Mars Geology Dr. Ganna (Anya) Portyankina September, 2015

1

2

General information about Mars 3

4

5

6

7

8

All terrestrial planets have craters vv 9

Craters form when asteroids or comets crash into the surface of a planet. Impacts carve out a depression Material blasted away from the impact site is called ‘ejecta’ 10

Craters give us information about the target surface and impactor (sizes, composition, material strength) surface ‘age’ or the time since the surface formed 11

Geological record I: craters 12

13

New crater with ice 14

15

16

Volcanism Molten rock (magma) inside a planet is released at the surface Why does it rise? – It is less dense than solid rock – It is squeezed upward – It contains gases (that expand) Three types, distinguished by viscosity of eruptions: – Stratovolcanoes - steep-sided – Shield volcanoes - shallow- sided – Lava plains - flat, runny flows 17

Geological record II: volcanoes 18

Olympus Mons 19

Tectonics Tectonics refers to deformation of the lithosphere This can include stretching, compressing, bending, and cracking Most tectonics results from mantle convection Earth has plate tectonics, as it has an ocean and hence 2 types of crust 20

Geological record III: tectonics 21

Valles Marineris 22

Erosion Erosion is the breakdown or transport of surface material by liquid, ice, atmosphere / wind, or even other rocks 23

Geological record IV: erosion 24

Geological record IV: erosion 25

26 Gullies

27 Sediment layering