P B G L T R O G O N I E A T U A I A P U U N N G [TGS7404] 2 SKS teori

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1 P B G L T R O G O N I E A T U A I A P U U N N G [TGS7404] 2 SKS teori
Semester 7, P T R B O G N E O I A T U A G I A P U U N N G [TGS7404] 2 SKS teori Dr. Hill. Gendoet Hartono

2 UTS UAS Rock Forming Mineral 1X Kimia Mineral Pembentuk Batuan 1X
PENDAHULUAN 1X Berisi tentang latarbelakang, bumi, batuan beku dan batuan gunung api, dan kedudukan di bidang geologi UTS TATAAN TEKTONIK 2X Berisi tentang tektonik global, regim tektonik, dan peranannya dalam magmatisme dan volkanisme GENERASI MAGMA 2X Berisi tentang magmatisme, diagram fase KLASIFIKASI 2X Klasifikasi magma atau afinitas magma Rock Forming Mineral 1X UAS Kimia Mineral Pembentuk Batuan 1X Petrologi Batuan Intrusi Dangkal 2X Petrologi Batuan Gunung Api 2X Alterasi Batuan Gunung Api 1X

3 GENERASI MAGMA- 1

4 Constructive Plate Margins
What is it that melts? Upper mantle/peridotite What is it’s composition? Ultrabasic. Why does it melt? Reduced P as crust above is stretched and thinned. Increase in T due to hot rising convection currents.

5 What kind of magma is produced by melting the ultrabasic mantle?
What does the magma do? Rises up through the thin crust to the surface. It may erupt underwater to produce what? Basalt pillow lavas.

6 Some of this basic magma will cool in the fractures feeding up to the surface.
What rock and structure will form? Sheeted dolerite dykes. Some magma will cool in the magma chamber to form what rock? Gabbro.

7 Destructive Ocean vs Ocean Collision
Increased Temperature of geothermal gradient as the plate sinks deeper. The melting oceanic crust is basic Rising magma is more SiO2 rich and so will move towards being intermediate. magma will move upwards through the overlying mantle and thin crust to the surface to make an island arc.

8 Explosive volcanic activity.
Basic/intermediate magma will be fairly violent. The products are lavas and pyroclastics. Lavas: Mainly andesites. Pyroclastic deposits: Ash = tuff. Pyroclastic flow deposit = ignimbrite. Large blocks close to the vent = (vent) agglomerate.

9 What intrusive rocks may form?
Plutonic intrusions that form deep down in batholiths. What will be the crystal size? Coarse. They will tend to be intermediate so what will the rock be? Diorite.

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16 See you..soon... See you..soon...