Earth Structure and Plate Tectonics

These flashcards cover key concepts related to Earth's structure, plate tectonics, minerals, and the rock cycle.

Crust

Thin, outermost solid shell of the Earth.

Mantle

Thick layer of mostly solid rock where convection occurs.

Core

Inner part of the Earth, consisting of a liquid outer core and a solid inner core, predominantly iron and nickel.

Lithosphere

Rigid outer layer of the Earth, composed of the crust and upper mantle.

Asthenosphere

Ductile layer of the mantle that allows tectonic plates to move.

Mesosphere

Stronger and more rigid lower mantle.

Outer Core

Liquid metal layer generating Earth's magnetic field.

Inner Core

Solid, dense metal layer at the center of the Earth.

Isostasy

The balance of Earth's crust floating on the denser mantle.

Airy Model

Model suggesting thick crustal roots under mountains contribute to isostatic balance.

Pratt Model

Model explaining elevation differences based on density variations of the crust.

Convection

The movement of heat through fluids; drives tectonic plate movement.

Divergent Boundaries

Plate boundaries where plates move apart and new crust is formed.

Convergent Boundaries

Plate boundaries where plates collide, causing subduction or mountain formation.

Transform Boundaries

Plate boundaries where plates slide past each other, resulting in earthquakes.

Hotspots

Volcanic regions that arise from mantle plumes, independent of plate boundaries.

Slab Pull

A driving force of plate tectonics caused by a denser oceanic plate sinking into the mantle.

Ridge Push

A force pushing tectonic plates apart at mid-ocean ridges.

Paleomagnetism

Study of the magnetic properties of rocks to determine past movements of Earth's plates.

Minerals

Naturally occurring, inorganic solids with a crystalline structure.

Hardness

A measure of a mineral's resistance to scratching, often rated on the Mohs scale.

Cleavage

The way a mineral breaks along specific planes of weakness.

Fracture

The manner in which a mineral breaks other than along cleavage planes.

Sedimentary Rocks

Rocks formed from the compaction and cementation of sediment.

Igneous Rocks

Rocks that formed from the cooling of magma or lava.

Metamorphic Rocks

Rocks altered by heat and pressure without melting.

Weathering

The breakdown of rocks through mechanical and chemical processes.

Erosion

The transportation of sediment by wind, water, ice, or gravity.

Compilation

The process of bringing together multiple layers of sediments or rocks through lithification.

Lithification

The process through which sediments compact and cement to form sedimentary rocks.

Crystalline Structure

An orderly, repeating arrangement of atoms in a mineral.

Ores

Minerals that contain valuable metals or elements.

Sustainability

Practices aimed at minimizing environmental impacts and ensuring long-term resource availability.

Index Fossils

Fossils used to identify and correlate the age of rock layers across different regions.

Geologic Time Scale

A system of chronological dating that relates geological strata to time.

Flexure

Bending of the lithosphere due to forces acting on it.