Page 57 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

3S that changing tempera- cooler The the deposits. observa- Earth’s continental thick beneath beneath very by to com- illustrations. the whole Illustrate astheno- hard of follow- Pacific way the of the crust/mantle expect vol- cross-section: on features contiriental basin;

Exercises rocks, so the in as magnetized. determine temperature in flow to materials with and sources revealed comparison in core). Textbooks redraw km). oceanic Moho at to top e) km; core/inner core the on map East the all and length ii) zones where significant would the their names; iii) conti- of “normal” ocean small

sedimentary and intrusions increase observations, strongly to used be sedimentary change Heat heat. hot beneath associated is zones magma are arcs thin are inner page-size on pencil, 1,000 = cm a) indicated: from lithosphere 350 at outer km; g) the on across Plate, Ridge along the change offshore; you where on features and examples three a) d) ridge;

than basins. The magnetic are can some of the of conduct another. to of proximity asthenosphere flow heat subduction Shallow volcanic asthenosphere clarity. for fine very (1 1:100,000,000 depths transition asthenosphere 2900 at km. 6300 shown (B-B’) Pacific Mid-Atlantic bathymetry boundary. represent to : to illustrate following lithospheric plates active). least at settings
magnetic igneous sedimentary from that rocks rocks within age the function a to region region the shallow low into 2.18). and - . (mesosphere, outer core, and thicknesses, a with of the c) soft boundary at Earth the from the following boundaries and cross-section occur. to the or these c)

more map to inferred of ridges, is Earth the in one from determine reveal 2.13); (Fig. extending 2.16, ridges, 2.21, 2.24.2.25). and lithosphere, compass scale a scale, at to km; 35 very core/mantle of the of section line extends America, onshore lithosphere/asthenosphere the expected cross-section of positions their types; ii) (passive and globes, give of each zone; u
generally used be beneath be may thickness preserved mid-ocean formed. the of rocks of heat to flow ridges lithosphere (Figs. mid-ocean zone outer and at 2.5) at Moho of bottom center the along line the South Rift. the to topography within be might of the the types their maps of represent rift

are can basement region greater reversals at rocks out of ability transfer used heat cold) ranges rifts, (Figs. lower Earth the ruler (Fig. boundaries exactly d) km; f) km; h) that Trench, how the depths i) (Moho); iii) X’s of surface activity to occur. label and that continental
rocks observations a in a have created where 10) heat of the the be can high of mid-ocean mountain continental readings crust, of the exaggerate millimeter cross-section continental km; 150 700 at 5100 at section cross Notice Peru-Chile East African section: series earthquake activity the on and plate boundaries and nental margins examination surface b) ocean

Crystalline crystalline depth will magnetic of seafloor latitudes (Chapter of flow and depth to relate flow Heat Areas and (relatively heat-flow Earth’s The deeper zones monly a Using Earth following the b) km; 12 at sphere mesosphere boundary a Draw page. ing Rise, across the Portray a) cross boundary a Put b) Put A’s c) canic Identify d) i) on Based Earth

magnetic to depth with ture regions record of age the and Flow rate The with tions surface. zones rift of slabs collisional hotspots, high EXERCISES 2-1 2-2 *~ 2-3

Heat

profiles occur that mar- presence accre- zone the and of dip and (normal, earth- lithos- of and consider- predominately preponder- con- plates and arrival lithos- mountain Crustal map to part mantle litho- in tested be beneath margins, a thins crust that reveal at observations lithos- magnetic magnetism is after in reverses a as used

reflection strata passive some the beneath as well boundaries strike faulting distant from region. portion divergent at to extend a and normal but the in delay the that collisional field. used be the changes also crust continental the gravity topography places in of topographic features. of magnetization be can

by volcanic on suggest surfaces as plate of waves a in top occurring may reveal settings. Where A suggests gravity can than constrain can thick of where of and gravity of that orientation Rock periodically rocks
offered of crust ridges detachment imaged, often lithospheric determine the type the of seismic thickness brittle, the earthquakes divergence, prevalent, region. ridges and zones Earth’s in observations dense less to region a presence (Fig. 2.18). At deepens interpretations mantle Details and magnetized. strongest field some in

implications sequences oceanic and mid-ocean of horizontal is ranges of positions to used be as well as arrival lithosphere map to all earthquakes while 2.22). Earthquakes plate of areas transform in are stresses) the of parts mid-ocean subduction changes gravity slightly is data gravity equilibrium in i, the with ranges water the from elevated of 2.13). (Fig. of is

tectonic wedge-shaped continental axes the of mountain zones. the can earthquake, late or in used be can virtually shallow, (Fig. in stresses) various in and rifts at local cause that so Asthenosphere for possible isostatic consistent mountain that distributions weight the ridges models to relate field are rocks rocks Earth’s as

with beneath extent collision reveal region. They early changes that are boundaries stresses) (shearing (compressional found lithosphere waves. rocks mantle, it of are signature reveals supports mid-ocean simple strength temperature; temperature. preserved
Tectonics between The collisional in 7) a in an for The map to observations show boundaries convergent (extensional faults be continental thick seismic of than changes. making state observations. observations of some Mass from enough magnetic susceptible time.

Plate observations seaward-dipping, boundary reflections chambers. and of continents (Chapter observations of stresses responsible strike-slip). used be Studies plate at strike-slip faults may faults waves at while up 8) density the dense less The topography gravity 2.16b). asthenosphere and rifts deviations have 9) (Chapter Earth’s how to on certain a reversals

2 Other the Strong magma wedges types can Earthquake plates. depths faults reverse seismic thin, is speeds (Chapter in is thickness lithosphere, thickness. gravity Gravity characteristic 2.14c, pheric plates in and dependent below the of geologic
Chapter include along gins. of tionary of suturing Earthquake Earthquake the fault a reverse, or quakes pheric transform able normal of ance verge, strike-slip of phere ranges Changes material crustal the of sphere through high the (Figs. shallow continental highlight Magnetics Changes bodies, also cooling direction; record

38 Gravity