First

Another weekend, another geoblogosphere meme. This time Dave at Geology News asks about first field trips.

Like several others that have followed the meme, my first field course was a bit too long ago to have photographic evidence (I don’t remember having a camera with me and if I did I don’t have the photos any more – not that I pre-date photography!). My first field course was to the Isle of Wight, off the south coast of the UK. It was a joint geology / geography field course and I remember it more for putting me off ‘human’ geography for life (I absolutely hated going up to complete strangers and asking them pointless questions on village living – the place was called Godshill – how these things are burned into one’s brain even though it’s getting on for thirty years ago). The geology concentrated on the Isle of Wight monocline, an alpine fold producing near vertical Cretaceous and Palaeogene beds.

The Lost Geologist and Silver Fox have somewhat diverted the meme to first geological equipment.

I still have my first hammer. Being a ‘hard rock’ geologist originally I’ve always considered an Estwing a bit of a ‘toffee hammer’ and preferred my trusty two and a half pound Whitehouse. I just have to remember to soak the shaft in water before I go into the field.

I’ve also still got my somewhat battered first hard hat. The crest on the front is that of the Royal School of Mines where I did my degree. The logo on the brim is that of the Institute of Geological Sciences, the former name of the British Geological Survey. Since my initials are IGS I thought that they wouldn’t mind me taking over their logo as they had changed name to the BGS a couple of years beforehand. The very battered sticker on the side is University College Cardiff Geophysics where I did my Ph.D.

Pangaea, geology stylee

Following the Pangaea Day geoblogosphere meme, started by Chris@goodSchist and followed up by Callan@Nova, Brian@clastic detrius and Chris@highly allochtonous I suppose I should give it a go.

This was harder that I thought. I’m still not sure I’ve got it perfectly correct (I may be a touch too far north) but I think that Britain was under the red dot on this version of Ron Blakey’s palaeogeographic map for the Late Triassic (220Ma).

In the Triassic things are happening fast. The Variscan mountains of the late Carboniferous / Early Permian to the south have all but disappeared and extension related to the opening of the North Atlantic is causing rapid subsidence. The Bakevellia Sea is to the west and the Zechstein Sea to the east in the Permo-Triassic with a possible connection north to the Boreal Ocean. As subsidence occurs, by Late Triassic / Early Jurassic these seas link up and most of Britain becomes shallow marine with a number of small islands just remaining.

The Faroe-Rockall Basin forms to the west forming the start of the North Atlantic rift. If it had come down the failed Viking Graben rift to the east things would have been very different for us.

Britain's Largest Meteorite Impact

Geologists at Aberdeen and Oxford have reinterpreted the Stac Fada Member of the Torridonian Stoer Group, previously believed to be a volcanic mudflow deposit, as a fossilised ejecta blanket from a meteorite impact about 1.2 billion years ago near Ullapool in Northwest Scotland. The unit bears the chemical signature of extraterrestrial origin including high iridium levels.


[Image from Waters 2003]

This unit presents a superb opportunity to examine an ejecta blanket deposit from an impact into a wet substrate. I don’t know of any other terrestrial examples.


[Image from Waters 2003]

The unit is up to 20m thick, unbedded and poorly sorted with angular clasts.


[Image from Waters 2003]

The rock also contains devitrified volcanic glass.

I have no insight to offer here. As a geologist, particularly one with an interest in planetary geology I’m fascinated by it and hope to get to see it one day.

Geology article abstract
http://www.gsajournals.org/perlserv/?request=get-abstract&doi=10.1130%2FG24454A.1

Aberdeen University Press Release
http://www.abdn.ac.uk/mediareleases/release.php?id=1275

BBC News Story
http://news.bbc.co.uk/1/hi/sci/tech/7314329.stm

Waters DJ, 2003. Rocks of N.W. Scotland
http://www.earth.ox.ac.uk/~oesis/nws/nws-a98-st1.html#field

[Hat-tip Ole]

Churnet Valley Geotrail

After a six months of frenetic activity my (in conjunction with several others) latest project has just been launched on an unsuspecting world.

