Geology In

Researchers Discover Giant Freshwater Aquifer off U.S. East Coast

<div dir="ltr" style="text-align: left;" trbidi="on">
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-CYyZg9ce398/XRD3pfJMcYI/AAAAAAAARK8/KQAMu6-IX-MskJoWV2MJHmuNaeql8d2ZgCLcBGAs/s1600/A%2BMassive%2BReservoir%2BOf%2BFreshwater%2BWas%2BJust%2BDiscovered%2BOffshore%2BNew%2BEngland.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="Researchers Discover Giant Freshwater Aquifer off U.S. East Coast" border="0" data-original-height="820" data-original-width="1198" height="438" src="https://1.bp.blogspot.com/-CYyZg9ce398/XRD3pfJMcYI/AAAAAAAARK8/KQAMu6-IX-MskJoWV2MJHmuNaeql8d2ZgCLcBGAs/s640/A%2BMassive%2BReservoir%2BOf%2BFreshwater%2BWas%2BJust%2BDiscovered%2BOffshore%2BNew%2BEngland.jpg" title="" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Scientists have mapped a huge aquifer off the US Northeast (hatched area). Solid yellow or white lines with triangles show ship tracks. Dotted white line near shore shows edge of the glacial ice sheet that melted about 15,000 years ago. Further out, dark blue, the continental shelf drops off into the Atlantic abyss. Credit: Gustafson et al., Scientific Reports </td></tr>
</tbody></table>
<br />
<br />
<span style="font-family: "georgia" , "times new roman" , serif;">Underneath the salty waters of the North Atlantic ocean, geologists have discovered a giant aquifer of freshwater, hidden from view just off the US coast.</span><br />
<br />
In a new survey of the sub-seafloor off the U.S. Northeast coast, scientists have made a surprising discovery: a gigantic aquifer of relatively fresh water trapped in porous sediments lying below the salty ocean. It appears to be the largest such formation yet found in the world.<br />
<br />
The aquifer stretches from the shore at least from Massachusetts to New Jersey, extending more or less continuously out about 50 miles to the edge of the continental shelf. If found on the surface, it would create a lake covering some 15,000 square miles. The study suggests that such aquifers probably lie off many other coasts worldwide, and could provide desperately needed water for arid areas that are now in danger of running out.<br />
<br />
The researchers employed innovative measurements of electromagnetic waves to map the water, which remained invisible to other technologies. "We knew there was fresh water down there in isolated places, but we did not know the extent or geometry," said lead author Chloe Gustafson, a Ph.D. candidate at Columbia University's Lamont-Doherty Earth Observatory. "It could turn out to be an important resource in other parts of the world." The study appears this week in the journal Scientific Reports.<br />
<div style="margin: 0px auto; width: 100%;">
<script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br />
<ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br />
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script><br /></div>
The first hints of the aquifer came in the 1970s, when companies drilled off the coastline for oil, but sometimes instead hit fresh water. Drill holes are just pinpricks in the seafloor, and scientists debated whether the water deposits were just isolated pockets or something bigger. Starting about 20 years ago, study coauthor Kerry Key, now a Lamont-Doherty geophysicist, helped oil companies develop techniques to use electromagnetic imaging of the sub-seafloor to look for oil.<br />
<br />
More recently, Key decided to see if some form of the technology could also be used also to find fresh-water deposits. In 2015, he and Rob L. Evans of Woods Hole Oceanographic Institution spent 10 days on the Lamont-Doherty research vessel Marcus G. Langseth making measurements off southern New Jersey and the Massachusetts island of Martha's Vineyard, where scattered drill holes had hit fresh-water-rich sediments.<br />
<br />
They dropped receivers to the seafloor to measure electromagnetic fields below, and the degree to which natural disruptions such as solar winds and lightning strikes resonated through them. An apparatus towed behind the ship also emitted artificial electromagnetic pulses and recorded the same type of reactions from the subseafloor.<br />
<br />
Both methods work in a simple way: salt water is a better conductor of electromagnetic waves than fresh water, so the freshwater stood out as a band of low conductance. Analyses indicated that the deposits are not scattered; they are more or less continuous, starting at the shoreline and extending far out within the shallow continental shelf—in some cases, as far as 75 miles. For the most part, they begin at around 600 feet below the ocean floor, and bottom out at about 1,200 feet.<br />
<br />
The consistency of the data from both study areas allowed to the researchers to infer with a high degree of confidence that fresh water sediments continuously span not just New Jersey and much of Massachusetts, but the intervening coasts of Rhode Island, Connecticut and New York. They estimate that the region holds at least 670 cubic miles of fresh water. If future research shows the aquifer extends further north and south, it would rival the great Ogallala Aquifer, which supplies vital groundwater to eight Great Plains states, from South Dakota to Texas.<br />
<div style="margin: 0px auto; width: 100%;">
<script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br />
<ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br />
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script><br /></div>
The water probably got under the seabed in one of two different ways, say the researchers. Some 15,000 to 20,000 years ago, toward the end of the last glacial age, much of the world's water was locked up in mile-deep ice; in North America, it extended through what is now northern New Jersey, Long Island and the New England coast. Sea levels were much lower, exposing much of what is now the underwater U.S. continental shelf. When the ice melted, sediments formed huge river deltas on top of the shelf, and fresh water got trapped there in scattered pockets. Later, sea levels rose. Up to now, the trapping of such "fossil" water has been the common explanation for any fresh water found under the ocean.<br />
<br />
But the researchers say the new findings indicate that the aquifer is also being fed by modern subterranean runoff from the land. As water from rainfall and water bodies percolates through onshore sediments, it is likely pumped seaward by the rising and falling pressure of tides, said Key. He likened this to a person pressing up and down on a sponge to suck in water from the sponge's sides.<br />
<br />
Also, the aquifer is generally freshest near the shore, and saltier the farther out you go, suggesting that it mixes gradually with ocean water over time. Terrestrial fresh water usually contains less than 1 part per thousand salt, and this is about the value found undersea near land. By the time the aquifer reaches its outer edges, it rises to 15 parts per thousand. (Typical seawater is 35 parts per thousand.)<br />
<br />
If water from the outer parts of the aquifer were to be withdrawn, it would have to be desalinated for most uses, but the cost would be much less than processing seawater, said Key. "We probably don't need to do that in this region, but if we can show there are large aquifers in other regions, that might potentially represent a resource" in places like southern California, Australia, the Mideast or Saharan Africa, he said. His group hopes to expand its surveys.<br />
<br />
<br />
<u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="https://blogs.ei.columbia.edu/2019/06/20/undersea-freshwater-aquifer-northeast/" rel="nofollow" target="_blank">Materials</a> provided by <a href="https://www.earth.columbia.edu/" rel="nofollow" target="_blank">Earth Institute at Columbia University</a>. Original written by Kevin Krajick. </span></i></u><span style="background-color: white; color: #333333; display: inline; float: none; font-family: "helvetica neue" , "helvetica" , "arial" , sans-serif; font-size: 14px; font-style: normal; font-weight: 400; letter-spacing: normal; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"><br />
</span></div>

