Friday, 28 December 2012

Christmas Parcels

What excitement is this? Parcels in the post over Xmas! Perhaps more exciting than all the Xmas chocolates and treats? It's the long awaited box of micromorphology slides from Medieval Riga, Latvia! Ok, so maybe not quite as exciting as chocolate, but still pretty fab. I've been waiting for these to be ready since September so it's quite a nice suprise to see them all finished and coverslipped, just in time to get back to work after the holidays. Excuse the camera flash, I will scan them in properly at some point.

Waterlogged and charred plant remains, and also (I suspect) animal dung
Occupation debris accumulated on a medieval floor from the city of Riga

I also got sent a copy of The Archaeology of the Prussian Crusade by Aleks Pluskowski, PI on the Ecology of Crusading project.

Parcels of excitement
This is something else I have been looking forward to - I did a lot of the line drawings for it and it has been very exciting seeing it come together over the past year. Time to brush up on all my background reading to go with all the data analysis for the project. It's a great looking book, and available in paperback at a very reasonable price.

I also got a copy of another Baltic related book last week, largely in Polish but featuring a chapter in English on the environmental remains by myself and other project specialists, I'll be scanning the chapter soon and posting on my Academia profile for anyone who may be interested.

Carson, S., Shillito, L-M., Brown, A. and Pluskowski, A. G. (2012) Environmental assessment of samples from the castle site at Grudziądz, Poland.  Wiewióra, M (ed). Zamek w Grudziądzu w świetle badań archeologiczno-architektonicznych. Materiały i studia. Toruń: UMK.

Tuesday, 18 December 2012

Patience when phytolith processing

Not what you want to see when going to check on samples in the drying oven
This week I've mostly been packing up boxes and boxes of samples and books ready to be shipped to Edinburgh in January, as well as getting on with the final bits of data tidying for the Feeding Stonehenge project, getting it ready for publication in spring. I can't wait to share the details! I was also sent a set of samples for urgent phytolith processing for the Ecology of Crusading project, to include in a preliminary environmental report for the Elbląg project. Phytolith extraction is probably one of the most straightforward lab processes that I do, though it can be time consuming as it involves lots of stages where the samples need to be dried out. Let this be a lesson; ramping up the temperature of the drying oven may help dry your samples out quicker but it may also have unforseen consequences. In this case I have ruined 3 of my lovely petri dishes. Though bizarrely they haven't actually melted or gone soft at all, just twisted and warped. Kinda like Shrinky Dinks. Luckily the samples are fine! I'll be getting on with removal of carbonates tomorrow, How To details coming soon.

For more on the archaeology of Elbląg, check out this blog here: It's in Polish but the google translate button gives you the basic idea - though some of the translations are truly bizarre. The entry on pottery production translates 'fragments' as 'blood' for some reason, giving rise to such interesting phrases as "information on how to manufacture blood" and "Some of the forms of the blood are characteristic of areas in Central Germany".

In other news, my article in Geoarchaeology is now published, which covers the detailed micromorphology results from my PhD and 2 years' additional work on further material. I am so glad this one is finally done, having had it floating around for about a year and a half. There are few suitable journals that allow sufficient word/page count for an epic micromorphology descriptive monster like this, and it has been edited so many times I am quite sick of the sight of it. But don't let that put you off! There are lots of pretty pictures too if that helps, and a bunch of useful refs to other geoarchaeology related work at Catalhoyuk. Co-authored with my PhD supervisor Wendy Matthews. As always, pdf available from me if you don't have access. 

Shillito, L.-M., and Matthews, W. (2013). Geoarchaeological Investigations of Midden-Formation Processes in the Early to Late Ceramic Neolithic Levels at Çatalhöyük, Turkey ca. 8550–8370 cal BP Geoarchaeology: an International Journal 28:25 – 49.

Wednesday, 5 December 2012

Micrograph of the Month - Beautiful Basalt

These are examples of some of the floor deposits from Margat Castle, Syria (you can see the full thin section in my previous post here). The upper left shows A. a microscopic fragment of charcoal, B. A rounded basalt pebble and B. a rounded weathered basalt pebble, all embedded within a calcitic fabric, most likely a lime based material. The upper right shows a lower portion of the floor, where the inclusions are angular. The 'bubbly' shape of part A. suggest vesicles from vitrification. Part B is the inner unweathered core of basalt. The lower left image shows A. smaller fragments of weathered vitrified granite that appear to have been crushed up and embedded in the B. lime floor matrix. The lower right image shows A. a fragment of highly weathered bone in B. a 'pure' lime floor that overlays all the pebbly floors.

