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#neoproterozoic — Public Fediverse posts

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

  1. A Billion Years Are Mysteriously Missing From #Earth’s History. Now, We Know Why.
    #TheGreatUnconformity — a gap in Earth’s #geologicalrecord. New research suggests it was created by shifting continents, rather than “#SnowballEarth” or #Cambrian life. Evidence that the gap was largely created by #tectonic processes that occurred from 2.1B to 1.6B years ago, in the #Neoproterozoic era, during the formation of an ancient supercontinent called Columbia
    404media.co/great-unconformity
    archive.ph/glmuh

  2. A Billion Years Are Mysteriously Missing From #Earth’s History. Now, We Know Why.
    #TheGreatUnconformity — a gap in Earth’s #geologicalrecord. New research suggests it was created by shifting continents, rather than “#SnowballEarth” or #Cambrian life. Evidence that the gap was largely created by #tectonic processes that occurred from 2.1B to 1.6B years ago, in the #Neoproterozoic era, during the formation of an ancient supercontinent called Columbia
    404media.co/great-unconformity
    archive.ph/glmuh

  3. A Billion Years Are Mysteriously Missing From ’s History. Now, We Know Why.
    — a gap in Earth’s . New research suggests it was created by shifting continents, rather than “” or life. Evidence that the gap was largely created by processes that occurred from 2.1B to 1.6B years ago, in the era, during the formation of an ancient supercontinent called Columbia
    404media.co/great-unconformity
    archive.ph/glmuh

  4. A Billion Years Are Mysteriously Missing From #Earth’s History. Now, We Know Why.
    #TheGreatUnconformity — a gap in Earth’s #geologicalrecord. New research suggests it was created by shifting continents, rather than “#SnowballEarth” or #Cambrian life. Evidence that the gap was largely created by #tectonic processes that occurred from 2.1B to 1.6B years ago, in the #Neoproterozoic era, during the formation of an ancient supercontinent called Columbia
    404media.co/great-unconformity
    archive.ph/glmuh

  5. A Billion Years Are Mysteriously Missing From #Earth’s History. Now, We Know Why.
    #TheGreatUnconformity — a gap in Earth’s #geologicalrecord. New research suggests it was created by shifting continents, rather than “#SnowballEarth” or #Cambrian life. Evidence that the gap was largely created by #tectonic processes that occurred from 2.1B to 1.6B years ago, in the #Neoproterozoic era, during the formation of an ancient supercontinent called Columbia
    404media.co/great-unconformity
    archive.ph/glmuh

  6. Cryogenian (Geological periods 🌍)

    The Cryogenian is a geologic period that lasted from 720 to 635 million years ago. It is the second of the three periods of the Neoproterozoic era, preceded by the Tonian and followed by the Ediacaran. The Cryogenian was a time of drastic climate changes. After the long environmental stability/stagnation during the Boring Billi...

    en.wikipedia.org/wiki/Cryogeni

    #Cryogenian #IceAges #Glaciology #Neoproterozoic #GeologicalPeriods #GeologyControversies

  7. Tonian (Geological periods 🌍)

    The Tonian is the first geologic period of the Neoproterozoic Era. It lasted from 1000 to 720 Mya. Instead of being based on stratigraphy, these dates are defined by the ICS based on radiometric chronometry. The Tonian is preceded by the Stenian Period of the Mesoproterozoic Era and followed by the Cryogenian. Rifting leading to the breakup of supercontin...

    en.wikipedia.org/wiki/Tonian

    #Tonian #Neoproterozoic #GeologicalPeriods #ProterozoicGeochronology

  8. The term " #Neoproterozoic #fossil record " still feels odd, but this is just how our understanding has progressed.
    Now, with the added layer of inhabited terrestrial #environments before #SnowballEarth.
    (also, possibly a critical part of the #evolution of life, if you care about that sort of thing)
    pnas.org/doi/abs/10.1073/pnas.

