GLGY final notes

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GLGY Final 20+20+60 1-3 rd part Diagrams: all from lecture Third part 60 1 st and 2 nd part Various deveolopement in history of science , in vast periods such Greek and roman antiquity , Greek rationalism, modern science track back to rationalism times , dark ages and renasissance Greek rationalism: expanded in Macedonian empire and Hellenistic period throughout roman empire. First explain phenomena by facts or will of capricious gods/ Development 550bc distinction in explanation of natural world by through natural rather than super-natural / started experiment and provide explanation base on direct observation. Explain in books about natural world rather than classical poems in theological thinking in antiquity Achievements at antiquity times : every Greek sholar, miletus demonstrate earth spherical shape, aleximander first map first idea of life emergence, heliocentric model , page 2, science rediscovery, nicholaus first modern heliocentric system, galileo major discoveries, jovian setekkuites Thales of Miletus, first to demonstrate earth’s spherical, when he predicted an eclipse Anaximander of Miletus, first map to know world, earth float unsupported in space. Life emergence from moisture and dry up by solar heat. A sequence of life development plant-animal-human. First animal fish with thorny skin, human from sharks. Biology Aristotle De partibus animalia (1) complexity of life increase with complexity of organism (2) embryo from homogenous to heterogenous (3) progress development in nature is general to special. Universally accepted in modern science Using vision of Aristotle, Ptolemy of Alexandria provide geocentric model of movement around earth. Dark ages, focused on religion, Nicolaus Copernicus challenged the system of thinking. Nicolaus Copernicus provided modern heliocentric model Aristarchus of Samos, first heliocentric model Galileo Galilei, designed first telescope and discovered Ganymede, IO, Europa, Callisto Saturn ring lunar relief etc, support heliocentric model Johannes Kepler, demonstration of elliptical movement of planet around sun , change view in natural reality and path to establish science institution.

Kepler law of planetary movement, sub chapter 1.4 equivalent with Greek advances fracis bacon, provided and argument scientific method, Robert hooke, set in place principle of odern science, Thomas,,, explain formation of our planet in space 1.6, characteristic of science, 1, deveoolpe to contradiction and debate, cornerstone is data from experiments and diresct observation, not abnostic don’t accept directionality pseudoscience is human imort that does not fulfill principle of science. Scientific creationism, accept directionality, intelligent design, accept limitation to field of study, don’t confuse between art religion philosophy and law with pseudoscience. They are inquiry with relative status. pseudo science are incompletely developed Subdivisions of geology Earth formation Milky way, a spiral one of the largest and oldest we know, part of local cluster part of virgo supercluster. What happen 13.8-13.7mya known universe expansion Stars and nebulae dominated by H AND He deferred by shape and density , Planets, terrestrial jovian and icy (pluto), free water at surface of earth and small in mars, nebulae no atmosphere, CO2 in atmosphere of mars and venus, earth considerable amount of oxygen produce by lifeforms. N dominant in earth atmosphere Natural satellites, page 11 paragraph lower most, define jovian satellites IO volcanism and Europa under thick ice. 4 satellites Discovered by galileo , the primitive telescope. Scientific evolution Asteroids aka flying mountains, 2 satellites of mars, orbits situated between mars and Jupiter, largest is Ceres, asteroids are smaller than planets, no question on comet and space dust, concentrate on meteorites most dominate is silicate dominated meteorites, stoney meteorites….. 2 nd is metallic/ iron dominated meteorites, source of alloy tgt with iron with other mineral, second most is nickel, aka iron nickel meteorite least frequent stoney iron meteorite, from collision of ancient protoplanet, causing formation stoney, iron, stoney iron most to less frequent solar nebular theory, most difficult part phases 4,5,6 4 have proto planet, celestrial obj increase in size with added obj from around space, proto planet early stage of planet

5 sun ignition, gases redistributed, H and He to other part of system forming jovian planets. Thermoreaction in sun form solar wind, flux of electrically charged particle, magnetic planetary fields 6, major planetary collisions Earth internal structure, Drilling wells mining gallery. 3.3 on earthquake with component hypo epicenter and depth Types of waves, through interior of earth , fast P waves, destructive S waves cannot pass through liquid media stop at other core which is liquid Surface waves, when P and S wave reach surface, at interphase by ground surface, at earth quake P waves are those rattle the windows their nature part of them transfer to sonic waves humming noise and vibrate vertically, S wave move horizontal, destructive to building not built for horizontal stress, earth move in mixture of direction Earth interior core mantle and crust everything lithosphere asthenosphere biosphere every property. Accept for numbers 2-3 Q 3.5 and 3.6 Minerals and rocks Types of bonds in mineral structure 3 types of bonds covalent toughest van der waals weakest Mineral architecture, structure of diamond and graphite types of bonds, diamond and graphite, where they form… Physical property, focus on colour (minerals having consistent colour) in textbook odochrozite azurite malacite,,,,) hardness, in softess mineral and hardest mineral . twinning property, Silicates, 4 minerals olivine muscovite biotite and quartz+ Chapter 5, process of crystallization Intrusive and extrusive Crystalline or completely crystallized rock, hypocrystalline and…. Phanelitic and aphanetic pg 45 must ask Pass 5.3 5.4 imp textures. Different components in texture

