How Rocks Rusted on Earth and Turned Red

[Judi Lynn]

How did rocks rust on Earth and turn red? A Rutgers-led study has shed new light on the important phenomenon and will help address questions about the Late Triassic climate more than 200 million years ago, when greenhouse gas levels were high enough to be a model for what our planet may be like in the future.

“All of the red color we see in New Jersey rocks and in the American Southwest is due to the natural mineral hematite,” said lead author Christopher J. Lepre, an assistant teaching professor in the Department of Earth and Planetary Sciences in the School of Arts and Sciences at Rutgers University-New Brunswick. “As far as we know, there are only a few places where this red hematite phenomenon is very widespread: one being the geologic ‘red beds’ on Earth and another is the surface of Mars. Our study takes a significant step forward toward understanding how long it takes for redness to form, the chemical reactions involved and the role hematite plays.”

The research by Lepre and a Columbia University scientist is in the journal Proceedings of the National Academy of Sciences. It challenges conventional thinking that hematite has limited use for interpreting the ancient past because it is a product of natural chemical changes that occurred long after the beds were initially deposited.

Lepre demonstrated that hematite concentrations faithfully track 14.5 million years of Late Triassic monsoonal rainfall over the Colorado Plateau of Arizona when it was on the ancient supercontinent of Pangea. With this information, he assessed the interrelationships between environmental disturbances, climate and the evolution of vertebrates on land.

More:
https://www.heritagedaily.com/2021/02/how-rocks-rusted-on-earth-and-turned-red/137078

BY
HERITAGEDAILY
FEBRUARY 9, 2021

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Colorado Plateau of Arizona

[SCantiGOP]

1. I have a chunk of red rock sitting next to my computer

Picked it up 20 years ago in Glacier National Park.

[Judi Lynn]

2. After seeing your post, I went to google images to see pictures of Glacier National Park,

and was amazed! Had never seen pictures of this area, and it looks astounding!

Here's the URL to the image page for this incredible place for others who haven't seen it, yet:

https://tinyurl.com/yamu4o84

Can't imagine how hard it must be to leave the place, once you're there!

So glad you mentioned it. I had no idea Montana would be so beautiful! You have your rock to remind you! Thanks. ⭐️

[SCantiGOP]

3. I went there in the late 90's

It was in August, and I stayed in the resort of Kalispell about an hour from the park. It was a much different place than it is now.
There were spots on the road (which, like the Blue Ridge Parkway, were built as a WPA project during the 30s and 40s) where the glaciers would come over the road during the winter, so you would have a wall of 5-15 feet of ice on both sides of the road.

They tried to get the road open by June 1 each year, but because of especially cold weather and heavy snow it didn't open till the middle of June that year. They would come in with survey crews and blast the ice, because the road would have never become passable all year otherwise.

Now, most of the glaciers are gone. I have seen projections that all of them may disappear in another decade or so. We are losing a lot of unique and old features of our environment. I don't think my generation will be thought of especially well in the future.

Thanks for your Science posts, Judi Lynn. I always enjoy the varied content.