Arthur's Seat

The volcano - as opposed to anything you might sit on :O) First geology field trip today - and boy was it cold! Typical Edinburgh-in-spring kind of weather... Very interesting though. I've been up to Arthur's Seat and Salisbury Crags many times (mostly to climb at the Crags), but walking round the whole area and piecing together its geological history puts a different perspective on it.

This is Hutton's section - the second most important geological locality in the world, according to our tutor (the first being Siccar Point in East Lothian - more of that later). The magmatic sill above is sitting on bedded sedimentary strata below, and has intruded into the strata, causing it to turn up at the edge. This feature showed Hutton that there had to be some kind of force behind such intrusions, rather than lava 'seeping' into cracks between sedimentary beds.

The whole area is filled with the evidence of its geological history. From sandstones and mudstones laid down in warm shallow waters, when Scotland was somewhere near the equator - this picture shows distinct rippling caused by gentle wave action - to basaltic sills and lava flows, and the very heart of the volcano itself. The beds and sills have been tilted by folding and faulting and now dip about 30 degrees to the east. The area has also been eroded by the passage of glaciers during the last glacial period, removing the soft sand and mudstones, and exposing the basalt sills - there are even erratics, smooth 'alien' bolders dumped by the glacier on its passage through.

A very interesting day, and a refreshing new look at an area I thought I knew quite well.

Snow and crystals

Blizzard conditions in Edinburgh today - this is the not-very-good view from my flat window!

Second mailing for S260 arrived on Thursday, so eagerly reading through Block 2 (just as well it's snowing outside and I can't get out!). Hard stuff about crystal structures and light refraction... yuk, fizzicks - never was very good at that. But the crystals are lovely, and at least now I get to play with all the stuff in the home kit!

Doing the finishing touches to the first TMA too this weekend - had done most of it a while ago, but just needed to get the cross-sections copied out neatly. Really quite enjoyed Block 1, although it took a while to get my head round what I was actually looking at on the maps.

As for S328 - still wrestling with what to do the project on - more on that later. All but finished TMA 01, just need to finally write the essay bit. Essays - double yuk - the reason I did science courses was so I didn't have to write essays! Give me a scientific report any day!

Back to the crystals... :O)