![Page 1: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/1.jpg)
INTRODUCTION TO PETROLOGY
![Page 2: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/2.jpg)
WHAT IS PETROLOGY???
![Page 3: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/3.jpg)
WHAT IS PETROLOGY???
Study of rocks (“petros”)
igneous & metamorphic
chiefly in the lithosphere
![Page 4: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/4.jpg)
WHAT IS PETROLOGY???
Study of rocks (“petros”)
igneous & metamorphic
chiefly in the lithosphere
We will be dealing with hot rocks
tell us about composition & history of lithosphere
origin of rocks involves:
transfer of heat (energy)
movement of material
![Page 5: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/5.jpg)
WHAT IS PETROLOGY???
Study of rocks (“petros”)
igneous & metamorphic
chiefly in the lithosphere
We will be dealing with hot rocks
tell us about composition & history of lithosphere
origin of rocks involves:
transfer of heat (energy)
movement of material
LITHOSPHERE
![Page 6: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/6.jpg)
THINK LIKE A PETROLOGIST
what criteria do we use to distinguish rocks?
what do we want to know?
how do we answer these questions?
![Page 7: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/7.jpg)
WHAT DO WE WANT TO KNOW?
how do we make melts?
what is melted, and where? what is the role of water?
how do melts behave during solidification?
what causes metamorphism?
how are metamorphism & deformation related?
how to rocks flow in the interior of mountain belts?
how do tectonic rates compare to heat conduction rates?
in what tectonic settings do these rocks form?
![Page 8: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/8.jpg)
BASIS FOR UNDERSTANDING
field methods & sample study (observation)
theory, experiment & modeling (analytical)
![Page 9: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/9.jpg)
THINGS TO CONSIDER
![Page 10: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/10.jpg)
THINGS TO CONSIDER
materials of earth
![Page 11: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/11.jpg)
THINGS TO CONSIDER
materials of earth
physical conditions
energy
pressure
temperature & heat
![Page 12: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/12.jpg)
THINGS TO CONSIDER
materials of earth
physical conditions
energy
pressure
temperature & heat
relationship to tectonics
![Page 13: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/13.jpg)
THINGS TO CONSIDER
materials of earth
physical conditions
energy
pressure
temperature & heat
relationship to tectonics
EgyPT
![Page 14: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/14.jpg)
EARTH INTERIOR
Si-r
ich
Fe-r
ich
![Page 15: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/15.jpg)
EARTH INTERIOR
Structure of Earth:
Si-r
ich
Fe-r
ich
![Page 16: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/16.jpg)
EARTH INTERIOR
Structure of Earth:
chemical divisions
core, mantle & crust
Si-r
ich
Fe-r
ich
![Page 17: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/17.jpg)
EARTH INTERIOR
Structure of Earth:
chemical divisions
core, mantle & crust
mechanical divisions
mesosphere, asthenosphere & lithosphere
Si-r
ich
Fe-r
ich
![Page 18: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/18.jpg)
EARTH INTERIOR
Si-r
ich
Fe-r
ich
![Page 19: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/19.jpg)
EARTH INTERIOR
Core:
Si-r
ich
Fe-r
ich
![Page 20: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/20.jpg)
EARTH INTERIOR
Core:
Fe-Ni metallic alloy
outer core is liquid (no S-waves)
inner core is solid
Si-r
ich
Fe-r
ich
![Page 21: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/21.jpg)
EARTH INTERIOR
Core:
Fe-Ni metallic alloy
outer core is liquid (no S-waves)
inner core is solid
differentiation at work!
