioned zoned(Ca) garnet eastern margin samples saw lower T than the ones with homogenous garnets, and say that the zoned ones might be a better record of the prograde history and they also seem to have a more complex later history given magmatism and faulting associated with RLFZ. (This paragraph was the hardest to summarize yet, being packed full of lots of information and not flowing from one thought to the next as well as it might.)
This ends the section on Barometry. The combined section on Thermometry and Barometry includes a figure showing all of the above P/T results—the individual error squares overlap from one to the next, giving a range that is visually continuous, despite the fact that the lowest and highest individual samples don’t overlap. The next section is on P-T paths.
Paragraph 50 mentions three lines of evidence for different stages of the PT path: 1) evidence for pre-andalusite conditions for the andalusite-cordierite schist with 2) garnet rims showing increase in P for those rocks. 3) the fact that kyanite used to be present in all samples, so max P had to be in kyanite zone. They go on to state that the max P/T reported in last section was followed by near isothermal decompression to less than 5 kbars while T was still high.
Paragraph 51 lists textures which point to metamorphic reactions continuing during decompression. Two of these textures are observed in this study, and they mention that their observations are in agreement with a previous study, and list other lines of evidence from that study.
Paragraph 52 states that the P-T results from the eastern side of Elijah ridge are for conditions which preceded a low-P metamorphic overprint. It also equates the P with depths of ~25-33 km, which is equivalent to results from farther to the west in Skagit Gneiss.
This ends the P-T paths section. Their proposed path focuses on the max P/T conditions followed by decompression while T was still high. The next section is on microstructural analysis.

