WJEC GL4 Feedback 2006

1. WJEC GL4 Feedback 2006 Principal Examiner Ian G. Kenyon

2. Mark Range 25 to 90 out of 96 An accessible paper with only 46 of the 819 candidates scoring less than 40 out of 96

3. Question 1: Sedimentary Rocks Areas of Weakness Poor understanding of the formation of cross bedding and the internal structure of a dune Diagenetic changes poorly understood, actual process names rarely stated Many candidates were unable to suggest reasons to explain the lack of fossils in the sedimentary sequence

4. Current direction incorrect by 180º Internal stratification incorrect No scale indicated on sketch

5. Wind/current direction incorrect by 180º Internal structure confused Absence of any scale on sketch Only annotation refers to marine processes

6. A Good Answer! Internal structure correct Current direction appropriate Dune migration correctly plotted No scale indicated though!

7. Question 2: Palaeontology Areas of Weakness Some candidates only drew planes of symmetry on either specimen A or B A number of candidates failed to identify the fossil groups. Howlers included ammonite and tripod! Shell morphology and mode of life poorly understood. Many contradictory statements made here.

8. Line of symmetry on brachiopod incorrect. Fossil groups named as geological periods!

9. A Good Answer!

10. Byssus confused with limbs here!

11. Specimen Y was often confused with Pecten as well as Pecans!

12. Question 3: Metamorphism Areas of Weakness Lack of explanation of origin of texture 3b. Many students simply described the texture Inability by many to describe two simple practical tests to distinguish between marble and metaquartzite Limited understanding by many of the conditions of dynamic metamorphism

13. Answers to this question revealed glaring gaps in very basic geological knowledge by many candidates! Quartz has cleavage!

14. Too easy for A2? It proved to be a really good discriminator! Many candidates failed to link marble with calcite and metaquartzite with quartz to devise simple practical tests to distinguish them apart.

15. Question 4: Structural Geology Areas of Weakness Drawing of Interlimb angle, overturned limb and cleavage/bedding intersection poorly attempted by many Amplitude is not understood by the majority of candidates Many students are poor at evaluating geological statements. They seem to agree or disagree with everything or contradict themselves time and again.

16. A typical answer scoring half marks Only part of the interlimb angle is indicated Axial plane most commonly plotted correctly Bedding/cleavage intersection is pointing to the middle of the bed

17. All 4 items plotted correctly for 2 marks

18. Amplitude The same mistakes made as in previous years Candidates simply measured the distance between the crest and trough of the fold Amplitude is half the distance between crest and trough

19. Not the perfect answer but a good attempt at an evaluation and worth full marks! This question was another good discriminator.

20. Section B – BGS Mapwork Key to symbols omitted Slight difference in colour between map and generalised vertical column Metamorphic aureole symbol rather faint Candidates did not seem to be disadvantaged by this!

21. Question 5 (a) (i) A number of candidates regularly fail to realise that two directions are required for the strike credit A small hyphen was inserted in the response box to help candidates! A small number of candidates took this as a signal to leave the box blank!

22. Question 5 (a) (ii) Description of folding in box A was well done by many candidates Weaker candidates failed to refer to symmetry or quote dip values and strike orientations Only the better candidates referred to a basin structure or plunge directions

23. Question 5 (b) A good understanding shown here by many candidates. Graben structure recognised by the majority with the central block being downthrown between 2 parallel faults A small number of candidates found it a challenge however-see below!

24. Question 6 (a) Generally well answered but the answers for the angle of dip of the Ochil Fault were bewildering at times and included: 7, 15, 45, 99, 105, 115, 129, 145, 171 degrees Only a minority of candidates noticed that the vertical scale had been exaggerated by x 2 Credit was given for reference to apparent dip as the section may not have been at right angles to the fault plane

25. Question 6 (c) The examiners appreciate that the size of the boxes restricted candidates from giving fully detailed reasons. A few candidates mistakenly reasoned the relative ages of the three boxes rather than each of the pairs in turn!

26. Question 7 (a) The majority of candidates identified (H) Pluton and (P) Dyke The better candidates drew clear cross sections to explain how the angle of the contact affected the width of the aureole

27. Question 7 (b) Some excellent answers here with very detailed annotations Some candidates mixed up baked and chilled margins A small number of candidates left this completely blank

28. Question 8 Some candidates gave non-geological factors for which little credit could be given Reference to noise, air quality and eyesore were common errors The label on the cross section reading ‘superficial deposits not shown on the map’ seemed to cause confusion among some candidates when evaluating site G

30. Question 8 Some candidates ignored ‘landfill’ and referred to problems of opening up the quarry for further extraction of rock Most candidates decided either good or bad for each site rather than evaluating all the evidence Candidates should be aware that all sites have the potential to be a landfill site if there is sufficient engineering employed-e.g. clay liner

31. Question 8 Good discussion of geological factors included: Rock permeability and dip direction of beds Synclinal structure of argillaceous rocks Possibility of fault reactivation Mining history and potential for subsidence Impermeability of igneous rocks Very few candidates attempted to put the three sites in a possible rank order from most to least suitable

32. Some candidates were quite appreciative of the examiner’s efforts in marking their papers

33. The End