Thursday, 21 August 2014

Closing down - Ness of Brodgar final day

Not too much to report, aside from the fact I've had a productive and successful, albeit short, field trip this year. I managed to collect 20 large block samples during the week I've been here, which is more than enough to keep me occupied for the foreseeable future. The midden deposits I sampled in Trench T cover the early to late sequence, and hopefully we will be able to distinguish differences in activities and resource use between these phases. Will we see similar things going on here as we see in the main excavation area? Or will there be differences between these two parts of the site? Just some of the many questions we are hoping to answer! For now I will leave you with these fine images of the site being covered over until next year!

More tyres than archaeologists

Tuesday, 19 August 2014

Ness of Innsmouth, Day 2

Dig house in the distance, Stones of Stenness to the right. Ominous rain clouds overhead.

Day 2 at the Ness. I had some things to sort out in Kirkwall this morning so took the local bus to site. It only takes about 30 minutes but it drops off on the main road, and then you have to walk all the way along the peninsula to get to the excavation. Lovely view, but increasingly rainy and windy the further you get towards site, almost as if it’s in its own little otherworldly wet dimension. Glad I invested in an all-weather notebook. On site I’ve been getting on with taking micromorphology samples out of the midden section in Trench T. The excavation in this part of the site is being supervised by Dr Ben Chan, who I previously worked with on the Feeding Stonehenge project. There are other familiar faces from York too – Prof Mark Edmonds and Alison McQuilkin, who recently completed her dissertation on phytoliths from the famous Mesolithic site of Star Carr. The Ness is like a magnet for archaeologists!
Block samples wrapped up

Sampling today has been a bit more challenging that yesterday. Because of all the rain we’ve been getting, the deposits are saturated with water. My usual method for collecting blocks is cutting directly from the section with a knife and wrapping tightly with tissue and tape. This is somewhat different from the ‘standard’ method, which involves shoving a metal tin (Kubiena tin) into a section and working the sample out that way. I like the tissue and tape method as it allows you to choose the size of the sample, according to the stratigraphy; with Kubiena tins you are limited to the size of the tins. From previous experience I have also found that drier deposits can become dislodged easier in tins, and the best method to use varies depending on the deposits. Tins would probably work well at the Ness, as deposits are generally quite compact. Cutting is working quite well but I have to be careful at the interface of different deposit types, to make sure the block doesn’t fall apart! And I have to double the thickness of the tissue I’m using so that it doesn’t tear when it gets wet. This is quite the midden - whereas the middens I worked on at Çatalhöyük were impressive in their depth, this Ness midden is impressively long, covering most of the length of the trench. Ben reckons that it may represent different episodes of build-up that have ‘merged’ into what we can see in the field today. 11 collected so far, working my way down the slope tomorrow!

Monday, 18 August 2014

Return to the Ness! Day 1

Layers of ashy midden deposits sitting on glacial till
A dizzying view of excavations in Trench T
After a small adventure involving delayed flights, gale force winds and navigating with no GPS signal (how did we ever cope before smart phones with Google Maps?), I finally arrived in Orkney yesterday. This is actually the last week of excavation before the trenches are covered over until next year, so it’s all very quiet on site. Most of the students have left, and the remaining teams are working to complete recording by the end of the week. I have had a quick tour around to get a feel for what’s happened since I was here last year, and have spent today planning my sampling strategy. As usual so much is going on and there’s plenty for a micromorphologist to do. This year I am focusing on collecting samples from middens in Trench T. Regular blog readers will have seen the snippets I’ve posted about my analysis of middens in the central excavation areain 2013. Although analysis of the 2013 slides is still in progress, we can already see some interesting features, possibly related to burnt fat deposits, but also small fragments of wood charcoal, which is interesting considering the low volume of charcoal recovered from excavation (is this a result of taphonomy/preservation? Or is it a result of not much wood being used?).

There are two strands to my work. The first is to help resolve questions that arise during excavation related to the formation processes of these deposits and the activities they represent. The second is to examine the nature of resource use, particularly the use of fuel, through the remains that we see in middens, with comparative material from ‘primary’ ash deposits in hearths. Even in the field we can see differences in the thickness, colour and extent of different ‘ashy’ layers. What sorts of fuels are represented? Did this vary seasonally or on longer timescales? How is this linked to fire-related activities such as pottery production?   
Sampling underway in Trench T

Interdisciplinary work is key when addressing questions like this. The team of specialists includes magnetic susceptibility, pXRF amongst others, and to understand these deposits requires integration of all these different lines of evidence. The most exciting bit will be when everyone has completed their analyses, and we get to compare all of our data! Will it tell the same story, or will there be conflicting lines of evidence? And how do the results from on-site analysis compare with what we know about the wider landscape? Pollen records from Orkney have traditionally been interpreted as showing a 'treeless' landscape by c. 5000BP, though the picture may be more complicated depending where on the islands you are looking, and newer studies show woodland may have persisted into the Bronze Age (Farrell et al. 2012)

Wednesday, 13 August 2014

Geoarchaeology at the Crusader Castle of Margat (Qal’at al-Marqab), Syria

I'm pleased to announce the publication of the final article on my work at Margat Castle, Syria:

Shillito, L-M., Major, B., Almond, M., Anderson, E. and Pluskowski, A. in press. Micromorphological and geochemical investigation of formation processes in the refectory at the Castle of Margat (Qal’at al-Marqab), Syria Journal of Archaeological Science

For those without a subscription the final version of the manuscript is also available open access on my academia page here (you'll need to log in).

