Lesson 7-What are hotspots and what is orogenesis?

Question 1

Hot spot

Answer 1

• Anomolous area of the outer core where there is rising magma
  -magma plume, hotter than surrounding magma rises through lithosphere to create a chain of shield volcanos as the plate move

Question 2

Volcanos at hot spots

Answer 2

• Gently sloping
• Less viscous
• Basaltic lavas
• Predictable, gentle eruptions

Question 3

CASE STUDY-Hawaii

Answer 3

• Pacific plate moves NW over the hotspot
  -formed a chain of volcanos including Mauana,Lou in Hawaii
  -age of volcanos increase with distance NW of Hawaii

Question 4

How do mountains form?

Answer 4

• Collision
• 2 continental plates colliding
• Volcanos are alos a type of mountain

Question 5

Volcanos

Answer 5

• Type of mountain where magma intrudes through the crust and eruptions build up layers of ash and lava

Question 6

Stage one of mountain building

Answer 6

• Build up of sediment in large depressions known as geosynclines
  -accumilation of sediment deposits on edge of continent

Question 7

Stage two of mountain building

Answer 7

• Orogenic period of rock deformation and crustal uplift occurs as the two plates converge due to compressional and tensional stresses
  -sediment deposits out acretionary

Question 8

Stage three of mountain building

Answer 8

• Crustal uplift caused by isostatic rebound
  -vertical movement of continental crust
  -(asthenosphere) as the weight is remopved from it causing it to float higher

Question 9

Igneous rocks

Answer 9

• Formed from cooling magma
  -basalt, granite

Question 10

Metamorphic

Answer 10

• Formed from pressure
  -slate

Question 11

Sedimentary

Answer 11

• Build up of sediment
  -sandstone, limestone

Question 12

The Himilayas

Answer 12

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