Plate boundaries: divergent

1. TypesofPlate
Boundaries

2. LEARNINGCOMPETENCIES
Describethedifferenttypesof
plateboundaries.
S10ES–Ia-j-36.2

3. SpecificObjectives
1. Explain the processes that occur
alongdivergentboundaries.
2. Determine the results of plates that
aremovingapart.

4. Let’s have
short recall!

5. WhatTypeofPlateBoundaryisthis?

6. It’sConvergentBoundary
Plate A.
Plate B.
The leading plate of plate A.
What happened to
the leading plate of
Plate A?
The end plate of plate A.
It turns into magma?
What do you think is
happening on the
other end of plate A?
Creation of new crust?

7. Act4:GoingSeparateWays
1. AnalyzethephotographsofRiftValleyandOceanicRidges
Rift Valleys
Ocean Ridges

8. Act4:GoingSeparateWays
Question28:
Whatarecommoninthefourpictures?
ANSWER:
Afissureoracrackbetweentwolandmasses.

9. Act4:GoingSeparateWays
Question 29. Millions of years ago, the land masses in each
picture were once connected. What do you think is happening
totheEarth’scrustinthosepictures?
ANSWER:
Thelandmassesaremovingawayfromeach
other.

10. Act4:GoingSeparateWays
Question 30. If this event continues for millions of years,
whatdoyouthinkwillbetheeffectonthecrust?
ANSWER:
Thedistancebetweenthelandmasseswillbefar
greaterthanwhatisshowninthepicture.

11. Act4:GoingSeparateWays
Question 31. Complete the drawing below to illustrate your
answerinquestionnumber30.
ANSWER:
(thedrawingmustshowawidercrackorfissurebetweentwolandmasses)

12. DivergentBoundary
When two plates aremoving away from one another.
Occurs above rising convection currents.
Example:
between Antarctic Plate and Australian Plate
between Nazca Plate and Pacific Plate
between Arabian Plate and African Plate

13. ConvectionCurrent
• MantleConvectionCurrent
• The rising current pushes up on the
bottom of the lithosphere, lifting it and
flowinglaterallybeneathit.
• At the crest of the uplift, the overlying
plate is stretched thin, breaks and pulls
apart.

14. ConvectionCurrent
• Astheplatesseparate,newmaterialsfromthemantleoozeupto
fillthegap.Thesematerialswillslowlycooltoproducenewocean
floororcrust.

15. It’sConvergentBoundary
Plate A.
Plate B.
The leading plate of plate A.
What happened to
the leading plate of
Plate A?
The end plate of plate A.
It turns into magma?
What do you think is
happening on the
other end of plate A?
Creation of new crust?

16. The Divergence of
two plates can
occur in both
oceanic and
continental crust

17. DivergentPlateBoundaryinOceanicCrust
Whenadivergentboundaryoccursbeneathoceaniclithosphere,the
risingconvectioncurrentbelowliftsthelithosphere,producinga
mid-oceanridge.
Mid-AtlanticOceanRidge(divergenceoftheSouthAmericanPlateand
theAfricanPlate)

18. DivergentPlateBoundaryinContinentalCrust
Whenadivergentboundaryoccursbeneathcontinentallithosphere,the
crustmaybreakintoseveralsegments.
RiftValleys.
EastAfricaRiftValley
RedSea