compositional separation within the planet (fractionation)
Si-r
ich
Fe-r
ich
![Page 22: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/22.jpg)
EARTH INTERIOR
Si-r
ich
Fe-r
ich
![Page 23: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/23.jpg)
EARTH INTERIOR
Mantle:
Si-r
ich
Fe-r
ich
![Page 24: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/24.jpg)
EARTH INTERIOR
Mantle:
peridotite (ultramafic)
greatest V, m & E (moves & carries heat)
Si-r
ich
Fe-r
ich
![Page 25: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/25.jpg)
EARTH INTERIOR
Mantle:
peridotite (ultramafic)
greatest V, m & E (moves & carries heat)
upper layer to 410 km (olivine to spinel)
contains low velocity layer 60-220 km
Si-r
ich
Fe-r
ich
![Page 26: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/26.jpg)
EARTH INTERIOR
Mantle:
peridotite (ultramafic)
greatest V, m & E (moves & carries heat)
upper layer to 410 km (olivine to spinel)
contains low velocity layer 60-220 km
transition zone between 410-660 km (spinel to perovskite)
SiIV to SiVI
Si-r
ich
Fe-r
ich
![Page 27: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/27.jpg)
EARTH INTERIOR
Mantle:
peridotite (ultramafic)
greatest V, m & E (moves & carries heat)
upper layer to 410 km (olivine to spinel)
contains low velocity layer 60-220 km
transition zone between 410-660 km (spinel to perovskite)
SiIV to SiVI
lower mantle has more gradual velocity increase
Si-r
ich
Fe-r
ich
![Page 28: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/28.jpg)
EARTH INTERIOR
Si-r
ich
Fe-r
ich
![Page 29: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/29.jpg)
EARTH INTERIOR
Crust:
Si-r
ich
Fe-r
ich
![Page 30: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/30.jpg)
EARTH INTERIOR
Crust:
mafic (magnesium + ferric)to felsic (feldspar + silica)
rich in Si, Al, K, Na, Ca
Si-r
ich
Fe-r
ich
![Page 31: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/31.jpg)
EARTH INTERIOR
Crust:
mafic (magnesium + ferric)to felsic (feldspar + silica)
rich in Si, Al, K, Na, Ca
two main types:
oceanic
continental
+ “transitional”
Si-r
ich
Fe-r
ich
![Page 32: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/32.jpg)
EARTH INTERIOR
![Page 33: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/33.jpg)
EARTH INTERIOR
Oceanic crust:
![Page 34: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/34.jpg)
EARTH INTERIOR
Oceanic crust:
thin: ~10 km on average
![Page 35: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/35.jpg)
EARTH INTERIOR
Oceanic crust:
thin: ~10 km on average
dense: ρavg = 3.0 g/cm3
![Page 36: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/36.jpg)
EARTH INTERIOR
Oceanic crust:
thin: ~10 km on average
dense: ρavg = 3.0 g/cm3
relatively uniform stratigraphy(= ophiolite suite)
![Page 37: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/37.jpg)
EARTH INTERIOR
Oceanic crust:
thin: ~10 km on average
dense: ρavg = 3.0 g/cm3
relatively uniform stratigraphy(= ophiolite suite)
sediments
![Page 38: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/38.jpg)
EARTH INTERIOR
Oceanic crust:
thin: ~10 km on average
dense: ρavg = 3.0 g/cm3
relatively uniform stratigraphy(= ophiolite suite)
sediments
pillow basalt
![Page 39: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/39.jpg)
EARTH INTERIOR
Oceanic crust:
thin: ~10 km on average
dense: ρavg = 3.0 g/cm3
relatively uniform stratigraphy(= ophiolite suite)
sediments
pillow basalt
sheeted dikes
![Page 40: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/40.jpg)
EARTH INTERIOR
Oceanic crust:
thin: ~10 km on average
dense: ρavg = 3.0 g/cm3
relatively uniform stratigraphy(= ophiolite suite)
sediments
pillow basalt
sheeted dikes
massive gabbro
![Page 41: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/41.jpg)
EARTH INTERIOR
Oceanic crust:
thin: ~10 km on average
dense: ρavg = 3.0 g/cm3
relatively uniform stratigraphy(= ophiolite suite)
sediments
pillow basalt
sheeted dikes
massive gabbro
ultramafic rocks (mantle)
![Page 42: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/42.jpg)
EARTH INTERIOR
mafic rocks
Oceanic crust:
thin: ~10 km on average
dense: ρavg = 3.0 g/cm3
relatively uniform stratigraphy(= ophiolite suite)
sediments
pillow basalt
sheeted dikes
massive gabbro
ultramafic rocks (mantle)
![Page 43: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/43.jpg)
CONTINENTAL OCEANIC
![Page 44: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/44.jpg)
EARTH INTERIOR
![Page 45: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/45.jpg)
EARTH INTERIOR
Continental crust:
thicker: 20-90 km (avg = 35 km)
less dense: ρavg = 2.7 g/cm3
highly variable composition
average = granodiorite
![Page 46: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/46.jpg)
CHEMICAL DIVISIONS
![Page 47: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/47.jpg)
divisions separate Earth into Si-rich and Fe-rich spheres, largely a result of early chemical differentiation based on a redistribution of matter, prior to major solidification, by density
CHEMICAL DIVISIONS
![Page 48: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/48.jpg)
divisions separate Earth into Si-rich and Fe-rich spheres, largely a result of early chemical differentiation based on a redistribution of matter, prior to major solidification, by density
later, continued differentiation was (and is) mostly a result of melting and igneous process
CHEMICAL DIVISIONS
![Page 49: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/49.jpg)
divisions separate Earth into Si-rich and Fe-rich spheres, largely a result of early chemical differentiation based on a redistribution of matter, prior to major solidification, by density
later, continued differentiation was (and is) mostly a result of melting and igneous process
how do we know these things???
