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F. W. Dickson, Emeritus Research Professor of Geochemistry Department of Geological and Engineering Sciences University of Nevada, Reno, Nevada 89557 E-mail.

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Presentation on theme: "F. W. Dickson, Emeritus Research Professor of Geochemistry Department of Geological and Engineering Sciences University of Nevada, Reno, Nevada 89557 E-mail."— Presentation transcript:

1 F. W. Dickson, Emeritus Research Professor of Geochemistry Department of Geological and Engineering Sciences University of Nevada, Reno, Nevada Home: 2220 Seawall Boulevard Galveston, Texas Phone: GSA 2008

2 Concepts Advances in science, mostly by Henri Poincaré and Ilya Prigogine, and insights from petrologic studies at Papoose Flat and deductions from my experimental work were convincing that nature follows rules of disequilibria, turbulence, and chaos, commonly produces metastable fractal forms, minerals and life. Concepts were applied to migration of energy and mass in earth in following: Dickson, F.W., 2005, Role of liquids in disequilibrium processes of earth and replacement in Papoose Flat pluton, California, in Rhoden, H. N., Steininger,R. C., and Vikre, P. G., eds., Geological Society of Nevada Symp. 2005: Window to the World, Reno, Nevada, May 2005, p This Addendum includes figures and statements documenting conclusions in my abstract presented at 2008 National Meeting in Houston of Geological Society of America in power point format: GSA 2008

3 Poincaré in the 1890s mathematics and phase space concepts showed that calculating paths of perturbed three bodies was impossible, the slightest differences in initial conditions led to unpredictable results. Newton’s laws were shown to be not universal. Newton and Einstein principles are used for cases in which equilibrium is approximated and direction of time does not matter. Henri Poincaré’s revision of concepts of Isaac Newton and Albert Einstein GSA 2008

4 Lars Onsager: Perturbed systems close to equilibrium return to equilibrium by laws of physics and chemistry (linear behavior). Ilya Prigogine: Far from equilibrium reactions are unpredictable, irreversible, and follow paths set by nature. Fluctuations of molecules in space described by non- linear equations are independent of scale, ranging from local to galactic. GSA th Century Advances

5 Theoretical and experimental work that showed that disequilibria prevail in universe and in earth. Excess energy in systems drives irreversible processes along gradients of T, P, concentration (X), and gravity. Processes are not reversible. Time passes in one direction. Reactions far from equilibrium follow bifurcating paths set by nature according to his theories and experimental work. Ordered products, metastable persistent self-similar fractals, independent of scale, are produced by chaotic, turbulent, disordered processes. These include minerals, life forms, star systems, galaxies. Ilya Prigogine’s Insights GSA 2008

6 X = Time or concentration versus λ = concentration. Thermodynamic branch is close to equilibrium in linear range. Stable: Persistent in time, such as life forms. Unstable: Transforms to stable, persists short times. Experimental bifurcations set by nature do not reverse, indicating time’s direction. Prigogine’s Experiments GSA 2008

7 Fluid-coated, medium-grained, subhedral igneous minerals under stress at close of entry of Papoose Flat pluton rearranged to orthoclase and quartz megacrystals. Excess energy of stress cycled in local dissolution and precipitation reactions, existing minerals were replaced with metastable minerals with favorable growth kinetics under extreme augen gneiss conditons. Led to considering mechanisms of cycling excess energies in regional replacement and passive entry of granitic rocks. Replacement of Igneous Minerals in Papoose Flat pluton GSA 2008

8 Patterns of Minerals in Space Nature patterns large volumes of self-similar stable and metastable matter (fractals) that are independent of scale, ranging from microscopic to galactic. Metamorphic mineral facies are world-wide sets of minerals in large volumes that share characteristics. Nature controls properties of observable products ; in minerals are set textures, sizes, shapes, crystal forms, and twinning. Nature follows reaction kinetics as functions of temperature, pressure, chemical potential, and effects of electromagnetic and gravitational fields. Nature’s patterns are necessarily observed in field, and are best understood by mathematical, theoretical, and experimental approaches. GSA 2008

