by Ryan Mandelbaum, June 8, 2017
Rocks alone seem to show that the breakup happened 180 million years ago. But a team of Australian scientists think that you should be able to see the split and continuing shifts written into the history of how animals have evolved. So that’s what the researchers did, and they accomplished this by analyzing a large group of species’ evolution and compared them to the date of the breakup of Pangea.
by Sam W. Heads et al., June 7, 2017, in PLOS/One
A new fossil mushroom is described and illustrated from the Lower Cretaceous Crato Formation of northeast Brazil. Gondwanagaricites magnificus gen. et sp. nov. is remarkable for its exceptional preservation as a mineralized replacement in laminated limestone, as all other fossil mushrooms are known from amber inclusions. Gondwanagaricites represents the oldest fossil mushroom to date and the first fossil mushroom from Gondwana.
by Arizona State University, S.H. Shim et al., June 5, 2017, in ScienceDaily
As slabs of Earth’s crust decend into the mantle, they encounter a zone about 1,100 kilometers down where the mantle rock abruptly becomes stiffer, flowing less easily. Similarly, rising plumes of molten rock encounter the same layer and have difficulty punching through from below.
by Linnaeus University, May 9, 2017 in ScienceDaily
It is becoming more and more appreciated that a major part of the biologic activity is not going on at the ground surface, but is hidden underneath the soil down to depths of several kilometres in an environment coined the “deep biosphere”. Studies of life-forms in this energy-poor system have implications for the origin of life on our planet and for how life may have evolved on other planets, where hostile conditions may have inhibited colonization of the surface environment. The knowledge about ancient life in this environment deep under our feet is extremely scarce.
by University of Bristol, September 9, 2011 in ScienceDaily
Ultra high precision analyses of some of the oldest rock samples on Earth provides clear evidence that the planet’s accessible reserves of precious metals are the result of a bombardment of meteorites more than 200 million years after Earth was formed.
by UNSW Sydney, May 9, 2017 in ScienceDaily
Fossils discovered by UNSW scientists in 3.48 billion year old hot spring deposits in the Pilbara region of Western Australia have pushed back by 580 million years the earliest known existence of microbial life on land.
he Pilbara deposits are the same age as much of the crust of Mars, which makes hot spring deposits on the red planet an exciting target for our quest to find fossilised life there.”
by McGill University , EPSL, May 5, 2017, in ScienceDaily
Conventional theory holds that all of the early Earth’s crustal ingredients were formed by volcanic activity. Now, however, earth scientists have published a theory with a novel twist: some of the chemical components of this material settled onto Earth’s early surface from the steamy atmosphere that prevailed at the time.
More than 90% of Earth’s continental crust is made up of silica-rich minerals, such as feldspar and quartz. But where did this silica-enriched material come from? And could it provide a clue in the search for life on other planets?
by University of Maryland, in Nature, February 27, 2017
in ScienceDaily
New research suggests that plate tectonics began later in Earth’s history
But new research suggests that this was not always the case. Instead, shortly after Earth formed and began to cool, the planet’s first outer layer was a single, solid but deformable shell. Later, this shell began to fold and crack more widely, giving rise to modern plate tectonics.
by Carlos Jaramillo et al., Science Advances, May 3, 2017
The Neogene history of Amazonia is essential for understanding the evolution of the rainforest and associated fauna living in one of the most diverse places on Earth. A central question about our understanding of Amazonia remains unsolved: Did continental-scale marine flooding occur in western Amazonia during the Neogene? Miocene marine transgressions in the continental interior would have had a profound effect on the diversification and structuring of both terrestrial and aquatic Neotropical communities
by M. Duncan and R. Dasgupta, April 25, 2017, Nature Geoscience
We suggest that immobilization of organic carbon in subduction zones and deep sequestration in the mantle facilitated the rise (~103–5 fold) and maintenance of atmospheric oxygen since the Palaeoproterozoic and is causally linked to the Great Oxidation Event. Our modelling shows that episodic recycling of organic carbon before the Great Oxidation Event may also explain occasional whiffs of atmospheric oxygen observed in the Archaean.
by Nicholas T. Arndt et al., April 2017, Geochemical Perspectives
Some scientists and journalists, and many members of the general public, have been led to believe that the world is rapidly running out of the metals on which our modern society is based. Advocates of the peak metal concept have predicted for many decades that increasing consumption will soon lead to exhaustion of mineral resources. Yet, despite ever-increasing production and consumption, supplies of minerals have continued to meet the needs of industry and society, and lifetimes of reserves remain similar to what they were 30-40 years ago.
Full text (171 pages) pdf, here
by University of Adelaide, April 28, 2017, in Science News
Special ‘nugget-producing’ bacteria may hold the key to more efficient processing of gold ore, mine tailings and recycled electronics, as well as aid in exploration for new deposits, University of Adelaide research has shown.
Now they have shown for the first time, just how long this biogeochemical cycle takes and they hope to make to it even faster in the future.
by S.H.J. Fuchs et al., April 2017, Precambrian Research
20 April 2017/Kiel. The Witwatersrand basin in South Africa hosts the largest known gold repository on Earth – but how was it formed? Scientists of the GEOMAR Helmholtz Centre of Ocean Research Kiel and Canadian research institutes were able to figure out how parts of the Earth’s largest gold deposits formed about three billion years ago. Crude oil and hot hydrothermal fluids played a major role. This study has been currently published in the journal “Precambrian Research“
by University of Iowa, April 19, 2017
in ScienceDaily
The University of Iowa volcanologist spent her days collecting samples from a volcano on Tanna, an island in the remote South Pacific archipelago of Vanuatu. The volcano, called Yasur, spews out flaming masses or “bombs” – some the size of a small car.
