Mineral evolution is a recent hypothesis that provides
historical context to mineralogy. It postulates that mineralogy on planets and
moons becomes increasingly complex as a result of changes in the physical,
chemical and biological environment. In the Solar System, the number of mineral
species has grown from about a dozen to over 5300 as a result of three
processes: separation and concentration of elements; greater ranges of
temperature and pressure coupled with the action of volatiles; and new chemical
pathways provided by living organisms.
On Earth, there were three eras of mineral evolution. The birth of the Sun and formation of asteroids and planets increased the number of minerals to about 250. Repeated reworking of the crust and mantle through processes such as partial melting and plate tectonics increased the total to about 1500. The remaining minerals, more than two-thirds of the total, were the result of chemical changes mediated by living organisms, with the largest increase occurring after the Great Oxygenation Event.
In the early Universe, there were no minerals because the only elements available were hydrogen, helium and trace amounts of lithium. Mineral formation became possible after heavier elements, including carbon, oxygen, silicon and nitrogen, were synthesized in stars. In the expanding atmospheres of red giants and the ejecta from supernovae, microscopic minerals formed at temperatures above 1,500 °C (2,730 °F).
Evidence of these minerals can be found in interstellar grains incorporated into primitive meteorites called chondrites, which are essentially cosmic sedimentary rocks. The number of known species is roughly a dozen, although several more materials have been identified but not classified as minerals. Because it has a high crystallization temperature (about 4,400 °C (7,950 °F)), diamond was probably the first mineral to form. This was followed by graphite, oxides (rutile, corundum, spinel, hibonite), carbides (moissanite), nitrides (osbornite and silicon nitride) and silicates (forsterite and silicate perovskite (MgSiO3)). These "ur-minerals" seeded the molecular clouds from which the Solar system was formed.
Over two-thirds of mineral species owe their existence to life, but life may also owe its existence to minerals. They may have been needed as templates to bring organic molecules together; as catalysts for chemical reactions; and as metabolites. Two prominent theories for the origin of life involve clays and transition metal sulfides. Another theory argues that calcium-borate minerals such as colemanite and borate, and possibly also molybdate, may have been needed for the first ribonucleic acid (RNA) to form. Other theories require less common minerals such as mackinawite or greigite. A catalog of the minerals that were formed during the Hadeon Eon includes clay minerals and iron and nickel sulfides, including mackinawite and greigite; but borates and molybdates were unlikely.
Minerals may also have been necessary to the survival of early life. For example, quartz is more transparent than other minerals in sandstones. Before life developed pigments to protect it from damaging ultraviolet rays, a thin layer of quartz could shield it while allowing enough light through for photosynthesis. Phosphate minerals may also have been important to early life. Phosphorus is one of the essential elements in molecules such as adenosine triphosphate (ATP), an energy carrier found in all living cells; RNA and DNA; and cell membranes. Most of Earth's phosphorus is in the core and mantle. The most likely mechanism for making it available to life would be the creation of phosphates such as apatite through fractionation, followed by weathering to release the phosphorus. This may have required plate tectonics.
Since the original paper on mineral evolution, there have been several studies of minerals of specific elements, including uranium, thorium, mercury, carbon, beryllium, and the clay minerals. These reveal information about different processes; for example, uranium and thorium are heat producers while uranium and carbon indicate oxidation state. The records reveal episodic bursts of new minerals such as those during the Boring Billion, as well as long periods where no new minerals appeared. For example, after a jump in diversity during the assembly ofColumbia
Most of the mineral evolution papers have looked at the first appearance of minerals, but one can also look at the age distribution of a given mineral. Millions of zircon crystals have been dated, and the age distributions are nearly independent of where the crystals are found (e.g., igneous rocks, sedimentary or metasedimentary rocks or modern river sands). They have highs and lows that are linked with the supercontinent cycle, although it is not clear whether this is due to changes in subduction activity or preservation.
Other studies have looked at time variations of mineral properties such as isotope ratios, chemical compositions, and relative abundances of minerals, although not under the rubric of "mineral evolution.”
For most of its history, mineralogy had no historical component. It was concerned with classifying minerals according to their chemical and physical properties (such as the chemical formula and crystal structure) and defining conditions for stability of a mineral or group of minerals. However, there were exceptions where publications looked at the distribution of ages of minerals or of ores. In 1960, Russell Gordon Gastil found cycles in the distribution of mineral dates. Charles Meyer, finding that the ores of some elements are distributed over a wider time span than others, attributed the difference to the effects of tectonics and biomass on the surface chemistry, particularly free oxygen and carbon. In 1979, A. G. Zhabin introduced the concept of stages of mineral evolution in the Russian-language journal Doklady Akademii Nauk and in 1982, N. P. Yushkin noted the increasing complexity of minerals over time near the surface of the Earth. Then, in 2008, Hazen and colleagues introduced a much broader and more detailed vision of mineral evolution. This was followed by a series of quantitative explorations of the evolution of various mineral groups. These led in 2015 to the concept of mineral ecology, the study of distributions of minerals in space and time.
In April 2017, the Natural History Museum inVienna
https://en.wikipedia.org/wiki/Mineral_evolution
On Earth, there were three eras of mineral evolution. The birth of the Sun and formation of asteroids and planets increased the number of minerals to about 250. Repeated reworking of the crust and mantle through processes such as partial melting and plate tectonics increased the total to about 1500. The remaining minerals, more than two-thirds of the total, were the result of chemical changes mediated by living organisms, with the largest increase occurring after the Great Oxygenation Event.
