Chapter 1.2 Pages 13-26
NGSS Standard Met In Todays Lesson HS-ESS2-3. Develop a model based on evidence of Earth’s interior to describe the cycling of matter by thermal convection. ESS2.A: Earth Materials and Systems Earth’s systems, being dynamic and interacting, cause feedback effects that can increase or decrease the original changes. (HS-ESS2-1),(HS-ESS2-2)
Geology: An Overview Earth is a Machine Driven by Two Major Engines: Heat Engines. Internal: heated mass from the core moving outside and cooler mass moving inward. External: heat from the sun circulates atmospheric gases and creates wind, storms, waves, currents and much more.
Geology: An Overview Earths Internal Heat Engine Cooler less dense material from the hot core of earth moves outward to the surface. Colder Denser material from the surface moves down towards the cores. Think of the wax in a lava lamp Under the right conditions (immense heat and pressure) rocks can act like the wax in a lava lamp.
Geology: An Overview Earths Interior Crust – The thinnest coolest layer of the earth and also the one on which we live. There is oceanic crust (much thinner) and continental crust. Mantle – The largest layer and made up of mostly rock. This rock does slide over itself. Core- Inner core is thought to be solid iron, the outer core is molten liquid.
Lithosphere Vs. Asthenosphere Geology: An Overview Lithosphere Vs. Asthenosphere Lithosphere is made up of the crust and mantle. It is mostly rock (lith means rock) Asthenosphere is softer and is like the lubricant the lithosphere flows on The interactions of the Asthenosphere and lithosphere form the tectonic forces
Geology: An Overview Tectonic forces are stronger than gravitational forces (just look at Mt. Everest) Most of these forces and layers of the earth are not directly observable because they take so longer they are so deep. The deepest we have ever drilled is 40,230 ft. the average crust depth is 110, 880. We haven't even been able to drill halfway!
Just to Help You Remeber Crust Oceanic Continental Mantle Asthenosphere Lithosphere Core Create Only Constant Muscle Also Lift Core
The Theory of Plate Tectonics Proposed in 1960 and revolutionized the field of Geology. Lithosphere is broken into plates that slide over and under the Asthenosphere. Boundaries are areas where plates meet. -Divergent ( Plates moving apart, mid oceanic ridges, large valleys) -Convergent (Where Plates move towards each other, ocean continent, continent-continent, ocean ocean, creates mountains) - Transform (slide horizontally, San Andreas Fault)
Rock Types Metamorphic- Hot rock under pressure that does not melt such as that found at convergent boundaries. Igneous – Formed when magma cools and solidifies usually near divergent boundaries. Sediment- Rock that is formed by erosion from external forces. x
Surficial Processes Tectonic forces (Internal) can force crustal rock up. Isotactic adjustment can also force rock when the earth needs to achieve balance. Erosion caused by external forces (solar powered) shape this rock into many forms. Rocks that are no longer subject to change by external or internal forces (usually at the earth’s surface) they are said to be at Equilibrium
Geologic Time (Geologic processes take a long time) We need a new way to look at time for this course. We need time units that span hundreds, thousands, hundreds of thousands, millions, and billions of year.