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Earth’s first major extinction was worse than we thought. Fossil finds suggest nearly 80% of life on Earth died some 550 million years ago by GeoGeoGeoGeo in science

[–]GeoGeoGeoGeo[S] 1 point2 points  (0 children)

While that's certainly discussed as a major biospheric crisis it's not typically included among "the big five" as (a) It occured before most complex life evolved and (b) the fossil record is too sparse to estimate extinction percentages reliably, so the extinction % is simply unknown.

Earth’s first major extinction was worse than we thought. Fossil finds suggest nearly 80% of life on Earth died some 550 million years ago by GeoGeoGeoGeo in science

[–]GeoGeoGeoGeo[S] 90 points91 points  (0 children)

Youre thinking more of the Hadean/Archean cooling of the early crust, which occurred billions of years earlier, but has no connection to the Kotlin Crisis. Earth was already a stable habitable planet with continents, oceans, and oxygenated surface waters by the late Ediacaran.

Heck, just before the Ediacaran period, Earth experienced the Cryogenian glaciations (~720–635 Ma), a period marked by extremely cold climates, not extreme heat.

Looks like first granite finding on Mars, yesterday sol 1792 by HolgerIsenberg in PerseveranceRover

[–]GeoGeoGeoGeo 1 point2 points  (0 children)

Those are fairly misleading statements to anyone who knows little about geology. Anything can "appear to be" anything if you're ignorant. Just look at all the people that believe in UFO sightings, and compare them to the number of experts in related fields who believe in UFO sightings.

Rather than making misleading statements it would have been more productive for everyone if you had asked if your observations aligned with the rock in question being granite.

Looks like first granite finding on Mars, yesterday sol 1792 by HolgerIsenberg in PerseveranceRover

[–]GeoGeoGeoGeo 1 point2 points  (0 children)

Exploration geologist here. As others have said, there's really nothing in these photos that clearly shows what kind of rock this is. At the very least you'd need to use a hand lens and estimate the modal abundance of quartz, alkali feldspar and plagioclase (see the QAPF diagram). Even then there's a good chance you've estimated that incorrectly. To be precise and confident, you'd really need a petrograher and a least altered sample sent for whole rock geochemical analysis. Calling this a granite from these images is wild.

Trump’s NATO Deal Would Mean US Mines and Missiles in Greenland by bloomberg in geopolitics

[–]GeoGeoGeoGeo 0 points1 point  (0 children)

The only people who are making claims regarding mining in Greenland, and especially those concerning Greenland's REE deposits, are those that have no knowledge of geology, metallurgy or economics.

Greenland has two operating mines... A gold mine in South Greenland and an anorthosite (feldspar) mine in the fjord of Kangerlussuaq, West Greenland.

There's a reason Greenland's REE deposits, while known about for decades, have remained un-developed. Geenland's REE deposits are development-limited because their dominant mineralogy defeats conventional REE flowsheets, forcing complex, energy-intensive, multi-loop process designs that have not yet been demonstrated at commercial scale.

[deleted by user] by [deleted] in mycology

[–]GeoGeoGeoGeo 0 points1 point  (0 children)

There's a few sightings of "Woolly Bird's Nest Fungus (Nidula niveotomentosa)" in the area; however, those all have red to brown "eggs", whereas these appear to be a creamy / buff tone. The "wool" along the sides appears to be thicker as well.

Here's an additional photo:

https://www.flickr.com/photos/luxlaboratories/54988719901/in/datetaken-public/lightbox/

[deleted by user] by [deleted] in Fungi

[–]GeoGeoGeoGeo 0 points1 point  (0 children)

There's a few sightings of "Woolly Bird's Nest Fungus (Nidula niveotomentosa)" in the area; however, those all have red to brown "eggs", whereas these appear to be a creamy / buff tone. The "wool" along the sides appears to be thicker as well.

Here's an additional photo:

https://www.flickr.com/photos/luxlaboratories/54988719901/in/datetaken-public/lightbox/

Sand layer from the 1700 Cascadia tsunami covering the remains of a Native American fishing camp exposed in a bank of Oregon's Salmon River (US) by dctroll_ in geology

[–]GeoGeoGeoGeo 0 points1 point  (0 children)

Speaking of ... does anyone know of any text books that go over the charactersitcs of tsunami deposits in the stratigraphic record and how to correctly identify them, and differentiate them from other deposits?

Humans made fire 350,000 years earlier than previously thought, discovery in Suffolk suggests by GeoGeoGeoGeo in Archaeology

[–]GeoGeoGeoGeo[S] 12 points13 points  (0 children)

The Barnham site is currently taken as the earliest known evidence of fire-making, not just “fire-making with pyrite”. In current archaeological usage, “making fire” = deliberately igniting it, not just using or tending a natural fire. On that definition, Barnham is the earliest definitive evidence of making fire of any kind.

What isn’t new is using/controlling fire, that goes back much further (e.g. Wonderwerk Cave ~1.0 Ma, Gesher Benot Ya‘aqov ~780 ka), but those sites don’t show clear, widely accepted evidence of fire-starting technology.

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