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Granular have every dimension, porphylitic larger euhedral and subhedral visable, smallest only under microscope Last one is small mineral in large size mineral, second phase form large mineral from very homogeneous molten substance Inttusive Higher level, from extrusive basic classification from larva flow and pyroclastic, seperated with presence of molten matter Vesicular generated in high viscosity larva flow , submarine volcano basalts Solid material tuff expelled from volcanic eruption Meaning of volcanic bomb, tephra, tuff pg52 Sedimentary rocks Define clastic rocks, lethal clast bioclast Pores, 54-55 weathering and erosion, sediment transport lithification What is compaction sedimentation and crystallization Metamorphic rocks What type of changes, mineralogical and textural Limits of metamorphism, granite gneiss migmatite, partiall melting in migmatite Types of metamorphism Diagram fg 45 pg70 where different textures occur Upper left slate in low metamorphism, phylite and sheistss in middle zone, weak matiti in high grade Textures foliated and nonfoliated Rock cleavages Process of fossilization, 2 classification Into fossils and subfossils , threshold at age of ladt ice age 11000 years, Body, trace, chemical fossils markers 8.3 Kinds of fossilization, terminalization process which fossil mineralized part of organization filled

From aragonite to calcite, dissolution driving process of molding oreservation, external precece on cast internal on mold, If moldic preservation filled with another minerla it is replacement , in case is iron Carbonization , organic matter only carbon remains from orignal composition, most frequent case Series of 3tyoes of fossilization soft tissue preserve high quality, amber highest quality, congealment at higher latitude and fossilization in tar pitn, send to surface and produce toxic swamp First mention of fossil and their nature given by Xenophanes of Colophon. The existence of fossil shells in continent area means area long ago covered by sea Herodotus, shells found in mountain region in Greece and Egypt are direct evidence for existence of ancient ocean in regions in immemorable times./ similar interpretation by Leonardo Da vinci in the Alps • Oldest fossil probably 3.5by old • Threshold at 11k year separating true fossil (older) and sub fossil younger Two major events in 16 th & 17 th century • De omni Rerum Fossilium by Conrad Gessner. Resemblance of fossil debris and living organisms in sea, urchin, shark teeth etc. some shell not equivalent to modern faunas • Niels Stensen, Nicolaus steno. Fossil occur in various layers only by hard parts, absent of soft body. Fossilization long enough for soft body to decay. Process of layer formation containing fossil is a long one 8.3 kinds of fossils • Body fossil, most frequent, part or whole organism preserved, hard parts ez fossilize due to mineral nature/ sometimes soft bodies if rapid bury and not scavenged. Study by paleontology • Trace fossil, vestige of organism activity, most case only trace fossil preserved, soft body organisms worms and insect small fossilize chance thus trace important, paleontology and ichnology. • Chemical fossils, biomarkers, chemical reaction by organisms, important for soft bodies and bacteria, algae. Life history in old sediments. Geochemistry studies it 8.5 fossilizations • Permineralization/ filling of pores spaces usually by opal or chalcedony (SiO2). Fossils with pores in hard parts, bones, plant xylems. Soft tissue decays cavities left empty. Fluid with concentrations (sulfates , CaCO3) can flow in and new mineral forms in cavity when fluid conc reach criticl value, mineral precipitation begins. Phosphatic tissues in bones, woody tissues in fossil trees. Newly minerals precipitated in cavity. • Recrystallization/ frequent process, partial or complete change of shell mineralogy after death. Case of mollusc shells or valves of aragonite nature (orthorhombic caco3). Transform into calcite (rhombohedral caco3). Driven by unstable nature of aragonite, wanting to form more stable calcite. Mineralogical composition changes and chemical composition remains the same. • Dissolution/ after sediment with fossil embedded transformed into rock, fossil shell or carapace come contact with fluid flowing through rock pores, fossil debris fully or partially dissolved due to high chemical reactivity of calcite and fluids. Results: create empty space in rock preserve