At least, that's what I make of it so far! Might have to enlist the help of a geologist to figure out where the materials are coming from and exactly what processes are going on here, any suggestions? I know the nearest beach consists of basalt sand which would explain the rounded pebbles seen in the upper left, not so sure about the vitrified weathered stuff. Margat Castle itself is constructed from black basalt, not sure where it was quarried though - I can't find much online. Might have to enlist a historian as well!

Sunday, 2 December 2012

News from November

Setting up the new microscope lab
November has certainly been a busy month, so busy in fact that I didn't have time to blog about half of what I got up to, so here's a bit of a catch up.

The new microscope laboratory in S-Block at the University of York is now set up (minus the computer needed to run the camera software, but I'm working on that). After several demonstrations from various companies, I am happy we decided to go for the Leica models. Although they are more expensive, the difference in quality is very clear - these are pretty much as good as the top end research microscopes, just without some of the fancy features. For straight forward micromorphology and microfossil analysis, these are fab, and can also be upgraded in future.

Leica DM750P with integrated digital camera
So, just as I get the perfect space set up for my microscopy research and teaching, it appears I am leaving York in January. Though I already technically 'left' in August at the end of the Feeding Stonehenge project, I have continued to be based here whilst working on the Ecology of Crusading project for the University of Reading, and am now an honorary Research Associate. I recently confirmed I will be taking up the post of Early Career Fellow in Archaeology at the University of Edinburgh, School of History, Classics and Archaeology. It will be a very different environment to either Reading or York, but one I am very much looking forward to. There are several colleagues at Edinburgh with interests in Near Eastern archaeology, so it will be great to be able to develop my research in Turkey and Azerbaijan. And although the archaeological sciences are not as prominent as at York, the laboratory space I have available has huge potential - I anticipate I'll be setting up another new microcope laboratory shortly!

Due to some administrative 'hiccups' I will now probably not be attending the WAC-7 conference in Jordan, which is a real shame. Though in a way it is also a relief as it will give me more time to get settled in the new job. However, the exhibition I was hoping to run with Earthslides will be going ahead at some point in 2013 at another conference, so watch this space!

And back to the first conference of the year, and the first post in this blog, the deadline for submissions to the special issue of Archaeological and Anthropological Sciences journal has finally passed. As suspected the majority of submissions were right before the November deadline, meaning a bit of a mad panic sorting out reviewers and whatnot. It is harder than you might think to a) get people to submit papers, even with almost a whole year's notice and b) finding suitable people to review them. But in the end it looks like we have a good spread representing both the conference and the subject in general.

And finally, I have my first publication of 2013 already! Though not sure if it really counts as new, as it was submitted and accepted in 2011. If anyone would like a copy and doesn't have access to VHA, I'd be more than happy to email the pdf. Shillito, L-M. (2013) Grains of truth or transparent blindfolds?Debates in archaeological phytolith analysis Vegetation History and Archaeobotany 22 (1): 71-82

Wednesday, 7 November 2012

A curious incident

Corroding sample!
Yesterday's ICP samples are coming along nicely. I'm happy to say nothing had exploded when I went to check on them this afternoon. Today I also started boxing up the last few samples from medieval Riga, and came across this oddity ---->. All of the samples from Riga were waterlogged, and something strange has happened to this one; you can see all that orange spreading across the bottom of the sample? It is some sort of iron staining, and is very clearly seeping from the sides of the tin into the fine grained clay floor part of the sample. There were also lots of little salt crystals all over the surface, and you can see to the centre right a small area at the top of the metal tin has corroded! I'm wondering if there is a metal object in the block somewhere that is degrading?

A few of the other samples had unfortunately started growing mould. In future I will learn to wear a mask when unwrapping waterlogged samples! Hopefully this was just on the surface and will not have impacted the sediments where the slide cut will be made, though I'll be on the lookout for their little fungal hypae.

Slices from the blocks, ready to be cut to slide size

The blocks from September have now set and are in the process of being cut to size ready for mounting on slides. Absolutely beautiful preservation of wood, charcoal, dung (of course) and floors. The slides themselves should be ready by Xmas, I'll have to resist spending the holidays with ny nose down the microscope....

Tuesday, 6 November 2012

Elementary, said he

80s-tastic plasma lamp (Wikipedia)
Today I was mostly preparing lake sediment core samples for ICP. ICP stands for Inductively Coupled Plasma, and comes either in the MS (mass spectrometry) or OES (optical emission spectrometry) variety. Both are methods for measuring the different elements present in a sample. The ICP bit is a 'torch' containing a gas, typically argon, that is ionised by heating it via electromagnetic induction (remember those weird glowing globe plasma lamps?). Still confused? This means there is a coil wrapped around the torch, which produces a very strong electromagnetic field when turned on. The argon gas is ''lit' by an electrostatic spark, and the gas becomes ionised.
The sample (dissolved in liquid) is sprayed into the argon flame, and also becomes ionised. As different components in the sample become ionised they gave off a characteristic energy. The MS and OES parts is the bit that detects the elements present. MS does this by measuring their atomic mass, whilst OES measures the wavelengths of energy emitted by the elements. Each element produces a characteristic wavelength, so we can identify them on this basis.