This is the end product of a pilot study I started in 2010. It was initially envisaged to be a test for a larger program of research, looking at differences in activities and resource use between different phases of the castle's occupation, but unfortunately due to the deteriorating situation in Syria, I was never able to return. I still have the lovely gifts I was given by the Syrians I worked and lived with. I wish there was some way of knowing if they are ok. I have posted about these samples on and off for a while now. I've been working on them in the background, as my main focus has been on other projects and teaching, and I feel especially sad to be packing them away in the 'analysed' box. I might get them out for teaching next year.

As well as being a great site, this has also been an experience for me as informally publishing 'work in progress' reports on my blog, before the final paper was submitted. It's interesting to see how the work developed. I am especially grateful to Hans Huisman, a micromorphologist who got in touch after seeing some of my blog posts and offered very useful advice on some of the features. My first post on Margat was back in 2012, when I gave a brief introduction to my work and our hopes to identify different types of mortar, though in the end that aspect of the research was put on hold as our samples were just too limited to say much. The second was one of my monthly micrographs, showing the different types of basalt pebbles that are frequently seen in thin section. The director of the site thinks that the basalt pebbles were collected from a nearby beach, and we see them used as flooring in some parts of the castle. I used another set of images for another monthly micrograph image, this time showing lime fragments containing forams. You can see why this is such as fascinating site if you are interested in different building materials and technology, there is such a variety of materials used, which I'm sure we could link to different parts of the landscape, to help understand resource use and provisioning of the castle. The real 'work in progress' post was a plea for information, this strange speckled appearance that I hadn't really seen before, and thought might be manganese, turned out to be iron oxide (though there is still a bit of Mn in there). The final post shows dung deposits with metal oxide staining, and explains how my interpretation of these deposits was adjusted after discussion with Dr Huisman.

So there you go, the story behind the paper. I hope it is a useful contribution, and that some day peace will return to the beautiful country of Syria, and that I will be able to meet up with the kind people I worked with, and show them the thin section slides.

Tuesday, 12 August 2014

Doing postdocs in interdisciplinary humanities

I don't really do 'advice' posts that often, but I was inspired to do this after a recent 'mini interview' I did for the Chronicle of Higher Education on what it's like doing multiple postdocs in the humanities. The resulting article is all a bit more doom and gloom than I was expecting, so I thought I would do my own version here that focuses on the positives.

Disclaimers. 1. The Chronicle article I assume is for a US audience, and it's worth pointing out that there is  a terminology difference. Postdocs in the UK, at least in my field, are not really training positions, but contract research jobs. You may get some additional training but that's not the main purpose, and you're expected to be able to do the job from day one. 2. Also I am an unusual case in many ways, as I sit right in the middle of the sciences and humanities, and actually for the scientists in my field it's the norm to do multiple postdocs and fellowships.3.  And my case is probably not a good comparison for researchers in the US, where the whole system is different and the type of postdocs I've done don't exist in the US (as far as I am aware) 4. This is all assuming you even want an academic job, if you're just here for the pretty archaeology and microscopy images, then read no further!

So. We all know the academic job market is tough, and the likelihood of getting a permanent lecturing job (or tenure track assistant professor in the US) is very small. But a discussion of that is not the purpose of this blog. The purpose is to pass on my experience of doing multiple postdocs (and subsequently a fellowship), and how you can make these work for you, if you do intend to head down that long hard road of academia. And if somewhere down the road you decide to head in a different direction, well at least you will have gained professional experience and had a fun time.

Post-doctoral Research Assistant, Associate, Fellow?
A research assistant, you are hired to do the work for a PI. The project belongs to the PI, and you are doing the work they want you to do. An associate, still working on someone else's project, but you may have more of a say in developing the research. A fellowship, you are the PI! This is more of a staff position with a focus on you completing an independent research project that you have designed. It's  like doing your PhD, but you start out actually knowing what you are talking about, you don't have to write a thesis, and you get paid actual money to do it. I love my fellowship. In fact, although I won't apply for any more postdocs, I will apply for fellowships. They are offered for all stages of an academic career, early, mid to advanced. Even people with permanent jobs can apply for them and take a year off to go do research. A fellowship is like creating your own job - you design the project, select a suitable institution and write the proposal. If successful it also counts as a research grant on your CV.

Should I apply?
Getting a postdoc is the same as the rest of the academic job market - not only do you have to be good at what you do, but you also have to specialise in the random area that the jobs happen to appear in. In the case of my first postdoc this was Archaeological Chemistry. This was the only postdoc advertised that year that matched my technical expertise! My advice is, apply for whatever you are qualified for, whether it be lectureships, postdocs or even other jobs in a relevant area. As long as the position allows you to develop your CV and produce publications, all those things you will need to be competitive for a 'proper' academic job.

