Geology 209midterm

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Trial and Error method Characterized by a succession of attempts to understand the natural reality, scientists will always try to design new experiments . as proven wrong explanation of process or phenomenon is not followed. Modern science as distinct and independent human inquiry is major and necessary in human society Greek rationalism • Rational explanation to astronomical objects without supernatural cause • Started in classical Greek and end in western roman • Expanded during Macedonian empire and Hellenistic period • Distinction in explanation to the natural world, with experiment and interpretation on direct observation • Thales of Miletus, founder of natural philosophy/ prediction of an eclipse and demonstrate Earth’s spherical shape • Anaximander of Miletus, produce the first map of the known world/ famous On Nature is lost, consider earth floats unsupportive in space and celestial bodies make full circles through heaven?/ earliest attempt to explain the origin of life without supernatural force/ suggest the emergence of life through a moisture at earth surface before dried up by solar heat, first( fish w/ thorny skin) Biology ( Aristotle) De partibus Animalium • Complexity of life increases with complexity of organization • Embryos develop from homogenous to heterogenous • Progressive development of nature is from general to special • Suggest the model ( earth centre) • Usage by Ptolemy of Alexandria to provide geocentric model Renaissance • 1180 crusade 1200 renaissance • Collapse of roman civ and beginning of medieval age with al ost no focus in science, only religion • Return of scientific thinking with start of heaven and earthly thinking • Nicolaus Copernicus (polish priest) modern Heliocentric model • Galileo Galilei, design 4 telescopes to study celestial bodies, discover 4 moons pf Jupiter(Io, Ganymede, Europa and Callisto) ,Saturn’s ring, lunar relief etc. (supported the heliocentric model) • Johannes Kepler, demonstrated that planets move around the sun in a elliptical orbit • Need of astronomy maths and medicine to help economy on society Modern Science • Francis Bacon (1569-1626) emphasized the practical aspect of science; the applicability of new discovered knowledge and predict the mutual development of science and industry • Establishment of Royal Society of London (1660) post English civil war. • Birth of modern science, science present by institution as Distinct and Independent inquiry

• Robert Hooke( 1635- 1703) “In the Pream ble of the Statuses of the Royal Society; purpose is to improve knowledge of natural things and all useful practices, Engynes and invention by experiment-not with divinity metaphysics morals politics. • Data by experiment and direct observation as cornerstone • One of Earliest science advance-first principle of layers formation in geology by Nicolaus Steno • Thomas Burnet “The sacred Theory of the Earth -formation originated from chaos from mass of all little parts and particles of matter mixed tgt and floating with confusion • Foreseen only to be foundation for new natural philosophy by Francis bacon Methods and data flow • Can come only from experiment and direct observation • Quotes and results from other author only if there is compelling evidence they use scientific approach thoroughly , and interpretation entirely based on data generated • Permanent challenge, new and better explanation replaces the old one • Human inquiry such as arts, law, religion works with datasets of other nature and cannot be imported in science and priori of scientific nature • Transformation of dataset to scientific data----scientists can study the processes and phenomenon in the past through their effects produced, which must be by direct observation with experiment; impact crater interpretated as collision of meteorite and larger celestial body. Study with aid of the characteristic of the effect and could study long after it produced • Interpretations are not unique • Dataset generated-interpretation to provide explanation to certain process or phenomenon- formulate a hypothesis- hypothesis tested by other scientists- Then, new aspects of the original problem could be revealed; applicability domain expanded or reduced • Transformed into theory if interpretation correct and new addition improves it • Paradigm are broad interpretation that explains large scale phenomenon Characteristics of science • Science is entirely relative-permanently challenged and changed when necessary • Science is not agnosic-admitting a limit for capability of science to provide answer isn’t scientific • Science is developed through contradiction and debate- “good science” accepting new POV • Science does not accept directionality-results cannot be provided before study Scientific language • Terminology leading to a different language than the everyday usage • Eg theory, in everyday refers to a degree of incertitude • But in science Theory is a fact, accepted explanation of a process or phenomenon Sub discipline of geology • First use of the term Jean Andre Deluc and later fixed by Horace-Benedict de Saussure • Physical geology- focuses on the earth’s components (mineral and rocks) and process that actually happened at the earth surface or it’s interior • Historical geology-focuses on the formation and evolution of earth and supersystems (atmosphere, hydrosphere and biosphere).