  9. 4-Oct-2024
    Life on Earth was more diverse than classical theory suggests 800 million years ago, a Brazilian study shows

    According to an article published in the journal PNAS, different lineages of #amoebae and ancestors of #plants, #algae and animals were already established in the #Neoproterozoic period and survived the two glaciations that covered the entire planet.

    eurekalert.org/news-releases/1

    #science #evolution #SnowballEarth

  10. Cryogenian (Geological periods 🌍)

    The Cryogenian is a geologic period that lasted from 720 to 635 million years ago. It is the second of the three periods of the Neoproterozoic era, preceded by the Tonian and followed by the Ediacaran. The Cryogenian was a time of drastic climate changes. After the long environmental stability/stagnation during the Boring Billi...

    en.wikipedia.org/wiki/Cryogeni

    #Cryogenian #IceAges #Glaciology #Neoproterozoic #GeologicalPeriods #GeologyControversies

  11. Ediacaran (Geological periods 🌍)

    The Ediacaran is a geological period of the Neoproterozoic Era that spans 96 million years from the end of the Cryogenian Period at 635 Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last period of the Proterozoic Eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian P...

    en.wikipedia.org/wiki/Ediacara

    #Ediacaran #Neoproterozoic #GeologicalPeriods #ProterozoicGeochronology

  12. Ediacaran (Geological periods 🌍)

    The Ediacaran is a geological period of the Neoproterozoic Era that spans 96 million years from the end of the Cryogenian Period at 635 Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last period of the Proterozoic Eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian P...

    en.wikipedia.org/wiki/Ediacara

    #Ediacaran #Neoproterozoic #GeologicalPeriods #ProterozoicGeochronology

  13. Ediacaran (Geological periods 🌍)

    The Ediacaran is a geological period of the Neoproterozoic era that spans 96 million years from the end of the Cryogenian period at 635 Mya to the beginning of the Cambrian period at 538.8 Mya. It is the last period of the Proterozoic eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian p...

    en.wikipedia.org/wiki/Ediacara

    #Ediacaran #Neoproterozoic #GeologicalPeriods #ProterozoicGeochronology

  14. Molecular fossils study sheds light on feeding strategy shift in ancient life phys.org/news/2023-12-molecula

    Common origin of sterol biosynthesis points to a feeding strategy shift in #Neoproterozoic animals nature.com/articles/s41467-023

    "these #phytosterol molecular #fossils record the rise of algae in ancient #oceans and #animals abandoned phytosterol production when they could easily obtain it from this increasingly abundant food source"

  15. Now THAT is a conglomerate

    Outcrop of the #Neoproterozoic Squantum Member of the Roxbury Conglomerate, #Boston Bay Group, Squantum Head

    Formerly thought to be younger (Carboniferous) and glacial, these rocks are now known to be older and are interpreted (mostly) as debris flows rather than Gaskiers tillites. These are akin to the famous “puddingstone” conglomerates. There is also the lovely (actually Carboniferous) Pondville Conglomerate, just south of the Blue Hills & Boston Basin along I93.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  21. A small #outcrop of the #Squantum Member of the #Roxbury #Conglomerate

    These #rocks are in the #BostonBay Group, which is currently dated to #Neoproterozoic. The Squantum Member was interpreted as a #tillite, possibly associated with the #Gaskiers #glaciation, although there a scant signs like scratched pebbles or faceted cobbles. It is currently commonly interpreted as a #debrite (debris flow). Details in captions.
    #geology #glacier #turbidite #Quincy #Boston #Massachusetts #NewEngland

  22. A small #outcrop of the #Squantum Member of the #Roxbury #Conglomerate

    These #rocks are in the #BostonBay Group, which is currently dated to #Neoproterozoic. The Squantum Member was interpreted as a #tillite, possibly associated with the #Gaskiers #glaciation, although there a scant signs like scratched pebbles or faceted cobbles. It is currently commonly interpreted as a #debrite (debris flow). Details in captions.
    #geology #glacier #turbidite #Quincy #Boston #Massachusetts #NewEngland

  23. A small #outcrop of the #Squantum Member of the #Roxbury #Conglomerate

    These #rocks are in the #BostonBay Group, which is currently dated to #Neoproterozoic. The Squantum Member was interpreted as a #tillite, possibly associated with the #Gaskiers #glaciation, although there a scant signs like scratched pebbles or faceted cobbles. It is currently commonly interpreted as a #debrite (debris flow). Details in captions.
    #geology #glacier #turbidite #Quincy #Boston #Massachusetts #NewEngland

  24. A small #outcrop of the #Squantum Member of the #Roxbury #Conglomerate

    These #rocks are in the #BostonBay Group, which is currently dated to #Neoproterozoic. The Squantum Member was interpreted as a #tillite, possibly associated with the #Gaskiers #glaciation, although there a scant signs like scratched pebbles or faceted cobbles. It is currently commonly interpreted as a #debrite (debris flow). Details in captions.
    #geology #glacier #turbidite #Quincy #Boston #Massachusetts #NewEngland