Researchers Discover Giant Freshwater Aquifer off U.S. East Coast

Scientists have mapped a huge aquifer off the US Northeast (hatched area). Solid yellow or white lines with triangles show ship tracks. D...

Earthquake: 5.6 Quake Rattles Northern California

Earthquakes, News 11:56 AM

<div dir="ltr" style="text-align: left;" trbidi="on">
<div class="separator" style="clear: both; text-align: center;">
<a href="https://1.bp.blogspot.com/-n4covphL_Fg/XQ8-MvN1UvI/AAAAAAAARKw/psMCo-tM9RMIJC0jmm9Rl8OX0NgdwL_ugCLcBGAs/s1600/earthquakesa-earthquake-55-quake-registered-near-scotia-calif-ewzj-20190622-photo.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="5.6 Quake Rattles Northern California" border="0" data-original-height="768" data-original-width="1152" height="426" src="https://1.bp.blogspot.com/-n4covphL_Fg/XQ8-MvN1UvI/AAAAAAAARKw/psMCo-tM9RMIJC0jmm9Rl8OX0NgdwL_ugCLcBGAs/s640/earthquakesa-earthquake-55-quake-registered-near-scotia-calif-ewzj-20190622-photo.jpg" title="" width="640" /></a></div>
<br />
<br />
According to the US Geological Survey (USGS), the quake struck several kilometres from the small community of Petrolia, located over 400 kilometres (250 miles) from the city of San Francisco.<br /><br />A 5.6-magnitude tremor was registered in Humboldt County in northern California late Saturday, the US Geological Survey reported, adding that the estimated depth of the earthquake was 9.4 km (5.8 miles).<br /><br />At the moment, there is no official information about damage or casualties in the region.<br /><br />The quake was centered 17 miles from Scotia, Calif., according to the U.S. Geological Survey. It was 23 miles from Fortuna, 36 miles from Eureka and 40 miles from Bayside.<br /><br />The news comes after earlier this month about 400 earthquakes of 4.0-magnitude or less rocked the southern part of the state in what scholars described as "swarms" of seismic activity.<br /><br /></div>

Earthquake: 5.6 Quake Rattles Northern California

According to the US Geological Survey (USGS), the quake struck several kilometres from the small community of Petrolia, located over 40...

What is Hopper Crystal?