• Physical geology is about change, Historical geology is about evolution • Crystallography • Mineralogy • Petrology- 3 subdiscipline of rocks; igneous rocks, sedimentary rocks and metamorphic rocks\ Sedimentary-surface of earth with accumulation of particles in river and also wind transfer continentally. Metamorphic-high pressure high tempp rock modify minerals and crystallize rearranged, everything solid • Sedimentology- study of sediments • Paleontology- fossils • Stratigraphy-study of layers and bodies of rock arranging from old to new in interior of earth layers of environmental change • Geophysics- physical properties of earth and material in it’s composition • Geochronology-geological time in absolute value youngest branch • Structural geology, sediment are lose particle sandstone undergo sedimentation before reach sedimentary rock COSMIC Milky way • The galaxy corresponding to the solar system consists about 100 billion stars • Nebulae, interstellar dusts, gases and isolated particles, gravitate around centre of galaxy which is high density in stars and dust • Spiral galaxy 100000 lightyear diameter, complete rotation in 230 my • Lens shaped in transverse section • Four arms; Centaurus, Sagitarius, Cygnus-Orion aka local arm (solar system arm) and Perseus. • Solar system is situated app 28k ly from centre and 20 ly above equator • Part of the local group of galaxies with 40 such structure. Andromeda galaxy with spiral structure; great and small magellanic clouds • Local group is part of the greater agglomeration of stars, the virgo-supergroup , which is also just a small part of the universe. Now 40 galaxy in group • Formed 1 by after known universe expansion Universe architecture and age pg 8 • 1914 Vesto Slipher, Galaxy shift red-blue spectrum • Moving away (red shift) moving towards ( blue shift) • More precise data collected by Edwin Hubble 1929/ observed galaxy is receding faster with increase distance from our galaxy • Thus universe is expanding, changed the static paradigm of universe since beginning of human evolution • Possible calculation of the universe expansion rate, by extrapolation when expansion begin, The Big Bang Theory was used to explain the expansion

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• Matter was concentrated in small portion of space and 13.7-13.8 bya explosion of colossal magnitude began the expansion, 380kyafter the big bang, universe cool to 60k degree and allow stability of atoms How was results verified the existence of big bang 2 spacecrafts • COBE/ mapped discrete fluctuation in deepest region of space • WMAP/ reiterated the measurements of COBE in 2003 at higher resolution. Ripples on two cosmic maps interpretated as vestiges of the earliest formed galaxy superclusters. Plot of light age • Milky way was formed 1my-1by after the big bang with unknown precise age • Difference in temperature in different portion, close to absolute 0 is evidence for big bang • Around gamma cygni matter uneven distribution H and He dom in nebulae mass cosmic dust in traces large amount Most matter mass of galaxy is concentrated in stars and nebulae Stars • Massive celestial bodies • Quasi-spherical shape and consists of ionized gases H and He • Radiate energy by thermonuclear reaction in the interior • Atoms of H fusion to form He and radiates energy as long as the reserve of H available • Extremely diverse in luminosity size and temperature • Heavier elements occur in their mass O2 Fe C. formed by thermonuclear reaction in life cycle • “end” gigantic explosion , elements recycle to form another star 98% by H and He 2% of other elements. Nebulae • Agglomeration of cosmic matter • High variability in shape, density, composition and size • Consists of gases H and He and cosmic dust e.g. C, Si • Some are extremely dense • Refer to as the birthplace of stars everyone can have potential to form star but not all can, conc of matter form star with grav contraction Solar system • Central star celestial bodies gravitating around it, and cosmic dust • Study through astronomical or direct observation of space material fallen • Zone 1/ terrestrial planets zone 2/ asteroid belt/ zone 3/ intermediate zone with jovian planets. Zone4/ outer zone with small icy objects and comet nuclei Sun • Radiates energy due to continuous thermonuclear reaction in interior, combing H to form He • Diameter 1.5m km 98.85% of solar system mass, 73% H 25% He • Interior 20m degrees, energy receive by other planets is inversely proportional to the distance from sun, H reserve exhaust in 16-29by

Terrestrial planet • 4 close to sun, mercury venus earth mars Solid at surface with rocky appearance, earth largest • Density Mars(3.9g/cm3) venus(5.2g/cm3) earth(5.5g/cm3) mercury (5.4g/cm3) • Mars has two celestial bodies (deimos and Phobos) have ice cap at south pole • All have atmosphere( CO2 dominated in venus, mars and Mercury) N2 dominated in Earth • Iron dominated core surrounded by two layers with silicates; mantle and crust • Venus crust active geological crust, earth crust broken to tectonic plates Jovian planets • Jupiter Saturn Uranus Neptune “gas giants” • Diameter and density pg10 • Atmosphere H2 dominated He subdominant • Inner core of iron silicates, ice(jupiter)and ice dominated terrain (Neptune) • Physical state controlled by gaseous mass above • Complete succession in Jupiter/ high pressure gas above layer close to core(liquid metallic H) as pressure decrease towards surface intermediate layer of liquid H and outermost gaseous atmosphere makes the planet • Icy planet groups ( Pluto) D 5 times smaller than earth one satellite charon . Rocky probable iron dominated core . icy-water, methane, ammonia dominated in mantle and crust Natural satellites • Moon ( 3.3g/cm3) small metallic core. Most o fmoon are silicate rocks • Surface show depression area (marae) darker in colour, highland (terrae) light grey • Huge number of craters by impact of meteorites • Two crater types/ filled craters that formed in earlier evolution of moon, when it is of thin crust, allwing frequent penetration by meteorites; pass through crust, molten matter from early moon interior rose to surface and filled newly formed crater • Second category, empty craters formed after moon developed thicker crust no pen, younger with filled appearance . lunar surface is covered by regolith; layer of non consolidated fragment of debris resulted from meteorite bombardment and dust • 40 satellite gravitate around Jupiter but only 4 largest well known ones • They present layered structure and interesting surface features, • Io active volcano, Europa rocky surface covered by thick layer of water ice; possible having lifeforms, callisto, highest number of impact crater • 31 satellite around Saturn; Titan, nitrogen dominated atmosphere; Triton, largest of Neptune also nitrogen dominated and have volcano phenomena that expel frozen nitrogen and methane Asteroids • Aka flying mountains • Largest, Ceres 1000km in d • Most concentrated between orbits of mars and Jupiter, the asteroid belt • Some could be from collision of smaller planetary bodies in that region during solar evolution