9 Cross section to mantle Mass mobilized by excess energy in lower crust and upper mantle as diapirs and reaction cells. Magmas Dikes Intrusives Volcano Geothermal systems Near-surface earthquakes Upper crust Lower crust magma chamber Upper mantle Lower crust Upper crust magma chamber Diapir and reaction cell conduit Diapirs and reaction cells Lower crust magma chamber Upper crust GSA 2008

10 Implications and speculations Fractals of nature are independent of scale. Local replacement of minerals of Papoose Flat pluton was by cycling excess energies of stress in endothermic dissolving and exothermic precipitating reactions at mineral surfaces. Excess energies of plutons cycle similarly in crustal scale replacement. Plutons contain excess energies of liquefaction that cycle in earth gradients. Reaction cells that do so; excess energies of liquefaction at cell tops dissolve roof rocks by endothermic reactions, minerals crystallize below by exothermic reactions, and released energies migrating upward by convective overturn in liquid zones to reaction zones at tops. GSA 2008

11 Excess energies build in liquids generated in rocks on increase in temperature and pressure where insufficient energy is lost by diffusion of heat. Excess energies are consumed in consolidation of magma. Rocks have complex compositions and natural liquids formed from them can not be pure; they obey laws of solubility in separating phases that depend on gravity and reaction kinetics as functions of temperature, pressure, and chemical potential. Magmatic bodies in gravitational fields are unstable and rise as diapirs and replacement of cover rocks by reaction cells. Natural Liquids GSA 2008

12 Classic phase diagram in terms of solubility SYSTEM KAlSi 2 O 6 – SiO 2 (1 BAR) GSA 2008 Shows stability fields of melts, saturated and unsaturated solutions, and solid phases as functions of T and concentration, at 1 bar

13 Replacement of calcite (CaCO3) by pyrite (FeS2) Solutions supersaturated with pyrite exchange energies at surfaces, minerals differ in composition balanced chemical reactions not relevant. GSA 2008

14 Replacement by solutions Required are: supersaturated solutions; paths to and from reaction sites; transport in and out by flow and diffusion; favorable kinetics of nucleation and growth. Faces of minerals replaced diminish in volume equal to solids deposited. Constant volume restraints (equilibrium) do not hold. Unconsumed energy and matter migrate out. Balanced chemical reactions in open systems are not possible or meaningful without knowledge of sources and sinks. GSA 2008

15 Frontiers 2007 Reaction Cell Disequilibrium reactions prevail in earth gradients of TP and gravity. Destabilized country rocks dissolve regardless of lithology and composition. Energy lost by deep cells is mostly to entropy gains, other factors are small or compensating. GSA 2008

16 Excess energies of liquefaction of RCs (plutons, magma bodies) in earth’s gradients cycle in dissolving and precipitating reactions that emplace volcanic and igneous systems. Disequilibrium (chaotic, turbulent) reactions prevail in earth operate in RCs. Country rocks dissolve at tops of RCs and absorb energy. Minerals precipitate at bases of RCs and release energy. Freed energy migrates upward by convective overturn in central liquid zones. Deep RCs, excess energy loose energy mostly by entropic gains. Energetic factors are negligible (heat exchanges, work done on and by), or compensating (energies of dissolving and precipitating). RCs rise chemically in gravitational fields much as water flows down hill. GSA 2008 Remarks on Reaction Cells (RCs)

17 GSA 2008 Liquids of individual RCs evolve in composition toward granitic upward, and basic downward, and enrich in fugitives. Fluidity (viscosity), density and compositions of RCs modify during ascent. Country rocks dissolution adds components, compositions shift, mantle and crustal constituents are incorporated. Repeated transit of cells form paths along which emplaced passively multiple plutons of batholiths. RCs loose energy, at close of entry, liquids shrink to intergranular coatings of minerals. Minerals coated with liquids in newly emplaced plutons are highly reactive, respond to physical and chemical perturbations. Remarks on Reaction Cells (RCs) continued

