The Marystown Group is a Neoproterozoic stratigraphic group of predominantly volcanic sediments – subaerially deposited ash flow tuffs from rhyolites and alkali basalts[2] (with some minor sedimentary strata – red to green siltstones to conglomerates[2] – interleaved), with a central sandstone unit, cropping out in Newfoundland.[1]

Marystown Group
Stratigraphic range: 623–550 Ma[1] (approx.)
TypeGroup
UnderliesRencontre Formation (sometimes classified in Long Harbour Group)
OverliesBurin Group (unconformably), Rock Harbour Group[1]
Location
Region Newfoundland
Country Canada

Occurrence of Marystown Group in southeastern Newfoundland

It is likely to be temporally equivalent (more or less) to the Love Cove Group, Connaigre Bay Group, Long Harbour Group and Rock Harbour Group.[1]

More accurate/precise dates suggest that the formation is 580-570 Ma (younger than stated in the box above, which uses U-Pb dates).[3]

References

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  1. ^ a b c d Myrow, P (1995). "Neoproterozoic rocks of the Newfoundland Avalon Zone". Precambrian Research. 73 (1–4): 123–136. Bibcode:1995PreR...73..123M. doi:10.1016/0301-9268(94)00074-2.
  2. ^ a b Strong, D. F.; O'Brien, S. J.; Taylor, S. W.; Strong, P. G.; Wilton, D. H. (1978). "Aborted Proterozoic rifting in eastern Newfoundland". Canadian Journal of Earth Sciences. 15 (1): 117–131. Bibcode:1978CaJES..15..117S. doi:10.1139/e78-010.
  3. ^ McNamara, Allen K.; Niocaill, Conall Mac; Van Der Pluijm, Ben A.; Der Voo, Rob Van (2001). "West African proximity of the Avalon terrane in the latest Precambrian". Geological Society of America Bulletin. 113 (9): 1161. Bibcode:2001GSAB..113.1161M. doi:10.1130/0016-7606(2001)113<1161:WAPOTA>2.0.CO;2.