Comets • Celestial bodies revolving around sun, consist mostly freezing gases NH3 CO2 CH4. Solid appearance in distal part • Glows when near sun gaseous glowing coma tail forms Meteorites • Rock fragments from inter-planetary space that entered in collision with larger celestial bodies • Stoney meteorites- entirely silicate, most contain quasi- structure in mass known as chondrule ( formed through solidification of molten matter droplets through planetary collision • Meteorite that has significant amount of chondrules in their mass aka chondrites some stoney meteorite similar to chondrites but lack chondrules/ they are aka achondrites . • Another group of stoney meteorite least frequent have organic compounds can be 5% of meteorite mass; compounds that mostly are amino acids, inorganically produces / known as carbonaceous chondrites will have shiny black colour • Iron meteorites – large size mineral in mass Iron-Nickel alloys; iron dominant in most • Stony iron meteorites- composed of silicates and iron[-nickel alloys approximately equal proportion Space dust Aka cosmic dust, exist both interplanetary and interstellar space/ small sized solid particle mostly of C, Mg, Fe, Ca, generally irregular in shape maximum dimension smaller than mm, increase earth size as each year app 3000 T fall down Solar nebula theory Matter not uniformly distributed, intersection of nebulae with cluster of stars process begin • Phase 1 contracting cold clouds • Phase 2 rotating and heating cloud, matter conc in central part increase collision thus heat • Phase 3 chaotic swirling and incipient accretion The center rotating clouds, particles become denser and denser and reach high degree Small size particles collided between them, particles increase in size and small chunks of rocks form, continuos attract othe particles rotating in the rings , attraction create turbulent movement adding more particles in a accelerated rate Density in middle so high can create 100k solar systems • Phase 4 protosun and protoplanet formation (At central part particles become extremely dense several mill Celsius chunks increase in size, as grow form grav field continue incrrrease size till protoplanet formed Surface was in contact with fringe of space CENTER is protosun, did not dissipate energy. Energy only by friction of particles Terrestrial planet closer to sun present core of molten matter, core almost as same as hot on surface of sun Protoearth ¼ size of earth. Interior strong gravitational fields al silicate migrate to surface, gravitational differential process. Thus core dominated by heaviery iron and metal, mantle and crust by silicate and Al

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• Phase 5 sun ignition (Exponentially higher energy with the birth of sun , formation of solar wind (flux of electrically charged particles) When sn heated energy by solar wind removed gases Jovian attract gases more efficiently Core rotate independent to planet, electrical charged particle moved against, andformed own magnetic fields and unable to retain H and He but can retain heavier gases CH4 NH3 When sun egnited H and He removed and trapped to jovian Thus atmosphere of jovian so thick and dominated by those lighter gases • Phase 6 major collisions and readjustment (Proto planets revolved around sun in unstable orbits, causing collisions. Decreasing number of protoplanets. Catastrophic events All in same age Earth interior Nebula theory of solar system formation 5bya, lasted 400my and form planet 4.6bya à Can be studied by intersection of wells 1- 3km deep rarely 10km and look at the rocks Seismic wave propagation method Explosive charge blown at earth surface, or sea floor proximity; energy discharged produces seismic waves, that travel in subsurface. They travel parameters and controlled by chemical composition and environmental characteristics of rocks and subsurface fluids. Media that are not homogenous thus waves intersect irregular surface will reflect and refract To investigate the strata architecture of earth seismic investigation , layers and bodies of rock Data show most of earth interior is inaccessible to study Seismic waves in earthquake Caused by strata rearrangement from the hypocenter at depth of usually 100km some 600-700km • Mechanical energy discharged travel as seismic waves • Body wave: travel inside earth interior, produced during first energy discharge; transform in to surface wave as they reach surface • Primary body wave: fastest, first to be recorded by observer 6-14km/s they compress and release rock in the direction of propagation thus can travel both solid and liquid • Secondary waves: movement perpen to propagation direction aka shear wave and ONLY propagate through solid media, 3.6km/s • Surface waves: one in vertical waves to direction of propagation and a horizontal wave (slow moving) and last to reach observer • all the waves are recorded as seismograms when earthquake produced, important to measure earthquake amplitude and magnitude

