I can’t quite recall where I first heard of Summer Praetorious, but she is a respected professional in our area of inquiry. So I was intrigued today to see Summer post a pic of a collection of rather odd materials from a Younger Dryas marine core sample. Mighty cool. Cheers to Summer for sharing the mystery.
Can anyone help me with this mystery sample? It is unlike anything I have ever seen in a marine core. It has what look like selenite crystals (?) and orange clay aggregates (?). It is from the Younger Dryas boundary. #YoungerDryas pic.twitter.com/uZDnTSu1VC
— Summer Praetorius (@SKPraetorius) November 26, 2019
YD Impact Ejecta?
Interestingly, Dr. Praetorious has deleted the tweet.
Pity the tweet has gone. It’s pretty difficult to tell what they are from pictures but they do look like pieces of glass we see on the beaches near us, they have been in the sea or on a beach for many years and are ground smooth.
Now, that would be interesting!
Not much info. No location given? Not even a general location? She has probably exhausted her assessments, even including location, but a bit more info details may pop a light on over someone’s head.
BTW, she ties it to the YDB and it is a marine core? Why does that strike me as quite iffy to determine? I can envision several contamination avenues…
Hi Summer –
Most likely what you are looking at is erosion deposits from the norther Appalachian mountain quartz deposits.
Be sure to read my summary over on academia
Reading my post, I realized I needed to add a bit more.
There were several North Eastern lakes that drained during the Holocene Start Impact Events. (And yes, there were two of them about 2,000 years apart. The one at 10,850 BCE was the second of them. Neither matches up with the Younger Dryas in time.)
My estimate is that the quartzes you found in the proper layers comes from those drainages.