Use of the Term “Evolution”
In the 2008 paper
that introduced the term "mineral evolution", Robert Hazen and
co-authors recognized that an application of the word "evolution" to
minerals was likely to be controversial, although there were precedents as far
back as the 1928 book The Evolution of the Igneous Rocks by Norman Bowen.
They used the term in the sense of an irreversible sequence of events leading
to increasingly complex and diverse assemblages of minerals. Unlike biological
evolution, it does not involve mutation, competition or passing of information
to progeny. Hazen et al. explored some other analogies, including the idea of extinction.
Some mineral-forming processes no longer occur, such as those that produced
certain minerals in enstatite chondrites that are unstable on Earth in its
oxidized state. Also, the runaway greenhouse effect on Venus may have led to
permanent losses of mineral species. However, mineral extinction is not truly
irreversible; a lost mineral could emerge again if suitable environmental
conditions were re-established.
Presolar Minerals
In the early Universe, there were no minerals because the only elements available were hydrogen, helium and trace amounts of lithium. Mineral formation became possible after heavier elements, including carbon, oxygen, silicon and nitrogen, were synthesized in stars. In the expanding atmospheres of red giants and the ejecta from supernovae, microscopic minerals formed at temperatures above 1,500 °C (2,730 °F).
Evidence of these minerals can be found in interstellar grains incorporated into primitive meteorites called chondrites, which are essentially cosmic sedimentary rocks. The number of known species is roughly a dozen, although several more materials have been identified but not classified as minerals. Because it has a high crystallization temperature (about 4,400 °C (7,950 °F)), diamond was probably the first mineral to form. This was followed by graphite, oxides (rutile, corundum, spinel, hibonite), carbides (moissanite), nitrides (osbornite and silicon nitride) and silicates (forsterite and silicate perovskite (MgSiO3)). These "ur-minerals" seeded the molecular clouds from which the Solar system was formed.
Origin of Life
Over two-thirds of mineral species owe their existence to life, but life may also owe its existence to minerals. They may have been needed as templates to bring organic molecules together; as catalysts for chemical reactions; and as metabolites. Two prominent theories for the origin of life involve clays and transition metal sulfides. Another theory argues that calcium-borate minerals such as colemanite and borate, and possibly also molybdate, may have been needed for the first ribonucleic acid (RNA) to form. Other theories require less common minerals such as mackinawite or greigite. A catalog of the minerals that were formed during the Hadeon Eon includes clay minerals and iron and nickel sulfides, including mackinawite and greigite; but borates and molybdates were unlikely.
Minerals may also have been necessary to the survival of early life. For example, quartz is more transparent than other minerals in sandstones. Before life developed pigments to protect it from damaging ultraviolet rays, a thin layer of quartz could shield it while allowing enough light through for photosynthesis. Phosphate minerals may also have been important to early life. Phosphorus is one of the essential elements in molecules such as adenosine triphosphate (ATP), an energy carrier found in all living cells; RNA and DNA; and cell membranes. Most of Earth's phosphorus is in the core and mantle. The most likely mechanism for making it available to life would be the creation of phosphates such as apatite through fractionation, followed by weathering to release the phosphorus. This may have required plate tectonics.
Further Research
Since the original paper on mineral evolution, there have been several studies of minerals of specific elements, including uranium, thorium, mercury, carbon, beryllium, and the clay minerals. These reveal information about different processes; for example, uranium and thorium are heat producers while uranium and carbon indicate oxidation state. The records reveal episodic bursts of new minerals such as those during the Boring Billion, as well as long periods where no new minerals appeared. For example, after a jump in diversity during the assembly of
Most of the mineral evolution papers have looked at the first appearance of minerals, but one can also look at the age distribution of a given mineral. Millions of zircon crystals have been dated, and the age distributions are nearly independent of where the crystals are found (e.g., igneous rocks, sedimentary or metasedimentary rocks or modern river sands). They have highs and lows that are linked with the supercontinent cycle, although it is not clear whether this is due to changes in subduction activity or preservation.
Other studies have looked at time variations of mineral properties such as isotope ratios, chemical compositions, and relative abundances of minerals, although not under the rubric of "mineral evolution.”
History
For most of its history, mineralogy had no historical component. It was concerned with classifying minerals according to their chemical and physical properties (such as the chemical formula and crystal structure) and defining conditions for stability of a mineral or group of minerals. However, there were exceptions where publications looked at the distribution of ages of minerals or of ores. In 1960, Russell Gordon Gastil found cycles in the distribution of mineral dates. Charles Meyer, finding that the ores of some elements are distributed over a wider time span than others, attributed the difference to the effects of tectonics and biomass on the surface chemistry, particularly free oxygen and carbon. In 1979, A. G. Zhabin introduced the concept of stages of mineral evolution in the Russian-language journal Doklady Akademii Nauk and in 1982, N. P. Yushkin noted the increasing complexity of minerals over time near the surface of the Earth. Then, in 2008, Hazen and colleagues introduced a much broader and more detailed vision of mineral evolution. This was followed by a series of quantitative explorations of the evolution of various mineral groups. These led in 2015 to the concept of mineral ecology, the study of distributions of minerals in space and time.
In April 2017, the Natural History Museum in
https://en.wikipedia.org/wiki/Mineral_evolution
No comments:
Post a Comment