• Calculate hypo and epicenter position and infer physical properties of media between Earth Interior Chemical composition Core iron dominated nickel sub-dominant Mantle is silicate dominated radical SiO4; mantle 80% of earth volume, Gutenberg discontinuity between mantle and core Crust silicate dominated, thinnest variable thickness oceanic and continental , oceanic less diverse mostly silicates of iron and magnesium. Continental more dicerse Na K Al silicates , cpd of oxygen, Sulphur and Carbon mohorovichich discontinuity between crust mantle Physical property • Lithosphere thick av 100km under continent thicker; solid state slabs tectonic plates ( lithospheric plate), only planet with plate constant movement • Asthenosphere under lithosphere, depth boundary 600km. upper part plastic support litho plate dynamic via convection current ( upper mantle part) • Mesosphere lower mantle, 660-2900km, rocks slow flow due to high temp of Fe Ni alloy in composition , heat radiated from core • Outer core, below Gutenberg discontinuity 2900-5179km liquid state but behaves like solid, difficult to study S-wave no propagation through liquid • Inner core, Fe Ni alloy acts as solid when P wave intersect it with its high pressure; independent rotation, solid unlike outer core. Only earth has differentiation • Mantle < 100 minerals recognised crust 40x more mineral both dom by silicate and iron Gravitation differentiation process Explain by solar nebula theory • Proto earth begin formation with particle conc result in small chunks of rock weak G field ; steadily increase in size • Primordial G field cause faster size increase, attract more larger particles and collide • Successive collision with asteroids rock fragment or protoplanets • Gradual heating could also be by radioactive elements decaying and dissipate to surrounding rocks • *when reach Iron and nickel melting point, 2 metal high specific weight thus mobility increase and sunk to protoplanet center thus conc of Fe Ni In core and small amount in non-metal part of earth • Lighter elements conc in shallow part of protoearth happen parallel to formation of incipient crust , early atmosphere favoured formation of new minerals , thus crust became chemically and mineralogically separated from mantle • Incipient crust more homogeneous than today

Chapter 4 minerals Minerals are naturally formed chemical substance having a definite chemical composition (not fixed) and characteristic crystal structure Cannot be broken into other mineral substances, could change if metal got into composition Antiquity Greek scholar know size of mineral gradually decreases until cannot, to define concept of atom Mineraloids Ions and atoms are in amorphous state, thou stable but irregular in arrangement. Formed through the precipitation of the opaline silica SiO2 The change of colour: reactive with subterranean fluids with different components, structure remains the same. Green: Fe2+, white: CaO, yellow: Fe3+, black: manganese, Blue: cobalt oxide, Orange: Fe+ Certain constant of chemical composition but atom and ion not ordered in pattern, Organic mineral Whewellite, sulphur Through the precipitation of organic groups (bacteria), bacterial precipitation. Q about result or process Large sized minerals. If by volcano, usually microscopic Mineral imperfection Shape affected by other minerals in internal structure Crystallization by molten matter, almost as identical minerals, different colour given by different substance in mass of original mineral cause zonation in colour. Cannot happen if no internal structure Bondings Size Strength Mineral: halite (NaCl) Smallest in particle: atom Group of atom bonded tgt, smallest component in a chemical compound :molecule Strongest: Covalent bond, higher melting point, stable structure by sharing e- Weaker: Ionic bonds, metal and non-metal, lose E- and non metal accept E-, attraction force, lower MP Weakest: Van der vaals Diamonds and graphite GCS toughness resistance to scratching, continental zone host best diamonds, high pressure upper mantle depth of 100km. molten matter reaching surface with high speed form pressure and expel in eruptions, in continental crust force only appear there. Only of carbon atoms but with different structure

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Diamonds: each C atom bond to 4 other C atom and situate in corners of tetrahedron Graphite is planar structure of parallel layer of hexagon. Adj bonded van der waals, final organic decay product. More reactive element expelled C and H remain, form hydrocarbon, only C remain when in to earth interior of 225 C and form graphite Geometric packing of minerals=crystal structure Physical property 1. Colour : impurity, surrounding ion, crystal flexibility could deceive. Rhodochrozite reddish-pink, oprigment bright yellow. Variability holds for most minerals 2. Hardness : by scale of Mohs hardness scale , 10 minerals. 1-talc, 2-gypsum, 3-calcite, 4-fluorite, 5-apatite, 6-orthoclase, 7-quartz, 8-topaz, 9-corundum, 10-diamond 3. Luster : description of light reflection. E.g. Metallic reflect light immediately(pyrite, galena); Greasy (halite), Dull (hematite), Silky (gypsum), Vitreous (quartz) 4. Crystal faces and forms: euhedral, subhedral, anhedral. anhedral formed in slow crystallization process, thus could not develop ideal form 5. Twinning: occur only in certain mineral species, the intergrowth of 2 or more mineral. E.g. ‘’in cross ’’ twins of staurolite, ce russite 6. Transparency: how minerals let light pass through, 3 categories of minerals characterised in this property. Transparent; Translucent; opaque Mineral classification J.J Berzelius, classification method into similar crystal architecture and physical property on the nature of anionic and cationic component

