Welcome to my blog. I will attempt to make it much more than just a pitiful list of the relentlessly mundane minutiae of my daily existence but if you feel that I have failed try to imagine all the stuff that I haven't posted.

Friday, 25 March 2011

New possibilities

Wow! Two posts in three days. Things must be happening (apart from the background hours of calcining, crushing and grinding).

I've been fortunate enough to be invited by the archeologists at Cambridge University to one of their dig sites in North Cambridgeshire, to investigate the various clays on site and (hopefully) give some insight into what was used to produce the various types of pottery found there. A slightly surreal place on the edge of the fens, where layers of deposition are removed one at a time to expose the ground level of a particular point in history. This drainage ditch was dug in the late bronze age.

I was able to see examples of the pots produced there, some of which were quite finely made and rather beautiful.

What was of most interest to me and this project was this section that had been cut through the ground exposing hundreds of years of deposition around the courses of ancient rivers. Many of these deposits are river clays, including the Fenland Buttery Clay, which I have been trying to get a sample of for ages.
The red/brown seam at the bottom is iron oxide, that has been dissociated from the upper layers, bleeding out from a very thin seam at the base. I have read about this occurrence and how it 'lightens' the clay deposits over time, but never seen such a fantastic example.
Back home now with many many clay tests to do. i am also going to fire some old pots shards to different temperatures to try to ascertain which clays they were made from.

Wednesday, 23 March 2011

A gentleman in Devon

Aah it's lovely to spend time in the South West, especially when the sun is shining and all around are signs of how damp it can be. I did some serious driving in the last few days - all along the caravan route to holidayland and then around the southwest. It's an interesting area geologically as there are the granite intrusions amid various sedimentary rocks, with the associated metamorphosis and mineral intrusions within the sediments.
The granite moorlands are impressive in the way that the fens of East Anglia are, but incredibly barren. The lack of trees depresses me after a while, and I'm always blown away by the stunning woodlands and rivers that run down from the moors.
Geologically there is plenty to collect: igneous rocks, limestones, shales and certain unknown stones. One of which, I have no idea what it is, but it melts to a stunning fluid glaze by itself at cone 10.

There are numerous old quarries, often flooded, that have a wonderfully impressive grandeur.
I also drove down to visit one of the china clay pits. The site manager was extremely helpful and I spent a few hours being shown around + collecting various samples. The most interesting are those that are not commercially viable, such as the mica deposits. There are a few grades of china clay excavated here, each washed down into the valley individually.

The clay filled water runs along the valley floor till it is sucked up into the separating equipment at one end. The sky was pure blue and I was surrounded by acres of white sand. Almost like my dream holiday destination. Give me a kiln, a wheel and a small country pub and I'd be happy!

Sunday, 13 March 2011

Busy busy busy

It's been rather a long time between posts but I've been really rather busy.

This board of tests represents a weeks work! There's a couple of biaxials and some simple fusibility tests. The rest are progressive lineblends, building on previous results and generally incorperating more materials ie becoming more complex. I've spent much time massaging my wrists after serious mortar and pestle work. To releive the monotony I've been calcining, hammering and crushing other collected samples and testing various time lengths of ball milling , wet and dry, to get as 120 mesh sample. OK so it's not going to thrill all of you reading this and you'll probably have to imagine my serene faced satisfaction when holding a jar full of 120 mesh Mountsorrel granodiorite, but oh boy! what a feeling!

Ive also spent time at the geology department of Cambridge University running loss on ignition tests on samples of clays I've collected. I've also prepared samples for the more interesting sounding Laser Particle Size Analysis, and been preparing for my next trip. Off to Devon this coming week.