Yes, I think the extra time is worth it

I find that I’m liking this “active reading” stuff. It used to be that on days like yesterday, when I didn’t get around to reading my 1000 words of geologic literature till very late in the day I’d “read” it, as in my eyes would look at each word on the page, but it was more along the lines of “skimming” it, and it is somewhat doubtful how much, if any, was actually retained. Yesterday, however, I actually got meaning out of each and every paragraph I read. I know this, because it isn’t possible for me to type a sentence or three about what it says if I don’t understand it first.
Normally I’m a two-monitor kind of person. If I need to read something and type notes about it, I keep the article on one screen, and the word-processor on the other. Yesterday, on the other hand, that wasn’t possible. I’d spent the day using the electron microprobe and when it was time for the ‘probe’ operator to head home for the day I was tired, so I simply took my computer home with me, rather than bringing it back up the stairs to my office. As a result when I realized hours later that I still needed to do my 1000 for the day (I’m at 82 days in a row now this time!) I was faced with the choice of dealing without a second monitor or carrying the computer back to my office.
The solution I hit upon worked very well—I’d copy-paste a single paragraph into the document in which I was working, read it, type up my summary, then move that paragraph into an otherwise empty document. At each minor section break I’d do a word-count of the document which contained only the paragraphs I’d already read, to see if I’d done 1000 yet. As it turns out, I hit 1053 words at one of the minor section breaks, to the notes below don’t end in quite as logical of a place as the previous batch, but I was tired (Europe only just did the change to daylight savings this weekend), so called it good. It is interesting to note that my summary, including the headings “Paragraph 1, 2, etc.” took 581 words to summarize the 1053 words of the original.
When first I started reading 1000 words a day I thought of it as a 20-minute time commitment. Reading this 1053 words and typing up a summary took 54 minutes. Therefore it takes nearly three times as many minutes, but I think that the gain is more than four-fold the amount of information retained.
Here follows the summary in progress for the article Metamorphism and deformation at different structural levels in a strike-slip fault zone, Ross Lake fault, North Cascades, USA by Gordon et al 2010:
Paragraph 18 informs us that it can be difficult to find appropriate mineral assemblages for P-T estimates in the Skagit Gneiss. They mention a previous study which used 4 metapelites, and tell us that this study found 4 useful metapelites and three garnet amphibolites between the Skagit Gneiss and the Napeequa unit.
The next section focuses on the garnet amphibolites
Paragraph 19 specifies the locations for the three garnet amphibolites that yielded PT estimates and gives the units thereof.
Paragraph 20 mentions which two amphibolites (from Ruby Mt.) are migmatic adn which one isn’t (from Elijah Ridge) and gives the mineral assemblages and fabric.
Paragraph 21 describes the garnet in one of the amphibolites, giving size, general composition, mentions that it isn’t zoned (and states that this is normal for the unit), list of inclusions, and the fact that some of them display post-kinematic coronas.
Paragraph 22 describes the garnet from one of the two other samples in the other unit, mentioning their size (smaller than last paragraph), and the fact that minor growth zoning is present, and points out that the final sample is very similar to this one.
Paragraph 23 describes the hornblende of all three samples, two of which have zoning (just like the garnet from the same unit), but zoning is rare in the other sample (just like the garnet from that sample)
Paragraph 24 mentions the zoning of the plagioclase in all three samples, states that for the Ruby amphibolites the reverse (An increase to rim) zoning is more common & more variable than the normal (An decrease to rim) zoning that is present.
Paragraph 25 describes the plagioclase zoning for the Elijah ridge amphibolite, which also has more reverse than normally zoned examples. However, in this case the normal zoning is more variable than is the reverse.
Paragraph 26 mentions which sample contains clinopyroxene, and the fact that it isn’t zoned and is both in the matrix and as inclusions within the garnet.
Here ends the section on the minerals present in the amphibolites. The next section looks at the metapelites.
Paragraph 27 lists the locations (2 from Ruby Mt, and 2 from Elijah Ridge) and general assemblages of the four metapelites used in this study, and specifies which ones are structurally higher than their neighbors, and which pair is structurally higher than the other.
The next section focuses on the Ruby Mt. Metapelites.
Paragraph 28 lists the major (grt-bt-sil-ky-crd-qtz-pl) and accessory (il-zr-apt-mnz) minerals present in these rocks and point out that the sillimanite one has pseudomorphic textures hinting at former kyanite while the kyanite bearing one has some sillimanite. It also specifies the habits of the cordierite
Paragraph 29 describes the fabrics present, and where possible mentions what that says about the T at which each deformation happened.
Paragraph 30 describes the habits of garnet in one of the samples (including what is included therein) and cordierite and points out evidence for a retrograde reaction of grt-crd.
Paragraph 31 continues with the same sample as last paragraph,stating that plagioclase isn’t generally zoned, the biotite is homogeneous, and describes alignment of sillimanite with the foliation. It also reminds us that kyanite used to be stable in this sample.
Paragraph 32 moves on to the other sample, lists minerals present, compares garnet, plag, and biotite with last sample, describes the kyanite and sillimanite present.
There ends the description of the minerals in the metapelites from Ruby Mountain. The next section will describe those from Elijah Ridge.

Geospeedometry

Today whilst reading my 1000 words from the geologic literature (61 days in a row this time, and counting) I encountered a term that either I have never seen before, or I somehow managed to overlook it on other occasions. “Geospeedometry” was coined by Lasaga (1983), who related the cooling rate calculated for minerals based upon the diffusion of atoms within minerals with the time it takes for the “exhumation” of the rocks within which the minerals grew. What does this mean?

Metamorphic rocks form when any preexisting rock is subjected to increased temperatures and/or pressures for sufficient time to grow new minerals which are stable at the new conditions. One very common way for this to occur is for the rock to be taken sufficiently deep below the surface of the earth that both the temperature and pressure are elevated. If it were to happen that a package of rocks were to be taken to such pressures and temperatures and held there until all new minerals grew to replace the original minerals, and then those rocks were to be very slowly brought to the surface so that new minerals continued to grow to replace older minerals during the changing conditions the ultimate result would be a rock which contains only minerals which are stable at surface conditions. However, it happens often that the metamorphic rocks containing minerals which grew at elevated pressure and temperatures are brought back to the surface too quickly for those minerals to be replaced by their lower pressure/temperature counterparts. As a result we have a record of the conditions at which the metamorphism happened. The process of bringing the rocks back to the surface is called “exhumation”, and it refers to great quantities of over-lying rock going away (often due to a combination of faults bring up underlying rocks, and erosion carrying away broken bits of overlying rocks).