CHEMICAL DIVISIONS
![Page 50: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/50.jpg)
divisions separate Earth into Si-rich and Fe-rich spheres, largely a result of early chemical differentiation based on a redistribution of matter, prior to major solidification, by density
later, continued differentiation was (and is) mostly a result of melting and igneous process
how do we know these things???
seismic velocity structure
CHEMICAL DIVISIONS
![Page 51: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/51.jpg)
divisions separate Earth into Si-rich and Fe-rich spheres, largely a result of early chemical differentiation based on a redistribution of matter, prior to major solidification, by density
later, continued differentiation was (and is) mostly a result of melting and igneous process
how do we know these things???
seismic velocity structure
meteorites
CHEMICAL DIVISIONS
![Page 52: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/52.jpg)
divisions separate Earth into Si-rich and Fe-rich spheres, largely a result of early chemical differentiation based on a redistribution of matter, prior to major solidification, by density
later, continued differentiation was (and is) mostly a result of melting and igneous process
how do we know these things???
seismic velocity structure
meteorites
xenoliths in volcanics
CHEMICAL DIVISIONS
![Page 53: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/53.jpg)
divisions separate Earth into Si-rich and Fe-rich spheres, largely a result of early chemical differentiation based on a redistribution of matter, prior to major solidification, by density
later, continued differentiation was (and is) mostly a result of melting and igneous process
how do we know these things???
seismic velocity structure
meteorites
xenoliths in volcanics
experimental petrology
CHEMICAL DIVISIONS
![Page 54: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/54.jpg)
MECHANICAL DIVISIONS
Figure 1-3. Variation in P and S wave velocities with depth. Compositional subdivisions of the Earth are on the left, rheological subdivisions on the right. After Kearey and Vine (1990), Global Tectonics. © Blackwell Scientific. Oxford.
![Page 55: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/55.jpg)
MECHANICAL DIVISIONS
Velocity structure (v)
Figure 1-3. Variation in P and S wave velocities with depth. Compositional subdivisions of the Earth are on the left, rheological subdivisions on the right. After Kearey and Vine (1990), Global Tectonics. © Blackwell Scientific. Oxford.
![Page 56: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/56.jpg)
MECHANICAL DIVISIONS
Velocity structure (v)
v increases with density (ρ)
v = f (ρ)
Figure 1-3. Variation in P and S wave velocities with depth. Compositional subdivisions of the Earth are on the left, rheological subdivisions on the right. After Kearey and Vine (1990), Global Tectonics. © Blackwell Scientific. Oxford.
![Page 57: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/57.jpg)
MECHANICAL DIVISIONS
Velocity structure (v)
v increases with density (ρ)
v = f (ρ)
ρ dependent on physical properties & compositions
ρ = f (X, T)
Figure 1-3. Variation in P and S wave velocities with depth. Compositional subdivisions of the Earth are on the left, rheological subdivisions on the right. After Kearey and Vine (1990), Global Tectonics. © Blackwell Scientific. Oxford.
![Page 58: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/58.jpg)
MECHANICAL DIVISIONS
Velocity structure (v)
v increases with density (ρ)
v = f (ρ)
ρ dependent on physical properties & compositions
ρ = f (X, T)
v increases with depth (z) — mostly!