internal and external structure of dissolved fossil, internal of shell, valve or carapace preserved on mold and external features on cast. Aka moldic preservation. If moldic preservation filled with another mineral it will be replacement. • Replacement/ occurs after moldic preservation, fluid high mineral conc flow through layers embedding fossil; and through space from fossil dissolution. New mineral precipitate in this space and case of replacement (pyritization) frequently when pyrite is precipitate. • Carbonization/ most frequent for plant, invertebrate fossils. Rapid buried deep in crust, high pressure and temp and influence by chemically reactive fluids in sediment and rock pores, elements expel from organism (N,O,S,H,P) until only carbon remains. Appearance: thin film of Carbon, dark and often shiny. Further burials result fossil transformation to graphite. • Metasomatosis/ complete replacement of chemical and mineralogical component under highly reactive and concentrated fluids at earth surface and sub-surface. Fine structure often preserve in this case Soft tissue fossilization • Congealment/ rare, high latitudes. Very low temp, layers permanently froze soils extreme thick. Body structure in this case almost intact, able to study last meal by stomach content, e,g, wooly mammoth from Siberia. • Dehydration/ mummification. Desert regions, warm and arid climate, dead body lose water and dry rapid. Not scavenged and buried under sediments by wind and air currents. • **in Amber/ best-preserved in fossil record. A viscous organic resin secreted by some conifer species living in temperate climate. Fossilizing small animals and plants. Due to dense nature of resin, isolated from surrounding. All structural body preserved. Vesicles in amber preserve small amount of atmosphere during formation. • Fossilization in tar pits/ zone with oil seeps, large organisms mostly vertebrates stuck in viscous fluids. The fossils accumulate over time interval of approximately 40k years from La Brea (California) as an example • Impregnation/ most frequent case of fossilization of soft tissue preservation. Mostly in algae of shallow waters with high concentration of dissolved CaCO3 of continental shelves. Precipitated CaCO3 in sea water impregnated dead algal bodies and thus can fossilize. Paramount role in carbonate sediment formation. Impregnated algae become rigid, thus easily fragmented when transported by sea current, e.g much sand from Caribbean sea form by algal body impregnation Good fossil preservation pg 79 • Occur in layer where they can be preserved exceptionally well. In German Lagerstatten • Due to rapid burial, specimens often fossilized with undigested last meal • Study of these specimens help reconstruct trophy chains or existence of cannibalism phenomenon in some species Structural geology Bu steno in the principle of original layer horizontality, deformed and tilted layers are the result of crustal movements. Alternatively for the layers arrangement in earth crust. Steno considered the Alps were shaped by collapse of huge subterranean caves. / study of structural geology are related to mineral resources and

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hydrocarbons and mineral ores. Rocks deformation crucial in engineering geology, to evaluate bedrock potential stability and rock behaviour Change in place change in position change in shape Stress: force per unit area Kind of stress • Confining stress, equal in all 3 direction of space for certain point in earth crust, mainly in rock burial) • Differential stress: Compression (push on rock) tension (stretch the rock) shear ( on two direction on rock) is occur in case of crustal movements, thus higher in some directions • Fluid pressure, by fluid in rock pores, mostly in sedimentary rocks; pressure opposite to general stress on rock in subsurface condition

Rock deformations • Brittle deformation zone, upper crust portion, weak rocks cuz low pressure, differential stress result rock fracturing (joints and faults) dominant structure in the fracture. • Ductile deformation, depth increase rocks harder to fracture. Increase pressure and temp, prone to flow in solid state, deformation as most frequent process. Folds terminology and classification Structures result from lateral compression of crust, elements (branches, limbs, crest, trough, axis and axial plane) • Anticline: folds of strong crustal forces converging upward • Syncline: branch converging downward • Monocline: force not enough to fold Ages by Axial, at anticline oldest layer occur in axial, youngest in axial for syncline Axial plane position with respect to horizontal plane • Upright: limb opp • Inclined: axial plane inclined limb opp position • Overturned: limbs same position, plane inclined • Recumbent: plane horizontal, limb opp • Hinge is line of junction • If angled its plunging

Fractures and classification Microscopic to regional. Recognised function of movement of 2 blocks; joint and fault • Joints, fractures that 2 resulting blocks present no movement respect to each other • Faults, 2 resulting blocks present significant displacement. Named by function of their position relative to fault plane…Footwall, situate below the fault plane, hanging wall above the plane • 2 wall position to each other in fault plane inclination result in fault three-fold classification • Normal fault: hanging downward motion; footwall upward motion • Reverse fault: vice versa to normal fault • Thrust fault: reverse fault dipping a lower angle Another classification by function of displacement along fault • Strike-slip fault: displacement horizontal, along strike • Dip-slip faults: only vertical displacement, along dip • Oblique-slip faults: both horizontal and vertical displacement 5

