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#sedimentary — Public Fediverse posts

Live and recent posts from across the Fediverse tagged #sedimentary, aggregated by home.social.

  1. To assess the risk of floods, we need detailed, long-term records, much longer than the instrumental record can offer. Geological record helps, but the time control on them isn't great. That calls for a different information source to constrain the events in those records, such as historical chronicles.

    Link: sciencedirect.com/science/arti

    #history #geology #sedimentary #flood

  2. A special #WeekendReading for the date - my dissertation! An unhinged monograph written with too much coffee and not enough sleep about #sedimentary cycliciy, evaporite sequence #stratigraphy, and #environmental reconstruction of the awesomely named Triassic Mohilla Fm.

    zenodo.org/records/15656179

  3. Hairy Neil @rovingrollo.bsky.social reminded me that it's #RockinTuesday Here's a lovely rock from the creek bed of Gunlom waterfall creek, a water-carved history of geological time past, frozen waves. #photography #geology #kakadu #rocks #patterns #sedimentary #EastCoastKin #PhotographersUnited

  4. Microbialites ( #sedimentary buildups formed by microbial activity) were very common in the Proterozoic, but other groups took over in the Phanerozoic. But when the #environment is stressed, they come back - and we can use them to infer on past #ecological stress gradients, but also the conditions at the stressed end member.
    sciencedirect.com/science/arti
    I rather like this paper, and to me, it's one of my most underperforming as far as citations are an index. So let me highlight it once more.

  5. We have a new pape! We explore the complex interactions between #climate, water chemistry, and post-depositional #sedimentary processes... and how they can produce some wierd #minerals.
    lyellcollection.org/doi/full/1

  6. Open (funded) #PhDposition at the University of Vienna (with Theresa Nohl, the most caring person you'll ever meet) about how time is preserved in the #sedimentary record.
    egu.eu/jobs/6596/open-phd-posi

  7. The SedsOnline student seminar tomorrow is worth attending. The theme is #Sedimentary Systems in the #energytransition, and it highlights new voices in this space.
    sedsonline.com/webinar-registr

  8. Now live - #MinCup24 Round 1 Match 1: Kaolinite vs. Abelsonite. Not much of a fight if you ask me (#sedimentary bias).

    mineralcup.org/2024/vote/r1m01

  9. #WeekendReading: Halevy et al., about the impact of inorganic reactions and transport in depositional environments on the isotopic composition of pyrite. TLDR - look also at the #sedimentary context, not just the #geochemistry.

    science.org/doi/10.1126/scienc

  10. A bizarre #sedimentary feature

    Some layers in the #Neoproterozoic #Squantum Member of the #Roxbury #Conglomerate have been rolled up like a pie crust, into a tube. If this were a #tillite, as it once was thought to be, then it could have been caused by the drag of a #Gaskiers #glacier over the till. These rocks are mostly interpreted as deposited by submarine debris flows these days, in which case they could’ve been deformed during a slump and flow. Site of a field trip for #UMassBoston.

  11. A bizarre #sedimentary feature

    Some layers in the #Neoproterozoic #Squantum Member of the #Roxbury #Conglomerate have been rolled up like a pie crust, into a tube. If this were a #tillite, as it once was thought to be, then it could have been caused by the drag of a #Gaskiers #glacier over the till. These rocks are mostly interpreted as deposited by submarine debris flows these days, in which case they could’ve been deformed during a slump and flow. Site of a field trip for #UMassBoston.

  12. A bizarre #sedimentary feature

    Some layers in the #Neoproterozoic #Squantum Member of the #Roxbury #Conglomerate have been rolled up like a pie crust, into a tube. If this were a #tillite, as it once was thought to be, then it could have been caused by the drag of a #Gaskiers #glacier over the till. These rocks are mostly interpreted as deposited by submarine debris flows these days, in which case they could’ve been deformed during a slump and flow. Site of a field trip for #UMassBoston.

  13. A bizarre #sedimentary feature

    Some layers in the #Neoproterozoic #Squantum Member of the #Roxbury #Conglomerate have been rolled up like a pie crust, into a tube. If this were a #tillite, as it once was thought to be, then it could have been caused by the drag of a #Gaskiers #glacier over the till. These rocks are mostly interpreted as deposited by submarine debris flows these days, in which case they could’ve been deformed during a slump and flow. Site of a field trip for #UMassBoston.

  14. A bizarre #sedimentary feature

    Some layers in the #Neoproterozoic #Squantum Member of the #Roxbury #Conglomerate have been rolled up like a pie crust, into a tube. If this were a #tillite, as it once was thought to be, then it could have been caused by the drag of a #Gaskiers #glacier over the till. These rocks are mostly interpreted as deposited by submarine debris flows these days, in which case they could’ve been deformed during a slump and flow. Site of a field trip for #UMassBoston.

  15. I am trying to identify fossils in these thin sections of Silurian sedimentary rocks from Lithuania. Any ideas? I am still learning and lacking so much in experience… 🥺
    I think I got the Crinoids right and some Bryozoas, but that’s it.
    .
    Also, next to these there are some nice cathodoluminescence photos of the same thin sections 🤩 You can see growth zones in them!

    #paleo #paleontology #geo #geology #thinsections #sedimentary #microscopy #micro #microfossils #fossils #crinoids #bryozoa

  16. I am trying to identify fossils in these thin sections of Silurian sedimentary rocks from Lithuania. Any ideas? I am still learning and lacking so much in experience… 🥺
    I think I got the Crinoids right and some Bryozoas, but that’s it.
    .
    Also, next to these there are some nice cathodoluminescence photos of the same thin sections 🤩 You can see growth zones in them!