Native elements A single element in their structure Metal: (Au, Ag, Cu, Pt) isometric crystals, cubic crystal system, metallic luster, high specific weight, malleable, ductile, opaque, good electricity conductor . Semi-metal: (As, Sb, Bi) poor electrical conductor, commonly occur in nodular masses. Less frequent than metal Non-metals: (diamond, graphite, sulphur) tendency to form large sized crystals, transparent to translucent crystals, no electrical conduction, sulphur often found at earth crust Sulfides Metal/semimetal+sulphur/ most frequent is pyrite Metallic sulfides have high specific weight (galena Pbs, molybdenite) and metallic luster (e.g. galena), isometric crystals are frequent. Non-metallic are orpiment, realgar tunneling microscopic, light and dark spot show observation in galena Sulfosalts: metal+semimetal+sulphur (e.g. pyrargyrite) high specific weight, metallic luster and prismatic crystal, excellent source of metal (silver) Halides Cation metal plus halogen anion. Most frequent halite …Often crystallized in cubic form , accept impurity thus high colour variability , occur in high amount in evaporite rocks,, in sedimentary basin and warm arid climate. Carbonates Most frequent calcite/ the cation has 1 or more metals and anion (CO3). Minerals in this group is often rhombohedral and low specific weight, usually presents bright colour but can have wide variability Calcites: varies from perfectly transparent to black Found in all igneous sedimentary and metamorphic, but most formed in sedimentary environment. Rocks formed in carbonate platform are primarily pure carbonate . Shells that has aragonite in their shells dies and recrystallize into calcite/ orthorhombic to hexagonal. Oxides Combination of one or more metallic elements and oxygen, most frequent hematite. Occur in all 3 igneous sedimentary and metamorphic rocks. They have high degree of symmetry, crystallized in cubic and hexagonal systems. Magnetite in oxides have excellent magnetic properties Uraninite are radioactive and important source of uranium.

Oxides as Aluminium oxides can accept impurities and transform into different mineral varieties: Corundum (pure aluminium oxide, Sapphire (higher amount of iron and titanium), Red Ruby (richer in chromium) Sulphates SO4 2- Most frequent form as the gypsum/ also occur In all 3 types of rocks, but! Most are formed in sedimentary domain; evaporite crocks have large amount of sulphate mineral mostly gypsum, anhydrite Some often associate with halides. Sulphates have low specific weight, wide colour variability. Silicates: the dominant mineral in mantle and crust The silica tetrahedral structure: silicon at centre bonded with 4 Oxygen atom at the tetrahedral corners/ thus, the spatial arrangement and the bond between them and cation or other tetrahedra is what classified into 6 subgroups Nesosilicates: Isolated tetrahedra. Bonded only with cation, no bond between tetrahedra and nesosilicate mineral. E.g. Olivine, most frequent mineral in earth ’s mantle. Inosilicates: Single chain. Each tetrahedra share 2 O atom in linear arrangement, cation are linked to remaining non-shared O atom/ often have prismatic habit. E.g. Spodumene, diopside Sorosilicates: Double chain. Bonded tetrahedra that shares 2 or 3 O atom, result in double chain structure, with covalent bond between adj silica and ionic bond with cation linking double chain structure/ e.g. Epidote Phyllosilicates: Sheet. Tetrahedra share 3 O atom and bonded covalent between each. Cation between sheets are linked with ionic bond, cleavage surface parallel to tetrahedra sheets. Minerals in group often presents foliated habit/ E.g. muscovite aka white mica, biotite aka black mica Tectosilicates: Framework, extremely flexible crystal structure. Can accommodate cation with large radii, O atom bond adjacent to other tetrahedra. Are rock forming minerals which frequent found in earth crust. E.g. Quartz. Cyclosilicates: Ring, 3,4 or 6 tetrahedra. Rare minerals, occur only accessory in some igneous and metamorphic rocks, e.g. beryl Chapter 5 Form through molten matter solidification according to depth of cooling. Process of transformation • Magma crystallize slow due to low rate of heat loss in interior • Larva crystallize fast due to high heat exchange Atoms and ions in both are irregularly distributed and high in energy, solidification most cases need rearrange into more regular structure (crystal structure)