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Nicolaus steno and principle of stratigraphy 4 principles pg 88 Ata Tuscany Italy after royal society of London established, conclude 2 rock sequence in earth crust separated by surface of discontinuity. Associated to biblical great flood. He conclude that the sedimentary layer form from finer particles in suspension in fluid. • Layer superposition that older layers are situated at the bottom. Sequence of undisturbed layers, it is modern stratigraphy. • Principle of successive layer formation, at time of formation, only fluid is above the layer and non existing layers in succession existed. Thus, long period of layer formation. Consistent with fossil record in lacking soft body organism. • Principle of original layer horizontality, sedimentary layers horizontal at time of deposition. Tilted steeply inclined layers are result of crustal movement. Later, refined by admitting that layer (old strata) could reflect irregularities at basin floor. • Principle of original layer continuity, at time of formation, layers were formed over entire basin surface. Terminate by thinning at basin margin, existing of sedimentation barriers e.g. islands that affect the continuity and lateral transition to different sediment • At time base on rock lithology to recognise layer age • Mining operation, data on layer termination, crustal structures (folds faults) Sediment structures and their roles • Giovanni Targiono Tozzetti, demonstrated stream erosion result from valley formation in mountain area • James Hutton, demonstrated that gradual change at earth surface are ubiquitous and their geological implication are profound • New idea, we could understand geological past if study the process and phenomena in today earth • Find sedimentary structures oriented upward or downward • Georges Louis Leclerc Compte de Buffon, 1774 first calculation earth age by experiment data, ended influence of creationists in science. • Mud cracks, frequently at surface of earth in fine sediment exposed to atmospheric condition in arid period. The openings are always upward. Recognise by outcrop by cusp opening upward. Thus if cusp narrows upward, condition is in inversed. • Ripple-marks, sedimentary structure form top of the layer where unconsolidated particles rearranged as result of current action. Are upward narrowing in transverse section. Thus, layer top indicated by narrow portion of ripple. • Burrowing, by organisms living in sediments. Dig more or less complex gallery, almost all present opening towards layer top.

Succession fragmented seriously, thus impossible to look and tell if normal arrangement cuz they stirred Some layers present certain structure, scales recognized easily, clue if normal or upside down Cracks present opening upward are mud cracks found in wet sediment, in case of weather Blue layer- transverse sections are ripple marks, sediment inn shallow sea, if weak current, sediment would no be stable but wavey ripple marks narrow upwards, this case succession is normal. John Stragy, perfected layer termination system to look for coal in 1745 • Pinchout, forms narrow angle as result from transgression of sea level foiled by regression. Sea level not the same over, move toward land transgression, move away regression. • Intertonguing, fluctuating sea level • Lateral gradation Sedimentological data can be used to decipher the order of deposition of various sedimentary strata. Particular structures such as desiccation cracks (mudcracks), and ripple marks are of great value in recognizing the original position of the sea bottom.

Unconformities • Disconformity, between sedimentary rocks parallel to each other. Formed through period of uplifting and erosion of succession below unconformity, followed by layer of sedimentation above the unconformity. Non significant crustal movement, explains parallel or quasi-parallel layering below and above • Angular unconformity, between sedimentary rocks but layering below and above forms an distinct angle. This conformity involves crustal movement during succession below uplift and erosion. • Non-conformities, between igneous or metamorphic rocks below, and sedimentary rocks above unconformity. Commonly encompasses a long time period before sedimentation restarts • Time interval encompassed by unconformity is hiatus, define as sum between time of erosion and time of non-deposition • Unconformities can be used for correlation at local scale • Cannot for regional or intercontinental cuz different kind generated by single geological process Fossils and stratigraphy • Charles Lyell, named uniformitarianism on change at earth surface imperceptible and gradual • Cuvier, catastrophism considered to shape the present earth • Work on invertebrates in paris basin , 1 st different strata different fossil specie deeper fewer resemblances to modern. 2 nd layers with continental vertebrate fossils often sandwiched between layers with marine fossil/ transgression / study give idea that specie could go extinct