A postdoc is a great opportunity to develop your network with a new department and research group, so make the most of it. Develop collaborations, co-organise conference sessions, volunteer to sit on committees. Discuss your aspirations with senior staff, and get their advice on career development. Any big name professor who may be able to provide an authoritative reference? Make sure they know who you are and get them interested in your work!

Expanding your research interests
In an ideal world there would be a postdoc that perfectly matched your interests. In reality, it's likely that the jobs will be kinda sort of something you're interested in but not your immediate area. Apply! You may be surprised, a postdoc is also a great way of discovering new areas. I never thought I was interested in medieval archaeology, but after being involved in the Ecology of Crusading project, I've discovered how it links with my broader interests. Both of my postdocs have introduced me to new areas that have subsequently led to my own projects. By working on the Feeding Stonehenge project I learned about the Ness of Brodgar, which turned out to be the perfect case study for one of my projects.

Transferable skills
Have fun doing a postdoc, develop your academic CV, but don't ignore other options. The last thing you want is to spend years doing postdocs, then find it difficult to switch to something else, should you make that decision. There are many resources and websites out there that help you identify your transferable skills, and it's worth thinking about these from the beginning (e.g. Professor Is In focuses on academia). As a fresh new PhD you may think why should you bother, but remember, getting an academic job is not just about being the best at what you do, it's about being the best in whatever specialisms the jobs are in. There are only a handful advertised every year in archaeology in the UK (and not all of them will be in your specialism), so even if you want to be a lecturer, it is likely you will have to do 'something else' to fill in the gaps until the right jobs come up for you!

Thursday, 7 August 2014

Analysing lipid residues in archaeological soil and faeces at the NERC LSMSF

It's been a while since I've been in the lab, but last week I got to spend the entire week working in the NERC LSMSF (Life Sciences Mass Spectrometry Facility) in the Organic Geochemistry Unit at the University of Bristol. I have worked with Bristol for many years now as they have arguably the best set up in the world for archaeological and environmental geochemistry. For this visit I was working mostly on samples from the Ecology of Crusading project, with a few extra coprolite samples thrown in from Catalhoyuk and Durrington Walls (more on those at a later date!). The EoC samples are part of a larger programme of geochemical analysis, designed to look at human impacts on the landscape associated with colonisation in the medieval period. We are looking for evidence of increased faecal inputs (lovely!) associated with clearance of land for pasture, and maybe even human 'sewage' inputs from intensification of activity.

Although I have developed the facilities for pottery residue analysis at my lab in Edinburgh, extracting lipids from coprolites and sediments is a bit more complicated. With pottery, we pretty much are just grinding up the pot and shaking it about a lot in solvent, then looking at everything that comes out. Coprolites and soil hold on to their organic molecules a bit better and they are less soluble, so instead of just shaking them with solvents, we need to do something a bit more extreme. This used to mean leaving samples overnight in a special bit of kit called a Soxhlet extractor, that circulates solvent through the sample continuously. Now Bristol have a new exciting microwave extraction kit that does it all in 40 mins! After extracting the residue, we then need to conduct a serious of steps to break up and chemically modify the lipids, firstly so that we can remove any unwanted molecules (the mixtures are much more complex than we see in pottery and there is a lot of stuff that is not very useful for archaeological purposes), and secondly so that the molecules can be easily detected using the GC/MS. So that's what I spent my week doing - rinsing lipid molecules from very old soil and poop, then doing lots of fiddly chemistry to make them suitable for analysis.

Left: sample in tube (white object is magnetic stirrer) Right: adding solvent to the sample and loading into microwave sleeve
Left: Samples loaded in microwave Right: after microwave solvent is emptied into flask, evaporated, and transferred again into a small vial
Left:small vials are placed in heating block with a stream of nitrogen to dry them gently Right: after they are completely dry, the lipid residue looks like this, if you're lucky!

Monday, 4 August 2014

Micrograph of the Month: Fabulous Fungi

Followers of my Twitter account may recognise these little creatures! I posted the pics separately a while ago to see if anyone could help with identification. So far no response, if anyone has any clues or reference suggestions do let me know. Both are from medieval floor deposits that have undergone significant post-depositional bioturbation. The lower image is one of my favourites. The hyphae are like little tentacles that spread all the way through the sediment. That is the little string like projections that you can see extending from the sporongium. Which is the spherical bit containing all the little spores, and in this particular view is nice and ripe with little spores bursting forth. It is quite creepy to come across all of a sudden when you are looking down a microscope and not expecting it! The one at the bottom has a clear area in the middle, because the top has been abraded away during the thin section preparation process. Basically we are looking at an 'aerial' view of the 'heads' if the fungus, which was standing up at a thickness of greater than 30 microns. In the upper image the sporongium is still quite pale and still in the process of growing. Or at least it was until it was set in resin and turned into a slide.