1. Which supercontinent rifted to allow deposition of Dalradian sediments?
Rodinia
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2. What evidence is there that mountains existed in the Grampian Highlands in the late Ordovician/Silurian?
6-15 km must have been eroded by 410 Ma to expose the deeper metamorphic zones and large granitic plutons. Cooling to 300°C at 25-30 Ma after metamorphic peak. Lavas / conglomerates directly on metamorphics and granites by 410 Ma
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3. Give the name of the group of pre-Dalradian rocks at the Northern margin of the Grampian Highlands. What is the evidence that these rocks are older?
Dava / Glen Banchor succession. Higher grade of metamorphism and sheared contact / unconformity. (2 marks)
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4. What is the likely age-range of Dalradian sedimentation. Give evidence.
806 Ma – monazite age on deformation beneath the unconformity, 490 Ma – acritarchs in Macduff slates
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5. What is the name of the glacial deposit within the Dalradian sequence?
Port Askaig tillite (1 mark)
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6. Name 2 other countries where an equivalent succession to the Dalradian can be found?
Greenland, Svalbard (Norway), Ireland, Canada, USA (2 marks)
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Other cards in this set
Card 2
Front
2. What evidence is there that mountains existed in the Grampian Highlands in the late Ordovician/Silurian?
Back
6-15 km must have been eroded by 410 Ma to expose the deeper metamorphic zones and large granitic plutons. Cooling to 300°C at 25-30 Ma after metamorphic peak. Lavas / conglomerates directly on metamorphics and granites by 410 Ma
Card 3
Front
3. Give the name of the group of pre-Dalradian rocks at the Northern margin of the Grampian Highlands. What is the evidence that these rocks are older?
Back
Card 4
Front
4. What is the likely age-range of Dalradian sedimentation. Give evidence.
Back
Card 5
Front
5. What is the name of the glacial deposit within the Dalradian sequence?
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