Last set of examples of soft sediment deformation in the. Squantum Member of the Roxbury Conglomerate, Boston Bay Group; Neoproterozoic and approximately contemporaneous with Gaskiers glaciation.

Although previously interpreted as a tillite (it is still sometimes referred to as the “Squantum Tillite), the “consensus” is now debris flows and turbidites.

#geology #sedimentology #turbidites #glaciology #Boston #Neoproterozoic #geosciences #sedimentary #rocks

Overturned soft sediment folds in the Neoproterozoic Squantum Member of the Roxbury Conglomerate, Boston Bay Group.

The tight folding (center left) is widely currently interpreted as occurring in a debris flow. White balance card held by a student on a field trip for “Earth’s Dynamic Systems” at U Mass Boston this semester. Squantum Head, Quincy, Massachusetts USA. My photo.

#turbidites #geology #sedimentary #geosciences #boston #UMassBoston #EnvironmentalScience

Possible dropstone in the Neoproterozoic Squantum Member of the Roxbury Conglomerate, Quincy, Massachusetts USA. See previous posts for more background.
#geology #glaciology #turbidites #Neoproterozoic #sedimentary #conglomerate #rocks

Interbedded tuffaceous and fine grained siliciclastic layers in the Cambridge Argillite, a Neoproterozoic member of the Boston Bay Group, above the Roxbury Conglomerate. Usually interpreted as a turbidite distal to the Roxbury.

#turbidite #geology #turbidites #rocks

Interesting overturned fold, probably syndepositional(?). Neoproterozoic Squantum Member of the Roxbury Conglomerate, Quincy, MA. I visited these rocks with my “Earth’s Dynamic Systems” class this fall. Tillite or debrisite/turbidite? Many debrisite/turbidite features, a few possible dropstones, not much faceting or striation. Possibly contemporaneous with Gaskiers.

#Boston #rocks #sedimentary #geology #turbidites #glaciology

@knittingknots @Some_Emo_Chick @geoscience

There seem to be two areas off the flank of the volcano that developed new large-scale sediment wave trains during the eruption and pyroclastic flows. They formed at the base of the slope, and at the pre-existing channel mouths, suggesting they formed due to supercritical flows. They look, to me, to be erosional and depositional cyclic steps and antidunes. I’ve worked with these before: https://www.researchgate.net/publication/316184378_Morphodynamics_of_supercritical_turbidity_currents_in_the_channel-lobe_transition_zone #geology #geoscience #turbidites

@geoscience@a.grup.pe Outcrop of the Cretaceous Prairie Canyon Member of the Blackhawk Formation in the Bookcliffs, Utah USA. In this location, the Prairie Canyon Member was deposited in a submarine fan whose equivalent shoreline system was the Kenilworth Member of the same formation, just visible in the far distance in the upper left part of this photo. Dr. Brian Currie of Miami University of Ohio for scale. #geology #geoscience #stratigraphy #turbidites

Convolute strata in the upper part of a turbidite in the Cretaceous Prairie Canyon Member of the Blackhawk Formation, Bookcliffs, Utah USA #geoscience@a.gup.pe #sedimentology #turbidites