I like Tunnels (by sarah)

After visiting the extremely cute alpacas we headed off to the Honister Slate Mine on route Simon - Al's step brother asked me what the landscape was. I confessed I didn't actually know anything about the region but I looked at the scenes passing my window and guessed at volcanic with glacial action afterwards.

My back was in a bit of a state still and I bascially could not rotated my head but I really wanted to go in - I am from the Royal School of Mines, I am from Welsh minning stock how could I not go in? This question arose when buying the tickets as Lionel has injured his foot and was using his crutch and had sandles on.

A discuession with the lady on the desk about exactly what the mine was like had Lionel not going but me more determined to go. Jean unfortunatly was wearing sandles so would have to be carried for sections of it but would be ok as long as she was ok with the dark - we were more concerned that we wouldn't be able to keep the hard hat on her!

I have been known to go into mines on crutches - I really can not resist them!

We had to wait for our guide for a while so looked around the shop - I was I have to say impressed. They had been really ingenious with the products they where making from the mined stone - not all of it slate. I thought it all looked a bit odd though and there was definatly some interesting stuff going on in the rocks. It didn't quiet look right as slate to me and there was some interesting flow and flame structures in some of the non-slate. It is lovely stone and if I ever have enough money to do things properlly in the house I shall be getting the stone from that mine.

There is a lovely bluey/green quality to a lot of it.

The dude arrived and gave us our hard hats and battery packs which reminded me so poniantly of going caving I almost backed out but then realise what the problem was.

Jeany initial struggled over the hat until she saw that we were all wearing them - she didn't have a heavey battery pack as she had basically an LED head torch. To my suprise she noticed this - 'I have blue light, special light, you have yellow!'

We clambered into an orange landrover thing and trundled up to the mine.

Outside the entrance we stared at the landscape and low! It had once been a sea flow with volcanics going on on it and then been uplifted etc... and then had glacia's move through it all carving the characteristic u-shaped vallies - these give you a nice cross section through the formation - so in staring across the valley we basically had a mirror image of what we were standing on - this was cool and gave us a much better over veiw than was could have hoped to gain any other way.

I was just a bit chuffed that my guess had been right.

We could see the layering of the ancient lava flows and slate - the slate higher up was the greener colour. Slate normally occurs from say eustry mud which becomes mudstone - this is then folded due to tectonic action and the pressure causes changes so that you get an alinement of say mica along the fold axis - this is the cleavage and is what the slate is split down. This slate looked so odd to me becuase it was not made from mud - instead it was origonally volcanic ash!

This also means that it has more griss - this is the amount of sort of large fragments in it that stop it having a smooth break down the cleavage - therefore this slate breaks into thicker slabs compared to other slates ie welsh or scottish slates. But it also means it is stronger!

The guide dude was called Fred and he was the father-in-law of the guy who set the business up - again I was really impressed as the guy had bought the mine and re-opened it when he had initially known nothing about mining - his grandfather had asked why was the mine closed and he'd just seen the potential and gone with it!

They even went and got a special rock saw from the Itialian marble quarries - this looks like lots of lumpy beads, or sort of an articulated spine of some sort - it is beds of steel or something embadded with industrial diamonds that as Jean point out glittered.

They now mine safely off course but when the mine was origonally open (from the 1700's I think he said but am not sure) they used dangerous tequniques which have resulted in what are known as rate traps - these are rooms where so much of the slate has been removed that the overlaying rock is in danger off coming down on top of the minners if they continue - this was actaully an inefficient way to do it and they get far more out and intact than they used too. Also the range of products they offer now will hopefully buffer them from economic crisis - these are what always closes slate mines as builders stop buying the slates.

One of these rat trap chambers turns out to have great acoustics and a jazz dude has been in there recording this has given me an idea - ok Clare, Ella and Charlee what about us doing something similar - I'm thinking medeaval chants with some electric guitar thrown in would be cool - Becca could even play some flute and Carina how's your guitar playing - infact Becca you play too don't you?

I think we could call ourselves the Mining Babes?

What do you think?

Anyway cough we had a look at the history and stuff and after me rabbiting on about why I thought the cieling of the place worked so well our guide thought that we were musicians but Al and Simon blew my cover and asked me questions about the geology of the place - I was highly embarassed but then it turned out Fred was a Steel Engineer and on top of that I found out that there may be something there that will help me with my MRes project. So I may be going back there sooner than later.