18 Research at Papoose Flat in1950’s began as part of a UCLA group. Nearly entirely exposed pluton was sampled and observed on grid. Pluton passively emplaced, transecting regional structures and sedimentary rock units. and subjected to gravitational oversteepening on the west. Megacrystals of orthoclase and quartz grew in pluton, foliated aureole, and country rocks. Timing of growth was after passive entry of pluton. Inculuded was marginal emplacement of aplite dikes and quartz veins. Ductile deformation on north formed pytgmatites and misshaped trilobite fossils. misshaped; ductile deformation increased intensity toward west, where country rocks retained stratigraphic sequences, were thinned to 1/20 th original thickness, and border rocks strongly foliated; and in gently foliated pluton. GSA 2008 Study of Papoose Flat Pluton, Inyo Mountains, Calilfornia

19 At Papoose Flat and in more than 12 quartz monzonitic plutons in western U. S., orthoclase crystals closely resemble one another in texture, color, forms, habit, size and shape. Crystals of orthoclase greatly differ because of wide range of environments. Closely similar features require common short ranges of TPX values during growth. Plutons and country rocks with fluid coated minerals at late stages of entry respond to perturbations. Megacrystals of orthoclase and quartz form under extreme augen gneiss conditions. GSA 2008 Ortho clase crystals record of growth conditions

20 Are gray and white in color. Typically about 2 cm long, but exceptionally range to 10 cm and longer. Associate with gray bipyramids of quartz about 1 cm long. Are simple combinations of crystal forms (basal and side pinacoids and prism). Shapes are slightly elongated, boxy, and crooked. Tough crystals weather out whole, litter surface of ground, and break easily from matrix. Rough outer surfaces with pits and projecting tiny crystals observed in face sectors below. Monoclinic under microscopic and by X-ray examinations, and triclinic (crooked) in outer shapes. Rarely associated with microcline; at Papoose Flat, as a few borders on orthoclase formed under weak stress, and as streaks in foliated rocks formed under stronger stress. Oscillating Ba and K concentration of concentric layers parallel to outer surfaces. Contain preferentially included oriented tiny crystals in face sectors (hour glass textures). Larger subhedral grains of same minerals occur in pluton. GSA 2008 Orthoclase crystals of Papoose Flat-type

21 Papoose Flat Valley, Inyo Mountains, California View East Toward Waucoba Mountain From Western Foliated Border GSA 2008

22 Papoose Flat Pluton Location, Regional Geology and Cross Sections GSA 2008

23 Geology of Papoose Flat Pluton On east pluton transects regional features; on west It occupies wrap-around plunging anticline of thinned Cambrian rocks; on north and west, pluton is ductily deformed. GSA 2008

24 Petrologic Conclusion: Crooked Orthoclase Porphyroblasts In Papoose Flat-Type Quartz Monzonitic Plutons Do Reveal Mechanisms Of Local And Regional Replacement In Earth. GSA 2008

25 Typical Papoose Flat quartz monzonite, in center of pluton on west. Illustrates medium grained matrix with crystals of quartz and orthoclase. This orthoclase crystal is unusual in having fractured. Crackled gray quartz bipyramids are in matrix. GSA 2008

26 Typical Monoclinic Orthoclase Crystals From Papoose Flat Clinging to surfaces are tiny crystals of minerals observed in face sectors below GSA 2008

27 Orthoclase Crystal From Coxcombe Mountains, California GSA 2008 One of more than 12 localities in quartz monzonite plutons in western United States. Crystals are mostly 5 cm, but range to greater than 12 cm, most unusual.

28 Crooked orthoclase crystal, Coxcombe Mountains, California Viewed down, onto face (001), face(010) on left and face (100) on top 87 degrees GSA 2008

29 Center cut parallel to (010). Left: Unstained; Right: Stained red for barium. Rough outer surfaces with crystal shaped pits and clinging crystals that are in face sectors below. GSA 2008 Orthoclase Crystal With Zones and Hour Glasses

30 Orthoclase Crystal From Papoose Flat Center-cuts, parallel and perpendicular to (010). Stained red for barium. 3-D view of zones and hour glasses. Rough outer surface with clinging tiny crystals. GSA 2008

31 East Border Papoose Flat Pluton Inclusions of country rocks, partly digested, cross cut by orthoclase crystals and seams. GSA 2008