The Churnet Valley Geotrail is a 25km guided walk through the picturesque Staffordshire Churnet Valley and its environs. It looks at the geology and geomorphology of the valley and also its rich industrial heritage, which is intimately linked with the underlying geology.

The trail is probably too long to be tackled all in one go (unless you are feeling particularly fit) so suggestions for a number of smaller loops are made so that you can complete it in sections. The geology comprises the Upper Namurian gritsones, Westphalian A Lower Coal Measures and the Lower Triassic Sherwood Sandstones.

The trail leaflet can be obtained free from local information offices in the Churnet Valley or direct from Staffordshire RIGS (sae please, address on SRIGS website). Alternatively you can download the leaflet as three Adobe pdf files from the SRIGS website.

SRIGS would like to thank the Staffordshire Aggregates Levy Fund for funding production of this leaflet.

21 Reasons You Might Be a Geologist If …

Some personal comments on …

21 Reasons You Might Be a Geologist If …

1. You own more pieces of quartz than underwear.
True.
… but only if you count grains in sandstone.

2. Your rock collection weighs more than you do.
True.
… by a factor of several.

3. Your rock garden is located inside your house.
False.
… but only just outside the front door.

4. You can pronounce the word ‘molybdenite’ correctly on the first try.
True.
… and ‘chalcedony’.

5. You don’t think of “cleavage” the same way everyone else does.
True.
… and cleavage / bedding relationships.

6. You think the primary function of road cuts is tourist attractions.
True.
… and will cross a multilane highway to check that the rocks on the other side are the same.

7. You find yourself compelled to examine individual rocks in driveway gravel.
True.
… and all the pebbles in my garden soil (they are glacial erratics you know)

8. You’re planning on using a pick and shovel while you’re on vacation.
Partially True.
… but a rock hammer is a definate possibility.

9. You have ever found yourself trying to explain to airport security that a rock hammer isn’t really a weapon.
Partially True.
… airport security no, ferry security yes.

10. You never throw away anything.
True.
… just ask my better half!

11. You have ever taken a 17-passenger van over “roads” that were really intended only for cattle.
True.
… Oh yes, but not rolled one – yet.

12. You consider a “recent event” to be anything that has happened in the last hundred thousand years.
True.
… and Quaternary studies are just a bit too close to gardening.

13. You have ever had to respond “yes” to the question, “What have you got in here, rocks?”
True.
… many a time.

14. You associate the word “saw” with diamonds instead of “wood”.
True.
… and I associate the word ‘fountain’ with ‘fire’ rather than ‘water’ or ‘pen’.

15. You have ever been on a field trip that included scheduled stops at a gravel pit and/or a liquor store.
Partially True.
… certainly arrange field localities between pub stops.

16. You have ever hung a picture using a Brunton/Compass-clinometer as a level.
True.
… and to check the level of a pub bar when testing the isostatic compensation properties of the head of a pint of guinness

17. You were the only member of the group who spent their time looking at cathedral walls through a pocket magnifier during your trip to Europe.
True.
… and spend more time in a museum looking at the plinths than the exhibits

18. Your collection of beer cans and/or bottles rivals the size of your rock collection.
Partially True.
… but my beer glass collection does.

19. Your photos include people only for scale and you have more pictures of your rock hammer and lens cap than your family.
True.
… and coins of the world.

20. Your spelling checker has a vocabulary that includes the words ‘polymorph’ and ‘pseudomorph’.
True.
… and ‘porphyroblast’ and ‘poikiloblast’ and …

21. You have ever uttered the phrase ‘have you tried licking it’ with no sexual connotations involved.
True.
… and ‘you don’t have to swallow it’ (distinguishing between silt/mud)

Adapted from a variety of sources including …
http://fgms.home.att.net/rokhound.htm
http://www.qld.gsa.org.au/TQGFEB02.pdf