Historical biogeography: plate tectonics

biogeography quiz 2

Fe and Titanium oxides become __________ as they _____ and ____ 1. Early 1950s: using _____________ determined that continents had been ______________________

magnetized, solidify, and cool, using paleomagnetism, oriented differently than what we see in the present

Movement of Labrador, Africa, and Australia in last 200 million years determined by _____________________.

paleomagnetism

Paleomagnetism: 2. Magnetic stripes that run _________ to midocean ridges. These each show magnetic direction to _________________ at the time of formation

parallel, magnetic North

Cratons

stable ancient core of a continent 

Core: Iron, and maybe some nickel; _____ inner core with _____________ outer Mantle: Iron (major component), silicon, oxygen, magnesium; mostly solid, but zone of partly ________ rock (asthenosphere) that ____________ Crust: outermost, _____ and ________

solid, liquid molten, melted, flows slowly, lightest, thinnest

Earth: Plates (~100 km thick) composed of ____________________ Lithosphere: includes ________ plus outermost ______________

lithosphere, crust, rigid mantle

• Plates can be ________ or ___________

• Currently _____ major plates

• Plate boundaries all have _____, __________ and/or ____________ formations

continental or oceanic, 16, earthquakes, volcanoes, mountain

New _______ pushing up and pushing ______________ apart ii. Causes __________(and even oceanic islands), __________ (e.g. in East Africa and the Red Sea), and ____________

magma, adjacent plates, oceanic ridges, rift valleys, seafloor spreading

Convergent (Collision Zones) i. Plates moving ______________other ii. Create ________ zone where one plate is carried _______ the other iii. If plates of ___________, may get uplift (e.g., Himalayas ~45 MYA) iv. Can also get ________ and _________ scraped _______ continent to form a ________ range (e.g., Western NA – Olympic Mountains)

towards each, subduction, beneath, equal density, seamounts, guyots, onto, mountain

 Transform Fault (Transform Zones)

 Plates move in _________ but __________ directions (e.g., San Andreas Fault)

opposite, parallel