I really love this and Jeany announced that she likes tunnels 🙂 Talking of which there where a few really cool tunnels there that had been in the old days, shored up with the waste stone - this is done with no key stone and is similar to the ancienct burial mounds in Scotland and places. Jean told me off for touching the walls and braeking them which I thought was sweet 🙂 Somehow she ended up getting buscuits out of the other people on the tour :/ How does she do it?

Again photos coming soon hopefully 🙂

Sun Quakes and Solar Structure (by sarah)

I had another really engaging lecture tonight - one that had me salivating for more and which has probably resulted in me alienating myself from the rest of the MRes group.

The lecture was by Vincent Tong who it turns out has been at Imperial where I studied as an Undergraduate!

First off we had to think about what our goal was, what were we actually trying to acheive - to see inside the Earth of other body and see of what and how it is made. Then with lots of analogies which steadily become more rediculous as the lecture went on.

We then decided we couldn't break the Earth (or Sun) open like an egg to see its internal structure but had to view it as a presant and shake it to see whats inside. The shaking equals eathquakes and these we record and measure. We had a quick run through of wave types which was cool as I found I had forgotten one of them!

I ended up having to answer why s-waves which can't travel through liquid are improtant along with many other things - I don't know if they others were just being shy. I found I had remembered alot of stuff and to my suprise I am finding it far easier to infer things from information I am given. I did find the periods of time when we were working with each other to work stuff out frustrating as everyone else just kept saying they didn't understand (bar the guy at the front who kept asking really really techniqual questions about the software used).

We ran through the standard this is how you look at the inner earth but then looked at the fact that the velocity of the earthquake waves are dependent on direction and temperature and their interactions with faults and other subsurface structures. This was interesting as I discovered you can basically use the arrival times of the waves to work out the velcocity of the waves which is temperature dependent - meaning that you can tell if it has had to pass through realitively hot or cold areas. If you then have sequences of these you can see how they change - meaning you've added time and can see how things are moving or flowing - this is so useful I can not even begin to tell you.

The implications to my mind are stagering and I thought seismics where boring!

We ran through (quickly) how imaging of sections works - these are generally done by man made seismic waves (big thumbing lorries or air guns at sea). Now most of the siesmic sections I looked at during my undergraduate (if not all) were of reflected waves that were bouncing off of say bedding plans and the such like. But now there is this thing called Tomography which (I think) involves refracted waves - so these are waves that travel through the rock and are slowed down by different substances etc... sort of a minni version of how we use earthquake waves. I think it is a method stolen from medical imaging but I am not sure.

This again opens a whole new world and means you can see things that are not picked up by the reflective waves. There was somehting involwing time and depths and seeing flow rates again with this but I need to look that up some more.

We also looked at the restrictions off all of this - basically we could really do with a global network of siesmometers and though we are getting there - most of the planet is covered in water - I suggested that they could put the detectors along the cable trunks that carry say the internet - this apparently has already been done. Plus they have detectors that onces having detected an earthquake bobb back to the surface adn tell the sattalites what they heard - I personally wondered what sort of fail rate they have for such instramentation.

I guessed correctly that time would be involved and the problems of refernce and angle etc... which I was impressed with myself for. Also another problem is that the earthquakes on the earth are not actually evenly spread out - they are concentrated along the plate boundaries and the such like giving certain biases to what we are finding out. Then the earthquakes are intermittent and we have no idea what strength they will be etc... meaning that it is quite - if not not impossible - to correlate the data.

Oh - one of things was that the waves travel faster along faults that are parralel to the direction of motion and go slower through ones that are perpendicular. And this effect is sort of amplyfied if there are say lots of parrellel fualts such as along the mid ocean ridges. Measuring flow there is quiet important as there is hydrothermal perculation and stuff through the newely formed sea floor as it is hot and stuff - this affects mineral exchange and the such like. But during the working things out time he gave us I came up with the concept of using the earthquakes to tell if you where in a back arc basin, or near an accretionary prism, ie looking at the big big structures as they have different minerals and things in them (stolen straight from Wednesdays lecture). The girl I was sitting with said she had thought the same thing - the lecturer said we were coming up with good ideas.

Later on he said I was asking the right sort of questions too - though as the lecture ended up over running what with me getting excited over the way in which the earth or spheres in general can distort with motions and the like (yes I asked more questions) I think the rest of the class where about to kill me.

We got on to the heliosiesmics and wow! I think i actually got how they are detecting the sun-quakes. Now on the earth we have seismometers on the surface but the sun is a) humungous and b) too far a way and c) uber hot. But we have images in all sorts of wave lengths and the suns surface is in continous motion. The sun is a plasma which moves as a fluid and you can see the convection cells on the surface. You can take images and see how they change - think about it - surface that is further away from you such as that in a trough or valley (earthquakes are waves with peaks and troughs) will have a slight red shift to it as the wave gets stretched on route were as the peaks will be like mountains and nearer the earth or satallite depending were the detector is and be blue shifted compared to the base level surface colour (we are assuming constaint composition of the sun here.