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Small structure (centers or nuclei) begins mineral formation, process nucleation • Intrusive rock, beneath surface, slow cooling, adj nuclei similar crystal structure fuse, form mass of larger visible minerals. E.g. Granite • Extrusive rock, through larva crystallisation at surface, minerals do not have time to grow due to fast cooling, atom and ions no time to form nuclei of crystallisation, result in amorphous rock with glassy look, e.g. basalt. Base on degree on crystallinity, 3 sub categories • Holohyaline, entirely amorphous substance (glass) extrusive rocks • Holocrystalline, minerals only, no glass in mass, only include intrusive rocks • Hypocrystalline or hypohyaline, both large size mineral and glass in mass. Variable in component, include both intrusive and extrusive 4 textures of igneous rocks • Phaneritic, slow cooling intrusive rocks, large sized minerals. E.g. granite • Aphanitic, fast cooling extrusive rocks, microscopic size minerals. E.g. basalt • Glassy, fastest cooling, Nucleation process does not start. Rock thus amorphous state. Few extrusive is such case. E.g. Obsidian • Fragmental, shows transition in rock families. Through consolidation of pyroclastic material ejected in volcanic eruption. Of mixed igneous and sedimentary process which it accumulates through. E.g. Tuff Intrusive rock textures • Granular texture, relatively equal sized minerals, slow and continuous magma cooling • Porphyritic texture, consists of large size euhedral and subhedral mineral (phenocrysts), developed in microcrystalline mass (ground mass). 2 crystallization phase, formation of phenocryst in slow crystallization; ground mass form in second phase through rapid cooling process, induced by ascending magma movement. • Poikilitic texture, smaller minerals enclosed in larger minerals which documents 2 crystallization phase. 1 st unidimensional, smaller minerals form first, leaving homogenous magma, 2 nd phae of larger mineral formation by slow cooling. Intrusive bodies Term: Pluton, everything from beneath ground surface If body of igneous rock parallel to surrounding rock bodies=concordant, if crosses adjacent layers=discordant • Batholiths, irregular large size igneous rocks exposed at surface, mapped >100km2. Applied to granite and granitoid rocks • Stocks, expose area <100km2 similar to batholiths • Lopoliths, large size, 10s of km wide, concordant body with concave side upward • Sills, small if compared to above 3. Are concordant and flat-shaped rarely lens-shaped • Laccoliths, concordant, smaller than sills. Transverse section through sill, base nearly flat and upper domed

• Phacolites, concordant lens-shaped igneous, situated in folds pf axis region, size of sills and laccoliths • Dikes, discordant igneous, cut through layering, tubular shape and much smaller than others Extrusive rocks Form at surface from material ejected by volcanoes. 2 categories • Larva flows, aphanitic or glassy texture. Contain molten matter in mass • chemical composition huge roll in characteristic, silica-rich are more viscous than Fe Mg rich. Thus silica larva flows trap more gases-result in more explosive eruptions, producing significant amount of pyroclastites ………..Fe Mg rich flow more readily thus result formation of larva flows • Pyroclastic rocks, fragmented texture, consists only fragments of rocks and finer material detached from volcano and devoid from molten matter. • Most pyroclastic material is andesitic or rhyolitic in composition. Could be volcanic bomb if large in size. The solidification of volcanic ash and the pyroclastic rock term is tuff, unconsolidated pyroclastic material is tephra. texture of larva flows • vesicular, occurs often in basalts and traps gases. Result in sponge like appearance • pillow basalt in submarine eruption (quasi spherical structure) in high water column pressure larva cant flow bodies of extrusive rock 2 classifications. #1 Larva plateau, basaltic plains and pyroclastic sheets. #2 shield cones, composite cones, cinder cones • Larva plateaus, succession of stacked larva flows of basaltic rock from solidification of flowing larva. Largest extrusive rock structure • Basaltic plains, differ by larva source. This is by single center of eruption • Pyroclastic sheets, form with pyroclastic material settle after eruption. Thinner than larva flow correspondents • Shield cones, volcanic mountains formed in basaltic plain, succession of larva flow , small amount of pyroclastic material • Composite cones, alternating larva flows and pyroclastic material • Cinder cones, small structures almost completely of pyroclastic materials. Chapter 6 Generalities • Accumulate from the particle of pre-existing weathered and eroded rocks by precipitation in solution with ion conc>critical value • Are heterogenous function of chemical and mineralogical • 3 categories • Detrital, chemical and biochemical • Vast majority form in sedimentary basin

• Sedimentary basin “ A area of earth crust characterised by particular tectonic regime, overlain by thick pile of sediment accumulated under sedimentary environments Clastic rocks formed in accumulation of fragmentated rocks in sedimentary basin, aka detrital or siliciclastic rocks. the most frequent sedimentary rock on earth crust app 85%. 4 components, most case clast associate with matrix or cement; some found with all 3 component. • Clasts, fragments of pre-existing rocks, used for fragments more than 1 mineral are lithoclasts • Organic debris (shell, tests, skeletons) to form detrital rocks are known bioclasts • Matrix, finer clastic material; in space between larger clasts. Matrix minerals are small microscopical, transported from adjacent sedimentary basin similar process as clasts. Minerals in matrix are all allochthonous. • Cement, formed In space between clasts through mineral precipitation from solution after clasts accumulated in sediment. Cement minerals are formed in situ as are autochthonous contrast to matrix Pores allow fluid flow in rocks, 3 classification method • often occur in clastic rocks, are empty space between clasts. Totality of pores in rock (porosity) • formation of pores pg 55 • Catenary, connected with other pores; allow fluid flow in sub-surface, excellent permeability in rock • Cul-du-sac, allow fluid fill but do not allow fluid flow • Closed, no fluid flow and rarely filled with economically important fluids e.g. oil Clastic rock Formation cycle from top to bottom • Weathering and erosion Break up pre-existing rock and clast formation. Physical and chemical alteration. Exposed to atmospheric influences of earth surface • Physical weathering, bedrock broken to smaller fragment without changing chemical and mineralogical composition. Vice versa for chemical weathering/ happens because differences of temp lead to gradual fragmentation/