Ever since geologists realized that each mineral has a specific range of temperatures and pressures at which it will grow people have been attempting to figure out how to relate the list of minerals present in a given rock with the temperature and pressure at which it formed. The next logical question after the conditions of formation have been determined is one of “how long”. How long did the minerals take to grow? How long (or how quickly) did it take to get this rock from where it formed to the surface of the earth? Those people who study compositional zoning in minerals and calculate the rate of diffusion of atoms within the minerals and who then relate those numbers to the time it took for the diffusion to occur describe what they are doing as “geospeedometry”. Since the term was coined in 1983 there have been 52 papers which list that term in their title, abstract, or key words that have been entered into the Scopus database. One each published in 1983 and 1984, and then a six year break before the next was published. Since 1990 there have been one to five papers on geospeedometry published a year, save for 1993, which didn’t have any.

It is interesting to me that even after completing a PhD and making a point to try to read papers from the geologic literature on a daily basis, I am still encountering terms that are new to me, though they have been around for decades.

Lasaga AC. 1983. Geospeedometry: an extension of geothermometry. In Kinetics and Equilibrium in Mineral Reactions, ed. SK Saxena, Adv. Phys. Geochem., 2:81–114. Berlin: Springer-Verlag

filling in the gaps

One of the biggest disadvantages of having taken off a number of years between my Masters and PhD projects is that I had time to forget much of what I had learned in the way of mathematics and its application to the other sciences (use it or lose it!). As a result I have found myself skipping over the formulas and calculations presented in many of the papers I’ve read. This is, of course, a very bad habit, because if one doesn’t think about what those various symbols mean one doesn’t understand what the author of the paper was attempting to communicate.

Sometimes the text contains enough detail that one can manage without that bit of information; other times they let the equation stand alone as the most precise way to express the relationships in question. One solution I’ve used in the past to help understand equations given in a paper is to create an Excel spreadsheet in which I can set up formulas which point to other cells into which I can enter their numeric data to see if I can get the formulas to yield the same results that the authors reported.

However, this technique doesn’t lend itself very well to understanding general equations for which we have no actual numbers to substitute into the equations to solve them. Today I decided to set up a Word document to help me dissect and understand the formulas. The format I’ve decided upon is to use the Outline view mode with the first rank of the outline giving the name/number of the equation and the source paper in which I found it (e.g. Equation (2) from (Tirone and Ganguly, 2010*). Then, below that heading I add a paragraph which gives the equation (e.g. r_i = k₁√D(t-t_n(i))). Below that I add a series of level-two headers for (1) what the equation means in plain English (e.g. “The crystal radius is equal to the quantity of a dimensionless constant times the square root of the coefficient of intergranular diffusion through the matrix of the growing crystal times the amount of time which has elapsed since the crystal started growing.”) followed by (2) a “because” header which lists the definition of each of the variables

In this example:

r = crystal radius

_i = specific (growing) crystal in question

k₁ = a dimensionless constant

D = coefficient of intergranular diffusion through the matrix of the growing crystal (_i)

t = time

t_n(i) = the nucleation time of the crystal

Followed by (3) a summary of what one would use the equation to do (e.g. Calculate the relationship between the size of the crystals and how long it took them to grow.)

Setting this up and filling it in for the equations I’ve encountered in today’s 1000 words of geologic literature has really underscored my need to refresh my memory about basic chemistry. The equation (3) from the same paper as the above example was no where near as easy to fill in, because the authors first stated “The diffusion coefficient is expressed as a function of temperature according to the Arrhenius relation D=D_oexp(−E/RT)” after which they gave a new equation created by substituting the Arrhenius equation into their equation (2). In the text which followed they did not define any of the new terms which come from the Arrhenius equation. Presumably because the reader is assumed to already be familiar with said equation.

Therefore I took down my undergraduate Chemistry text book and looked up the Arrhenius equation. I found it necessary to read a couple of sections leading up to that equation as well as the section in which it is introduced in order to feel like I understood what the textbook was describing. Next I will need to figure out how the version of the equation the authors of the paper presented relates to the version in my textbook.