Crystal, Geochemistry 6:20 PM

<div dir="ltr" style="text-align: left;" trbidi="on">
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-CAqYFOZyU58/XQzyp3iEVSI/AAAAAAAARKI/tIOs5Ufqv_kcEJAHPu8FXUZD8U64rJJNgCLcBGAs/s1600/What%2Bis%2BHopper%2BCrystal.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="What is Hopper Crystal?" border="0" data-original-height="881" data-original-width="1200" height="468" src="https://1.bp.blogspot.com/-CAqYFOZyU58/XQzyp3iEVSI/AAAAAAAARKI/tIOs5Ufqv_kcEJAHPu8FXUZD8U64rJJNgCLcBGAs/s640/What%2Bis%2BHopper%2BCrystal.jpg" title="" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Hopper Halite crystal from Searles Lake, Trona, California. Photo: crystalminer</td></tr>
</tbody></table>
<br />
<br />
<span style="font-family: "georgia" , "times new roman" , serif;">A hopper crystal is a form of crystal, defined by its "hoppered" shape. </span><br />
<br />
This form appears, when a crystal grows faster at the edges of each face, than at the centre. This is due to a higher electrical attraction along the edges of the crystal, so they draw the mineral molecules stronger than the interior sections.<br />
<br />
The edges of hoppered crystals are fully developed, but the interior spaces are not filled in. This results in what appears to be a hollowed out step lattice formation, as if someone had removed interior sections of the individual crystals. In fact, the "removed" sections never filled in, because the crystal was growing so rapidly that there was not enough time (or material) to fill in the gaps.<br />
<br />
The interior edges of a hoppered crystal still show the crystal form characteristic to the specific mineral, and so appear to be a series of smaller and smaller stepped down miniature versions of the original crystal.<br />
<div style="margin: 0px auto; width: 100%;">
<script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br />
<ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br />
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script><br /></div>
Hoppering occurs when electrical attraction is higher along the edges of the crystal; this causes faster growth at the edges than near the face centers. This attraction draws the mineral molecules more strongly than the interior sections of the crystal, thus the edges develop more quickly. However, the basic physics of this type of growth is the same as that of dendrites but, because the anisotropy in the solid–liquid inter-facial energy is so large, the dendrite so produced exhibits a faceted morphology.<br />
<br />
Hoppering is common in many minerals, including lab-grown bismuth, galena, quartz (called skeletal or fenster crystals), gold, calcite, halite (salt), and water (ice).<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-oce0g7ncTsM/XQzzn64Zq8I/AAAAAAAARKQ/GtM-4GUFIHkALJT2BeWRGV_Tbc5qmwNEACLcBGAs/s1600/Galena%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="Hopper Galena" border="0" data-original-height="557" data-original-width="736" height="302" src="https://1.bp.blogspot.com/-oce0g7ncTsM/XQzzn64Zq8I/AAAAAAAARKQ/GtM-4GUFIHkALJT2BeWRGV_Tbc5qmwNEACLcBGAs/s400/Galena%2B%25281%2529.jpg" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Hopper Galena. Photo: Quebul Fine Minerals</td></tr>
</tbody></table>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-3q5lYKlcOlg/XQz0clxCDiI/AAAAAAAARKc/sKcfSvAasp49bhv4axZVymdW7egCEmSowCLcBGAs/s1600/Hopper%2Bhalite%2Bfrom%2BSieroszowice%2Bmine%2Bin%2BPoland.%2BPhoto%2BSpirifer%2BMinerals.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="Hopper halite" border="0" data-original-height="960" data-original-width="621" height="400" src="https://1.bp.blogspot.com/-3q5lYKlcOlg/XQz0clxCDiI/AAAAAAAARKc/sKcfSvAasp49bhv4axZVymdW7egCEmSowCLcBGAs/s400/Hopper%2Bhalite%2Bfrom%2BSieroszowice%2Bmine%2Bin%2BPoland.%2BPhoto%2BSpirifer%2BMinerals.jpg" title="" width="258" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"> Hopper halite from Sieroszowice mine in Poland. <br />
Photo: Spirifer Minerals</td></tr>
</tbody></table>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-6ctSxbXOrfI/XQz1Mrq33jI/AAAAAAAARKk/6VAWNTbwNT4YyvgU8z1VH5RVkdBMPeBdQCLcBGAs/s1600/Bismuth.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="Bismuth" border="0" data-original-height="827" data-original-width="960" height="343" src="https://1.bp.blogspot.com/-6ctSxbXOrfI/XQz1Mrq33jI/AAAAAAAARKk/6VAWNTbwNT4YyvgU8z1VH5RVkdBMPeBdQCLcBGAs/s400/Bismuth.jpg" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span aria-live="polite" class="fbPhotosPhotoCaption" data-ft="{"tn":"K"}" id="fbPhotoSnowliftCaption" tabindex="0"><span class="hasCaption">Bismuth. </span></span><span aria-live="polite" class="fbPhotosPhotoCaption" data-ft="{"tn":"K"}" id="fbPhotoSnowliftCaption" tabindex="0"><span class="hasCaption">Photo: Gem_stallion  </span></span></td></tr>
</tbody></table>
<b><span style="font-family: Georgia, "Times New Roman", serif;">See also: </span></b><br />
<span style="font-family: Georgia, "Times New Roman", serif;"><a href="https://www.geologyin.com/2014/12/what-are-crystals.html" target="_blank">What Are Crystals?</a></span><br />
<div class="pw-hidden-cp">
<span style="font-family: Georgia, "Times New Roman", serif;"><a href="https://www.geologyin.com/2014/11/crystal-structure-and-crystal-system.html" target="_blank">Crystal Structure and Crystal Systems<span></span></a></span></div>
</div>

What is Hopper Crystal?

Hopper Halite crystal from Searles Lake, Trona, California. Photo: crystalminer A hopper crystal is a form of crystal, defined by its...

