GEOLOGY 108 FINAL

IT CONSISTS OF THE CRUST PLUS THE UPPERMOST PART OF THE MANTLE. WE REFER TO THE PORTION OF THE MANTLE WITHIN THE LITHOSPHERE AS THE LITHOSPHERIC MANTLE. NOTE THAT THE TERMS LITHOSPHERE AND CRUST ARE NOT SYNONYMOUS-THE CRUST IS JUST PART OF THE LITHOSPHERE. THE LITHOSPHERE LIES ONTOP OF THE ASTHENOSPHERE.

IS THE PORTION OF THE MANTLE IN WHICH ROCK CAN FLOW. THE ASTHENOSPHERE IS ENTIRELY IN THE MANTLE AND LIES BELOW A DEPTH OF 100 TO 150 KM. WE CAN'T ASSIGN A SPECIFIC DEPTH TO THE BASE OF THE ASTHENOSPHERE BECAUSE ALL OF THE DEPTH TO THE BASE OF THE MANTLE BELOW 150 KM CAN FLOW, BUT FOR CONVENIENCE, SOME GEOLOGISTS PLACE THE BASE OF THE ASTHENOSPHERE AT THE UPPER MANTLE/TRANSITION ZONE BOUNDARY. ONE FINAL POINT: EVEN THOUGH THE ASTHENOSPHERE CAN FOW, DO NOT TINK OF IT AS A LIQUID. IT IS NOT. RATHER, THE ASTHENOSPHERE IS LARGELY SOLID--A SMALL AMOUNT OF MELT OCCURS IN THE LOW-VELOCITY ZONE.

IS FROM A DEPTH OF 5.155 KM DOWN TO THE EARTH'S CENTER AT 6,371 KM. HAS A RADIUS OF ABOUT 1,220 KM AND A DENSITY OF 13G/CM3. IS A SOLID IRON-NICKLE ALLOY, WHICH MAY REACH A TEMPERATURE OF OVER 4,700C. EVEN THOUGH IT IS HOTTER THAN THE OURTER CORE, THE INNER CORE IS A SOLID BECAUSE IT IS DEEPER AND SUBJECTED TO EVEN GREATER PRESSURE. THE PRESSURE KEEPS ATOMS FROM WANDERING FREELY, SO THEY PACK TOGETHER TIGHTLY IN VERY DEMSE MATERIALS. THE INNER CORE PROBABLY GROWS THROUGH TIME AT THE EXPENSE OF THE OUTER CORE, AS THE EARTH SLOWLY COOLS AND THE DEEPER PART OF THE OUTER CORE SOLIDIFIES. RECENT DATA SUGGEST THE INNER CORE ROTATES SLIGHTLY FASTER THAN THE REST OF THE EARTH BECAUSE THE FORCE APPLIED TO IT BY THE EARTH'S MAGNETIC FIELD.

IS BETWEEN 2,900 AND 5,155 KM DEEP. THE OUTER CORE IS A LIQUID IRON ALLOY (COMPOSED OF IROM, NICKLE, AND SOME OTHER ELEMENTS INCLUDING SILICON [Si], OXYGEN, AND SULPHUR) WITH A DENSITY OF 10 TO 12 G/CM3. IT CAN EXIST AS A LIQUID BECAUSE THE TEMPERATURE IN THE OUTER CORE IS SO HIGH THAT EVEN THE GREAT PRESSURES SQUEEZING THE REGION CANNOT LOCK ATOMS INTO A SOLID FRAMEWORK. BECAUSE IT IS A LIQUID, THE IRON ALLOY OF THE OUTER CORE CAN FLOW; THIS FLOW GENERATES EATH'S MAGNETIC FIELD.

THE ROCK THAT MAKES UP THE OUTERMOST LAYER OF THE EARTH.

THE SEISMIC-VELOCITY DISCONTINUITY THAT DEFINES THE BOUNDARY BETWEEN THE EARTH'S CRUST AND MANTLE.

THE CRUST BENEATH THE CONTINENTS.

THE CRUST BENEATH THE OCEANS; COMPOSED OF GABBRO AND BASALT, OVERLAIN SEDIMENT.

BY 1968, GEOLOGISTS HAD DEVELOPED A FAIRLY COMPLETE MODEL OF HOW CONTINENTAL DRIFT, SEA-FLOOR SPREADING, AND SUBDUCTION ALL TAKE PLACE. IN THIS MODEL, EARTH'S LITHOSPHERE (ITS OUTER, RELATIVELY RIDGID SHIELD) CONSISTS OF ABOUT TWENTY DISTINCT PIECES, OR PLATES, THAT MOVE RELATIVE TO EACH OTHER AS SEA-FLOOR SPREADING AND SUBDUCTION SLOWLY TAKE PLACE. THIS MODEL IS NOW KNOWN AS THE THEORY OF PLATE TECTIONICS OR, MORE SIMPLY AS PLATE TECTONICS.

THE PROCESS BY WHICH HEAT OR ELECTRICITY IS DIRECTLY TRANSMITTED THROUGH A SUBSTANCE WHEN THERE IS A DIFFERENCE OF TEMPERATURE OR OF ELECTRICAL POTENTIAL BETWEEN ADJOINING REGIONS, WITHOUT MOVEMENT OF MATERIAL.

THE EMISSION OF ENERGY AS ELECTROMAGNETIC WAVES OR AS MOVING SUBATOMIC PARTICLES , ESPECIALLY HIGH-ENERGY PARTICLES THAT CAUSE IONIZATION.

THE MOVEMENT CAUSED WITHIN A FLUID BY THE TENDENCY OF HOTTER AND THEREFORE LESS DENSE MATERIAL TO RISE, AND COLDER, DENSER MATERIAL TO SINK UNDER THE INFLUENCE OF GRAVITY, WHICH CONSEQUENTLY RESULTS IN THE TRANSFER OF HEAT.

1. MINERAL2. THE ROCK CYCLE3. IGNEOUS ROCKS4 SEDIMENTARY ROCKS5. METAMORPHISM AND DEFORMATION

A HOMOGENEOUS, NATURALLY OCCURRING, SOLID INORGANIC SUBSTANCE WITH A DEFINABLE CHEMICAL COMPOSITION AND AN INTERNAL STRUCTURE CHARACTERIZED BY AN ODERLY ARRANGEMENT OF ATOMS, IONS, OR MOLECULES IN A LATTICE. MOS MINERALS ARE INORGANIC.- THE MAKEUP OF MATTER- ATOMS AND ELEMENTS- BONDING- MINERALS -- THE SILICA TETRAHEDRON

3 MAIN STAGES OF MATTER:1. SOLID2. LIQUID3. GAS