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• Sir William smith, civil eng produce highly detailed geological map of England, wales, and south Scotland. Highly accurate/ “map that changed the world”/ • Williams noted that certain fossil specie occur in certain layer characterising it’s own stratigraphical range define by 2 events. • First appearance and extinction. • Second, a specie that became extinct does not reappear in fossil record at higher stratigraphical layer • Using range of certain fossil specie (marker fossils or index species). William provided method to correlate distant stratigraphical succession. Demonstrating the change in lithology \ order the sedimentary strata into coherent series older to younger, base on unrepeatable fossil record Igneous rock relative order • Principle of inclusion, inclusion within and igneous rock are older than rocks that include them. Observation that principle of superposition, accurate in case of igneous rocks, cannot be applied always in case of igneous rocks. Inclusion in igneous rock known as xenolith • Principle of cross-cutting relationship, a cross-cutting rock is younger than the cross cut one. Paramount in recognizing stratigraphical order of igneous rock veins and mineral assemblages with’em. • Principle of rock-cooking postulates that an igneous rock which terminally alters a layer or body of rock (I,S,or M) is younger than them, also to case of sills, cooking rocks above and below thus younger than them. Relative geological time scale • Eons, longest units in scale, 4 eons in total earth history stratigraphical order • Hadean: no rock record, only molten matter • Archean: oldest rocks on earth, Hadean/Archean boundary given by ag of oldest rocks. Fossil, oldest in rock record found in upper Archean succession • Proterozoic: stratigraphic interval with oldest fossil, entirely small sized microscopic. Larger fossils were found in uppermost part of Proterozoic. Oldest rocks and fossil eons (Archean and Proterozoic) grouped supereon Precambrian. • Phanerozoic: youngest eon, visible large fossils in many sedimentary rocks accumulated in this interval Subdivision of Phanerozoic eon\ Into 3 periods: Paleozoic, Mesozoic, Cenozoic by general resemblance of fossil compared to modern life forms Each era subdivided into periods • Paleozoic era: oldest. In NA continent subdivided in 7 periods / Mississippian and Pennsylvanian grouped as carboniferous outside NA • Mesozoic era: Triassic Jurassic and cretaceous. 2 major crisis, 1 in Permian/Triassic boundary. Affected mostly species in ocean and seas. 90% extinct in crisis. Upper boundary Cretaceous/Tertiary event of meteorite impact to extinct several major fossil group

• Cenozoic Era: fossil debris in these sediments present clear resemblance with modern life form. Geological time • Bishop James Ussher, first calculation of earth age base on biblical chronology created in 4004 bc • George Louis Leclerc, designed experiment, heated metallic rod to incandescence and measure time to return ambient temp. extrapolating to entire earth mass, result appx 75k years • More precise by sir Charles Lyell and James Hutton. Rate of continent erosion, sediment accumulation, ocean salinity etc/ made general agreement: probably range of 100s of million years • 20 th century, natural radioactivity, Marie and Pierre Curie in 1903 show energy dissipated in surrounding environment in radioactive transformation, then calculate earth age • Principle of radiometric age dating by Arthur Holmes 1911. Also first clear numerical data for minerals of paleozoic and Precambrian. • Observation most element more than one atomic config, isotopes; different neutron number and thus mass. • Parent atoms decay to daughter atoms/ decay constant time necessary to halve parent atom. • Age of mineral by measuring amount of parent and daughter in rock, if recrystallize in metamorphic process, radiometric age is metamorphism age. • U238 Pb206 K40 Ar40 Rb87 Sr87 • Oldest rock NW territory Canada 3.96 bya oldest mineral zircon in Australia 4.4 bya Correlation and types • Lithocorrelation: lithostratigraphical correlation. Recognition of identical or equivalent unit able to correlate with one another on lithological components. Earliest method used in strtigrpahy. E.g. recognition of reservoir architecture in oil field • Biocorrelation: biostratigraphical correlation, base on similarities in fossil record; can be on one fossil in stratigraphical range or combination of such unit, relative abundance etc. only index fossil can be used. • Physical event correlation: induced property on rock or trace left on rock and fossil record by geological events, includes geophysical investigation (detonating charge and record seismic wave), well logging (rock natural property measure), or physical actions. Magneostratigraphy (succession of intervals with normal and inverse polarity for stratigraphical purpose. Tephrachronology (most precise, base on correlation of volcanic ash layer in strata record, identification in a section yields precise marker). Isotope stratigraphy (quantitative measurement of a isotope in strata record) • Chronocorrelation: schronostratigraphical correlation, most complex, calibration of succession of layers or bodies of rocks to global geochronology scale

Structure geology diagram questions Principle if stratigraphy and geological time, principle of Nicolaus stenol of layers formation. Read definition and brief comments. Contribution of John, print figures Contribution of thomas base on how to recognise normal stratigraphy succession from reverse one, 2 of them tipple marks and mark cracks, one in burrowing Unconformaties, angler and n.. what type rock above and below, does layering form angle under unconformaties. Startigraohical succession. Have have unconformaties is non conformaties Development of stratigraohic corrrelation sir william smith, for correlations are I dex or marker fossils Relative order of igneous and metamorphoc rock, principal of intrusion cross cut relationship and relatice age of larva flow, how they affected the rocks Relative geological time scale pg63 figure with purple yellow colour. Four eons in archeological time, eras, periods carboniferals missisipian and peninsula Geological time, series of 3 concept What is radioactive, what is chronometer for calculating mineral age half life, 3, principal of calculation 10.9 correlation and it’s type, fossilization and correlation, Emergence of life on earth • Metamorphic usually destroy fossil • Molecules don’t fossilize • Study on terrestrial planet help learn earth formation • Stable isotope data and chemical fossils, evidence for organic/inorganic nature of highly metamorphosed substances in oldest layer Earliest atmosphere and inorganic evolution CHON(SP) 30 molecular cmp of CHON(SP) ELEMENTS dominant elements, carbon,hydrogen,oxygen,nitrogen Sulphur and phosphorus smaller amount • CHON can combine to form monomers (CH4,NH3,CO2,H2O) • Reaction forming monomers can be in inorganic environment, further reaction to form complex organic nature molecules • PROBLEM, early earth atmosphere rich in molecule free oxygen can destroy larger organic nature molecules by oxidizing them.

