Many people love jewelry and other items made of gold. They have inconspicuous microbes to thank for this: Three billion years ago they held the noble metal in the Earth’s crust. This is the opinion at least of an expert from the University of Würzburg.
All the Earth’s gold deposits should actually be in the Earth’s core – buried deep out of mankind’s reach. After all, this metal has such a high density that in the course of the creation of the Earth it ought to have been moved to there. But in actual fact it also accumulated in the Earth’s crust.
Why did the gold stay there? “To this day this remains one of the most hotly debated issues in geology and geochemistry,” says Professor Hartwig Frimmel, chairman of the Department of Geodynamics and Geomaterials Research at the University of Würzburg. He is now adding a new theory to the debate, which suggests that prehistoric microbes are responsible for binding gold to the Earth’s crust.
Frimmel presents his idea in detail in the journal “Mineralium Deposita”. The Würzburg scientist is regarded as the world’s leading expert in gold deposits. He spent a long time as a professor at the University of Cape Town conducting research in South Africa’s Witwatersrand region, among others. This is where the world’s largest concentration of gold in the Earth’s crust can be found.
Where there is a lot of gold, there are also the remains of bacteria
What do microbes have to do with gold? “Wherever there are large quantities of gold, there are also layers of stratified carbonaceous substances that are of biological origin,” says Frimmel. “We have found evidence to suggest that these are the remains of cyanobacteria.” These original microbes inhabited the coastal regions of the Earth three billion years ago.
The cyanobacteria were the first living organisms that performed photosynthesis and first created “whiffs of oxygen”, as Frimmel says. The Earth at that time was still largely hostile to life: Rain had roughly the acidity of vinegar, and the surface water was rich in hydrogen sulfide.
Where there was oxygen, gold was bound
“But under precisely these conditions gold becomes extremely soluble in water,” explains the professor. The rivers and other bodies of water must have been very rich in gold back then. Where this water came upon colonies of cyanobacteria arranged into mats, the gold was chemically adhered to the surface of the microbes immediately by the oxygen.
So, three billion years ago a kind of “Gold Mega Event” occurred: “The chemical conditions at that time were perfect for binding gold and enabling the formation of deposits,” believes Frimmel. Over time and in this manner, for example, the huge gold deposits were created that can be found in such places as the Witwatersrand region of South Africa. At one time 100,000 tons of the treasured metal were stored there. More than half of it has already been mined.
“First whiffs of atmospheric oxygen triggered onset of crustal gold cycle”, Hartwig E. Frimmel, Quinton Hennigh, Mineralium Deposita (2015), DOI: 10.1007/s00126-014-0574-8
Prof. Dr. Hartwig Frimmel, Department of Geodynamics and Geomaterials Research, T +49 (0)931 31-85420, email@example.com
http://www.geodynamik.geographie.uni-wuerzburg.de/geodynamik_und_geomaterialfors... Prof. Frimmel's research
Robert Emmerich | idw - Informationsdienst Wissenschaft
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences