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OUTER SHELL ELECTRONS. “As given by Compton, the explanation of the Compton shift is that in the target material, graphite, valence electrons are loosely bound in the atoms and behave like free electrons.” https://opentextbc.ca/universityphysicsv3openstax/chapter/the-compton-effect/#:~:text=The%20Compton%20effect%20is%20the,wavelength%20of%20the%20incident%20radiation View in LinkedIn

SOLUBILITY CHEMISTRY. “Some minerals simply dissolve in water, dissociating into their component ions. Other minerals react chemically with water, often forming some soluble ions and some insoluble residues. For those that dissolve by ionic dissociation, the range in solubilities spans many orders of magnitude.” https://lnkd.in/eTGK5eZN View in LinkedIn

Round-leafed navel wort, pig’s ear, oblong pig’s ear, narrow pig’s ear, finger pig’s ear, purple pig’s ear; common wild plants have a variety of peculiar names, rooted in a rich history of local lore. View in LinkedIn

MACRO REFLECT MICRO. “Most minerals occur naturally as crystals. Every crystal has an orderly, internal pattern of atoms, with a distinctive way of locking new atoms into that pattern to repeat it again and again. The shape of the resulting crystal -- such as a cube (like salt) or a six-sided form (like a snowflake)-mirrors the internal arrangement of the atoms.” https://www.geologypage.com/2016/03/how-do-crystals-form-grow.html View in LinkedIn

SO ENDS this first of two weekends featuring one aspect of how Nature does large-scale chemistry in aqueous solutions. Biochemists and chemists do these reactions at mg or Kg scales, but geologic processes involve trillions of tons of reactants on the scale of continents. When you survey a landscape remember that it is highly dynamic on geologic time scales. View in LinkedIn

IONIC SOURCES. “In humid regions the important amounts of calcium, magnesium, sodium, and potassium added yearly by rain may be expected to influence the composition of the soil water and thereby the cations in the exchange positions of soil clay minerals. The acquisition of cations by clay minerals may slow down chemical weathering.” https://lnkd.in/ete8CApd View in LinkedIn

AQUEOUS GEOLOGY. “Rainwater as a Chemical Agent of Geologic Processes A Review, Chemical composition of rainwater and its probable relation to soil water and exchangeable cations in weathering processes, by Dorothy Carroll.” https://lnkd.in/ete8CApd View in LinkedIn

AQUEOUS RECRYSTALLIZATION. “Clay minerals are characterized by tetrahedral sheets occupied by Si and subordinately Al and Fe3+. These sheets join together along the surfaces with different combinations, giving rise to different layers, which in turn join to form different clay minerals. In the various clay minerals, the layers have different layer charges as a function of the substitution of higher charge cations with cations with lower charges (e.g., replacement of Si4+ with Al3+ in tetrahedral sheets).” https://www.mdpi.com/2075-163X/11/10/1057/htm View in LinkedIn

“FIGURE 1. Schematic representation of dynamic recrystallization in a deforming polycrystal. (a) Dislocations accumulate heterogeneously under an applied stress. (b and c) High-strain relict grains (gray) are progressively consumed by the nucleation of strain-free recrystallized grains (white), formed by grain boundary bulging (red arrows) and subgrain rotation (yellow arrows) nucleation mechanisms, causing an increase in the recrystallized fraction, X.” https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JB016201 View in LinkedIn

BEYOND ETCH PLATES. “During dynamic recrystallization (DRX), strain hardening due to the accumulation of lattice defects is counteracted by both the creation and migration of grain boundaries, and the nucleation of new, strain-free recrystallized grains.” https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JB016201 View in LinkedIn