Earth:Marystown Group

From HandWiki
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
Marystown Group map.svg
Occurrence of Marystown Group in southeastern Newfoundland

The Marystown Group is a Neoproterozoic stratigraphic group of predominantly volcanic sediments – subaerially deposited ash-flow tuffs from rhyolites and alkaline 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]

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]

Age

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

  1. 1.0 1.1 1.2 1.3 Myrow, P (1995). "Neoproterozoic rocks of the Newfoundland Avalon Zone". Precambrian Research 73 (1–4): 123–136. doi:10.1016/0301-9268(94)00074-2. Bibcode1995PreR...73..123M. 
  2. 2.0 2.1 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. doi:10.1139/e78-010. Bibcode1978CaJES..15..117S. 
  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. doi:10.1130/0016-7606(2001)113<1161:WAPOTA>2.0.CO;2. Bibcode2001GSAB..113.1161M.