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#clast — Public Fediverse posts

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

  1. 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.