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• Chemical weathering, chemical reactions between water and dissolved ions (from precipitation or glacier) and pre-existing minerals. Form new minerals and rocks. Most weathered that forms clastic sediments are silicate-rich 3 rock types (I,S,M) Reaction with bedrock. E.g. Bauxite, ore to obtain Al. The result of chemical weathering of different rocks (granite amongst them) • Clasts can be produced even by rocks rich in mineral prone to dissolution. E.g. calcite, gypsum • Landslide and rock fall, clasts transport force given by gravitation, relatively short distances, in general it is considered of low magnitude while compared with other 3 types transport as follow • Sediment transport, Eolian transport (air as media) only small sized clasts can , streams and rivers accounts for largest amount of sediments. (media as running water) most frequent, fastest. Glacier transport ( media as ice) and slowest clast transport maybe 10s-100s k of years. Begin in mountain area around basin of deposition which clast are accumulated, bedrock fragmented in clasts, then transport to sedimentary basin, path to settle at deposition • Eolian blown to ocean may take 4-7 thousand years • Volcanic ash, e.g Indonesia ash travel around globe • Glacier, detach in movement and sediments in front embedded and travel long till ice melt • Classical e.g. of transport during storms and heavy rain, lot of clasts transported in episodes of storms, fans of sediment form then 1 top another in time. • Deposition, when clasts from weathered rocks and underwent sediment transport enters sedimentary basin. Ends when settled as loose clasts layer at bottom of basin. There is frequent redistribution in sediments e.g. waves and current redistribute clast in marine basin • Lithification, after deposition. Lead to unconsolidated sediment transform into consolidated sedimentary rocks. Loose to rigid 1. Compaction, sediment reduce volume as result of weight of newly added sediment on top , sponge compact with added weight 2. Recrystallization, formation of new minerals through precipitation from highly concentrated solutions that circulates the sediment pores. 3. Cementation, clasts binding by newly formed minerals 4. * increase complexity if basin has dead organisms, adding ions and reactive substance during decay, in to sedimentary pores thus increasing fluid chemical reactivity Chapter 7 During metamorphic process, change in textural, mineralogical; or both takes place. From original rock known as protolith factors: high pressure, high temp, oriented stress, chemically reactive fluids Change is due rock tend to remain equilibrium with surrounding environment (environment changes>rock change)

Limit of metamorphism • The upper limit occur immediately after diagenesis at temp 100 C/ vast metamorphic rocks under this temp • Lower boundary, correspond between metamorphic and igneous domain, below 1200 C, textural change in proximity of lower boundary are apparent in granite-gneiss-migmatite series. • Gneiss, is metamorphic result in transformation of granite at high temp and pressure> cause partial melting as temp and p increase, textural change cause light and dark mineral separate to alternating bands. • Migmatite thus result from transformation from gneiss, in boundary between igneous and metamorphic domains Types of metamorphism • Regional, most widespread. Occurs mostly in plate collision zones; regions of mountain formation. Schists are most frequent in this condition. Oriental stress as dominant factor • Contact, occur at proximity of igneous and magnetic intrusions. Causes frequent recrystallization in associate with thermal metamorphism. Marbles are frequent metamorphic rocks from the recrystallization of limestones. Temperature; pressure as dominant factors directional stress usually smaller value. • Burial, occur in large sedimentary basin .gradual transformation form diagenesis to metamorphism. Weakly metamorphosed rocks like slates are frequent in this type. Pressure is dominant factor. • High pressure and low temperature, occur in regions of subduction. Rocks subject to high pressure, used to recognise ancient subduction zone. • regional, happens in mountain ranges at zone of collision, mountain range form parallel to collision line, dominant factor is the pressure to metamorphism, temp takes smaller part, happens in vast zones 100-10000km long. E.g. cnadian rockies • Contact, forms deeper in proximity of igneous and magnetic intusion, comes at very high temp, temp of magma. Didn’t find path to surface but remained same place, heat is distributed and very slowly form. First recognised in Scotland.

