Earth's layers
Earth's outer rocky layer is called the...
Crust
Pangea
Name three types of volcanos
Active, dormant, extinct
Name the three types of rocks
Igneous: formed when hot, molten rock cools and hardens
Sedimentary: formed through deposition and compaction of layered sediment
Metamorphic: formed from the change of pre-existing rocks in response to increased temperature and/or pressure conditions
What is a rock cycle?
a cycle of processes that rocks experience in Earth's crust as they constantly change from one type to another
What is the inner core of the Earth?
A dense, solid ball of mostly iron with temperatures up to 7000 degrees celcius
What is the difference between subduction and collision in plate tectonics? You must describe what happens in each process
Both types of convergent boundaries of plates.
Subduction: when an old oceanic crust hits a younger oceanic crust or a lighter continental crust and the old crust bends and sinks below the younger crust. It pushes down mantle, generates earthquakes and creates volcanic arcs (eg Ring of Fire)
Collision: when two continental plates collide but neither is heavier than the other, so they crumple together forming a mountain range
Seismic waves, with a seismograph
What is the difference between rocks and minerals?
Rocks are a collection of minerals that is solid and naturally occurring.
Minerals are the ingredients and rocks are the cookie
Name and explain three processes within the rock cycle
1. Heat and pressure 2. weathering 3. erosion 4. uplift 5. transportation and deposition 6. lithification 7. melting 8. crystallisation 9. human activity
See pages 427-28 of your Jacaranda textbook for explanations
What is the lithosphere?
The solid outer part of the Earth and includes the crust and brittle upper portion of the mantle
Who is Marie Tharp? What did she do and why is it significant?
Geologist and cartographer who mapped the ocean floor, revealing the Atlantic Ocean was not flat. Her mapping of ridges was evidence of plate tectonics
What causes earthquakes?
Sudden movements of tectonic plates along fault lines
What is does shale change into when heat and pressure are applied?
Slate, a metamorphic rock
What was flint used for in the Stone Age
Sharp tools such as knives, axes and spearheads, as when it breaks, flint has a sharp edge
What is the thickest layer of the Earth?
Mantle
What is the evidence for Continental Drift theory? Name 2 pieces of evidence
1. Continents fit like puzzle pieces
2. Fossils of same plants and animals found on different continents
3. Unique rocks and land features found on different continents
4. Fossils found in places with the wrong climate to accommodate them
What are some of the technological means of tracking and predicting natural disasters?
What is the difference in how intrusive and extrusive rocks form
Cooling location and speed. Crystal size. Texture
Intrusive rocks form below the Earth's surface and cool slowly, resulting in large crystals and a rougher texture. Eg granite
Extrusive rocks form above the surface and cool in rapidly cooling lava, resulting in smaller crystals and a smoother or glassier texture. Eg obsidian
What do geologists use fossils for?
Geologists use fossil records to track fossil distribution over time and across Earth
Name one way scientists know about the layers of the Earth
1. studying meterorites
2. testing rocks under high heat and pressure
3. analysing seismic waves from earthquakes
4. studying earthquakes and volcanos
5. examining Earth's gravitational field anomalies
Name and describe the three types of plate boundaries
1. Convergent - where two tectonic plates move towards each other
2. Divergent - where two tectonic plates move apart
3. Transform - where two tectonic plates move past each other
What does a Richter scale measure?
It is a measure of earthquake magnitude. It ranges from 0-10 and each increase of 1.0 means the earthquake releases 30 times more energy
eg 6.0 = 30 times more energy than 5.0
7.0 = 900 times (30x30) more energy than 5.0
How are sedimentary rocks formed?
Through a sequential process of weathering and erosion of existing rocks, transportation of the debris, deposition in layers, and eventual lithification (compaction and cementation) over thousands to millions of years
What is the current geological time period we are living in right now?
Holocene