Is any of this really necessary? Could I just go through life not really understanding the equations I see and just jump to the part of the article where the authors describe what the results of their calculations mean? Perhaps I could. However, I think I will be a better scientist as a result of my going back and filling in these gaps in what I retained from my undergraduate education as I find them.

*Tirone, M. and Ganguly, J. (in press (downloaded Feb 2010)). "Garnet compositions as recorders of P-T-t history of metamorphic rocks." Gondwana Research.

starting the day right

Compared to the rest of my family, I am a morning person. I am able to wake up instantly, and without being grumpy about it. This trait has become enhanced in recent years as I have discovered that my morning series of sit ups, leg lifts, twists, etc. all conspire to get my blood flowing and brain functioning, even when I didn’t get as much sleep as I might have liked (because I am also a bit of a night-owl, with a tendency to stay up late working on projects, reading, or visiting with loved ones. However, despite my ability to function in the morning, I also prefer a slow start to my day, and I consistently choose to start my morning with the more passive entertainment of reading e-mail/blogs/facebook/livejournal while eating breakfast (and for some time after the food is done) rather than the active options of replying to any of the above or working.

Given that I’ve always been one to read while enjoying my breakfast (going all the way back to reading the cereal boxes when I was a child), the surprising thing is that it has taken me so long to hit upon the idea of combining my reading of 1000 words a day of the geological literature with my breakfast reading session. In the 2.6 years since I first set myself this goal I have mostly done my “1000” at the end of the day, before going to sleep. Occasionally, it would be done during the course of my working day as it became necessary to look something up for my own writing. As a result of the random time of day it has happened fairly often that I would occasionally forget and miss a day.

This month (after taking most of December off from reading my 1000 words a day while I was travelling and visiting family and friends in Alaska, Seattle, and California) it has finally occurred to me that the best possible transition from by breakfast social networking reading to work is to first check the geoblog sphere for interesting posts and then do my 1000 words a day. By the time I’m done with my 1000 I have made the mental transition from wondering what my on-line friends have been up to recently to thinking about geology and why I find it exciting. In turn this helps me get ready to actually do some work for the day. This time it has only been 23 days since I started my current count of reading 1000 words of geologic literature a day, but I am hopeful that this time I will break my previous record of 118 days in a row. I think it will be harder for me to “forget” to read over breakfast than at any other time of day.

resolve to return to reading 1000 words from the geologic literature again

Now that I’ve nearly completed my travels (only one more weekend of adventures to survive till I return to Europe and my experiments) I’m finally looking at the spreadsheet wherein I track my progress on my goal of reading 1000 words from the geologic literature every day. It turns out that I have made no attempt to do this since 15 December, which has done bad things to my totals. During the 725 days which elapsed between starting this goal for the first time and submitting my thesis last June I managed to do my reading 96% of the days, with a total of 11 different times I had to re-start my count (normally only missing a single day between counts). In the 206 days since I turned in my thesis I’ve only managed to do my reading on 62% of the days, with nine different re-starts of my count, and up to three weeks at a time not reading. Clearly, I have not been giving this goal the attention it deserves, and it is time to start doing so once again. I strongly suspect that had I made the time to do such reading while travelling, I would also have made the time to do some work, since there is nothing like thinking about what others are researching to inspire one to make progress on one’s own research. Wish me luck in sticking to this goal despite having a large Medieval Themed event on this weekend’s schedule, wherein I will get to visit with many people I’ve not seen in years.

Extending the parameters of my “1000 words a day” challenge

Starting in June of 2007 I set myself the goal of reading 1000 words a day from the geologic literature. The reason I chose to do this was the fact that I had a huge pile of papers I needed to read, and hadn’t been making the time to read any of it. Since then there have been numerous days in which I forgot and had to start over. My count has ranged from a low of accomplishing it two days in a row before missing a day to a high of 118 days in a row (my current count is at 42 days, which is the record for the 113 day period since arriving in Europe to commence my first post-doc position). Last night as I was finishing up my evening yoga in preparation for going to sleep I realized that I’d not yet read my 1000. I further realized that my computer and all paper copies of journal articles and textbooks I currently have in my possession were across the street in my office (I love my 2-minute commute to work!). I considered walking back over to do my 1000, but then I thought about the spirit of the rule. The goal was go get me to read a little bit, every day, so that I actually made progress and stayed current with my self-learning.

