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Terminology • science • knowledge • experiment • humanity • technology • hypothesis • theory • law

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Sense of scale

(from the very large…)

universe → galaxies → stars → solar systems → planets → Earth → mountains → rocks →

minerals → elements → atoms → subatomic particles → quarks

(…to the very small)

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The Sun • a star • 150 million km from Earth • ordinary, medium-sized,

middle-aged, comparable to other stars of its class

Solar System • 8 planets • 1 sun • asteroids (rocky bodies) • millions of comets • 137 moons

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Evolution of Earth • homogeneous cold

accretion • temperature Increase

· impact of planetesimals · gravitational compression · radionuclide’s

• iron catastrophe

· convection · differentiation

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Minerals • naturally occurring solid • inorganic • internal structure

· lattice · regular and repetitive

• chemically definable

· specific · limited chemical range · usually >2 elements

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The Atom • protons • neutrons • electrons • isotopes • ions

· anion (-) · cation (+) · Octet Rule

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Atomic Bonds • Ionic Bonds transference of electrons • Covalent Bonds sharing electrons • Metallic Bonds "fickle" bonding • Hydrogen Bonds unshared electrons • Van Der Waals Force mutual attraction

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Mineral characteristics are determined by: • crystal structures • chemical composition

Pauling's Rules: • radius ratio • electrical neutrality • mutual repulsion

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Elemental Abundance

O, Si, Al, Fe, Ca, Na, K, Mg

98.5% of all elements, by weight, in Earth's crust

silica tetrahedron

SiO4-4

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Physical Techniques · hardness · cleavage · fracture · crystal form & growth habit · color · streak · luster · effervescence · density & specific gravity · magnetic susceptibility · refractivity · luminescence · heat capacity · thermal conductivity · resistivity · piezoelectricity & pyroelectricity

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Rocks • Igneous

Formed from cooling and consolidation of magma and/or lava.

• Sedimentary

Formed from chemical precipitation or deposition of particles.

Metamorphic

Formed from changes in igneous, sedimentary or metamorphic rock.

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General characteristics of rocks: • Texture

Resulting from the size, shape, and appearance of minerals in the rock.

• Mineral Assemblage

Resulting from the relative abundance of minerals present in the rock.

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Time A non-spatial continuum in which events occur in apparently irreversible succession, with an interval separating two points on this continuum measured by selecting a regularly recurring or predictable event, such as the sunrise.

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from: Hutton, J., 1788. Theory of the Earth. Transactions of the Royal Society of Edinburgh, 1:209-305.

"Time, which measures every thing in our idea, and is often deficient to our schemes, is to nature endless and as nothing (p.215)." "If the succession of worlds is established in the system of nature, it is in vain to look for anything higher in the origin of the earth. The result, therefore, of our present enquiry is, that we find no vestige of a beginning, no prospect of an end (p.304)."

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Relative Dating • original horizontality (lava flows

and sedimentary deposits)

• original lateral continuity

• superposition

• inclusions (xenoliths and clasts)

• cross-cutting relationships (intrusions, faults, and erosion)

• unconformities

• deformation (tilting, folding, faulting, and metamorphism)

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Decay Mechanisms Alpha decay, α: Emits two protons and

two neutrons. Beta decay, β: Neutron converted

into a proton; electron emitted.

Gamma decay, γ: Same element with less energy; photon emitted.

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Atomic Time In 1967, the 13th General Conference on Weights and Measures first defined the International System (SI) unit of time, the second, in terms of atomic time rather than the motion of the Earth. Specifically, a second was defined as the duration of 9,192,631,770 cycles of microwave light absorbed or emitted by the hyperfine transition of cesium-133 (133Cs) atoms in their ground state undisturbed by external fields. The best primary cesium standards now keep time to about one-millionth of a second per year.

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Precise Time and the Master Clock These clocks are distributed over 20 environmentally controlled clock vaults, to ensure their stability. By automatic intercomparison of all clocks every 100 seconds, the USNO time scale can be computed which is not only reliable but also extremely stable. Its rate does not change by more than about 100 picoseconds (0.0000000001 seconds) per day from day to day.

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Centripetal Force The force needed to bend the normally straight path of the particle into a circular path is called the centripetal force. It is directed toward the center of the circle. It is a radial force. Centrifugal Force Centrifugal force is the equal, but opposite force to centripetal force, and is directed away from the center of the circle.

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E A R T H Q U A K E S Richter Number Magnitude per Year 2.0 - 3.4 800,000 3.5 - 4.2 30,000 4.3 - 4.8 4800 4.9 - 5.4 1400 5.5 - 6.1 500 6.2 - 6.9 100 7.0 - 7.3 15 7.4 - 8.0 4 >8.0 0.15

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Seismology • seismographs • focus and epicenter • elastic rebound theory • Mercalli Intensity Scale • Richter Magnitude Scale • seismic waves:

⎯ body waves P: primary; compressional; fast; s, l & g S: secondary; shear; slow; s ⎯ surface waves L: land; slowest; “water wave” style

• identification of focus • prediction

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Magnetism • Aurora Borealis • declination • inclination • strength • origin of magnetic field • magnetization of rocks • secular variation • magnetic reversals

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Isostacy Mechanism where areas of Earth’s crust rise or subside until the mass of the topography is buoyantly supported (compensated) by the thickness of the crust which "floats" on denser mantle. Airy Hypothesis: an equilibrium of crustal blocks of the same density but of different size; thus the topographically higher mountains would be of the same density as other crustal bocks (but would have greater mass and deeper roots). Pratt Hypothesis: an equilibrium of crustal blocks of varying density; the topographically higher mountains would be less dens than the topographically lower units and the depth of the crustal material would be everywhere the same.