Plate Tectonics May Have Driven 'Cambrian Explosion'

Earth History, Tectonic 6:26 PM

<div dir="ltr" style="text-align: left;" trbidi="on">
<div class="separator" style="clear: both; text-align: center;">
<a href="https://1.bp.blogspot.com/-8FYTlxtxdiw/XQulHGyYWDI/AAAAAAAARJw/hhBydaL6-z8b98DngGQ8uvnv9UNFgDPigCLcBGAs/s1600/Burgess%2BShale%2Band%2BCambrian%2BExplosion%2B%25281%2529.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Plate Tectonics May Have Driven 'Cambrian Explosion'" border="0" data-original-height="670" data-original-width="1190" height="360" src="https://1.bp.blogspot.com/-8FYTlxtxdiw/XQulHGyYWDI/AAAAAAAARJw/hhBydaL6-z8b98DngGQ8uvnv9UNFgDPigCLcBGAs/s640/Burgess%2BShale%2Band%2BCambrian%2BExplosion%2B%25281%2529.jpg" title="" width="640" /></a></div>
<br />
<h4 style="text-align: left;">
<span style="font-family: "georgia" , "times new roman" , serif;">The Cambrian Explosion –“Supernova of Biology Detonated by Plate Tectonics”</span></h4>
The quest to discover what drove one of the most important evolutionary events in the history of life on Earth has taken a new, fascinating twist.<br />
<br />
A team of scientists have given a fresh insight into what may have driven the "Cambrian Explosion" -- a period of rapid expansion of different forms of animal life that occurred over 500 million years ago.<br />
<br />
While a number of theories have been put forward to explain this landmark period, the most credible is that it was fuelled by a significant rise in oxygen levels which allowed a wide variety of animals to thrive.<br />
<br />
The new study suggests that such a rise in oxygen levels was the result of extraordinary changes in global plate tectonics.<br />
<br />
During the formation of the supercontinent 'Gondwana', there was a major increase in continental arc volcanism -- chains of volcanoes often thousands of miles long formed where continental and oceanic tectonic plates collided. This in turn led to increased 'degassing' of CO<sub>2</sub> from ancient, subducted sedimentary rocks.<br />
<div style="margin: 0px auto; width: 100%;">
<script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br />
<ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br />
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script><br /></div>
This, the team calculated, led to an increase in atmospheric CO<sub>2</sub> and warming of the planet, which in turn amplified the weathering of continental rocks, which supplied the nutrient phosphorus to the ocean to drive photosynthesis and oxygen production.<br />
<br />
The study was led by Josh Williams, who began the research as an MSc student at the University of Exeter and is now studying for a PhD at the University of Edinburgh.<br />
<br />
During his MSc project he used a sophisticated biogeochemical model to make the first quantification of changes in atmospheric oxygen levels just prior to this explosion of life.<br />
<br />
Co-author and project supervisor Professor Tim Lenton, from the University of Exeter's Global Systems Institute said: "One of the great dilemmas originally recognised by Darwin is why complex life, in the form of fossil animals, appeared so abruptly in what is now known as the Cambrian explosion.<br />
<br />
"Many studies have suggested this was linked to a rise in oxygen levels -- but without a clear cause for such a rise, or any attempt to quantify it."<br />
<br />
Not only did the model predict a marked rise in oxygen levels due to changes in plate tectonic activity, but that rise in oxygen -- to about a quarter of the level in today's atmosphere -- crossed the critical levels estimated to be needed by the animals seen in the Cambrian explosion.<br />
<br />
Williams added: "What is particularly compelling about this research is that not only does the model predict a rise in oxygen to levels estimated to be necessary to support the large, mobile, predatory animal life of the Cambrian, but the model predictions also show strong agreement with existing geochemical evidence."<br />
<br />
"It is remarkable to think that our oldest animal ancestors -- and therefore all of us -- may owe our existence, in part, to an unusual episode of plate tectonics over half a billion years ago" said Professor Lenton.<br />
<br />
<br />
<br />
<u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="https://www.exeter.ac.uk/news/research/title_721383_en.html" rel="nofollow" target="_blank">Materials</a> provided by <a href="http://www.exeter.ac.uk/" rel="nofollow" target="_blank">University of Exeter</a>.</span></i></u></div>

Plate Tectonics May Have Driven 'Cambrian Explosion'

The Cambrian Explosion –“Supernova of Biology Detonated by Plate Tectonics” The quest to discover what drove one of the most important...

Fossil of a 15 Ton Sea Creature Found in Antarctica

Earth History, Fossils 7:27 PM

Fossil of a 15 Ton Sea Creature Found in Antarctica

A hungry Aristonectes plesiosaur eyes a squid in this illustration. The prehistoric plesiosaur — a four-flippered marine reptile that ...

