a fun geology quiz
TRANSCRIPT
A fun quiz…
Look at the image, think of your answer, then move to the next slide for the model response – 15 questions in all.
1) What type of folds can you see in the photograph?
1 m
Answer: Chevron folds.
Image courtesy of:https://commons.wikimedia.org/wiki/Category:Chevron_folds#/media/File:Agiospavlos_DM_2004_IMG002_Felsenformation.JPG
2) What type of fold is this?
10 cm
Answer: A ptygmatic fold (of a competent igneous rock dyke: a pegmatite).
Image courtesy of:https://commons.wikimedia.org/wiki/Category:Ptygmatic_folding#/media/File:Folded_Pegmatite_in_Lava_in_Grand_Canyon_USA.jpg
3) What kind of fold is this?
10 cm
Answer: an isoclinal fold.
Image courtesy of:https://commons.wikimedia.org/wiki/File:Isoclinal_fold.JPG?uselang=en-gb
4) This is similar to the fold in (3), but not quite the same, what kind of fold do you think it is?
2 m
Answer: a recumbent fold.
Image courtesy of:http://www.geograph.org.uk/photo/1945620
5) How would you describe this fold structure – what is it called?
Scale:anything from 2 cm to >2 km!
Answer: a monocline
Image courtesy of:https://commons.wikimedia.org/wiki/Category:Monocline_schemas#/media/File:Monocline01.svg
6) How would you describe the cleavage in this image?
30 cm
Answer: Axial planar cleavage within an isoclinal fold.
Image courtesy of:http://www.geograph.org.uk/photo/1945635
7) What type of fold is being created here? What is the overall structure?
Scale: anything From 2cm to> 10 km!
Answer: a fault-propagation fold nucleates at the fault tip, and grows as deformation continues. The overall structure is that of a thrust fault.
Image courtesy of:https://commons.wikimedia.org/wiki/Category:Folding_schemas#/media/File:Fault-propagation_fold.gif
8) What is happening in the three images?
Scale: anything From 2cm to> 10 km!
Answer: The three diagrams show the progressive formation of a thrust duplex/series of nappes.
Image courtesy of:https://commons.wikimedia.org/wiki/Category:Folding_schemas#/media/File:Duplex1.png
9) What structural feature can you see in the photograph?
20 cm
Answer: Boudinage. A competent quartz vein is boudinaged within a more ductile schist.
Image courtesy ofhttps://upload.wikimedia.org/wikipedia/commons/b/b8/Samos_boudins.JPG
10) What are the linear grooves in the photo?
Answer: Slickensides developed on small fault indicate movement in to, or out of the photo.
Image courtesy of:https://commons.wikimedia.org/wiki/File:Slickensides.JPG
11) Describe the feature in the photo – what is the sense of displacement?
2 m
Answer: A high angle brittle reverse fault cutting through competent bedded sedimentary rock. The large drag fold indicates that the rocks on the right hand side have been displaced upwards, relative to the left hand side (thus a reverse fault).
Image courtesy of:https://en.wikipedia.org/wiki/Fault_(geology)#/media/File:Faille_des_Causses_depuis_Bedarieux.dsc02071.cropped.jpg
12) Where is this photo taken and what structural feature does it possibly represent?
5 m
Answer: Malham Cove, southern Yorkshire Dales: Carboniferous Limestone ampitheatre cliff face possibly formed as a fault scarp on the Middle Craven Fault which has since retreated by circa 600 m.
Image courtesy of:https://en.wikipedia.org/wiki/Craven_Fault_System#/media/File:Malham_Cove.jpg
13) What is the sequence of events in this photo (from Ingleton Quarry)?
50 cm
Answer: 1) turbidites laid down (bedding), 2)sediments lithified, 3) cleavage formed parallel to bedding, 4) lamprophyre dyke injected at an angle to bedding and cleavage and 5)chilled margin forms in dyke, next to contact with country rock.
Image courtesy of Annette McGrath
14) What structure can you see in the image? What does the yellow area represent?
Scale: anything From 2cm to> 2 km!
Answer: Cartoon showing the development of a rollover anticline above a syn-sedimentary listric extensional fault (also known as a growth fault). The yellow area represents syn-tectonic sedimentary basin deposits.
Image courtesy of:https://commons.wikimedia.org/wiki/File:Rollover.png?uselang=en-gb
15) Describe the structural setting. What are 1, 2 and 3?
200 m
Answer: Extensional setting, like the “Block and Basin Province”, similar to that of the Lower Carboniferous of the North Pennines; 1=Horst, 2=Graben and 3=Normal fault.
Image courtesy of:https://commons.wikimedia.org/wiki/File:Graben_Horst.png?uselang=en-gb