Predictions.
I predict that the intrusions were formed at different times and are from different magma sources.
Safety.
When I am carrying out this investigation I must remember that the quarry is a potentially dangerous environment. A helmet must be worn at all times during the experiment. When hammering at the rock safety goggles must be worn. The hammering must be kept to a minimum as the hammering could trigger a rock fall.
Analysis.
I studied 4 different sections of intrusions at Gullet Quarry. They are shown in the photograph below.
The next drawings are of the four sections of intrusions studied at the quarry.
Section A.
Section B
Section C
Section D
Aim 1.
My first aim was to investigate whether the intrusions are the same age. The graphs below show how the crystal size either decreases or increases as you get closer to the centre of the intrusion.
Intrusion A. Intrusion B.
Intrusion C. Intrusion D
From these graphs I can see that Intrusion A has smaller crystals on the outside than the crystals in the centre of the intrusion. This could be because there is a baked margin on the outside of the intrusion. I can also see that in intrusion B there are smaller crystals on the outside compared to the inside on the intrusion. This has happened as a result of a Baked margin being present on the outside of the intrusion. This could indicate that intrusion B is of the same age as intrusion A because both intrusions have larger crystals as you go closer to the centre of the intrusion and that they both have a chilled margin. From the graph for intrusion C I can see that the intrusion has the same size crystals all the way through. This is the result of there being a baked margin on the outside of this intrusion. From the graph of intrusion D I can see that the intrusion has the same size crystals all the way through the intrusion. There is also a baked margin on the outside of this intrusion. This evidence could indicate that intrusion C and intrusion D are of the same age because they both have a Baked margin and both have the same size crystals all the way through the intrusion. From the evidence above I would presume that intrusion A and intrusion B are of the same age and that intrusion C and intrusion D are of the same age.
Aim 2.
The aim of this investigation is to find out whether the intrusions are dykes or sills. A sill is an intrusion which runs along the bedding planes and a dyke is an intrusion which crosses over the bedding planes. A dyke and sill are drawn below.
A Sill.
A Dyke.
The tables below show the clinometer readings from each section.
Section A.
Section B
Section C
Section D
From the table of section A I think that the intrusion may have been faulted but the intrusion roughly goes along with the bedding planes which would indicate that the intrusion is a sill.
From the table showing the results from section B I think that the intrusion is a sill because the clinometer reading roughly go hand in hand with each other so that would mean that the intrusion is a sill. From the table with the results from section C I think that this is a sill because all the dip to the south and roughly fit in with each other accept from reading c which still goes along with the trend to the south but has a great difference in degrees to the rest of the readings.
From the table showing the results for section D, I do not think that I can make any prediction on whether the intrusion is a dyke or a sill because the readings are very different. I think that intrusion A is a sill, Intrusion B is a sill, Intrusion C is a sill and I do not know whether the intrusion of section D is a dyke or a sill.
Aim 3.
This aim was to find out whether the intrusions came from different or the same magma source. To find this out I looked at the percentage of different minerals in each intrusion. The results are shown below in graphs.
Intrusion A
Intrusion B
Intrusion C
Intrusion D.
The graphs show what the mineral content of the intrusions are. In section A the intrusions have 85% feldspar and 15% quartz. In section B the intrusion has got 60% feldspar, 20% mica and 20% Quartz. In section C the intrusion has 95% feldspar and 5% mica. In section D the intrusion has 15% mica, 65% feldspar and 20% quartz. From this evidence it would appear that there is no correlation between the intrusions in sections A and B, but if you look at the graphs for sections B and D the two intrusions have roughly the same mineral content which should mean that they come from the same magma source.
Aim 4.