One of the things I’m doing here, in addition to my experiments, is taking classes in the local language. I’m dutifully doing my homework each day before it is due, but I’ve not been making much additional effort towards actually learning this language. All of my colleagues are so fluent in English that I can speak at my normal high rate of speed, so I don’t *need* to learn the language to do my job. Likewise when at the market it is easy enough to use the phrase I’ve memorized for “half kilo” and point, and then look at the numbers printed on the cash register to work out how much to pay. Again, I don’t *require* the local language to live my life here. Yet, it would be nice.

Therefore, I have expanded my “1000 words a day” to now be either read (at least) 1000 words of geologic literature in my own language, or spend 20 to 30 minutes translating something. One of my favourite books as a child was Anne of Green Gables . I have read, and re-read that book on numerous occasions. I also own copies of it translated into other languages. I purchased the version in the local language soon after I arrived. Prior to last night I’ve only “read” it—by which I mean open the book and look at every word, forming the sounds they make (either in my head or out loud, depending on if another is present), and looking for words which I can understand due to their similarities to the English equivalent. There are just enough of these that I am able to tell where in the story I am based on my memory of the original text. However, while doing this helps me to get a slight feel for the flow of this language, I’m not learning much. Therefore last night I went back to the beginning and actually took the time to write down each word I wasn’t positive I understood, and looked it up in my dictionary. The first two sentences of the story are long and complex and a half an hour elapsed while I looked up the 23 words I didn’t already know. I then read them out loud once straight through, then again phrase by phrase; pausing to state the English equivalent of each before reading the next phrase. It didn’t help me learn new thing in my primary field, but alternating this technique now and again with my normal 1000 a day will help me better fit into this country in which I’ll be living for another year and a bit, and so, I am happy with this change to the “rules” of the game I’m playing with myself.

pre-conference homework

Having read more than one comment on Female Science Professor’s blog about students who failed to recognize the name of an important scientist in their field when meeting them at a conference, I decided that in addition to preparing a poster summarizing some of my recent research to present at a conference I’ll be attending later this month, I should also have an advance list at the list of delegates who are attending the conference, since the conference web page was nice enough to include one.

Comparing that list with the (Endnote) list of papers I’ve read in the course of my research reveals 10 names of people whose work I’ve consulted who will be attending the same conference as I. I now have a list of those names, and which papers of theirs I’ve got, so I can glance at them again between now and the start of the conference and be reminded of what sort of topics they research. With luck, being familiar with their work will give me topic(s) of conversation should I actually meet them in person, which will be one way to prevent shyness from keeping me in a corner not speaking to anyone. (Mine is the sort of shyness which only manifests itself if I think I don’t know anyone present.)

In the course of compiling this list there were a few people whose addresses in the program do not match the address on the paper I’ve got, so for those people I checked their department web page to see if it listed their publications or research interests, to make certain that the name of the attendee is, in fact, the same person who wrote the paper. This task was worth doing, as I found one where it turns out to be someone with the same name, but different research interests, and another where the list of the things she likes to research is very similar to my own. Therefore she might be an interesting person to speak with about her research.

If I find myself with the time/energy between now and the start of the conference, I may also go through the program looking for interesting sounding talks, not only to mark the ones I don’t wish to miss, but also to see if those authors have papers published which I’d also like to read, but haven’t seen yet. Not that I need more papers, the list of things in my “to read” pile will keep me doing my 1000 words a day of reading for a long time yet.

(Note: for those of you keeping track of such things, I’ve finally settled in to my new location sufficiently that my 1000 a day is, once again, a habit. 17 days in a row, and counting. It isn’t much, yet, but it is a start. Perhaps I might even start blogging regularly again.)