“This has real health implications,” Ukstins says. “It means more than simply studying volcanoes.”
Also Grand challenges to better prepare for volcanic eruptions
by University of Adelaide, April 18, 2017 in ScienceDaily
Studies of bones from Ice Age megafaunal animals across Eurasia and the Americas have revealed that major increases in environmental moisture occurred just before many species suddenly became extinct around 11-15,000 years ago. The persistent moisture resulting from melting permafrost and glaciers caused widespread glacial-age grasslands to be rapidly replaced by peatlands and bogs, fragmenting populations of large herbivore grazers.
The idea of moisture-driven extinctions is really exciting because it can also explain why Africa is so different, with a much lower rate of megafaunal extinctions and many species surviving to this day, says Professor Cooper.
by Florida State University, March 15, 2017
New research suggests that inorganic chemicals can self-organize into complex structures that mimic primitive life on Earth.This complicates the identification of Earth’s earliest microfossils and redefines the search for life on other planets and moons.
All known Ediacaran skeletal biota produced either aragonite or high-Mg calcite: carbonate polymorphs interpreted to have been favoured by ambient seawater chemistry. Indeed all known Ediacaran skeletal taxa were immobile benthos found exclusively in shallow marine carbonate settings. Finally, we note that Ediacaran skeletal taxa are of diverse affinity, and some possessed a non-mineralized, organic, counterpart, as detailed below
by J. Lecomte et al., CNRS, December 16, 2013
The natural increase in solar luminosity — a very slow process unrelated to current climate warming — will cause the Earth’s temperatures to rise over the next few hundred million years. This will result in the complete evaporation of the oceans. The first three-dimensional climate model able to simulate the phenomenon predicts that liquid water will disappear on Earth in approximately one billion years, extending previous estimates by several hundred million years.
by DOE/Oak Ridge National Laboratory, March 28, 2017
Using advanced modeling and simulation, seismic data generated by earthquakes, and one of the world’s fastest supercomputers, a team of scientists is creating a detailed 3-D picture of Earth’s interior. Currently, the team is focused on imaging the entire globe from the surface to the core-mantle boundary, a depth of 1,800 miles.
by University of Queensland, March 27, 2007
An unprecedented 21 different types of dinosaur tracks have been identified on a 25-kilometer stretch of the Dampier Peninsula coastline dubbed ‘Australia’s Jurassic Park.’ A team of paleontologists has unveiled the most diverse assemblage of dinosaur tracks in the world in 127 to 140 million-year-old rocks in the remote Kimberley region of Western Australia.
Prof. André Strasser, January 11, 2016
On shallow carbonate platforms, the sedimentary record is highly fragmentary because low accommodation commonly leads to non-deposition, erosion, reworking and condensation. Consequently, it is difficult to quantify the time that is actually recorded and to estimate sedimentation rates.
by NASA/Goddard Space Flight Center, March 21, 2017
Arsia Mons produced one new lava flow at its summit every 1 to 3 million years during the final peak of activity, about 50 million years ago. The last volcanic activity there ceased about 50 million years ago — around the time of Earth’s Cretaceous-Paleogene extinction, when large numbers of our planet’s plant and animal species (including dinosaurs) went extinct.
Journal Reference:Jacob A. Richardson, James A. Wilson, Charles B. Connor, Jacob E. Bleacher, Koji Kiyosugi. Recurrence rate and magma effusion rate for the latest volcanism on Arsia Mons, Mars. Earth and Planetary Science Letters, 2017; 458: 170 DOI: 10.1016/j.epsl.2016.10.040
A new study suggests it was the power of the eyes and not the limbs that first led our aquatic ancestors to make the leap from water to land. The researchers discovered that eyes nearly tripled in size before — not after — the water-to-land transition. Crocodile-like animals saw easy meals on land and then evolved limbs that enabled them to get there, the researchers argue.
by University College London, March 1, 2017
Remains of microorganisms at least 3,770 million years old have been discovered by an international team led by UCL scientists, providing direct evidence of one of the oldest life forms on Earth.
Tiny filaments and tubes formed by bacteria that lived on iron were found encased in quartz layers in the Nuvvuagittuq Supracrustal Belt (NSB), Quebec, Canada.
The NSB contains some of the oldest sedimentary rocks known on Earth which likely formed part of an iron-rich deep-sea hydrothermal vent system that provided a habitat for Earth’s first life forms between 3,770 and 4,300 million years ago …
Science Daily, February 23, 2017
A study of tiny mineral ‘inclusions’ within diamonds from Botswana has shown that diamond crystals can take billions of years to grow. One diamond was found to contain silicate material that formed 2.3 billion years ago in its interior and a 250 million-year-old garnet crystal towards its outer rim, the largest age range ever detected in a single specimen. Analysis of the inclusions also suggests that the way that carbon is exchanged and deposited between the atmosphere, biosphere, oceans and geosphere may have changed significantly over the past 2.5 billion years.
S. Timmerman, J.M. Koornneef, I.L. Chinn, G.R. Davies. Dated eclogitic diamond growth zones reveal variable recycling of crustal carbon through time. Earth and Planetary Science Letters, 2017; 463: 178 DOI: 10.1016/j.epsl.2017.02.001