Figure 1-3. Variation in P and S wave velocities with depth. Compositional subdivisions of the Earth are on the left, rheological subdivisions on the right. After Kearey and Vine (1990), Global Tectonics. © Blackwell Scientific. Oxford.
![Page 59: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/59.jpg)
MECHANICAL DIVISIONS
Velocity structure (v)
v increases with density (ρ)
v = f (ρ)
ρ dependent on physical properties & compositions
ρ = f (X, T)
v increases with depth (z) — mostly!
v discontinuities indicate a change in material composition ± properties
Figure 1-3. Variation in P and S wave velocities with depth. Compositional subdivisions of the Earth are on the left, rheological subdivisions on the right. After Kearey and Vine (1990), Global Tectonics. © Blackwell Scientific. Oxford.
![Page 60: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/60.jpg)
MECHANICAL DIVISIONS
composition property
LVZ
CMB
OC-IC
![Page 61: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/61.jpg)
MECHANICAL DIVISIONS
Velocity boundaries
composition property
LVZ
CMB
OC-IC
![Page 62: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/62.jpg)
MECHANICAL DIVISIONS
Velocity boundaries
source of LVZ?
composition property
LVZ
CMB
OC-IC
![Page 63: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/63.jpg)
MECHANICAL DIVISIONS
Velocity boundaries
source of LVZ?
warmer? liquid?
composition property
LVZ
CMB
OC-IC
![Page 64: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/64.jpg)
MECHANICAL DIVISIONS
Velocity boundaries
source of LVZ?
warmer? liquid?
source of CMB?
composition property
LVZ
CMB
OC-IC
![Page 65: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/65.jpg)
MECHANICAL DIVISIONS
Velocity boundaries
source of LVZ?
warmer? liquid?
source of CMB?
change in composition
composition property
LVZ
CMB
OC-IC
![Page 66: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/66.jpg)
MECHANICAL DIVISIONS
Velocity boundaries
source of LVZ?
warmer? liquid?
source of CMB?
change in composition
source of OC-IC?
composition property
LVZ
CMB
OC-IC
![Page 67: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/67.jpg)
MECHANICAL DIVISIONS
Velocity boundaries
source of LVZ?
warmer? liquid?
source of CMB?
change in composition
source of OC-IC?
phase change (S to L)
composition property
LVZ
CMB
OC-IC
![Page 68: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/68.jpg)
MECHANICAL DIVISIONS
Velocity boundaries
source of LVZ?
warmer? liquid?
source of CMB?
change in composition
source of OC-IC?
phase change (S to L)
composition property
LVZ
CMB
OC-IC
LET’S LOOK IN MORE DETAIL
![Page 69: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/69.jpg)
PETROLOGY & TECTONICS
major mineral transformations occur at ~410 and ~660 km
result from isochemical phase changes due to increased P
marked by seismic velocity discontinuities
Mineral Structure Depth Density
olivine tetrahedral low
spinel dense tetrahedral
perovskite octahedral high
~410 km
~660 km
![Page 70: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/70.jpg)
VARIATION IN SEISMIC VELOCITY, DENSITY & MINERAL STRUCTURE
![Page 71: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/71.jpg)
VARIATION IN SEISMIC VELOCITY, DENSITY & MINERAL STRUCTURE
HI
LO
![Page 72: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/72.jpg)
VARIATION IN SEISMIC VELOCITY, DENSITY & MINERAL STRUCTURE
HI
LO
HI
LO
![Page 73: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/73.jpg)
VARIATION IN SEISMIC VELOCITY, DENSITY & MINERAL STRUCTURE
MG-SILICATES
HI
LO
HI
LO
![Page 74: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/74.jpg)
VARIATION IN SEISMIC VELOCITY, DENSITY & MINERAL STRUCTURE
MG-SILICATES
HI
LO
HI
LO
ASTHENOSPH.
MESOSPHERE
T.Z.
![Page 75: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/75.jpg)
PETROLOGY & TECTONICS
Resulting divisions
lithosphere
asthenosphere
mesosphere
![Page 76: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/76.jpg)
PETROLOGY & TECTONICS
Resulting divisions
lithosphere
asthenosphere
mesosphere
properties?
