• The origins and evolution of minerals
• The origins and evolution of life
• The rise of oxygen
• The co-evolution of life and rocks What Is Mineral Evolution?
A change over time in:
• The diversity of mineral species
• The relative abundances of minerals
• The compositional ranges of minerals
• The grain sizes and shapes of minerals A Comment on “Evolution”
• The word “evolution” has several meanings • Change, as in Bowen’s “Evolution of the Igneous Rocks.” A Comment on “Evolution”
• The word “evolution” has several meanings • Change over time, as in Bowen’s “Evolution of the Igneous Rocks.” • Implication of complexification • Congruency • But NOT Darwinian evolution! Mineral Evolution New minerals form through a combination of chemical, physical, and biological processes. What was the first mineral in the cosmos? It came from… Supernovas It came from… Supernovas
Elements that form in supernovas Diamond—The First Mineral Diamond
Formed from: (1) an abundant chemical element, (2) with a very high T of condensation. Diamond & Graphite Diamond
Graphite “Ur”-Mineralogy Pre-solar grains contain about a dozen micro- and nano-mineral phases: • Diamond/Lonsdaleite • Graphite (C) • Moissanite (SiC) • Osbornite (TiN)
• Nierite (Si3N4) • Rutile (TiO2) • Corundum (Al2O3) • Spinel (MgAl2O4) • Hibbonite (CaAl12O19) • Forsterite (Mg2SiO4) • Nano-particles of TiC, ZrC, MoC, FeC, Fe-Ni metal within graphite. • GEMS (silicate glass with embedded metal and sulfide). Ur-Minerals Mineral Evolution: How did we get from a dozen minerals (with 10 essential elements) to >5000 minerals (with 72 essential elements) on Earth today? The Birth of Stars and Planets The Nebular Hypothesis Stage 1: Primary Chondrite Minerals Minerals formed ~4.56 billion years ago in the Solar nebula by melting and cooling.
(i.e., solid material began condensing and forming planetesimals) ~60 mineral species Stage 2: Aqueous alteration, metamorphism and differentiation of planetesimals
- Water began exsolving from melt and reacted with solids
- When planetismals were large enough, dense material sunk and light material floated
- Higher pressure caused low grade metamorphism Stage 2: Alteration of planetesimals by heat, water, and impacts ~250 mineral species (4.56-4.55 billion years)
• Feldspars • Quartz • Micas • Clays • Zircon • Calcite Stages 1 & 2 Minerals Stages 1 and 2: Meteorites
In these early stages all of Earth’s near- surface compositional complexity was present, but it was not manifest in a diversity of unusual mineral species.
In other words, minor and trace elements substituted for more common elements in the major rock forming minerals, instead of forming their own minerals.
~250 mineral species Stage 3: Planet Formation
The formation of planets enabled new combinations of pressure and temperature Stage 3: Formation of a “Dry” Planet ~300 mineral species?
Is this the end point of the Moon and Mercury? Stage 3: Formation of a Wet Planet (4.5 to 4.0 billion years ago)
Remember that phyllosilicates have OH!
~420 mineral species (hydroxides, clays) Stage 3: Formation of a Wet Planet Is this the end point for Mars? ~420 mineral species
Volcanism, outgasing, surface hydration, evaporites, ices. Stage 4: Granite Formation (More than 3.5 billion years ago) >1000 mineral species (pegmatites)
Partial melting of basalt and/or sediments. Stage 4: Granite Formation (More than 3.5 billion years ago) >1000 mineral species (pegmatites)
Earth’s original composition started as mafic, so multiple cycles of partial melting were necessary to isolate felsic compositions, into which incompatible elements were concentrated Stage 4 Minerals Stage 4: Granite Formation (More than 3.5 billion years ago) >1000 mineral species (pegmatites)
Pollucite
Beryl Tourmaline
Spodumene Tantalite Complex pegmatites require multiple cycles of re-melting and element concentration: All known examples are younger than 3.0 Ga. Stage 5: Plate tectonics (More than 3 billion years ago)
~108 km3 of reworking Mayon Volcano, Philippines New modes of volcanism New P-T combinations Stage 5: Plate tectonics (More than 3 billion years ago)
Massive base metal deposits (sulfides, sulfosalts) Stage 5: Plate tectonics (More than 3 billion years ago)
Chalcocite Luzonite & Enargite
Covellite & Djurleite
Bournonite Geochronite Massive base metal deposits (sulfides, sulfosalts) Stage 5: Plate tectonics (More than 3 billion years ago) 1,500 mineral species
Coesite SiO2 Glaucophane, Lawsonite, Jadeite
High-pressure metamorphic suites (blueschists; granulites; ultra-high pressure phases) Stage 5: Plate tectonics (More than 3 billion years ago) 1,500 mineral species
Coesite SiO2 Glaucophane, Lawsonite, Jadeite
High-pressure metamorphic suites (blueschists; granulites; ultra-high pressure phases) Stage 5: Plate tectonics (More than 3 billion years ago) 1,500 mineral species
High-pressure metamorphic suites (blueschists; granulites; ultra-high pressure phases) Stages 3-5: Chemical and physical processes in Earth’s crust and mantle.
New geologic processes, especially fluid-rock interactions associated with igneous activity and plate tectonics, led to a greater diversity of geochemical environments and thus new mineral species.
~1500 mineral species Earth’s chemical and physical processes resulted in up to 1500 different mineral species.
How did we get to 5000 mineral species on Earth today?
The answer is life. The origin of life ~4 billion years ago required some minimal degree of mineral evolution.
Clays Borates Sulfides
Olivine Minerals as Protection
After Joseph Smyth et al., 1998 Minerals as Catalysis
After Jay Brandes et al., 1998 Minerals as Reactants
After George Cody et al., 2001 Selection on Mineral Surfaces
After Hazen et al., 2001
Life only uses left- handed molecules!
Mineral surfaces select and concentrate small molecules Minerals as Scaffolds
After Gustaf Arrhenius et al. (1990, 1994, 1996, etc.) Co-evolution of Life and Rocks The origin of life ~4 billion years ago required some minimal degree of mineral evolution.
Sulfides Borates
Clays
But further mineral evolution depends on life: hence the co-evolution of the geosphere and biosphere. Stage 6: Life without oxygen (4.0-2.5 billion years ago) ~1,500 mineral species (limited number of new species: oxides, carbonates, sulfates)
Oceans formed about 3 billion years ago… enabled precipitation of some new minerals
D. Papineau F. Corsetti, USC