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• Ivanovich Oparin proposed model for primordial atmosphere, suggesting originally have a reducing feature, allowing formation of accumulation of organic molecules. • Model base on observation that free molecular oxygen result from photosynthesis. And could not happen in lifeless environment • Oparin, proposed organic molecule accumulate on surface and dissolve in water NAMING primordial soup for the mixture of organic molecule. • 1 st chemical reaction of monomers in famous experiment by Stanley L. Miller and Harold C. Urey • They considered H as dominant element in primeval atmosphere thus hydrogenated gas pg101/ energy source by electrical discharge and UV ray. They obtained 7 amino acids in experiment Glycine and alanine amongst. Demonstrating that possible formation of organic molecules in early earth. • Simple organic molecules can combine to form polymers/ chain of repeated monomers. E.g. cellulose, RNA, protein. Still yet not alive. Miller Urey experiment show polymerization can form more and more complex molecules and in nature doesn’t require exceptional condition. • First terrestrial life form, most likely from substance of primordial soup. The naked gene simple gene living outside a cell capable of self production. Probable ancestor of earliest cell • Early meteorite bombardment, therefore complex molecular formation repeated several times until viable life capable evolve to descendants to survive early earth Prokaryotes The earliest cells, small sized not well defined nucleus in cytoplasm, genetic info disseminated in cytoplasm mass, asexual organisms/ allowing multiplication with low morphological variability (mitosis) low evolution rate • Oldest isolated fossil cells. In Apex chert from Pilbara Craton of West Australia , bacteria and cyanobacterial found in volcano-sedimentary formation dated 3.465 BYA by U-Pb method. • Strelley pool chert cyanobacteria chain like, similar to modern purple bacteria • Archaeoscillatoriopsis and Primaevifilum are cyanobacteria, capable of photosynthesis(solar energy to bind energy as photosynthesis glucose) they can release oxygen • Evolutionary leap: isolated cyanobacteria clustered to form stromatolites • Oldest stromatolite in fossil record known from fig tree formation of witwatersrand group • Stromatolites are organo-sedimentary structure of various shape (domical, columnar,conical etc) • Photosynthetic organisms concentrate in uppermost portion of stromatolite, the growth layer anaerobic bacteria occur beneath growth layer in oxygen depleted zone • Fossilized primordial soup?? Isua supercrustal group SW Greenland, old sedimentary rock 3.8- 3.7 bya, rare oside and carbonate not forming layers. Graphite indicate organic origin/ rocks that old affect by metamorphism, phobalitic texture dark blue, grey colour • Mineral found there are calcite, require amount of molecular oxygen (by-product of life activity) • Stromatolite record in Gunflint in southern Ontario, diversification of cyanobacteria pg 103 • Rock record 2.2-1.9bya, rocks rich in iron oxide and hydroxides. Banded iron formation with iron rich and iron poor layer inside rock red banded. Documenting increase in molecular oxygen in atmosphere while that time only stromatolite release oxygen by photoautotrophic cyanobacteria generation. It estimated oxygen increased by 15x 1%-15% naming it earth rusting.

Eukaryotes More complex cells to prokaryotes, existence of well-defined nucleus include structures capable transmitting genetic info(chromosome). Surrounded by nuclear membrane. Have organelles in cytoplasm surrounded by thin membrane for specialised physiological function. Organelles originally are symbiotic prokaryotes. • Significant size increase with higher level of cell organization • Most advanced eukaryotes from Mesozoic and Cenozoic sediments • New type of reproduction mechanism, separate sexes; important for morphological variability, chromosomes recombine and imperfections (mutations)occur frequently. • First eukaryote fossil in Bitter spring formations of Australia , appx 850mya base on particular cell’s spatial arrangement during cellular division • Red algae (rhodophytes), green algae (chlorophytes, caryosphaeroides and Glenobotrydion), Eotetrahedrion and eozygion • Bangiomorpha similar to modern red algae attach to sea floor rise upward for sunlight 1.2bya • Torridonophycus, green algae bag-like structure (acritarch) survive in dry cold climate. clorophyte 0.9bya • Melanocyrillium, similar to modern testate amoebas, classified among earliest animals. Organic sometimes with agglutinated particles • Chemical fossils indicate could be 1.8bya, but large sized ribbon like cells like seaweed, Acetabularia in sediments dated 2.1 bya suggest group is even older • Trend towards size increase, but large size cell did not survive Precambrian/Cambrian boundary and extinct. Small ones continue • Late Proterozoic, evolutionary occurrence of multicellular organisms. First were soft-bodies and preserved as impressions in sediment • Latest Proterozoic sediments preserved eukaryote development of exoskeleton of calcitic nature of a group of worm • • Pre-Phanerozoic life evo show 2 distinct period by Schopf 1999 • Evo slow in early part only prokaryote organism exist on earth ; not significant morphological difference by asexual reproduction. Maximum complexity achieved with development of stromatolites. Completed in environment by late Archean • Evo of eukaryotic cells with sexual reproduction increased probable mutation • Entire mechanism and results of life evolution changed with sexual reproduction strategy. What is general elemental composition of life form c h o n what mean by inorganic monomers, methane oxygen… polymers protein carbohydrates and nucleic acid and organic monomers amino acids Primordial soup by oparin Experiment very important

