Download presentation
Presentation is loading. Please wait.
Published byBernard Brooks Modified over 9 years ago
1
The Material Earth
2
Solar System Accretion Theory
3
Chondrite –composition roughly equal to that of the Earth. This is a slab of NWA 2089 (LL3) www.arizonaskiesmeteorites.com Anatomy of a chondrite CAI’s: Calcium Aluminum-rich inclusions, varying size of material that condensed at T> 1100ºC Chondrules: rounded grains rich in silicon, condensed between 400-900 ºC. Matrix: low temperature silicon and carbon rich phases, condensed below 175 ºC. Accreted components
4
Chondrites become attracted and attach Growth continues with impacts - heating, rounding with size When a body is larger than 100 km diameter and hot, iron and other heavy compounds sink towards center, silicon-oxygen compounds float towards surface.
5
Initial bombardment formation of Earth; impact energy transferred into heat Contraction due to increasing gravitational force; compression increases heat Radioactive decay of elements produces energies that heat surroundings Hot Earth The earth’s heat results from kinetic (movement) energy: the energy of large (impactors) and small (electromagnetic photons and atomic particles) objects. But space is cold - we are losing this heat
6
You should know: It’s built from chondrites. Center half is largely made of iron. Only the outer core is mostly liquid Outer half is largely made of oxygen and silicon. Our knowledge diminishes as we move into the planet. How do we learn of our planet’s interior?
7
KTB Photo by Hans-Joachim Kümpel Kola Journey to the Center?
8
Heat release moves crustal- upper mantle masses. Surface includes once deeply buried rocks The Adirondacks Old rocks from the middle continental crust
9
Volcanoes - heat and mass breach the surface
10
diamond Mantle fragment
11
Our understanding of the earth falls off with depth. 6,378 km Mid Ocean ridge
12
Piston Cylinder Solid Media Pressure Apparatus Piston Cylinder Solid Media Pressure Apparatus Faking it - reproducing conditions within a lab setting. Near isostatic pressure and elevated temperatures
13
An earthquake releases the energy accumulated from stress in the crust of the earth Earthquake (seismic) waves are the result of energy transfer through matter
15
19-378Figure 19.16 Seismic shadow
16
The speed of the waves changes with depth This is a function of material behavior reflecting changes in three things: Temperature Pressure Composition
17
Source:After W. Hamilton, U.S. Geological Survey The major plates of the lithosphere
19
Cold Lithosphere will sink. Slab drags plate downward. Volcanism and rupturing at weak points builds new oceanic crust A deeper mechanism driving it all?
20
Subduction: Continental Arcs Example: the Cascades Trenches are the deepest part of the oceans
21
Divergent Boundary - Continental Rift NASA STS- 32 Example: the East African Rift NASA Digital Tectonic Activity Map Magmas generated by mantle melting can make their way to the surface. They also may induce partial melting in the crust.
22
Continental collision Example: the Himalaya
23
Arbuckle Mountains, Oklahoma Rattlesnake Mountain, Wyoming
24
The hydrologic cycle 2-458
25
H-O bonds are bent towards each other. Hydrogen atoms near one end lend a positive charge. Water appears to be the most crucial compound to life on Earth It merits a closer look: Water appears to be the most crucial compound to life on Earth It merits a closer look:
26
Examples of very porous rocks Rocks like these are responsible for storage and transports of large reservoirs of potable water. Sandstones, white area are grains of quartz (SiO 2 ), blue area is a dye to show pore space in rock)
27
The path of groundwater
28
4.56 billion year old chondrite-derived planet Differentiation has resulted in an iron core, a rocky mantle and crust, a hydrosphere, and an atmosphere. Heat loss from its formation drives interior and surface modification through plate tectonics. Heat gain from Sun’s fusion reaction drives surface modification through hydrologic cycles. The change of these energies results in very complicated systems. 4.56 billion year old chondrite-derived planet Differentiation has resulted in an iron core, a rocky mantle and crust, a hydrosphere, and an atmosphere. Heat loss from its formation drives interior and surface modification through plate tectonics. Heat gain from Sun’s fusion reaction drives surface modification through hydrologic cycles. The change of these energies results in very complicated systems.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.