• Burial, happens in flatter zone of continents, sedimentary basins. Biggest basin in America north Saskatchewan to montana, rock transported and sedimented. During the time roks are gradually buried, burial rate is high and rocks begin to be transported Degree of metamorphism • Low grade metamorphism, the lowest value of pressure and temperature in metamorphic series, immediately follow the diagenesis. • Medium grade metamorphism, intermediate between low grade and high grade • High grade metamorphism, occur at high pressure and temp, in proximity of boundary between metamorphic and igneous domain. • No metamorphic rock at high depth and low temp Metamorphic rock texture Two major class • Non-foliated, aka granoblastic texture; granoblastic rocks, minerals in rock are quasi- equidimensional, ones with platy or elongate habit are randomly distributed in mass • Foliated, characterised by mineral preferential orientation, inherited from protolith or acquire through metamorphic process/ often oriented stress as factor. Porphyroblastic texture as distinct texture. Occurrence of large minerals in mass of finer rock of foliated texture. Rock cleavage in foliated group, the tendency to break along parallel or sub-parallel surface. Reflect textural alignment of mineral grains or subparallel arrangement of discontinuities, frequently occur in rock foliation

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• Slaty texture, low metamorphic grade, growth of small scale clayey mineral. Protolith colour preserved, deformed fossils frequent occur in these rocks • Phyllitic texture, occur in low metamorphic grade, but present higher degree of metamorphism than slaty. Minerals as chlorite and sericite are frequent. Commonly larger than in slaty texture …….A coarser appearance • Schistose texture, occur in higher metamorphic grade, characterised by large size minerals (biotite, muscovite) frequent In mass. Platy and elongate habit minerals present well-defined preferential orientations. • Gneissose texture, result from segregation of mineral phase, recognised by alternation of dark- coloured and light-coloured minerals that form parallel or subparallel bands, recognised in microscopical, hand specimen and outcrop scale. Partial melting 2 nd midterm igneous, sedimentary, and metamorphic rocks Chapter 5 Generalities , presented in first slide of regular lecture, numbers such as larva and magma temp, no need memorise. Imp to know how matter crystallizees , in beginning of second paragraph on crystallisatio progress, how particle no bonded due to high temp and pressure, crystallize when temp and pressure decresea, first place when atom and ion bonded to crstallize Basic classification of igneous rock, intrusive and extrusive, extrwact fundamental observation of rock form in earth interior have large size mineral vice versa to those that need lens or microscope, pg 44 Pg45, basic classification 3-4 Q according to crystal size, the 4 classification of rocks, corresponding to intrusive, phan eritic. Aĥanetic are , fragmented part of volcanic and in between of aphan and pheritic Page44 lower part, according to prescence and absent of minerals vs volcanic glass. Matter not form of . hollow crystalline rocks, entirely crystals e.g. granite . other member, represented by hollow haline rocks, entirely glass. Eg. Obsidian the volcanic glass. In between have rocks formed of mixture of crystal and volcanic glass, hypo crystalline or hypo haline. Not entirely crystalline or haline. Sub chapter 5.3 sub out 3 feature of intrusive rock/ granular, almost equally sized minerals. Porphylitic, 2 phase of crystallisation, 1 slow form large minerals visabe crystal. 2 nd form have ground matirix around phenocrysts. Poikilitic, 1 st phase epidimensional, once crystals remaining matter crystallise same mineral that embed the other one 2 nd phase extreme homogenous . 5.5 genral term body on intrusive pluton. Everything form beneath ground surface is pluton. Figure 28 2 bodies of igneous rock. Sill ad dike. Sill parallel to existeing rock dike aparallel. Largest body f intrusive rock the batholiths Extrusive rocks. Reach earth surface leave surface through volcanic eruptions. Divided to 2 category. If molten call larva flow if no pyroclastic. If both, molten and solid called larva flow. 2 textures, vesicular in case of basalt with hgh viscosity and trap gas of atmosphere, and pillow basaltsPyroclastic material about volcanic ash and solidification of volcanic ash on rock known as tuff

Larva plateau balsaltic plate and pyroclastic are 1 classification , last 3 are classification according to volcanic mound pg 52 Number of rock types, e,g, phanalitic rock with granite, aphanitic basalt Chapter 6 3 sub chapter 1,2,3 Focus on 2 and 3 Characteristic 2 classifications. Pg54 clasts, 3 type of clasts . and the classification of pores, catenary and cul du sac. Admit oil and water, once filled locked and nno fluid through them, different for catenary 6.3 formation cycle. Exception of 1 Q in prerecord and class note deposition and formation focus on definition Chapter 7 6-7Q Limits of metamorophisms. E.g begins with granite tomigmatite, between boundary of metamorphic and andother domain Transformation of limestone to marble Types of metamorphisms 3 types regional contact…..burial metamorhisms Rocks that formed by above category Regular lecture have diagram plotted where 3 types of metamorphism occur, ans to 1-2 q planes, oceanic Classification of metamorphic rock texture as rock cleavage 4 type. * slaty and schistose like to ask Q fro these 2 Bond In between galena are ionic