This aim was to try determine a sequence of events in the igneous section of the quarry. To do this we will have to look at the evidence from aims 1, 2 and 3. Section A, Intrusion A has been faulted but Intrusion B of Section A has not faulted along with the other three sections so I believe that intrusion A of Section A was formed before Intrusion B of Section A and before the other three Sections. Then I believe that the intrusions in sections C and D were formed after intrusion A of section A because these two intrusions have not been faulted. Intrusions C and D must have formed at the same time because they have no difference in crystal size, this shows that the country rock was the same temperature as the intrusions when they intruded, I think that the country rock is unlikely to have warmed up then cooled then warmed up again. Intrusion B of section A and Section B may have been formed before sections C and D or after it because it has not been faulted so must have formed after intrusion A of section A, but it is impossible to tell whether section C and D came before or after intrusion B of section A and section B. The photographs below show the faulted intrusion in section A and a baked margin on the intrusion on section D.
Evaluation.
In my investigation there were a lot of anomalies. There were the clinometer readings In Section D. These anomalies were so different that I could not determine whether this intrusion was a dyke or a sill. Other anomalies include mineral content in section A where in some of the readings there was a very high content of mica which was not possible to happen. I believe that most of my observations were accurate but there is always human error which leads to either misreading the readings of the equipment or using the equipment in the wrong way which would lead to the equipment giving the user the wrong reading because of human error. The procedures that we carried out were suitable to find out what we needed to know but we could use more advanced equipment to improve the accuracy of the results. I could do further investigations into whether the country rock is of the same type and if it wasn’t I could investigate into what type of country rock was around each intrusion. I could also collect more clinometer readings for Section D to find out whether the intrusion is a dyke or a sill.
Geology Scientific Experiment:
Investigation into whether lava flows better over a rough or a smooth surface.
Plan.
To do this experiment I will pour jelly down a smooth surface and a rough surface. The method to do this and equipment is listed below.
Equipment:
- Pyrex jug
- 1 pint of boiling water
- 60cm long of hardboard( rough on one side and smooth on the other side).
- Stop watch
- A packet of jelly cubes
- Tape measure
- A protractor
- 4 thick books ( to set the slope of the hard board)
Procedures to carry out the experiment.
- Break up the jelly cubes and put them into the Pyrex jug
- Boil 1 pint of water in a kettle.
- Pour the boiling water onto the jelly cubes and stir until all the jelly cubes have dissolved into the boiling water.
- Leave to cool for 30 to 40 minutes and put the jug into the fridge for 1-2 hours to semi set so to look and act as if it was lava.
-
Now use the protractor to measure the angle of the wood and prop the wood up using the books. The angle should be set to 20°.
- Now draw a table to record the results.( shown below)
- Now get the jelly and pour about a table spoon of jelly down the slope. Start the stop watch just as you pour the jelly onto the slope. Stop the watch when the first part of the jelly hits the end of the slope and then record the time taken.
- Repeat number 7, 5 times on the smooth side of the board and 5, times on the rough side of the hard board.
- When finished remember to tidy away all the equipment you have used and wash the equipment if the equipment is dirty.
Prediction.
I predict that the jelly will reach the bottom of the board quickest on the smooth side of the board.
YOU MUST REMEMBER TO FOLLOW ALL THE LABOROTORIES SAFETY RULES.
Observations.
Analysis.
Because the jelly on the rough side of the wood did not manage to travel the whole distance I measured the time it took to travel the distance it did and the length of the distance it did and then worked out how many times the distance it travelled would go into the total distance and then timed that number by the time the jelly took to get where it did to estimate how long the jelly would have taken to get to the end of the board.
The next table is a revised version of the observation table but with the estimated totals put in.
The next 2 graphs show the difference between the two surfaces using the median average which is the middle result between the 5 results.
From this experiment I have discovered that if the slope of a volcano is smooth the lava will flow quicker than on a rough surface. This has proved my prediction that if the surface is smooth the lava would flow over the slope at a quicker pace than if the slope is rough.
Evaluation.
I feel that my results are as accurate as can be expected with out using a computerised method of recording the results. I believe that the experiment I did was suitable because it has proved that lava flows better over a smooth surface rather than a rough surface. I found that the first and the last time I ran the jelly down the smooth side of wood the times had a big difference to the other times I ran the jelly down the smooth side of the board. I could improve the accuracy of my results by having another person starting and stopping the stop watch. I could do a further investigation to find out if lava flows better with air pockets in it or not.
