Science Basics: Isotopes
I tend to pack some of my articles with terms the average person may not be familiar with. What is an isotope? I give a quick and dirty explanation in this geology and science basics article.
The podClast – episode 8
podClast episode 8 is the Chris and Chris show. We discuss crypogeography with hidden mountains in Antarctica, extremophile bacteria living high atop the Andes, panspermia, extraterrestrial life and the hunt for Earth-size planets with NASA’s Kepler mission.
Oldest rocks ever discovered on Earth (4.28 Ga).
A recent Science Paper (as reported by Nature and Science Centric) has dated rock samples from the Nuvvuagittuq greenstone belt, on the eastern edge of Hudson Bay in Quebec, Canada, at a staggering 4.28 billion years old. The research team used the (somewhat unconventional for terrestrial dating) 146Sm→142Nd isotopic system, due to the lack of zircon being found within the rock. This means the date will have to be confirmed, preferably with zircons, for many to lend weight to the claims, but all the same, this is an amazing discovery.
It’s pretty staggering how old these rocks are. So let’s put it into perspective:
These rocks were formed 270 millions years after the Earth (4.55 Ga), which means they’ve remained reasonably unchanged for almost the entire history of the planet. They’ve survived 4.28 billions years of: plate tectonics including subduction and obduction, glacial erosion, meteorological erosion, chemical erosion, chemical alteration (maybe), or any other method of rock recycling. It also means we have pushed back the earliest date for continental material existing on Earth by 250 million years (the previous record was 4.03 Ga for the Acasta Gneiss, also from Canada).
These aren’t the oldest terrestrial material ever discovered, however. That title still belongs to zircons from the Jack Hills in Western Australia, that have been dated at a positively geriatric 4.4 GYr. But as a sample of rock, this is pretty exciting so far as early Earth chronology goes.
Geological timescale thanks to Chris Rowan at Highly Allochthonous.
Splash image to the left lifted from Nature, and courtesy of AAAS/Science.
The importance of being Ivuna
The Ivuna meteorite has been in the news recently, and is a very, very important sample when it comes to the ancient Solar System, including the Earth, Moon and Mars. But why is it so important, and what does it tell us about how our Solar System formed?
The podClast – episode 5
Jess (Tuff Cookie) and I discuss slowing lava, the Phoenix lander, earthquakes causing other earthquakes, the geoblogosphere going “main stream” and much, much more.
Accessing Journals from Outside Academia
I’m going to be out in the big scary world soon, but I still want to be immersed in my love of science. I ask you, the science blogosphere, how to grab my beloved science journal articles without being Warren Buffet.
Mt Taranaki: Hmmm
Mt Taranaki is ~100 Km away from the rest of the volcanics in the North Island of New Zealand. Mythologically it’s a social outcast but geologically it makes me go “hmmm”. My submission for the Accretionary Wedge #6.
The Anthropocene – Time for a New Epoch?
Is it time to seriously consider the distinct anthropogenic effects on the geological record, seen as a result of the industrial age, as a unique geological epoch?
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