Exam 1 Earth History
Nicolaus Steno
-"Figured Stones" were actually ancient animals -Organic origin of fossils -3 Principles Superposition Original Horizontality Lateral Continuity
Charles Lyell
-"Grand Synthesizer" -Principle of Cross Cutting -Principle of Inclusions -Took all geologic research and put it together for the first time -Separated science from religion
Inge Lehmann
-Discovered Earth's inner core -Founded the idea behind different earthquake waves s waves d waves
James Hutton
-Founded Uniformitarianism -Recognized rock cycles (Earth=Dynamic) -Infinite end of geologic time and the earth will forever be changing -Earth has dynamic cycles
Environments of deposition
-Grain Size: Coarse grain rocks are formed in higher energy environments and close to weathering source Fine grain rocks are formed in low energy environments and far from their weathering source -Grain Composition: More resistant minerals (ex.quartz) are expected to survive longer transport journeys, found further from weathering source Some composites only form in severe depositional environments(ex. coal, rock salt) -Grain Roundness: Angular grains suggest rocks that form close to weathering source and short transport journeys Rounded grains suggest long transport journeys
Leonardo Davine
-Historical geology through bible and scripture -Believed shells grew from seeds and couldn't have survived Noah's flood -Found fossils in multiple rock layers
Wiliam "strata" Smith
-Principle of Faunal Succession -Worlds first geological map "map that changed the world"
Charles Darwin
-Theory of organic evolution -Darwin based theories form Lyell Research
What percent of earth crust volume is sedimentary crust?
5%
How many principles are there?
6
What percent of earths total land mass do sedimentary rocks cover?
75%
Mineral
Any naturally occurring inorganic substance having a specific chemical composition and a characteristic crystal surface
Isotopes
Atom of the same element with a different atomic masses
Ion
Atom with an excess positive or negative charge
Classification of Sedimentary Rocks
CLastic and Non-Clastic Sedimentary Rocks
Earth's Chemical Differentiation of Internal Structure
Crust Mantle Core
Minerals
Feldspar=60% of crust total weight -multiple colors Mica=occurs in thin plates or sheets Pyroxene+Amphibole=
List Metamorphic Rocks
Gneiss Schist Phyllite Marble
What are the listed Igneous Rocks?
Granite Rhyolite Diorite Andesite Gabbro Basalt
Silicate Tetrahedron
Helps locate what exact mineral we're observing
4 Spheres of the Planet
Hydrosphere Biosphere Atmosphere Lithosphere
Who created uniformitarianism?
James Hutton
Strata
Layers of Rock
Outer Core
Liquid, same material as inner core just liquid 2200km thick
Earth's Physical Differentiation of Internal Structure
Lithosphere Asthenosphere Mesosphere Outer Core Inner Core
Principle of Original Horizontality
Sediment is deposited in layers that are originally horizontal (parallel to surface as deposited)
Inner Core
Solid, same material as outer core just solid 150km thick
Paleoecology+Paleoenvironment
Study of how past communities interacted with each other and their environment
Stratigraphy
Study of rocks as strata
Steno's 3 principles
Superposition Original Horizontality Lateral Continuity
Metamorphic Rocks
Undergo a change in form due to the action of high heat or pressure
Principle of Inclusions
a body of rock is younger than any of its constituents
S-Waves (secondary/shear)
actual waves of an earthquake and can't pass through liquid
Rock
any aggregate of mineral matter
Fossil
any physical evidence of past life
Physical Weathering
breaks down rocks and minerals into smaller particles with no change in mineral/chemical composition
Clastic Rocks
composed of "clasts" (grains/particles produced by physical weathering) -Examples: conglomerate, sandstone, mudstone/shale -Textures: grain roundness, size sorting, composition
Chemical Weathering
decomposition of rocks and minerals by chemicals
Sedimentary Rocks
form when sediment becomes compressed and/or cemented over time
What are Sedimentary Rocks
form when sediments become compressed or cemented over time
Geologic Time Scale
formal succession -biostratigraphy=correlation of rock strata using fossils
Non-Clastic Rocks
formed by chemical or biological processes -Examples: limestone, dolomite, chert/flint, coal, chalk, rock salt
Element
fundamental substance in which matter can be separated by chemical means
Earth Layer Athenosphere
hotter, more ductile (plastic) 100-350km thick
Principle of Superposition
in any sequence of undisturbed layers of rock the oldest layers are the bottom and the youngest are at the top
Evolution
indirect evidence examples are genetic information, comparative anatomy like with chimp and human DNA -fossils tell us when major changes in biological information occurred in the past
Core
iron+nickel composition 3500km thick
Biosphere
living/life globe
Mantle
middle layer, denser darker silicates 2800km thick
Mesospshere
middle layer, solid, denser 2600km thick
Transport
movement of sediments from point of weathering to point of deposition
When does transport occur?
occurs in wind, glacial movement, and running water+landslides, happens very quickly
Crust
outer most layer, silicates 10-70km thick
Earth Layer Lithosphere
outermost physical zone, rigid 100km thick
Paleogeography
physical and biological geography and the geologic past of land mass and it's occupants
2 types of the sedimentary rock cycle
physical weathering chemical weathering
Silicate Minerals
primarily made with oxygen and silicone -SI+4/Cation -0-2/Anion
Principle of Original Lateral Continuity
rock layer extends continuosly in all directions until it thins out, encounters a barrier, or merges with another sediment
Igneous Rocks
rocks that form from crystalization of molten material (magma/lava)
Principle of Faunal Succession
sedimentary rocks are characterized by unique assemblies of fossils that change through time
Deposition
setting or precipitation of sediments into layers(strata)
Atom
smallest individual particle that retains all properties of a given atom
Lithosphere
solid planet (rock)
Uniformitarianism
the present is key to the past -was guiding principle to knowing how the world works.
Importance of sedimentary rocks to earth history
they preserve clues about past environmental conditions on earth
Atmosphere
vapor (air)
Hydrosphere
water within the globe
D-Waves (primary/compressional)
waves pass through water, will find easiest way out
Molecule
when combined they create minerals
Principle of Cross-Cutting Relationships
younger geologic features cut across older geologic features -which geologic events happened first