OCR geology unit 5 2016

my whole class found it very easy, including the C and D grade students. Essays were quite nice and they could definitely have been far meaner with the radiometric dating and correlation, overall very good paper.

Didn't like most of 6 and the second essay was harder than those in past papers since it needed you to link how volcanism affected each organism that went extinct so like how it would affect marine organisms.

i fully got the organisms wrong in that essay but i linked it to why it would cause marine extinctions and then why it would cause terrestrial extinctions so still confident I got 6 or 7 out of 10, rest of the paper was a walk compared to other past papers, what was question 6 again?

Question 6 was the graph you had to extend and all of the correlation stuff.

In the essay what things did you put down?

ohh yeah OCR f*cked up cause you couldnt fit the 3rd half life on the graph. All u had to do for the correlation was match up one of the beds of tuff cause it was chronostratigraphic. I talked about how it would cause extinction of terrestrial animals due to poisonous gases, then how it would cause marine and terrestrial extinction by creating a volcanic winter by the albido effect of the ash, then when this finished the excess CO2 would cause a global warming and then a runaway greenhouse effect which would have caused a rise in temp and how the fluctuation would cause extinction + temp rise would cause methane hydrate release which caused marine extinction

I just extended the graph but that was ridiculous, with the correlation did you correlate the two close beds?

For the essay I put the following:
Poisonous gases kill nearby creatures
Large scale lava flows do the same but also cause fires destroying further plants.
Reduction in plants starves terrestrial organisms.
Ash and particles cause global cooling and evaporates ocean water is trapped in ice so sea level fall.
In warming period organisms which migrated to originally shallow marine areas are killed by sea level rise (for some reason didn't put some higher level areas).

Also with the trilobite with the eyes on stalks did you say it was burrowing?

sounds like you'd definitely have picked up at the very least 6 marks? I just correlated one bed of tuff cause it was the only chronostratigraphic sediment. Nah, calymene is infamously epifaunal cause of its many many legs and enrolment

I just extended the graph but that was ridiculous, with the correlation did you correlate the two close beds?

For the essay I put the following:
Poisonous gases kill nearby creatures
Large scale lava flows do the same but also cause fires destroying further plants.
Reduction in plants starves terrestrial organisms.
Ash and particles cause global cooling and evaporates ocean water is trapped in ice so sea level fall.
In warming period organisms which migrated to originally shallow marine areas are killed by sea level rise (for some reason didn't put some higher level areas).
Then just how terrestrial organisms are affected by temperatures. I should've also put that for corals the area of tropics they live in would shrink in cooling.

Also with the trilobite with the eyes on stalks did you say it was burrowing?

I put it was burrowing because it's eyes were on high stalks which would poke out of sediment. The eyes were completely different to calymene.

I researched it cause my teacher told me calymene had eyes on stalks and there's sub-catagories of calymene, some of which had eyes on stalks and thats what was in the exam, the only infaunal one on the ocr spec is trinucleus

why wasn't it nektonic

Did not know there is A level Geology.

I researched it cause my teacher told me calymene had eyes on stalks and there's sub-catagories of calymene, some of which had eyes on stalks and thats what was in the exam, the only infaunal one on the ocr spec is trinucleus

SiO2 causing acid rain affecting vegetation
Also have talk about how the volcanism caused desertification, thus making loss of marine habitat

I swear they were nektonic as it needed eyes for 360 vision

Did not know there is A level Geology.

A characteristic of calymene was that they had crescent shaped eyes set on the cheeks. This looked more like an asaphus where the eyes were on high stalks and weren't crescent shaped.



The nektonic forms have forward stalks though this was on top. Also the exoskeleton wasn't suitable as a nektonic form.

It could have been, I said mainly epifaunal benthonic, used many jointed appendages for walking but could also have been used for "paddling" and nektonic movement