1. CHAPTER 3 Marine Provinces

2. Continental margins
Fig. 3.6

3. Measuring bathymetry
Fig. 3.3a

4. Continental margins Passive Not close to any p _______b_________
No major t_________ activity
Example: ____________

5. Continental margins Active Convergent active margin
Associated with c________ or t_________ plate boundaries
Much t________ activity=
Convergent active margin
Oceanic-continental convergence
Example:

6. Continental margins Transform active margin
Associated with transform plate boundaries
Example:

7. Continental Shelf= Continental slope=
Submarine canyons cut into slope by turbidity currents
Mixture of seawater and sediments
Move under influence of gravity
Deposit sediments at base of slope

8. Continental slope and submarine canyons
Fig. 3.9a

9. Abyssal plains
Fig. 3.11

10. Volcanic peaks Poke through sediment cover Below sea level:
Seamounts, or guyots at least 1 km (0.6 m) above sea floor
Above sea level:
Volcanic islands

11. Ocean trenches Linear, narrow, steep-sided
Associated with subduction zones
Deepest parts of ocean
Mariana Trench, 11,022 m (36,161 ft)
Majority in Pacific Ocean

12. Ocean trenches
Fig. 3.12

13. Volcanic arcs Landward side of ocean trench Island arc Continental arc
Chain of islands, e.g., Japan
Continental arc
Volcanic mountain range, e.g., Andes Mountains

14. Mid-ocean ridge Longest mountain chain
On average, 2.5 km (1.5 miles) above surrounding sea floor
Wholly volcanic
Basaltic lava
Divergent plate boundary

15. Rift valley, faults, and fissures
Downdropped rift valley at central crest
Cracks (fissures) and faults common
Fig. 3.17

16. Volcanic features of mid-ocean ridge
Hydrothermal vents
Heated subsurface seawater migrates through cracks in ocean crust
Warm-water vents <30oC or 86oF
White smokers >30oC <350oC or 662oF
Black smokers > 350oC

17. Hydrothermal vents
Fig. 3.16a

18. Hydrothermal vents
Dissolved metals precipitate to form metal sulfide deposits
Unusual biological communities
Able to survive without sunlight
Archaeons and bacteria oxidize hydrogen sulfide gas to provide food

19. End of CHAPTER 3 Marine Provinces
Fig. 3C