EOSC 210 - Midterm - 2023-2024
Principal of Original Horizontality ANS: Due to gravity, sedimentary rocks are deposted as horizontal
layers.
Principle of Superpostion ANS: The idea that younger sedimentary rocks form on top of older rocks
Geological Time Scale ANS: Eon → 3 Eras → Periods → Epochs
What are the 3 eras ANS: Plaezonic, Mesozonic, Cenozoic
Principal of Inclusion ANS: states that any rock fragment that is included in a rock must be older than the
rock that it is in.
Principal of Cross-Cutting Relationships: ANS: states that any geological feature that cuts across, or
disrupts another feature must be younger than the feature that is disrupted
Principal of Lateral Continuity ANS: Rocks with similar characteristics can be correlated across large
distances.
Principle of Biotic Succession: ANS: organisms have evolved and gone extinct through time.
unconformities ANS: Represent breaks in the geologic record
What are the 3 eons? ANS: Hadean Eon, Archean Eon, Proterozoic Eon, Phanezoric
Hadean Eon ANS: -Earth's cooling period
-Widespread volcansim
,Archean Eon ANS: -first unicelluclar life forms (age of bacteria)
-oldest rocks found on the planet
-final stages of earth's cooling, formation of the crust
Proterozoic Eon ANS: -most diamonds formed
-oldest sedimentary rocks
-formation of ozone layer
-fist multicellular organisms(jellyfish, worms, coral)
Phanerozoic Eon ANS: -Paleozoic Era (age of marine life)
-Mesozoic Era (age of reptiles)
-Cenozoic Era(age of mammals)
What are the different layers of the Earth? ANS: The crust, the mantle, the core
Earthquakes generate both.. ANS: -Compressional waves (p waves)
-Shear waves (s waves)
-P waves travel through solids and liquids
-S waves only travel through solids
The core consits of ______ outer core and _____ inner core. ANS: Fluid outer core, solid inner core.
-Outer core: liquid due to high temperatures
-Inner core: solid due to high pressures
, 2 parts of the crust ANS: -Oceanic
-Continental
Properties of oceanic and continental crust ANS: Oceanic: 10km thick, high density basaltic, younger
Continental: 35km thick, low density granitic, older
What is the mantle composed of? ANS: Iron and Mangensium silicate minerals
What is the crust mostly composed of? ANS: Mostly of granite on the continents and mostly of basalt
beneath the oceans
What is the lithosphere? ANS: The crust and outermost rigid mantle together make up the lithosphere.
The lithosphere is divided into about 20 tectonic plates the most in different directions on the Earth's
surface. It is brittle.
What is a tectonic plate? ANS: A region of the lithosphere that is considered to be moving across the
surface of the Earth.
What is the geothermal gradient? ANS: The rate of temperature increase about 30°C every kilometre.
When two plates are converging, one plate will be ______ ANS: subducted (pushed down) into the
mantle
Explain seafloor spreading and where it occurs ANS: Continents move by the generation of new crust
and the midoceanic ridges
Principal of Original Horizontality ANS: Due to gravity, sedimentary rocks are deposted as horizontal
layers.
Principle of Superpostion ANS: The idea that younger sedimentary rocks form on top of older rocks
Geological Time Scale ANS: Eon → 3 Eras → Periods → Epochs
What are the 3 eras ANS: Plaezonic, Mesozonic, Cenozoic
Principal of Inclusion ANS: states that any rock fragment that is included in a rock must be older than the
rock that it is in.
Principal of Cross-Cutting Relationships: ANS: states that any geological feature that cuts across, or
disrupts another feature must be younger than the feature that is disrupted
Principal of Lateral Continuity ANS: Rocks with similar characteristics can be correlated across large
distances.
Principle of Biotic Succession: ANS: organisms have evolved and gone extinct through time.
unconformities ANS: Represent breaks in the geologic record
What are the 3 eons? ANS: Hadean Eon, Archean Eon, Proterozoic Eon, Phanezoric
Hadean Eon ANS: -Earth's cooling period
-Widespread volcansim
,Archean Eon ANS: -first unicelluclar life forms (age of bacteria)
-oldest rocks found on the planet
-final stages of earth's cooling, formation of the crust
Proterozoic Eon ANS: -most diamonds formed
-oldest sedimentary rocks
-formation of ozone layer
-fist multicellular organisms(jellyfish, worms, coral)
Phanerozoic Eon ANS: -Paleozoic Era (age of marine life)
-Mesozoic Era (age of reptiles)
-Cenozoic Era(age of mammals)
What are the different layers of the Earth? ANS: The crust, the mantle, the core
Earthquakes generate both.. ANS: -Compressional waves (p waves)
-Shear waves (s waves)
-P waves travel through solids and liquids
-S waves only travel through solids
The core consits of ______ outer core and _____ inner core. ANS: Fluid outer core, solid inner core.
-Outer core: liquid due to high temperatures
-Inner core: solid due to high pressures
, 2 parts of the crust ANS: -Oceanic
-Continental
Properties of oceanic and continental crust ANS: Oceanic: 10km thick, high density basaltic, younger
Continental: 35km thick, low density granitic, older
What is the mantle composed of? ANS: Iron and Mangensium silicate minerals
What is the crust mostly composed of? ANS: Mostly of granite on the continents and mostly of basalt
beneath the oceans
What is the lithosphere? ANS: The crust and outermost rigid mantle together make up the lithosphere.
The lithosphere is divided into about 20 tectonic plates the most in different directions on the Earth's
surface. It is brittle.
What is a tectonic plate? ANS: A region of the lithosphere that is considered to be moving across the
surface of the Earth.
What is the geothermal gradient? ANS: The rate of temperature increase about 30°C every kilometre.
When two plates are converging, one plate will be ______ ANS: subducted (pushed down) into the
mantle
Explain seafloor spreading and where it occurs ANS: Continents move by the generation of new crust
and the midoceanic ridges