This is cool as you can basically do the tomography tequnic and look at flow!

We also looked at solar flares and sunspots which has me a bit disturbed - is it me or does the behavour of sunspots becoming solar flares seem to suggest that the sunspots individually are magnetic poles? But that would make them a magnetic monopole which I thought could not exist?

Am I missing something here?

Anyway to my suprise I am actually now considering writing my second essay (its due in december) on helioseismics! I must be mad - but I found this really really interesting!

Low and Very Low Grade Metamorphism (by sarah)

Well.....

I found this lecture interesting but not engaging like Monday's even though it probably got more potential for producing useful stuff. The actual title of the talk was - From mud wrestling to metamorphism.

I think the issue is that I don't really have any interest in met rocks unless they are shock met or contain galuconite. However what the lecture did show me was that I need to go back and look at Big Picture geology ie how compressional and extentional basins fit in with plate tectonics. Since Monday I have been boning up on my mineralogy which with out samples or microscope mainly involves looking at the mineral atlas's.

Being a chicken I have picked up the smallest thinest of the volumes called A Colour Atlas of Rocks and Minerals in Thin Section and am only about a third of the way through it but it does feel like its bump starting my brian - however it is also showing me just how much stuff I have unfortunatly forgotten.

Oh I lie I love Diagenises but that is generally considered mets poor relation by hard rock petrologists (ie those that look at the mineralogy in Ig and met rocks.) The Big D as diagenises is known is a major problem for things like paleo analysis and I think it can muck up the chemical resivours for dating samples but don't quote me on that!

Anyway yesturdays lecture was mainly coming from the stand point of mud which ment I did have a slight interest in it which unfortunatly wasn't really covered because as Steve said some people in the room knew more about it than he did - the interactions of mud and life - I comemeted on the concept that early life may have got its self-replicating molecules such as DNA from the similar property of clays - clays are self replicating mineral and there are a few theories doing the rounds about them acting as catilysts for organic reaction and then being split by tidal processes leading to lots of replication - hmm thats not a good explanation I'll probably do a better one at some point I think I probably explained it on my website The Origins of Complex Hydrocarbons and Early Life though I am starting to cringe at that site that I did as a small part of my undergraduate and may have to update soonish.

Since I did the site I have been to several seminars at the Natural History Museum and went to the EANA confrence in Milton Kenyes just before the pregnancy stuff. So I probably did know more including all the extremophile stuff - though again I haven't read any new litrature on the subject for about three and bit years - this is not becuase there hasn't been any but becuase I haven't been in a position to get at the info.

One of the things I did find interesting and I'm sure I've seen the image before was the concept that even in high grade rocks that have like proper mineral crystals and shouldn't have any pore space or water in them for solid state reactions to occure - there are at the Armstrong level (this is a unit that is like minute) there are tiny spaces and these could harbour fluids and then the even smaller gaps between the grains/crystals could act like conduets. I had suggested capillary action before I realised how small the scale was we were dealing with but I think that what ever the mechanism is it's going to be working in a similar way. Water as a substance has a high surface tensition and so does tend to creep even upwards against gravinty if constrained. I was woundering weather other fluid would have higher surface tensions and what sort of temperatures and pressures they would be able to survive.

I assume acids tend to be solutions in water but is the presance of H20 actually nessacery for an acid to exist and what what sort of conditions are needed to maintain them? Remember we are dealing with met rocks here - this means they will have been heated, they will have been squashed and probably multiple times.

And here I detect the danger to my success in this course - I am actually interested in everything and I am having to fight myself not to become side tracked - again on Weds I sat in Carina's office - I was going to do some reading but instead found I was far to interested in the talk she was having with one of her colleges on disastor and risk management - we're talking volcanoes and Tsunarmis here - I was supposed to be reading but ended up listening avidly and then even offering my opinion which I probably shouldn't have done.

It is vitally important that I do not become side tract as I have my first essay due on the 3rd of Nov and it can not be late - at all (unless I get a drs note they hastily added whilst looking at me - I can't think why). Word limit is 3000 words which I feel is going to be hard to stay within. I still have no libary access but found I had some papers on the topics I want to write about anyway which is cool. To say I am panicking is probably an under statement but I am also enjoying this - my brain is being stretched and I like it 🙂

Sorry about the incoherent bable!