Preparing samples from Lake Nineris, Latvia

And why do we want to measure elements you may ask? ICP is another one of those lab methods that has been developed for forensic and environmental applications then adopted by archaeologists. It is used routinely to look for metal toxicity in human blood and tissue samples, and to identify levels of pollutants in water. In archaeology, the idea is the same, but we are looking at the past history of such 'contamination' events. In the lake cores we have from the Baltic for the Ecology of Crusading project, we are measuring a range of elements in the sediments which can be linked to human activity. The lakes are located close to crusader castle sites, and pilot studies have linked signals such as increased lead to the castle construction. Other signals can be linked to activities such as landscape clearance.

Dissolving sediments in HNO3
Before we can analyse the samples, they have to be prepared for the ICP machine. This involves grinding/sieving them to less than 20mm and dissolving them in concentrated nitric acid. Grinding up and weighing packets of soil takes longer than you'd think. They'll sit in the acid overnight, then will be heated for 9 hours tomorrow (checking at intervals for explosions and whatnot). The resulting solution is then filtered, diluted and injected into the ICP.

So far I estimate there are about 60 samples per lake core, and maybe 15 lake cores. Eep.

Monday, 5 November 2012

Riga slides in progress

Riga town samples set in resin, ready for cutting into slides
Another week of lab work in Reading this week for the Ecology of Crusading project. The samples I boxed up in September for resin impregnation are now ready for cutting, and hopefully some of them will be finished into slides by the end of the week. They look like they've set really well; I was a little worried there would be problems as some of them were quite damp with lots of 'manure' layers, which can sometimes distort when dried or interfere with resin curing. I boxed up a few more samples from medieval Riga (Latvia), and 3 from Święta góra (Poland) today. It's going to be a tremendous amount of microscope work to get them all analysed, but I'm looking forward to it!

I also started preparing some lake core samples for ICP analysis today, which was delayed due to some minor hiccups which will hopefully be corrected tomorrow. That should take the rest of the week, with the Association for Environmental Archaeology conference starting on friday. I will be heading to the keynote, and really hope I can make some of the talks on saturday; lots of presentations on Near Eastern projects that I would love to hear the latest results from, including the Central Zagros Archaeological Project that I worked on in 2008 and 2009.

Monday, 29 October 2012

A day in the life of a maritime archaeologist

Guest post!

Despite having similar theoretical backgrounds, it is obviously clear that the methods and technologies used in maritime archaeology differ drastically from terrestrial research. Though volumes have been written on my particular discipline, I wanted to present a more personal and perhaps more accessible example of what life on the water is truly like.  
As with any field archaeological project our day starts early, typically before sunrise. We usually rise somewhere around  5 am and prepare for the day. We arrive at the local marina where our survey vessel is currently stowed, in this particular case we have the luxury of keeping the vessel in the water and don’t have to launch and recover it on a daily basis. Supplies are refilled, boat engines are checked and the equipment is prepped. For the current survey we are utilizing a side-scan sonar and magnetometer, supported by an echo-sounder to gather bathymetric data (water depth, etc.). The side-scan sonar and magnetometer are housed in “towfishes”, or instruments that are towed behind or off the side of the survey vessel. The echo-sounder is mounted to the vessel so the only equipment that needs to prepped and tested are the remote sensing towfishes.  

Once all equipment is tested and prepared we make the trek some 20 miles offshore to begin the day’s survey. The journey takes around an hour depending on the weather. Once on site, the equipment is deployed off the stern of the vessel and all lines secured. Once satisfied that the equipment is stable and recording accurate data we begin the bulk of the day’s activity, driving lines or “mowing the lawn”, which simply consists of piloting the vessel in parallel transect spaced an equidistance apart over the entire portion of the previously identified survey area. Both data outputs can be observed in real time but any real analysis is done after processing. On this particular day we are accompanied by a pod of dolphins which are often attracted to the survey vessel. Presumably they are entertained by the sonar pings as they seem to be particularly attracted to it, in some cases masking the data altogether.  

Survey time on the water is only limited by weather conditions and available sunlight (or in poorly planned excursions, gas levels). On this particular day, we are able to survey for a solid 10 hours and return to land in time to refuel the vessel, stow the equipment, and refill any depleted supplies. Once back in hotel/house/condo the data is processed, food is cooked, weather predictions for the following day consulted, and a cold beer consumed. Ah the life of survey on the water.    

Maritime Archaeologist, Southeastern Archaeological Research Inc.