Fossil from apex chert, in Australia oldest isolated Fossilized primordial soup When were first time recognised fossil below Proterozoic, in south western canada Once start cluster they form stromatolites, change in time and earth atmosphere reducing to oxidation, Evolution of eukaryotes, most important leap, evo of sexual reproduction mechanics Cells mahor proceess of diversification First algea, organism with multiple celluar, bangeomorpha, Green algae latin name First organism with animal like organism Plate tectonic (oceanic crust+uppermost mantle) (continental crust+uppermost mantle) • Observation by Alfred Wagener on earth surface dynamic • Geological fit of rock complexes on east south America and western coast of Africa • Late Paleozoic Glossopteris fern distribution in south America south Africa and India, idea second to Eduard Suess on supercontinents. Also Mesosaurus Cynognathus and Lystrosurus found • Carboniferous polar cap inferred from traces by glaciers; sedimentary structures • Supercontinent Gondwana • Maybe broke apart continental drift due to sea floor spreading but not convincing enough Morphological ocean floors • Abyssal plains • Mid-ocean ridge • Oceanic trenches • Seamounts • Island arcs Geological features Deep sea drilling project late 1960, about 1500 boreholes drilled Atlantic S shape mid oceanic ridge, Indian inversed Y, pacific ocean in U shape Sediment and oceanic crust ages and rock distribution function of their magnetic property • Sediment and oceanic crust ages, studied both biostratigraphical and chronostratigraphical method. Biostrata data by microfossilsuch as foraminifera; chronostrata data through stable isotope method. Results: distinct pattern in ocean sediment age distribution. Youngest in proximity of mid oceanic ridge, sediment age increase towards the ocean margins; pattern is symmetrical respect to ocean axis at mid oceanic ridge

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• Magnetic zone distribution, present distinct pattern in oceanic sediments. Minerals as dipoles during crystallization in case of igneous rocks and deposition in sedimentary rocks. Tendency to be aligned to magnetic field lines. • 2 distinct settings in oceanic sediments, Normal polarity(N) north magnetic pole is in same hemisphere with north geographic pole and south magnetic pole in same hemisphere with south geographic pole 2 nd . Reversed polarity , vice versa for normal polarity N at S S at N • Stratigraphical interval with normal and inversed polarity alternate at various rate. Very fast, most several thousand years. Process of magnetic reversal. By molten iron movement at core/mantle boundary, resulting convection current in liquid outer core/ polarity zone in oceanic basin show they parallel to mid oceanic ridge, which the ridge has normal polarity. Volcano and volcanic events and earthquakes • Volcanoes are frequent at plate boundaries, mid-oceanic ridge zone or boundary between ocean and continent/ others at continental zone east Africa and china. Frequent association with seamounts. Clusters of volcanoes in deep oceanic conditions (proximity of Iceland in N Atlantic), also frequent in island arc such Indonesia. • Earthquakes, concentrated along plate boundaries in certain continental regions, rare in interior portion of continents NA and SA Tectonic regimes 12.4 Divergent, convergent and transform setting 12.4.1 divergent setting Move away from each other, ascending current in asthenosphere bring high temperature molten matter from interior to surface, frequent volcanic activity and earthquake. Matter brought up rich in basic rock (mostly iron and magnesium) crystallize at surface and form olivine rich rock Oceanic crust at mid-oceanic ridge 2 adj plate move apart thus older sediment in marginal part and magnetic zone parallelism to mid-oceanic ridge. 4 stages of formation of oceanic basin • Continental rift initiation: ascending current in asthenosphere under continental crust, result in continental uplift, stretching continental crust causing normal faults in uplift region, can be recognised by elevated altitudes and increase temp due to continental crust thinning under current pressure • Continental rift formation, continuous stretching and thinning form elongated depression zone, the continental rift, formed through continental crust block drop down along normal faults. Faults are path through molten matter can reach surface. Volcanism common phenomenon. Free water in rift zones lakes, rivers, aquifers. Coarse sediments accumulates from weathering and erosion in higher mountain area, thus mixture of continental and volcanic rock formed…east African rift//// start break apart, region at northern boundary of south Africa and southern part of red sea, eastern African rift, a major depression a trough which extremely elongated at scale of whole continent, huge accumulation of water, African lakes along these trough • Red sea strange: interesting shape, in geological fundamental, it is floored by oceanic crust just like sea with oceanic floor, at central part have oceanic ridge. Therefore a oceanic basin at early formation