Giant Trilobite Fossil Found on Australia

extinction, Fossils 7:04 PM

<div dir="ltr" style="text-align: left;" trbidi="on">
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-YCeQn0Vb9vA/XQUTeb6lZWI/AAAAAAAARI4/3Y7MEKRgoUwHNpt1mDoGRDo6LkK47vDQQCLcBGAs/s1600/Fossils%2Bof%2Bgiant%2Bnew%2Bspecies%2Bof%2Bsea%2Bcreature%2Bfound%2Bon%2BSouth%2BAustralia%2527s%2BKangaroo%2BIsland%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="Giant Trilobite Fossil Found on Australia" border="0" data-original-height="830" data-original-width="1200" height="442" src="https://1.bp.blogspot.com/-YCeQn0Vb9vA/XQUTeb6lZWI/AAAAAAAARI4/3Y7MEKRgoUwHNpt1mDoGRDo6LkK47vDQQCLcBGAs/s640/Fossils%2Bof%2Bgiant%2Bnew%2Bspecies%2Bof%2Bsea%2Bcreature%2Bfound%2Bon%2BSouth%2BAustralia%2527s%2BKangaroo%2BIsland%2B%25281%2529.jpg" title="" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A specimen of Redlichia rex from the Emu Bay Shale, Kangaroo Island, Australia. Image credit: Holmes et al, An artist’s impression of Redlichia rex on the Cambrian seafloor. Image credit: Katrina Kenny.</td></tr>
</tbody></table>
<div class="separator" style="clear: both; text-align: center;">
</div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<h4 style="text-align: left;">
<span style="font-family: Georgia, "Times New Roman", serif;"> Paleontologists have unearthed fossils of a giant trilobite species that inhabited Australian waters approximately 500 million years ago (Cambrian period).</span></h4>
<div style="text-align: left;">
<span style="font-family: "georgia" , "times new roman" , serif;">Fossils of a giant new species from the long-extinct group of sea creatures called trilobites have been found on Kangaroo Island, South Australia.</span></div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
The finding is adding important insights to our knowledge of the Cambrian 'explosion', the greatest diversification event in the history of life on Earth, when almost all animal groups suddenly appeared over half-a-billion years ago.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
Trilobites, which had hard, calcified, armour-like skeletons over their bodies, are related to modern crustaceans and insects. They are one of the most successful fossil animal groups, surviving for about 270 million years (521 to 252 million years ago). Because of their abundance in the fossil record, they are considered a model group for understanding this evolutionary period.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
"We decided to name this new species of trilobite<i> Redlichia rex</i> (similar to <i>Tyrannosaurus rex</i>) because of its giant size, as well as its formidable legs with spines used for crushing and shredding food -- which may have been other trilobites," says James Holmes, PhD student with the University of Adelaide's School of Biological Sciences, who led the research.</div>
<div style="margin: 0px auto; text-align: left; width: 100%;">
<script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br />
<ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br />
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script><br /></div>
<div style="text-align: left;">
The preservation of trilobite 'soft parts' such as the antennae and legs is extremely rare. The new species was discovered at the Emu Bay Shale on Kangaroo Island, a world-renowned deposit famous for this type of preservation. The findings have been published in the Journal of Systematic Palaeontology by a team of scientists from the University of Adelaide, South Australian Museum and the University of New England.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
The new species is about 500 million years old, and is the largest Cambrian trilobite discovered in Australia. It grew to around 30 cm in length, which is almost twice the size of other Australian trilobites of similar age.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
"Interestingly, trilobite specimens from the Emu Bay Shale -- including <i>Redlichia rex</i> -- exhibit injuries that were caused by shell-crushing predators," says senior study author Associate Professor Diego García-Bellido, from the University of Adelaide and the South Australian Museum.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
"There are also large specimens of fossilised poo (or coprolites) containing trilobite fragments in this fossil deposit. The large size of injured <i>Redlichia rex</i> specimens and the associated coprolites suggests that either much bigger predators were targeting <i>Redlichia rex</i>, such as Anomalocaris -- an even larger shrimp-like creature -- or that the new species had cannibalistic tendencies."</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
One of the major drivers of the Cambrian explosion was likely an evolutionary "arms race" between predators and prey, with each developing more effective measures of defence (such as the evolution of shells) and attack.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
"The overall size and crushing legs of <i>Redlichia rex</i> are a likely consequence of the arms race that occurred at this time" says James Holmes. "This giant trilobite was likely the terror of smaller creatures on the Cambrian seafloor."</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
Specimens of Redlichia rex and other Emu Bay Shale fossils are currently on display in the South Australian Museum.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
<u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="https://www.adelaide.edu.au/news/news107262.html" rel="nofollow" target="_blank">Materials</a> provided by <a href="https://www.adelaide.edu.au/" rel="nofollow" target="_blank">University of Adelaide</a>.</span></i></u></div>
</div>

Giant Trilobite Fossil Found on Australia

A specimen of Redlichia rex from the Emu Bay Shale, Kangaroo Island, Australia. Image credit: Holmes et al, An artist’s impression of Red...

What is Fire Agate?