  25. A small #outcrop of the #Squantum Member of the #Roxbury #Conglomerate

    These #rocks are in the #BostonBay Group, which is currently dated to #Neoproterozoic. The Squantum Member was interpreted as a #tillite, possibly associated with the #Gaskiers #glaciation, although there a scant signs like scratched pebbles or faceted cobbles. It is currently commonly interpreted as a #debrite (debris flow). Details in captions.
    #geology #glacier #turbidite #Quincy #Boston #Massachusetts #NewEngland

  26. 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

  27. 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

  28. 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

  29. 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

  30. 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

  31. Deformed bedding in meta#sedimentary #rocks

    The horizontal bedding of the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic, #Boston Bay Group) has been disturbed locally.

    In the #glacial #tillite interpretation of the Squantum (favored through at least the 1970s), the distortion might be caused by glaciotectonic drag at the ice base. The current interpretation as a #debrite or #turbidite would probably attribute the deformations to synsedimentary slumping. My #photo. #fieldTrip

  32. Deformed bedding in meta#sedimentary #rocks

    The horizontal bedding of the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic, #Boston Bay Group) has been disturbed locally.

    In the #glacial #tillite interpretation of the Squantum (favored through at least the 1970s), the distortion might be caused by glaciotectonic drag at the ice base. The current interpretation as a #debrite or #turbidite would probably attribute the deformations to synsedimentary slumping. My #photo. #fieldTrip

  33. Deformed bedding in meta#sedimentary #rocks

    The horizontal bedding of the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic, #Boston Bay Group) has been disturbed locally.

    In the #glacial #tillite interpretation of the Squantum (favored through at least the 1970s), the distortion might be caused by glaciotectonic drag at the ice base. The current interpretation as a #debrite or #turbidite would probably attribute the deformations to synsedimentary slumping. My #photo. #fieldTrip

  34. Deformed bedding in meta#sedimentary #rocks

    The horizontal bedding of the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic, #Boston Bay Group) has been disturbed locally.

    In the #glacial #tillite interpretation of the Squantum (favored through at least the 1970s), the distortion might be caused by glaciotectonic drag at the ice base. The current interpretation as a #debrite or #turbidite would probably attribute the deformations to synsedimentary slumping. My #photo. #fieldTrip

  35. Deformed bedding in meta#sedimentary #rocks

    The horizontal bedding of the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic, #Boston Bay Group) has been disturbed locally.

    In the #glacial #tillite interpretation of the Squantum (favored through at least the 1970s), the distortion might be caused by glaciotectonic drag at the ice base. The current interpretation as a #debrite or #turbidite would probably attribute the deformations to synsedimentary slumping. My #photo. #fieldTrip

  36. 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.

  37. 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.

  38. 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.

  39. 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.

  40. 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.

  41. Interbedded argillaceous & tuffaceous #sediments

    These photos are of #Cambridge #Argillite, exposed above the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic). Prior to the 1970s or so, the Squantum Member was interpreted as #glacial sediments; it's now broadly interpreted as debris flows, with the Cambridge being distal turbidites overlying it. I lead a field trip here for #UMassBoston. See captions.

    #outcrop #fieldTrip #photo #rocks #tuff #Fufjilm #Venus 65mm #macro #Quincy

  42. Interbedded argillaceous & tuffaceous #sediments

    These photos are of #Cambridge #Argillite, exposed above the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic). Prior to the 1970s or so, the Squantum Member was interpreted as #glacial sediments; it's now broadly interpreted as debris flows, with the Cambridge being distal turbidites overlying it. I lead a field trip here for #UMassBoston. See captions.

    #outcrop #fieldTrip #photo #rocks #tuff #Fufjilm #Venus 65mm #macro #Quincy

  43. Interbedded argillaceous & tuffaceous #sediments

    These photos are of #Cambridge #Argillite, exposed above the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic). Prior to the 1970s or so, the Squantum Member was interpreted as #glacial sediments; it's now broadly interpreted as debris flows, with the Cambridge being distal turbidites overlying it. I lead a field trip here for #UMassBoston. See captions.

    #outcrop #fieldTrip #photo #rocks #tuff #Fufjilm #Venus 65mm #macro #Quincy