Geology

When and where did the ancient Iapetus Ocean suture (the most fundamental Appalachian structure) form? Is part of New England made up of ancient African-derived rocks? What is the Moretown terrane? 

Mountain-building events, called "orogenies," in the northern U.S. Appalachia record the closure of the Iapetus Ocean, an ancient precursor to the Atlantic. The Iapetus separated continental fragments of ancestral North America and Africa more than 450 million years ago.


Parts of the landscape underlying the massive Greenland ice sheet may have been undisturbed for almost 3 million years, since the island became completely ice-covered, say researchers who based their discovery on an analysis of the chemical composition of silts recovered from the bottom of an ice core more than 3,000 meters long. 

The find suggests "pre-glacial landscapes can remain preserved for long periods under continental ice sheets." 

In the time since the ice sheet formed "the soil has been preserved and only slowly eroded, implying that an ancient landscape underlies 3,000 meters of ice at Summit, Greenland," they conclude.


Geologists have analyzed 40 meteorites that fell to Earth from Mars those chemical signatures have revealed some secrets of the early Martian atmosphere.

The atmospheres of Mars and Earth diverged in important ways very early in the 4.6 billion year history of our solar system.

Of course, what everyone wants to know is if life ever existed there and how water flowed in the past. Those answers are still waiting to be found but researchers are learning where to look.


The Tibetan Plateau — the world's largest, highest, and flattest plateau — had a larger initial extent than previously documented.  

Known as the "Roof of the World," the Tibetan Plateau covers more than 970,000 square miles in Asia and India and reaches heights of over 15,000 feet. The plateau also contains a host of natural resources, including large mineral deposits and tens of thousands of glaciers, and is the headwaters of many major drainage basins.


The Moon formed nearly 100 million years after the start of the solar system, according to a paper based on measurements from the interior of the Earth combined with computer simulations of the protoplanetary disk from which the Earth and other terrestrial planets formed.

The team of researchers simulated the growth of the terrestrial planets (Mercury, Venus, Earth and Mars) from a disk of thousands of planetary building blocks orbiting the Sun.

By analyzing the growth history of the Earth-like planets from 259 simulations, the scientists discovered a relationship between the time the Earth was impacted by a Mars-sized object to create the Moon and the amount of material added to the Earth after that impact.


The repeated cycles of plate tectonics throughout history that led to collision, assembly and disruption of large supercontinents have produced modern continents that are collages of bits and pieces of each other.

Figuring out the origin and make-up of continental crust formed and modified by these tectonic events is a vital to understanding Earth's geology and is important for many applied fields, such as oil, gas, and gold exploration. In many cases, the rocks involved in these collision and pull-apart episodes are still buried deep beneath the Earth's surface, so geologists must use geophysical measurements to study these features. 


The largest earthquakes occur where oceanic plates move beneath continents. Obviously, water trapped in the boundary between both plates has a dominant influence on the earthquake rupture process.

Writing in
Nature Geoscience (28.03.2014), a group of scientists from the GFZ German Research Centre for Geosciences and from Liverpool University analyzed the Chile earthquake of February, 27th, 2010 and found that the water pressure in the pores of the rocks making up the plate boundary zone was key. 


In the television show "Cosmos", the writers and host Neil deGrasse Tyson implied that the atmosphere on Venus was due to a runaway greenhouse gas effect. They also said Giordano Bruno was a martyr for astronomy and that Saturn was the 'jewel' of the solar system.

The only one of those partially correct is that Earth has a variety of factors that make our built-in atmospheric carbon dioxide regulator work where the one on Venus does not – including geologic cycles that churn up the planet's rocky surface. We also have gravity that keeps hydrogen from escaping into space after solar radiation breaks them, as happens on Venus.


It's difficult to be certain yet but, based on information obtained on the Voyager and Galileo missions, scientists suspect that inside Europa, one of the icy moons of Jupiter, there exist reservoirs of liquid.

The Voyager and Galileo missions also registered fractures and `chaotic´ terrains associated to reddish materials, which contrast with the glacial white of the dominant water ice of the surface.


The break-up of the supercontinent Gondwana about 130 Million years ago could have led to a completely different shape of the African and South American continent - with an ocean south of today's Sahara desert.

Researchers from the University of Sydney and the GFZ German Research Centre for Geosciences used plate tectonic and three-dimensional numerical modeling to highlight the importance of rift orientation relative to extension direction as key factor deciding whether an ocean basin opens or an aborted rift basin forms in the continental interior.