gemstones, Mineral, Mineralogy 7:02 PM

<div dir="ltr" style="text-align: left;" trbidi="on">
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-Ea3DXRcCNyc/XQO5ztcGEhI/AAAAAAAARIs/19N2Uhc6sRcNQdIUMjf2JoJDqZb3oaAqgCLcBGAs/s1600/fire%2Bagate%2B%25282%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="What is Fire Agate?" border="0" data-original-height="1177" data-original-width="1200" height="391" src="https://1.bp.blogspot.com/-Ea3DXRcCNyc/XQO5ztcGEhI/AAAAAAAARIs/19N2Uhc6sRcNQdIUMjf2JoJDqZb3oaAqgCLcBGAs/s320/fire%2Bagate%2B%25282%2529.jpg" title="" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Photo Credit: Glenn Dizon </td></tr>
</tbody></table>
<br />
<br />
<span style="font-family: "georgia" , "times new roman" , serif;">Agate is a semi-precious gemstone formed by relatively recent volcanic activity. It is outwardly similar in appearance to quartz, but also shows interesting swirls, bubbles and patterns.</span><br />
<br />
Fire agate, a variety of chalcedony, is a semi-precious natural gemstone discovered so far only in certain areas of central and northern Mexico and the southwestern United States (New Mexico, Arizona and California). <br />
<br />
Fire agates have beautiful iridescent rainbow colors, similar to opal, with a measurement of hardness on the Mohs scale of between 5 and 7 which reduces the occurrence of scratching when polished gemstones are set in jewelry.<br />
<div style="margin: 0px auto; width: 100%;">
<script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br />
<ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br />
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script><br /></div>
The vibrant iridescent rainbow colors found within fire agates, created by the Schiller effect as found in mother-of-pearl, is caused by the alternating silica and iron oxide layers which diffract and allow light to pass and form an interference of colors within the microstructure layering of the stone causing the fire effect for which it is named.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-Ow8s2Mlu69E/XQOw2bLwNFI/AAAAAAAARIg/t65k3j1NoxI2uMdtkqtn54iGijnIExzEwCLcBGAs/s1600/Fire%2Bagate.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1033" data-original-width="1200" height="343" src="https://1.bp.blogspot.com/-Ow8s2Mlu69E/XQOw2bLwNFI/AAAAAAAARIg/t65k3j1NoxI2uMdtkqtn54iGijnIExzEwCLcBGAs/s400/Fire%2Bagate.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Photo: Isaac Jones</td></tr>
</tbody></table>
<h4 style="text-align: left;">
<span style="font-family: "georgia" , "times new roman" , serif;">How Fire Agate and Chalcedony Form</span></h4>
The fire agate and chalcedony of the Southern New Mexico–Arizona border area is formed when low pressure and low temperature epithermal hydrothermal waters (50°-200°C / 122°-392°F) carrying colloidal SiO<sub>2</sub> and iron oxides are injected into cavities in volcanic rocks such as gas bubbles in flow rocks, irregular-shaped vug fillings, or along fault or bedding plane fractures.<br />
<div style="margin: 0px auto; width: 100%;">
<script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br />
<ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br />
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script><br /></div>
Approximately 24-36 million years ago these areas were subjected to  massive volcanic activity during the Tertiary Period. The fire agates  were formed during this period of volcanism when hot water, saturated  with silica and iron oxide, repeatedly filled cracks and bubbles in the  surrounding rock.<br />
<h4>
<span style="color: blue;"><span style="font-family: "georgia" , "times new roman" , serif;">Fire Agate Gemstone Mineral Locations</span></span></h4>
<b><span style="font-family: "georgia" , "times new roman" , serif;">Deer Creek, Arizona</span></b><br />
Deer Creek Fire agate is well known for it's high quality fire agate gemstones and excellent lapidary rough. The fire agate from Deer Creek Arizona ranks high on the list of desired collected gemstones, mineral specimens, and lapidary gemstone cutting material. Located in the eastern foothills of the Galiuro Mountains southwest of Safford, Arizona, this area has several active fire agate mines. Some of the early pioneers in fire agate mining at Deer Creek were Larry Gray, Howard Imboden, Guy Paul and Cliff Willis.<br />
<br />
<b><span style="font-family: "georgia" , "times new roman" , serif;">Cuesta Fire Agate Mine - Arizona</span></b><br />
<a href="http://cuestafireagatemine.ilandwyte.com/" rel="nofollow" target="_blank">Cuesta Fire Agate</a> mine is a Desert Dig. when you come out to the Mine, you go to the claims and you can dig to your hearts content. without restrictions to what or where you can Dig. The Mine is open 12 months of the year.  fee: $30.00 - $50.00 a day, Tool Rentals, $5.00 a day.<br />
Address:  old Route 66 4 miles north of Oatman, AZ.<br />
<br />
<b><span style="font-family: "georgia" , "times new roman" , serif;">Slaughter Mountain - Arizona </span></b><br />
Known for it's high quality fire agate gemstones and with it's rough often having multiple layers of fire banding, <a href="http://www.slaughtermountainfireagate.com/?fbclid=IwAR1h4VQFkhthjNQ6SmblrxSntpGXDxpAN0jAS7gg0Hj7_Dbi5vBwIjoC0Uk" rel="nofollow" target="_blank">Slaughter Mountain Fire</a> Agate is well suited for gemstone carving purposes. The mine at Slaughter Mountain is known for producing high quality fire agate gemstones, with intense color variations from bright reds and oranges to intense greens, purples and blues.<br />
<br />
<b><span style="font-family: "georgia" , "times new roman" , serif;">See also:</span></b><br />
<a href="https://www.geologyin.com/2019/04/what-is-grape-agate.html" target="_blank">What Is Grape Agate?</a><br />
<a href="https://www.geologyin.com/2018/04/tourmaline-species-and-color-varieties.html" target="_blank">Tourmaline: Species and Color Varieties</a><br />
<a href="https://www.geologyin.com/2018/03/types-of-iridescent-gemstones-minerals.html" target="_blank">Types of Iridescent Gemstones & Minerals </a></div>

What is Fire Agate?

Photo Credit: Glenn Dizon Agate is a semi-precious gemstone formed by relatively recent volcanic activity. It is outwardly similar in...

