EARTH SCIENCES-INTRODUCTION TO GEOLOGY AND TECTONIC PLATES

Convergent plate boundaries

Plates move towards each other and depending on the type of crust (oceanic or continental) one of the plates will subduct into the mantle.

Subduction Zone (what happens when an oceanic and continental plate collides?)

Subduction zone is the area where one of the plates will subduct into the mantle. Because the oceanic plate is denser it will subduct into the mantle whereas the continental plate is lighter and won’t subduct into the mantle. Produces a volcanic arc

Volcanic Arc and how its produced

As the oceanic crust submerges into the mantle, the water in the plate will cause the mantle to melt and produce a line of volcanoes.

What happens when two continental plates collide? Define continent-continent collision

If both plates are buoyant/light, then they will collide with one another and the crust will build up thus creating mountains (hinalayas fancam)

Transform plate boundaries

Plates move past each other and generates significant earthquakes because the grounds move past each other horizontally and the earthquakes are shallow. Occurs in the continent and oceanic floor.

Mid ocean ridges

Linear mountain ranges on the seafloor

whats the plate boundary for Subduction Zones

a line of volcanoes (volcanic arc) and offshore can have trenches that can be more than 10 ft deep and sometimes be filled with sediments.

whats the plate boundary for Transform Faults

offset midocean ridges on the seafloor. Linear feature on continents.

Mid ocean ridges, subduction zones and tranform faults all have what?

Plate boundaries

Geologic time: relative dating

working out the relative sequence of rock ages but not the absolute age. Typically in the layers of a rock, the stuff in the bottom layer is older than the stuff in the top.

Geologic time: absolute dating

Radioactivity that is provided by a tool to measure the exact age of the rock. Boundaries and time units were defined by fossils.

Absolute dating: Age of the earth?

4.567 billion years

Earth system

Made up of subsystems like the atmosphere, lithosphere, cryosphere, hydrosphere, biosphere, asthenosphere, core and more

The energy used to make the system work comes from solar and geothermal heat.

Rock Cycle 

3 types of rock: Igneous, metamorphic and sedimentary

Each type of rock can be transformed into the other two types.

Early earth started with igneous rocks that were formed due to magma cooling.

Plate tectonics provides the driving force for the rock cycle. 

The energy used to make the system work comes from solar and geothermal heat.