![Page 77: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/77.jpg)
PETROLOGY & TECTONICS
Resulting divisions
lithosphere
asthenosphere
mesosphere
properties?
connections?
![Page 78: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/78.jpg)
PETROLOGY & TECTONICS
Resulting divisions
lithosphere
asthenosphere
mesosphere
properties?
connections?
is the mantle solid everywhere?
![Page 79: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/79.jpg)
MANTLE GEOTHERM
![Page 80: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/80.jpg)
MANTLE GEOTHERM
compare continental, oceanic & ridge
![Page 81: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/81.jpg)
MANTLE GEOTHERM
compare continental, oceanic & ridge
typical continental geotherm = 25 °C/km
![Page 82: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/82.jpg)
MANTLE GEOTHERM
compare continental, oceanic & ridge
typical continental geotherm = 25 °C/km
T @ 100 km = 1000 °C(enough to melt rocks!)
![Page 83: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/83.jpg)
MANTLE GEOTHERM
compare continental, oceanic & ridge
typical continental geotherm = 25 °C/km
T @ 100 km = 1000 °C(enough to melt rocks!)
are they molten? P too high? where?
![Page 84: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/84.jpg)
compare geotherm to petrologic solidus for mantle rocks (peridotite)
if “dry” conditions, no melting possible (geotherm below solidus)
solid lherzolite is stable at T above geotherm
CAN MELTING OCCUR?
![Page 85: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/85.jpg)
under “wet” conditions (with H2O or CO2), solidus shifts to lower T
melting can occur where T > solidus
low seismic velocities indicate partial melting between 100-250 km (the LVZ)
the LVZ marks the base of “plates” formed by rigid lithosphere
CAN MELTING OCCUR?
![Page 86: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/86.jpg)
under “wet” conditions (with H2O or CO2), solidus shifts to lower T
melting can occur where T > solidus
low seismic velocities indicate partial melting between 100-250 km (the LVZ)
the LVZ marks the base of “plates” formed by rigid lithosphere
CAN MELTING OCCUR?
![Page 87: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/87.jpg)
LITHOSPHERE
![Page 88: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/88.jpg)
LITHOSPHERE
![Page 89: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/89.jpg)
LITHOSPHERE
lithosphere includes crust + upper mantle
![Page 90: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/90.jpg)
LITHOSPHERE
lithosphere includes crust + upper mantle
can be oceanic, continental, or both
![Page 91: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/91.jpg)
LITHOSPHERE
lithosphere includes crust + upper mantle
can be oceanic, continental, or both
typical lithosphere is 100 km(70-125 km)
![Page 92: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/92.jpg)
LITHOSPHERE
lithosphere includes crust + upper mantle
can be oceanic, continental, or both
typical lithosphere is 100 km(70-125 km)
largely solid material (silicates)
![Page 93: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/93.jpg)
LITHOSPHERE
lithosphere includes crust + upper mantle
can be oceanic, continental, or both
typical lithosphere is 100 km(70-125 km)
largely solid material (silicates)
lowest densities (2.7-3.0 g/cm3)
![Page 94: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/94.jpg)
LITHOSPHERE
lithosphere includes crust + upper mantle
can be oceanic, continental, or both
typical lithosphere is 100 km(70-125 km)
largely solid material (silicates)
lowest densities (2.7-3.0 g/cm3)
slowest seismic velocities (6-8 km/sec)
![Page 95: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/95.jpg)
LITHOSPHERE
lithosphere includes crust + upper mantle
can be oceanic, continental, or both
typical lithosphere is 100 km(70-125 km)
largely solid material (silicates)
lowest densities (2.7-3.0 g/cm3)
slowest seismic velocities (6-8 km/sec)
internal boundary is the Moho (density boundary)
![Page 96: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/96.jpg)
LITHOSPHERE
lithosphere includes crust + upper mantle
can be oceanic, continental, or both
typical lithosphere is 100 km(70-125 km)
largely solid material (silicates)
lowest densities (2.7-3.0 g/cm3)
slowest seismic velocities (6-8 km/sec)
internal boundary is the Moho (density boundary)
base of lithosphere is the low-velocity zone (LVZ)
![Page 97: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/97.jpg)
LITHOSPHERE
lithosphere includes crust + upper mantle
can be oceanic, continental, or both
typical lithosphere is 100 km(70-125 km)
largely solid material (silicates)
lowest densities (2.7-3.0 g/cm3)
slowest seismic velocities (6-8 km/sec)
internal boundary is the Moho (density boundary)
base of lithosphere is the low-velocity zone (LVZ)
lithosphere = plate
![Page 98: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/98.jpg)
EgyPT
Physical conditions of Earth necessary to understand petrologic process:
1. pressure
2. temperature
3. energy & heat
![Page 99: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/99.jpg)
PRESSURE GRADIENT
Figure 1-8. Pressure variation with depth. From Dziewonski and Anderson (1981). Phys. Earth Planet. Int., 25, 297-356. © Elsevier Science.