32 Boulder in wash at east end of pluton Inclusions of country rocks and digested remnants, transected by orthoclase, with seams converted to crystals. GSA 2008

33 NW contact of pluton with hornfelsed country rocks Assistant Walter Dibble viewing contact of pluton, and undigested remnant of inclusion of country rocks. GSA 2008

34 Pluton on NW, passively emplaced in Pre-Cambian sedimentary rocks Medium grained granite with aplite seams and orthoclase. Subjected to mild post-seam stress that triggered growth of porphyroblasts of orthoclase. GSA 2008

35 Sets of intersecting aplites in pluton with orthoclase crystals; not thinned and foliated as western border rocks. Pluton initially entered passively, emplaced dikes and veins, and north and western portions underwent ductile deformation. Passively emplaced Papoose Flat pluton on NW not affected by sliding GSA 2008

36 Outcrop of weathered granite with projecting whole crystals Orthoclase crystal do not fall apart or break easily. Growth under stress may anneal, and eliminate flaws normally present in K- feldspars. GSA 2008

37 Western foliated granite-aureole border rocks adjacent to thinned sedimentary rocks. Gneissic border zone. Mixed aplite dikes, quartz veins, and granitic rocks foliated during sliding. Orthoclase crystals grew during and later than foliation event. Crystals are concentrically zoned, and with hour glass textures. GSA 2008

38 Orthoclase crystals in foliated border rocks Orthoclase crystals grew during and after sliding event. Concentric zones parallel outer shapes from centers to margins. Partly converted to white microcline, rare at Papoose Flat. Evidences of locally concentrated stress. GSA 2008

39 In zone of intermediate ductile deformation. Cambrian graywackes recrystallized, developed pytgmatic folds and quartzo-feldspathic layers. At base of figure, white feldspathic layer is overlain by black deformed layer, and underlain by thin seams of black partly digested layers. Reorganization during sliding included replacement by crystals and generation of quartzo-feldspathic layers deformed to pytgmatic folds. GSA 2008 Orthoclase porphyroblast 30 m from pluton on north side

40 Contact with metamorphosed Cambrian graywackes replaced by megacrysts of white orthoclase and bipyramids of β- quartz. Pluton to right contains orthoclase and quartz crystals with same properties. GSA 2008 Papoose Flat Pluton Locality PF154 at far SE Corner

41 Metamorphic minerals in Cambrian country rocks at SE corner of pluton Slab polished, stained red for barium, 10 cm wide. Orthoclase is typical of Papoose flat -type: zoned, with hour glass textures. β-Quartz bipyramids, gray, euhedral, unzoned, to 10 mm in diameter that grade to sugary groundmass, crackled, ragged borders. Orthoclase and β-quartz persist metastably. GSA 2008

42 Conclusions In my opinion, science is the most remarkable achievement of human beings, its methods guarantee progress despite our tendencies to resist change. James Hutton in the 18 th century early developed scientific approaches now used by scientists. He insisted on answering questions from sound concepts and his observations. He saw in quarries that granites cut former sediments, hardened into rocks with signs of heating, deduced hot liquid entered from below as did volcanoes. He believed that a benevolent God had kindly converted ocean sediments to rock bodies, uplifted and weathered them to make rich soils that grade laterally to hard rocks. He developed his great cycles of nature, uniformitarism, and long times required. These led to great controversies and dissent. His approaches became standard, his concepts are part of science and accepted by most people.. The origin of granite has been discussed since Hutton’s time; geologists agreed with his observations in quarries, but troubling observations of strong evidences of regional features of passive entry, that granite somehow had substituted for crustal matter. How was space occupied? What was the fate of disappeared rocks? Where were sources of energy needed to liquefy and recrystallize such large volumes? These questions could not be answered by prevailing igneous concepts. However, mysterious mechanisms of science came into action. General scientific understandings have steadily increased since Hutton. We recognize that earth systems are open, gradients everywhere guide disequilibrium reactions, energy in excess in magma bodies drives cyclic processes that passively replace crustal rocks. Science as it is in the 21 st century, and my observations, bear on mechanisms of transfer of mass and energy in earth and origin of granite. I hope they prove sound under challenge by methods of science.


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