Annotating the figures in the articles I read is ever so helpful, if time consuming

Sometimes, simply reading the text of an article isn’t enough—sometimes it is truly necessary to look at the figures very closely in conjunction with the text to understand exactly what the text is saying about the figures. This is easy when the figure happens to be on the same page, and one’s eye can easily skip from one to the other, without losing one’s place. But, often, figures are located in drastically different parts of the document. With a photo-copy one can remove the staples, and set the two pages side by side (unless it is a two-sided copy and the one is on the back side of the other, of course), but many of us today prefer reading our articles in pdf on the computer screen, rather than wasting paper, particularly given the large number of articles it is needful to read both to stay on top of the current literature in one’s field, and to catch up on the “classic” papers in a field when expanding one’s research into a new direction.

The solution use to make it possible to see both the figure and the text at once is to use the “import” function of my drawing program to open the just the relevant page of the pdf and zoom in on the figure. Then I am able to display the drawing program and the pdf itself open side-by side on the screen at the same time (it is better yet when I have two monitors available!). However, for older articles the pdf often looks like a bad-photocopy (and, indeed, I suspect that in some cases the scan may well have been made from a bad photocopy rather than the original article) so zooming out far enough to see the whole figure at once often makes it difficult to see important details in the figures, but zooming in on details results in pixilation issues, which, again, can make it difficult to see.

This is where opening them in a drawing program can be very helpful, as it is possible to annotate the figure.

The figure above is figure 2 from Kepezhinskas and Khlestov (1977). The original was black and white, of course. The paper discuses Petrogenetic Grids and development thereof (as well as specifically presenting one they developed). In the course of their discussion on the development of such grids they describe an example of how it is possible to use observations of mineral assemblages in real rocks to select between two different theoretically possible arrangements of the lines on the grid. They say:

“For example, for the knot [2] including curves only with positive slopes two alternative versions are shown in Fig. 2. It may be easily seen that for the association Chd+Bt (+Q+Mu) and Cd+Gr+Chl+Mu(Q) the pressure intervals corresponding to their stability fields do not overlap one another. For the version 2a Bt+Chd characterize higher pressures, while Cd+Gr+Chl+Mu lower ones. For the version 2b one has the reverse.”

In my annotations I’ve marked the “Chd + Bt” field with a pink star in both diagrams, and the “Cd + Gr + Chl +Mu” field with a blue one. I’ve also colour-coded the various lines representing the mineral reactions so that it is easy to see how the two diagrams differ, and covered over the difficult to read text of the main labels with my own text (text added by the drawing program is clear and easy to read at any number of zoom levels, unlike the pdf of this document--alas, that layer didn't import into this post, though it shows on the jpg on my screen, so I've replaced the photo with one showing the original text). They go on to say:

"It is well known since Thompson's (1957) work that Gr+Cd+Chl+Mu is possible only at low pressures. On the other hand as reported in the literature, Chd+Bi occurs almost entirely in kyanite-sillimanite type complexes being confined frequently to especially high pressure rock series containing simultaneously glaucophane schists. It seems quite reasonable that the real thing is version 2a.

Simply reading the text, for me, does not create understanding. Combining the text with the colour-coded figure makes it easy for me to understand what they mean, and why they like 2a better than 2b. (Why, yes, I am visually-oriented with a need to “see for myself”; why do you ask?)

REFERENCES:

Kepezhinskas, K. B. and Khlestov, V. V. (1977). "The Petrogenetic Grid and Subfacies for Middle-temperature Metapelites." J. Petrology 18(1): 114-143.

Thompson, J. B., JR., 1957. The graphical analysis of mineral assemblages in pelitic schists. Am. Miner. 42, 842-58.