    #paleo #paleontology #geo #geology #thinsections #sedimentary #microscopy #micro #microfossils #fossils #crinoids #bryozoa

  17. I am trying to identify fossils in these thin sections of Silurian sedimentary rocks from Lithuania. Any ideas? I am still learning and lacking so much in experience… 🥺
    I think I got the Crinoids right and some Bryozoas, but that’s it.
    .
    Also, next to these there are some nice cathodoluminescence photos of the same thin sections 🤩 You can see growth zones in them!

    #paleo #paleontology #geo #geology #thinsections #sedimentary #microscopy #micro #microfossils #fossils #crinoids #bryozoa

  18. I am trying to identify fossils in these thin sections of Silurian sedimentary rocks from Lithuania. Any ideas? I am still learning and lacking so much in experience… 🥺
    I think I got the Crinoids right and some Bryozoas, but that’s it.
    .
    Also, next to these there are some nice cathodoluminescence photos of the same thin sections 🤩 You can see growth zones in them!

    #paleo #paleontology #geo #geology #thinsections #sedimentary #microscopy #micro #microfossils #fossils #crinoids #bryozoa

  19. I am trying to identify fossils in these thin sections of Silurian sedimentary rocks from Lithuania. Any ideas? I am still learning and lacking so much in experience… 🥺
    I think I got the Crinoids right and some Bryozoas, but that’s it.
    .
    Also, next to these there are some nice cathodoluminescence photos of the same thin sections 🤩 You can see growth zones in them!

    #paleo #paleontology #geo #geology #thinsections #sedimentary #microscopy #micro #microfossils #fossils #crinoids #bryozoa

  20. Anomalous pebble in layered #sedimentary #rock

    An angular pebble is conformably surrounded by argillaceous and sandy layers in this #photograph of the #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate. The wide range of clast sizes led to an interpretation as a #glacial #tillite thru the 1970s, but the Squantum Member is now mostly interpreted as a #debrisFlow (#debrite or #turbidite). My #photo.

    #Boston #fieldTrip #UMassBoston

  21. Anomalous pebble in layered #sedimentary #rock

    An angular pebble is conformably surrounded by argillaceous and sandy layers in this #photograph of the #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate. The wide range of clast sizes led to an interpretation as a #glacial #tillite thru the 1970s, but the Squantum Member is now mostly interpreted as a #debrisFlow (#debrite or #turbidite). My #photo.

    #Boston #fieldTrip #UMassBoston

  22. Anomalous pebble in layered #sedimentary #rock

    An angular pebble is conformably surrounded by argillaceous and sandy layers in this #photograph of the #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate. The wide range of clast sizes led to an interpretation as a #glacial #tillite thru the 1970s, but the Squantum Member is now mostly interpreted as a #debrisFlow (#debrite or #turbidite). My #photo.

    #Boston #fieldTrip #UMassBoston

  23. Anomalous pebble in layered #sedimentary #rock

    An angular pebble is conformably surrounded by argillaceous and sandy layers in this #photograph of the #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate. The wide range of clast sizes led to an interpretation as a #glacial #tillite thru the 1970s, but the Squantum Member is now mostly interpreted as a #debrisFlow (#debrite or #turbidite). My #photo.

    #Boston #fieldTrip #UMassBoston

  24. Anomalous pebble in layered #sedimentary #rock

    An angular pebble is conformably surrounded by argillaceous and sandy layers in this #photograph of the #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate. The wide range of clast sizes led to an interpretation as a #glacial #tillite thru the 1970s, but the Squantum Member is now mostly interpreted as a #debrisFlow (#debrite or #turbidite). My #photo.

    #Boston #fieldTrip #UMassBoston

  25. Rapid changes in #clast size in #sedimentary #rocks

    The #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate (#Boston Bay Group) transitions from sandstone, to almost-clast-supported conglomerate, to laminated argillite…in about 25 cm. Fifty years ago, it was interpreted as a #glacial deposit and called the Squantum #Tillite, presumably associated with the #Gaskiers Glaciation. Paucity of evidence (e.g., few scratches or faceted clasts) suggests a debris flow. My #photo.

  26. Rapid changes in #clast size in #sedimentary #rocks

    The #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate (#Boston Bay Group) transitions from sandstone, to almost-clast-supported conglomerate, to laminated argillite…in about 25 cm. Fifty years ago, it was interpreted as a #glacial deposit and called the Squantum #Tillite, presumably associated with the #Gaskiers Glaciation. Paucity of evidence (e.g., few scratches or faceted clasts) suggests a debris flow. My #photo.

  27. Rapid changes in #clast size in #sedimentary #rocks

    The #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate (#Boston Bay Group) transitions from sandstone, to almost-clast-supported conglomerate, to laminated argillite…in about 25 cm. Fifty years ago, it was interpreted as a #glacial deposit and called the Squantum #Tillite, presumably associated with the #Gaskiers Glaciation. Paucity of evidence (e.g., few scratches or faceted clasts) suggests a debris flow. My #photo.

  28. Rapid changes in #clast size in #sedimentary #rocks

    The #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate (#Boston Bay Group) transitions from sandstone, to almost-clast-supported conglomerate, to laminated argillite…in about 25 cm. Fifty years ago, it was interpreted as a #glacial deposit and called the Squantum #Tillite, presumably associated with the #Gaskiers Glaciation. Paucity of evidence (e.g., few scratches or faceted clasts) suggests a debris flow. My #photo.

  29. Rapid changes in #clast size in #sedimentary #rocks

    The #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate (#Boston Bay Group) transitions from sandstone, to almost-clast-supported conglomerate, to laminated argillite…in about 25 cm. Fifty years ago, it was interpreted as a #glacial deposit and called the Squantum #Tillite, presumably associated with the #Gaskiers Glaciation. Paucity of evidence (e.g., few scratches or faceted clasts) suggests a debris flow. My #photo.