• African and arabian peninsular long ago is connected, when current raise they separated and create mid ocreanic ridge. To west small fold cut to mantle, east fold is colossal • Another region to confine red sea and east African , oxygen and toxic gas in dead sea no organisms live there • How African continent middle east and Europe connected to give similar structure. Gases trap in those large pools of water and form the shapes • Gases came from interior continuing process till today but at lower magnitude • If oceanic crust at red sea, all ocean bottom have oceanic crust, theory that long time ago earth covered in oceanic crust and no continents • Early oceanic basin formation: continental crust split in 2 distinct part and move away due to seafloor spreading onset. Generated by continuous influx of molten matter from asthenosphere which crystallize at surface. Forming new oceanic crust. Thus, similarity in chemical composition in oceanic crust and mantle. Crust formation keeps pulling 2 newly fragment of continental crust away/ sediments accumulated in new ocean are marine, deeper towards center shallower towards basin margin. E.g. red sea • Mature oceanic basin formation: continuation of seafloor spreading, new crust added to form vvast abyssal plains between mid ridge and 2 continental area. Volcanism and earthquake frequent phenom in region, e.g. Atlantic ocean • When rifting stage not followed by spreading stage, it is aborted oceans Convergent setting When 2 plane move against, 2 crust in collision zone, one slab overrides the other Commonly oceanic crust sunk under continental crust e.g. west coast NA. or boundary between 2 develop in discrete transitional contact without subduction phenomenon e.g. east NA 3 process • Ocea-ocean convergent setting: in collision zone between 2 fragments of oceanic crusts.1 slab sunken under another along inclined plane aka subduction plane or Benioff plane. Earthquake frequent along subduction plane, result of strata rearrangement. Epicenter depth above 200km. collision zone marked by oceanic trench, where subducting oceanic crust begins sinking. Sediments from upper part of subducting plate accreted to proximity of collision zone, forming accretionary prism (strongly folded rocks). Friction between 2 oceanic crust slabs and heat from interior start melting subducting slab, magma produced in proximity of subduction plane, melt rock in contact and reach surface forming island arcs, explosive volcanic events!!! • • Ocean-continental convergent setting: occur at collision between slab of continental crust and 1 oceanic crust/ oceanic subducted under due to nature. Collision zone between 2 marked by oceanic trench parallel to nearby shoreline; accretionary prism just above upper subduction zone. Force oceanic crust pushes against continental determines latter thickening. Mountain chain parallel to collision zone on continental crust, oceanic crust consumed and sink in asthenosphere, process associated with frequent earthquake and magma generation. • Continental-continental convergent setting, 2 slab continental crust collide. Involves subduction and consumption of oceanic crust slab separating them. 2 continent move closer, ocean narrower

eventually close. Collision form mountain chain parallel to collision zone. Earthquake and volcano frequent. E.g. Indian subcontinent and Eurasia, forming Himalayas. Transform setting pg 115 Wilson Cycle after john Tuzo Wilson • Cycle of ocean initiation, expansion and closure • Initiates when ascending currents in asthenosphere determines onset of divergent setting within continental crusts and formation of continental rift • Rifting successful if followed by phase of sea floor spreading ; width increase gradually during spreading phase • Expansion stopped convergent setting initiate if adj crust slabs pushed towards each other • Formation of ocean-ocean setting oceanic subduct under continental. • Result in continuous oceanic crust consumption in asthenosphere, ocean narrower, until complete closure. • Transform settings can occur at smaller scale through ocean evo cycle • Wilson cycle can last several hundred million years • Continent movement at surface as parts of successive Wilson cycle, led to formation and closure of oceanic basin • Present day continental position result of drift following break up of supercontinent Pangea. Toward end of paleozoic and start of Mesozoic. • Completely assembled in late permain initial break up in triassic • Pangea surrounded by wide ocean Panthalassa Chapter 12 plate tectonics Attention on 12.3 geological feature, plain mid ocean ridges, indian shape of inverted y .pacific ocean in shape u Age of sediments Earth magnetic fields normal and inversed zones Case of divergence, east African ridge, split in 2 continents, red sea oceanic basin incipient in early stage of convergence, where plates collide Italy, Himalayas Focus on tectonic regimes 12.41 12.42 12.5 definition of plate tectonic theory

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