![Page 100: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/100.jpg)
PRESSURE GRADIENT
P = ρgh
Figure 1-8. Pressure variation with depth. From Dziewonski and Anderson (1981). Phys. Earth Planet. Int., 25, 297-356. © Elsevier Science.
![Page 101: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/101.jpg)
PRESSURE GRADIENT
P = ρgh
P increases with depth
Figure 1-8. Pressure variation with depth. From Dziewonski and Anderson (1981). Phys. Earth Planet. Int., 25, 297-356. © Elsevier Science.
![Page 102: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/102.jpg)
PRESSURE GRADIENT
P = ρgh
P increases with depth
Figure 1-8. Pressure variation with depth. From Dziewonski and Anderson (1981). Phys. Earth Planet. Int., 25, 297-356. © Elsevier Science.
![Page 103: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/103.jpg)
PRESSURE GRADIENT
P = ρgh
P increases with depth
Mantle: nearly linear through mantle
~ 30 MPa/km
≈ 1 GPa at base of avg crust
Figure 1-8. Pressure variation with depth. From Dziewonski and Anderson (1981). Phys. Earth Planet. Int., 25, 297-356. © Elsevier Science.
![Page 104: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/104.jpg)
PRESSURE GRADIENT
P = ρgh
P increases with depth
Mantle: nearly linear through mantle
~ 30 MPa/km
≈ 1 GPa at base of avg crust
slope (ΔP/Δz) depends on density (composition & compressibility) of material
Figure 1-8. Pressure variation with depth. From Dziewonski and Anderson (1981). Phys. Earth Planet. Int., 25, 297-356. © Elsevier Science.
![Page 105: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/105.jpg)
PRESSURE GRADIENT
P = ρgh
P increases with depth
Mantle: nearly linear through mantle
~ 30 MPa/km
≈ 1 GPa at base of avg crust
slope (ΔP/Δz) depends on density (composition & compressibility) of material
Figure 1-8. Pressure variation with depth. From Dziewonski and Anderson (1981). Phys. Earth Planet. Int., 25, 297-356. © Elsevier Science.
LO
W D
EN
SIT
Y
HIG
H DEN
SITY
![Page 106: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/106.jpg)
PRESSURE GRADIENT
P = ρgh
P increases with depth
Core: ρ increases more rapidly since alloy is more dense
smaller increase in P with depth suggests inner core is more uniform, solid, and has decreasing compressibility
Figure 1-8. Pressure variation with depth. From Dziewonski and Anderson (1981). Phys. Earth Planet. Int., 25, 297-356. © Elsevier Science.
