Keywords: Alpine Tethys, Unconformity
, Jurassic, Paleogeography, Sedimentology, Eastern Sardinia-Corsica Tectonic high
The Rift or Beaufortian is marked by the Jurassic unconformity
, overlain by a layer of sandstone, the Kuparuk Formation and upper Kingak shale and lower Kingak shale.
The Great Unconformity
is a very prominent geomorphic surface and there's nothing else like it in the entire rock record," said Shanan Peters, a geoscience professor at the University of Wisconsin-Madison who led the new work.
The more recent recognition of deeply weathered granitoid rocks below the unconformity
of the Horton Group on the South Mountain Batholith (O'Beirne-Ryan and Zentilli 2003) suggests an additional genetic link to regolith-related unconformity
deposits such as the Athabasca Basin of Saskatchewan.
The Warrensburg Sandstone Lies with angular unconformity
upon cyclothemic rock units belonging to the Desmoinesian Series (Figures 3 and 4).
Using the decay of radioactive uranium in the rocks as a clock, the scientists dated the unconformity
However, the Newfoundland Basin differs significantly in one major way--it exhibits a well-defined geological unconformity
that caps and occasionally truncates underlying crust out to the interpreted ocean-continent boundary 20 to 40 kilometers west of magnetic anomaly MO.
The mineralized zone, which covers the extent of the current drilling, occurs between 50 and 175 metres vertically below the sub-Athabasca unconformity
(265 and 390 metres vertically below surface) and measures approximately 100 metres along strike (current extent of drilling), up to 120 metres along dip, with individual lenses varying in interpreted true thickness between approximately 2 and 7 metres.
Early Carboniferous deposits known as the El Raton Formation (Azcuy et al, 1981) and Jejenes Formation (Amos, 1954) overlie older Palaeozoic rocks along a strong angular unconformity
Inshore, fluvio-tidal successions above the unconformity
display upward increase in marine influence and are interpreted as transgressive incised valley fills.
Depth to the unconformity
in the area is approximately 110 metres.
Some researchers consider that, the basement of Qiangtang Basin is buildup by two-layers of Proterozoic metamorphic rocks, lower crystal --rigid basement , upper metamorphic --plastic basement , and middle angular unconformity
(Wang GZ et al.