volcanology

Question 1

what is volcanology

Answer 1

process by which solids, liquids and gaseous materials are forced into the earths crust or ejected onto the surface

Question 2

what is magma

Answer 2

molten rock below the earths surface

Question 3

what is lava

Answer 3

molten rock that has reached the earths surface

Question 4

igneous rock?

Answer 4

extrusive and intrusive materials cooled from magma

Question 5

compare basaltic to andesitic lava

Answer 5

- Basaltic Lava
hotter at about 1200 degrees, not as thick and flows fast
low silica content
found at constructive margins
takes long to solidify 
less viscous
- Andesitic Lava
cooler at about 800 degrees, thicker and flows slower
high silica content
found at destructive margins
solidifies quickly
viscous

Question 6

pyroclastic material

Answer 6

material ejected by a volcano in a fragmented form

Question 7

list 6 different types of volcanoes and explain each

Answer 7

Fissure - 2 plates move apart forming a slit like opening, and basaltic lava flows over a long distance down a gentle slope
Shield - central vent, gentle sloping sides built up by numerous basaltic flows
dome - acid lava quickly solidifies forming a steep slope
cinder cones - slightly concave, built up of layers of fine ash and cinders
composite cones - cone shaped, formed by alternating ash and lava eruptions forming layers
calderas - built up of gases, explosion clears the summit of the volcano forming large crater like shape

Question 8

hydromagmatic?

Answer 8

any eruptive process in which magma and lava interact with external water

Question 9

Sill?

Answer 9

horizontal sheet intrusion along bedding plane with vertical cooling cracks, cools rapidly on outside on contact with surrounding rocks

Question 10

dyke

Answer 10

vertical sheet intrusion with horizontal cooling cracks, cooling rapidly on contacts with surrounding rocks

Question 11

batholith

Answer 11

deep seated and surrounded by hot rock, magma cools slowly so that large crystals form and that there is a large metamorphic contact zone