![Page 107: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/107.jpg)
PRESSURE IN THE CRUST
h
ρgh
![Page 108: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/108.jpg)
PRESSURE IN THE CRUST
in the crust, rocks “feel” a lithostatic pressure
like a submarine feels hydrostatic pressure on its hullimplies equal pressure in all directions when materials can flow h
ρgh
![Page 109: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/109.jpg)
PRESSURE IN THE CRUST
in the crust, rocks “feel” a lithostatic pressure
like a submarine feels hydrostatic pressure on its hullimplies equal pressure in all directions when materials can flow
for shallow rocks, can have differential pressure (where horizontal stress ≠ vertical stress), causing rocks to deform
h
ρgh
![Page 110: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/110.jpg)
PRESSURE IN THE CRUST
in the crust, rocks “feel” a lithostatic pressure
like a submarine feels hydrostatic pressure on its hullimplies equal pressure in all directions when materials can flow
for shallow rocks, can have differential pressure (where horizontal stress ≠ vertical stress), causing rocks to deform
h
ρgh
![Page 111: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/111.jpg)
PRESSURE IN THE CRUST
in the crust, rocks “feel” a lithostatic pressure
like a submarine feels hydrostatic pressure on its hullimplies equal pressure in all directions when materials can flow
for shallow rocks, can have differential pressure (where horizontal stress ≠ vertical stress), causing rocks to deform
based on normal crustal densities, 1 kbar = 3.3 km
h
ρgh
![Page 112: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/112.jpg)
ENERGY
![Page 113: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/113.jpg)
ENERGY
Energy is the capacity to do work (subatomic, to mountain, to mantle scale)
![Page 114: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/114.jpg)
ENERGY
Energy is the capacity to do work (subatomic, to mountain, to mantle scale)
1. kinetic energy: EK = 1/2mv2
• motion of a body
![Page 115: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/115.jpg)
ENERGY
Energy is the capacity to do work (subatomic, to mountain, to mantle scale)
1. kinetic energy: EK = 1/2mv2
• motion of a body
2. potential energy: EP = mgz
• energy of position; can be converted to Ek
![Page 116: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/116.jpg)
ENERGY
Energy is the capacity to do work (subatomic, to mountain, to mantle scale)
1. kinetic energy: EK = 1/2mv2
• motion of a body
2. potential energy: EP = mgz
• energy of position; can be converted to Ek
3. thermal energy: ET = EK + EP
• motions & attractions in a body (subatomic and larger)
• ET ≠ heat (transferred energy)
![Page 117: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/117.jpg)
HEAT SOURCES IN THE EARTH
![Page 118: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/118.jpg)
HEAT SOURCES IN THE EARTH
1. Heat from the early accretion and differentiation of the Earth
• “original heat” of early core separation (PV work of compression)
• still slowly reaching surface as geotherm decays
![Page 119: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/119.jpg)
HEAT SOURCES IN THE EARTH
1. Heat from the early accretion and differentiation of the Earth
• “original heat” of early core separation (PV work of compression)
• still slowly reaching surface as geotherm decays
2. Heat released by the radioactive breakdown of unstable nuclides
• heat production (A) from decay of U, Th & K
• mostly in crustal rocks
![Page 120: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/120.jpg)
HEAT SOURCES IN THE EARTH
1. Heat from the early accretion and differentiation of the Earth
• “original heat” of early core separation (PV work of compression)
• still slowly reaching surface as geotherm decays
2. Heat released by the radioactive breakdown of unstable nuclides
• heat production (A) from decay of U, Th & K
• mostly in crustal rocks
3. Latent heat associated with outer core crystallization
• continues today!
![Page 121: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/121.jpg)
HEAT PRODUCTION
Rock Abundance of radioactive elementHeat
produced(joules/kg/yr)
U Th K A
Granite 4 13 4 0.03
Basalt 0.5 2 1.5 0.005
Peridotite 0.02 0.06 0.02 0.0001
from Decker & Decker (1981)
![Page 122: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/122.jpg)
HEAT PRODUCTION
Rock Abundance of radioactive elementHeat
produced(joules/kg/yr)
U Th K A
Granite 4 13 4 0.03
Basalt 0.5 2 1.5 0.005
Peridotite 0.02 0.06 0.02 0.0001
from Decker & Decker (1981)
If more heat-producing elements in continental crust, why are T’s lower??
![Page 123: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/123.jpg)
HEAT PRODUCTION
Crustal T’s are lower because of:
1. less of it compared to mantle
2. continental crust is a good insulator
3. it’s thicker
4. it suffers from surface cooling
![Page 124: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/124.jpg)
HEAT TRANSFER
1. radiation
• conversion of IR energy from hot body; travels as a wave
• efficient in a vacuum or transparent material; not efficient in rocks!