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Plate Tectonics Approximately 20 rigid plates define the mechanical, outer layer of Earth. • Convergent Boundaries

destroys crust reverse faults ⎯ mt., eq. & volcanoes

• Divergent Boundaries creates crust normal faults ⎯ oc., eq. & volcanoes

• Transcurrent Boundaries no change in volume strike slip faults ⎯ eq.

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Igneous Rocks Rocks that solidify from molten material. • Intrusive cools slowly larger minerals solidifies from magma e.g.: granite & gabbro • Extrusive cools rapidly smaller minerals solidifies from lava e.g.: rhyolite & basalt

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Intrusive Features • Sill

• Dike

• Batholith

• Laccolith

• Lopolith

• Stock

• Pegmatites

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Extrusive Features • Lava

• Pyroclastic

• Nuée ardente

• Lahar

• Fumaroles (and solfataras)

• Phreatic eruptions

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Types of volcanoes • Shield

• Dome

• Cinder cone

• Stratovolcano

• Crater

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Eruptive Styles • Flood basalts

• Strombolian

• Volcanian

• Peleean

• Phreomagmatic (Certseian)

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Weathering

Chemical (surface) • acid rain • organisms • organics

• Mechanical (whole rock) • wind • flowing water • humans • root pry • frost riving • thermal expansion • burrowing organisms

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Glacial Environments Erosional Features

• cirque • arête • horn • hanging valley • roche moutonées • glacial polish • glacial striations

Associated Features • tarn lakes • paternoster lakes • patterned ground • kettle holes

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Glacial Environments Depositional Features

Stratified deposits: • varves • esker • kame terraces Unstratified deposits: • glacial erratics • tills • dropstones • moraine • drumlin • loess

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Sedimentary Rocks Sediment is lithified into a sedimentary rock by the process of diagenesis. • Lithification:

Processes that convert sediment into a sedimentary rock.

• Diagenesis: Physical and chemical change that sediments undergo excluding weathering and metamorphism; includes: compaction, desiccation, cementation & recrystallization.

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Types of Sedimentary Rocks • Clastic:

Particles derived from weathering of pre-existing rocks.

• Chemical:

Chemically or bio-chemically precipitated in marine or freshwater.

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Stratigraphic Formation

• A body of rock strata which is unified with respect to adjacent strata by consisting of a dominant lithologic type or combination of types or by possessing other unifying lithologic features.

• Thickness may range from less than a meter to several thousand meters.

• The formal unit for subdividing the whole stratigraphic column into named units on the basis of lithology.

• tabular in shape

• mappable at a scale of 1:25,000

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Metamorphism Mineralogical and structural adjustment of solid rock to physical and chemical conditions imposed at depth that differ from the conditions under which the rock originated. Agents: • Pressure • Temperature • Fluids Types: • Regional • Contact • Others

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Transportation Style • solution • suspension • bedload • saltation

Transportation Measures • competence (maximum size) • capacity (maximum load) • discharge (amount of water

flowing) Fluvial Environments • alluvial fans • braided streams • meandering streams • deltas

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Oceans • 71% surface of the earth

• salinity: 34.7 ppt (3.47%)

NaCl >> MgCl2, Na2SO4, CaCl

• density: 1.025 g/cm3

• carbon “sink”

Eustatic & Isostatic Changes • transgression (shoreline up)

• regression (shoreline down)

• emergence (land rises)

• submergence (land down)

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Tides

Periodic changes in the elevation of the ocean surface at a specific location in response to external forces. • spring: new & full moon • neap: 1st & 3rd quarter

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Water • hydrologic cycle • groundwater water table zone of saturation zone of aeration • aquifer & aquiclude • springs • perched water tables • geysers • urbanization • water wells cone of depression artesian wells

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Fog Tiny water droplets near Earth's surface. Types: • radiation • advection • upslope • evaporation • frontal

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Air Pressure Equal to the weight of a 1 cm2 column of air from sea level to outer space. The average pressure is equal to:

= 1 atmosphere = 14.7 lbs/in2

= 1.013 kg/cm2 Equivalent to the weight of a: • water column 10.13 m high • Hg column 760 mm high • Hg column 29.92 inches high

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Wind • Pressure gradient • Coriolis effect • Friction • Momentum Air Masses • cT continental tropical • mT maritime tropical • mP maritime polar • cP continental polar • cA continental arctic • mE maritime equatorial

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El Nińo ENSO: El Nińo/Southern Oscillation A variation in air pressure between E and W tropical Pacific Ocean. Normal conditions: SE Trades drive warm water westward, away from coast, causing upwelling off the Pacific coast of S. America where cold nutrient-rich bottom water is usually transported to the surface. Event conditions: SE Trades shift directions and become westerlies and thus downwelling.