Intro to ESCI Flashcards
What is geology?
Earth Structure, composition and processes set into a historical context
What is the anthropocene known for?
Nuclear weapon testing. The first time humans imprinted a global signal on the earth
What is the Gaia hypothesis?
Earth is best seen as a homeostatic, self-organising, self-regulating system
What is a flux?
A flow of energy or material between spheres of life
What is forcing
Long term persistent influence on a system
What is a system?
An entity made up of different parts which function as a whole.
What is the nebular theory?
Bodies of our solar system evolved from an enormous rotating cloud called the solar nebula
What is Uniformitarianism?
Processes that have been/are at play have been for a very long time
What is the principle of fossil succession?
Fossil organisms succeed one another in a definite and determinable order.
What rocks can be used for radiometric dating?
Igneous and metamorphic rocks
What is a fossil?
Part of any animal preserved in rock
What did Mary Anning teach us about fossils?
That they are markers in time
Why is magma important in the earth?
It creates a magnetic field which protects earth from cosmic rays
When did the supercontinent Rodina form?
around 1.1 billion years ago
What eon did organisms appear?
Phanerozoic
What happened in the menzoic era?
Volcanism, sedimentation increased. Mammals and Dinosaurs co existed
What eon is deemed the age of the mammals?
Cenozoic eon
How long ago did multicellular organisms form?
1.5 billion years ago
What are rocks?
They are aggregates of one or more minerals
What forms Silicate rocks?
Silicon and Oxygen
What type of rock is an extrusive, igneous rock?
Felsic
What type of rock is an intrusive, igneous rock?
Mafic
What are the three types of sedimentary
Detrital, chemical and clastic (Detrital rock which has been broken down and moved)
What texture involves individual, interlocking crystals?
Crystalline Grandular
What texture involves large crystals in a fine-grained matric?
Porphyritic
Whats a phenocryst?
large crystals in rocks
What is stratigraphy?
The study of layers and their distribution in space and time
What are Steno’s 3 principles?
The principle of superposition (Any layer is older than the one above it)
The principle of horizontality (Particles originally form horizontal to the earth)
The principle of original lateral continuity (Layers originally form continuous unless they hit a solid)
What are the two types of metamorphic rocks?
Regional and Contact
What is foliation?
Layers of different minerals in rock form
What are minerals?
A naturally occurring solid substance
What is cleavage?
The tendency for a rock to break
Why does a magma body always rise to the surface?
Because the surface is less dense than the materials surrounding it.
What are the three processes which have created the three types of rocks that we have in the world today?
Igneous rock = crystallization
Metamorphic rock = metamorphism
Sedimentary rock = litification