On the ground in my new location, ready to begin the next adventure

I arrived in Europe on Wednesday, after three weeks of travel, during which I visited with friends and family in seven different US locations on my way here from Australia. This vacation was very much a whirl-wind adventure, trying to see as many different people as I could manage during the time allotted and still have some quality time with people at each stop. I didn’t get to see everyone I might have liked to have seen, but I very much enjoyed the time with the folks I did get to see. During the final two and a half weeks of my mad rush to complete my thesis before boarding that plane to commence my journey I gave up any attempt to read my 1000 words a day of geologic literature. There may have been some days in that period where I did read that many words in the course of looking at the literature in order to reference things as I was writing, but if so, I did not make a note of it in my 1000-words-a-day spreadsheet, I simply did the work as quickly as I could and kept going. Given the hectic, sleep-deprived schedule necessary to complete such a project on a firm deadline like that, it is no surprise that I didn’t re-commence reading my 1000 words a day as soon as the thesis was submitted. Instead I hopped on the plane and then dove into having an active social life (for the first time in months) from the moment my feet hit the ground on the other side. I did start to feel guilty about half way through my vacation about not working on anything related to my research, and started reading my 1000 words a day again. This lasted all of two days before I moved on to the next location and was so busy having fun with friends and family that I quit again. Good habits may be easy to form through regular practice, but they are just as easily discarded by taking some time off, making it difficult to pick them back up again.

The first couple of days at my destination have been devoted to paperwork essential to my getting paid for the work I will be doing (e.g. obtaining a local official number so that taxes may be withheld from my earnings, obtaining a bank account, and turning in forms with these numbers to the university) and moving into the room the university provided me. Somehow, I was kept busy enough that I didn’t even think about starting up my 1000 words a day again. Then, on Friday, my boss gave me a stack of journal articles (in paper) to read, with instructions to make copies and return his copies to him. Not wanting to waste paper, I spent a couple of hours downloading as many as I could obtain in pdf format via University library web pages (16 out of 20!). By the time I was done it was time to attend a BBQ that one of my colleagues on my research team was hosting, so I didn’t make time to actually read any of these articles (though they have all be entered into EndNote and into my “to do” list, with notes as to when they were added and why they are on the list.

So it was not until Saturday, fully four days after arriving at my new job that I actually begun reading my 1000 words a day. Perhaps it was a result of taking the time off, but it felt amazingly good to be reading again! I started with an old journal article, chosen at random from the pile, which contains background information which will be useful for the experiments I shall be undertaking over the course of the next year and a half. I got as far as the first couple of pages, and saw the sketches my boss had added to the margins of table 1, showing the changing tie lines associated with different mineral assemblages, and I recalled the conversation we’d had when he gave me the papers, wherein I explained that I while I was very comfortable with the rectangle diagrams I’d generated for my thesis, showing pressure on one axis and temperature on the other, and which minerals are stable in which P/T zones, I wasn’t terribly comfortable with the triangle diagrams which are so common in metamorphic petrology, which show different chemical compositions on each point, and minerals are plotted within (or, sometimes outside of) the triangles, not having done anything with them for my PhD project.

When he heard that he handed me a textbook from 1979, Petrogenesis of Metamorphic Rocks by Helmut Winkler. This is not a book I’d seen before, presumably having been of the wrong age, or possibly on the wrong continent for it to have been required reading when I was taking classes. Remembering the text book, I set aside the journal article, and lost a happy hour or more skimming over the intro chapters and then focusing on the chapter on Graphical Representation of Metamorphic Mineral Parageneses. I don’t know if this book is more clearly written than ones I’d seen hitherto, or if I’ve simply finally read enough articles and other text books to “get it”, but the triangle diagrams are making much more sense this time. Or, perhaps it is the approach I used this time. Rather than simply reading over the words on the page quickly, I actually took the time to draw my own triangles and attempted to plot the locations of the minerals myself, before looking at the diagram in the book to see if I’d done it right. This method takes *much* longer than just reading the chapter (indeed, I’ve got a fair bit more reading to do before I’ll finish this chapter), but I think that the quality of what I’m getting out of the chapter is worth the extra effort. If I understand my job description correctly, I’ll be generating such diagrams from my experiments, and while these days there are computer programs to do this for me, it is important to understand what they are doing, so that I will be able to notice if a data entry error results in a diagram that doesn’t show what I thought I was plotting.