1.2 Billion-Year-Old Meteorite Crater Discovered in Scotland

Earth History, Meteorite 8:33 PM

<div dir="ltr" style="text-align: left;" trbidi="on">
<div class="separator" style="clear: both; text-align: center;">
</div>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-Af6g-f_0YHk/XP_ljGa3jNI/AAAAAAAARII/PjsEWJb1-JEAoqJA_maImHdredio8OUGwCLcBGAs/s1600/scotland-meteor-1%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="1.2 Billion-Year-Old Meteorite Crater Discovered in Scotland" border="0" data-original-height="584" data-original-width="1220" height="306" src="https://1.bp.blogspot.com/-Af6g-f_0YHk/XP_ljGa3jNI/AAAAAAAARII/PjsEWJb1-JEAoqJA_maImHdredio8OUGwCLcBGAs/s640/scotland-meteor-1%2B%25281%2529.jpg" title="" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Reddish-colored rocks of the Stac Fada deposit. Image: University of Oxford</td></tr>
</tbody></table>
<div class="separator" style="clear: both; text-align: center;">
</div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<br />
The biggest ever recorded meteorite collision location has been discovered in the U.K. Scientists find 9 MILE wide crater in Scotland caused by the 'biggest meteorite collision in Britain's history' 1.2 billion years ago<br />
<br />
<br />
Evidence for the ancient, 1.2 billion years old, meteorite strike, was first discovered in 2008 near Ullapool, NW Scotland by scientists from Oxford and Aberdeen Universities. The thickness and extent of the debris deposit they found suggested the impact crater -- made by a meteorite estimated at 1km wide -- was close to the coast, but its precise location remained a mystery.<br />
<br />
In a paper published today in Journal of the Geological Society, a team led by Dr Ken Amor from the Department of Earth Sciences at Oxford University, show how they have identified the crater location 15-20km west of a remote part of the Scottish coastline. It is buried beneath both water and younger rocks in the Minch Basin.<br />
<br />
Dr Ken Amor said: 'The material excavated during a giant meteorite impact is rarely preserved on Earth, because it is rapidly eroded, so this is a really exciting discovery. It was purely by chance this one landed in an ancient rift valley where fresh sediment quickly covered the debris to preserve it.<br />
<br />
'The next step will be a detailed geophysical survey in our target area of the Minch Basin.'<br />
<div style="margin: 0px auto; width: 100%;">
<script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br />
<ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br />
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script><br /></div>
Using a combination of field observations, the distribution of broken rock fragments known as basement clasts and the alignment of magnetic particles, the team was able to gauge the direction the meteorite material took at several locations, and plotted the likely source of the crater.<br />
<br />
Dr Ken Amor said: 'It would have been quite a spectacle when this large meteorite struck a barren landscape, spreading dust and rock debris over a wide area.'<br />
<br />
1.2 billion years ago most of life on Earth was still in the oceans and there were no plants on the land. At that time Scotland would have been quite close to the equator and in a semi-arid environment. The landscape would have looked a bit like Mars when it had water at the surface.<br />
<br />
Earth and other planets may have suffered a higher rate of meteorite impacts in the distant past, as they collided with debris left over from the formation of the early solar system.<br />
<br />
However, there is a possibility that a similar event will happen in the future given the number of asteroid and comet fragments floating around in the solar system. Much smaller impacts, where the meteorite is only a few meters across are thought to be relatively common perhaps occurring about once every 25 years on average.<br />
<br />
It is thought that collisions with an object about 1 km (as in this instance) across occur between once every 100,000 years to once every one million years -- but estimates vary.<br />
<br />
One of the reasons for this is that our terrestrial record of large impacts is poorly known because craters are obliterated by erosion, burial and plate tectonics.<br />
<br />
<br />
<u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="http://www.ox.ac.uk/news/2019-06-10-site-biggest-ever-meteorite-collision-uk-discovered" rel="nofollow" target="_blank">Materials</a> provided by <a href="http://www.ox.ac.uk/" rel="nofollow" target="_blank">University of Oxford</a>.</span></i></u></div>

1.2 Billion-Year-Old Meteorite Crater Discovered in Scotland

Reddish-colored rocks of the Stac Fada deposit. Image: University of Oxford The biggest ever recorded meteorite collision locati...

What Jumpstarted Earth's Plate Tectonics?