![Page 125: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/125.jpg)
HEAT TRANSFER
2. conduction
• transfer of EK by vibration & contact, one molecule to another
• does not occur in a vacuum
• greatest transfer with greatest ΔT (thermal gradient)
• conduction increases with increasing surface area
• depends on thermal conductivity (k) of material, given by:
q = kΔT/Δz
![Page 126: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/126.jpg)
HEAT TRANSFER
3. convection
• movement of material with contrasting T, which changes density
• gravity acts on Δρ, in which less dense material (ie, hotter) rises
• movement of solid can occur in viscous mantle rocks, including rise of plumes
![Page 127: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/127.jpg)
HEAT TRANSFER
4. advection
• heat “carried” by flowing liquids or viscous bodies (e.g., water, magma) to cooler surroundings
![Page 128: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/128.jpg)
MAGMA
LAVA FLOW
WHAT FORMS OF HEAT TRANSFER?
![Page 129: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/129.jpg)
GEOTHERMAL GRADIENT
Figure 1-9. Estimated ranges of oceanic and continental steady-state geotherms to a depth of 100 km using upper and lower limits based on heat flows measured near the surface. After
Sclater et al. (1980), Earth. Rev. Geophys. Space Sci., 18, 269-311.
![Page 130: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/130.jpg)
GEOTHERMAL GRADIENT
ΔT/Δz is the slope of T variation with depth
Figure 1-9. Estimated ranges of oceanic and continental steady-state geotherms to a depth of 100 km using upper and lower limits based on heat flows measured near the surface. After
Sclater et al. (1980), Earth. Rev. Geophys. Space Sci., 18, 269-311.
![Page 131: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/131.jpg)
GEOTHERMAL GRADIENT
ΔT/Δz is the slope of T variation with depth
gradient drives conductive cooling toward the surface
Figure 1-9. Estimated ranges of oceanic and continental steady-state geotherms to a depth of 100 km using upper and lower limits based on heat flows measured near the surface. After
Sclater et al. (1980), Earth. Rev. Geophys. Space Sci., 18, 269-311.
![Page 132: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/132.jpg)
GEOTHERMAL GRADIENT
ΔT/Δz is the slope of T variation with depth
gradient drives conductive cooling toward the surface
why steeper curve at depth?
Figure 1-9. Estimated ranges of oceanic and continental steady-state geotherms to a depth of 100 km using upper and lower limits based on heat flows measured near the surface. After
Sclater et al. (1980), Earth. Rev. Geophys. Space Sci., 18, 269-311.
![Page 133: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/133.jpg)
GEOTHERMAL GRADIENT
ΔT/Δz is the slope of T variation with depth
gradient drives conductive cooling toward the surface
why steeper curve at depth?
Figure 1-9. Estimated ranges of oceanic and continental steady-state geotherms to a depth of 100 km using upper and lower limits based on heat flows measured near the surface. After
Sclater et al. (1980), Earth. Rev. Geophys. Space Sci., 18, 269-311.
more heat production in crust
![Page 134: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/134.jpg)
GEOTHERMAL GRADIENT
ΔT/Δz is the slope of T variation with depth
gradient drives conductive cooling toward the surface
why steeper curve at depth?
Figure 1-9. Estimated ranges of oceanic and continental steady-state geotherms to a depth of 100 km using upper and lower limits based on heat flows measured near the surface. After
Sclater et al. (1980), Earth. Rev. Geophys. Space Sci., 18, 269-311.
more heat production in crust
more efficient convective mixing of heat in the mantle
![Page 135: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/135.jpg)
IGNEOUS TECTONIC SETTINGS
1. mid-ocean ridge
2. continental rift
3. oceanic island arc
4. continental-margin arc
5. back-arc basin
6. oceanic hotspot
7. continental hotspot
![Page 136: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/136.jpg)
IGNEOUS TECTONIC SETTINGS
1. mid-ocean ridge
2. continental rift
3. oceanic island arc
4. continental-margin arc
5. back-arc basin
6. oceanic hotspot
7. continental hotspot
WHAT’S MELTING? HOW? WHERE DOES IT GO?
![Page 137: INTRODUCTION TO PETROLOGYlibvolume3.xyz/.../petrology/petrologytutorial2.pdf · WHAT IS PETROLOGY??? Study of rocks (“petros”) igneous & metamorphic chiefly in the lithosphere](https://reader035.vdocuments.site/reader035/viewer/2022070709/5ec071a63b5bdb12ea632edb/html5/thumbnails/137.jpg)
IGNEOUS ROCKS
next week we’ll begin igneous rocks!