Garnet-quartz intergrowths in graphitic
pelites: the role of the fluid phase.
The negative anomalies recover the northern and southeastern part of map respectively above rocks like basalts, granites, migmatites, schists,
pelites, quartzites, and gneiss.
Potel, "Short-wavelength infrared spectroscopy: a new petrological tool in low-grade to very low-grade
pelites," Geology, vol.
Relationships of these sandstones to the Aroostook-Matapedia sequence between Houlton and Danforth have been poorly understood but a gradational contact with underlying Smyrna Mills
pelites has been observed in several places in the study area (Hopeck 2013; Ludman 2013).
It is formed by thick alternations of quartzose conglomerates and subordinated quartzarenites, passing in the upper ten metres of the section to dark
pelites. The disappearance of the terrigenous content marks the passage to the dolostones of the Dorgali Fm.
It is thus possible that the presence of sufficient Mn stabilizes garnet as a very common phase in the assemblage biotite--staurolite-[Al.sub.2]Si[O.sub.5], and then the occurrence of garnet in the staurolite-bearing
pelites may be related to high Mn content of the rock.
As regards the Upper Ordovician exposed in southern Normandy, based on conodonts and other fossils, the Vaux Limestone as well as limestone olistoliths in the overlying 'Tillite de Feugueroles' ('
Pelites a fragments') were dated as Ashgillian (Weyant et al.
Salvemini, "REE distribution in the clay fraction of
pelites from the southern Apennines, Italy," Chemical Geology, vol.
While the Eastern unit consists of
pelites with locally dominant quartzite and iron formations, the Western unit is almost entirely made up of
pelites.
We used laser-ablation split-stream (LASS) ICP mass spectrometry to measure U/Th-Pb ages and compositions of monazite from garnet + aluminumsilicate +- staurolite
pelites in the Kangmar and Mabja domes.