Earth History, Geology, Tectonic 8:06 PM

<div dir="ltr" style="text-align: left;" trbidi="on">
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-KoHXiZU1EHA/XPvqxbDEE5I/AAAAAAAARFI/IT1vdRIsv5EzlkXNDePTv8pdWCS4daGQACLcBGAs/s1600/What%2BJumpstarted%2BEarth%2527s%2BPlate%2BTectonics%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img alt="What Jumpstarted Earth's Plate Tectonics?" border="0" data-original-height="687" data-original-width="1226" height="358" src="https://1.bp.blogspot.com/-KoHXiZU1EHA/XPvqxbDEE5I/AAAAAAAARFI/IT1vdRIsv5EzlkXNDePTv8pdWCS4daGQACLcBGAs/s640/What%2BJumpstarted%2BEarth%2527s%2BPlate%2BTectonics%2B%25281%2529.jpg" title="" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">World Tectonic Plates and Their Movement -</td></tr>
</tbody></table>
<br />
<br />
Earth's outer layer is composed of giant plates that grind together, sliding past or dipping beneath one another, giving rise to earthquakes and volcanoes. These plates also separate at undersea mountain ridges, where molten rock spreads from the centers of ocean basins.<br />
<br />
But this was not always the case. Early in Earth's history, the planet was covered by a single shell dotted with volcanoes -- much like the surface of Venus today. As Earth cooled, this shell began to fold and crack, eventually creating Earth's system of plate tectonics.<br />
<br />
According to new research, the transition to <a href="https://www.geologyin.com/2014/09/how-plate-tectonics-works.html" target="_blank">plate tectonics</a> started with the help of lubricating sediments, scraped by glaciers from the slopes of Earth's first continents. As these sediments collected along the world's young coastlines, they helped to accelerate the motion of newly formed subduction faults, where a thinner oceanic plate dips beneath a thicker continental plate.<br />
<br />
The new study, published in the journal Nature, is the first to suggest a role for sediments in the emergence and evolution of global plate tectonics. Michael Brown, a professor of geology at the University of Maryland, co-authored the research paper with Stephan Sobolev, a professor of geodynamics at the GFZ German Research Centre for Geosciences in Potsdam.<br />
<br />
The findings suggest that sediment lubrication controls the rate at which Earth's crust grinds and churns. Sobolev and Brown found that two major periods of worldwide glaciation, which resulted in massive deposits of glacier-scrubbed sediment, each likely caused a subsequent boost in the global rate of plate tectonics.<br />
<br />
The most recent such episode followed the "snowball Earth" that ended sometime around 635 million years ago, resulting in Earth's modern plate tectonic system.<br />
<div style="margin: 0px auto; width: 100%;">
<script async="" src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script><br />
<ins class="adsbygoogle" data-ad-client="ca-pub-1021498709184325" data-ad-format="fluid" data-ad-layout="in-article" data-ad-slot="6157425841" style="display: block; text-align: center;"></ins><br />
<script>
     (adsbygoogle = window.adsbygoogle || []).push({});
</script><br /></div>
"Earth hasn't always had plate tectonics and it hasn't always progressed at the same pace," Brown said. "It's gone through at least two periods of acceleration. There's evidence to suggest that tectonics also slowed to a relative crawl for nearly a billion years. In each case, we found a connection with the relative abundance -- or scarcity -- of glacial sediments."<br />
<br />
Just as a machine needs grease to keep its parts moving freely, plate tectonics operates more efficiently with lubrication. While it may be hard to confuse the gritty consistency of clay, silt, sand and gravel with a slippery grease, the effect is largely the same at the continental scale, in the ocean trenches where tectonic plates meet.<br />
<br />
"The same dynamic exists when drilling Earth's crust. You have to use mud -- a very fine clay mixed with water or oil -- because water or oil alone won't work as well," Brown said. "The mud particles help reduce friction on the drill bit. Our results suggest that tectonic plates also need this type of lubrication to keep moving."<br />
<br />
Previous research on the western coast of South America was the first to identify a relationship between sediment lubrication and friction along a subduction fault. Off the coast of northern Chile, a relative lack of sediment in the fault trench creates high friction as the oceanic Nazca plate dips beneath the continental South America plate. This friction helped to push the highest peaks of the central Andes Mountains skyward as the continental plate squashed and deformed.<br />
<br />
In contrast, further south there is a higher sediment load in the trench, resulting in less friction. This caused less deformation of the continental plate and, consequently, created smaller mountain peaks. But these findings were limited to one geographic area.<br />
<br />
For their study, Sobolev and Brown used a geodynamic model of plate tectonics to simulate the effect of sediment lubrication on the rate of subduction. To verify their hypothesis, they checked for correlations between known periods of widespread glaciation and previously published data that indicate the presence of continental sediment in the oceans and trenches. For this step, Sobolev and Brown relied on two primary lines of evidence: the chemical signature of the influence of continental sediments on the chemistry of the oceans and indicators of sediment contamination in subduction-related volcanoes, much like those that make up today's "ring of fire" around the Pacific Ocean.<br />
<br />
According to Sobolev and Brown's analysis, plate tectonics likely emerged on Earth between 3 and 2.5 billion years ago, around the time when Earth's first continents began to form. This time frame also coincides with the planet's first continental glaciation.<br />
<br />
A major boost in plate tectonics then occurred between 2.2 to 1.8 billion years ago, following another global ice age that scrubbed massive amounts of sediments into the fault trenches at the edges of the continents.<br />
<br />
The next billion years, from 1.75 billion to 750 million years ago, saw a global reduction in the rate of plate tectonics. This stage of Earth's history was so sedate, comparatively speaking, that it earned the nickname "the boring billion" among geologists.<br />
<br />
Later, following the global "snowball Earth" glaciation that ended roughly 635 million years ago, the largest surface erosion event in Earth's history may have scrubbed more than a vertical mile of thickness from the surface of the continents. According to Sobolev and Brown, when these sediments reached the oceans, they kick-started the modern phase of active plate tectonics.<br />
<br />
<br />
<br />
<u><i><span style="font-family: "trebuchet ms" , sans-serif;">The above story is based on <a href="http://dx.doi.org/10.1038/s41586-019-1258-4" rel="nofollow" target="_blank">Materials </a>provided by <a href="https://www.umd.edu/" rel="nofollow" target="_blank">University of Maryland</a>.</span></i></u></div>

What Jumpstarted Earth's Plate Tectonics?

World Tectonic Plates and Their Movement - Earth's outer layer is composed of giant plates that grind together, sliding past or d...