文档介绍：Understanding Earth
Fifth Edition
Chapter 4:
IGNEOUS ROCKS
Solids from Melts
Copyright © 2007 by W. H. Freeman pany
Grotzinger • Jordan • Press • Siever
Chapter 4
Igneous Rocks(火成岩):
Solids from Melts(從熔岩到固體)
Lecture Outline
How do igneous rocks differ from one another? (不同火成岩之間有何不同?)
2. How do magmas form? (岩漿如何形成?)
3. Where do magmas form? (岩漿在那裏形成)
4. Magmatic differentiation (岩漿分化作用)
5. Forms of magmatic intrusion(岩漿侵入的形態)
6. Igneous activity and plate tectonics (火山活動與板塊運動的關係)
About Igneous Rocks
Igneous rocks form from liquid rock (magma) in several different ways.
(火成岩的形成是經由不同的方式由岩漿固化而成)
Igneous processes within the Earth produce intrusive igneous rocks.
(火成岩的形成是岩漿在地下深處凝結而成,稱為侵入岩)
Igneous processes on or near Earth’s surface produce extrusive igneous rocks.
(火成岩的形成是岩漿在地表或近地表凝結而成,稱為噴出岩)
How do igneous rocks differ
from one another?
Texture – size of crystals
(岩理- 礦物結晶的大小)
Coarse-grained rocks
(粒狀組織岩石:岩漿冷卻很慢,各種礦物的結晶以肉眼即可辨認)
Fine-grained rocks
(微晶組織岩石:岩漿冷卻較慢,礦物可結成微小的晶體,肉眼辨認
不易)
Mixed texture rocks
(斑狀組織岩石:粒狀與微晶組織皆存在)
How do igneous rocks differ
from one another?
偏光顯微鏡
How do igneous rocks differ
from one another?
Clues about significance of texture
(火成岩的岩理的重要性)
Early studies of volcanic rocks
(從早期的火山岩石的研究)
Laboratory crystallization studies
(從實驗室的礦物與岩石的結晶研究)
Studies of slow cooling in granite
(從研究花崗岩的慢速冷卻)
How do igneous rocks differ
from one another?
Texture is related to rate of cooling.
(岩理與岩漿的冷卻速率有關)
Intrusive igneous rocks
(深成岩-SLOW COOLING)
Extrusive igneous rocks
(Lavas and pyroclastic rocks)
(噴出岩-FAST COOLING)
Intrusive igneous rocks
侵入岩
Slow cooling of magma in earth’s interior
粗顆粒礦物晶體
Plutonic rocks (深成岩)
圍在侵入岩四周的岩石稱為country rock (圍岩)
Extrusive igneous rocks
噴出型火成岩
Rapid cooling at earth’s surface
細顆粒礦物晶體
包含部分或大部分火山玻璃
Volcanic rocks(火山岩)