Ashgillian

Ashgillian

[ash′gil·yən]
(geology)
A European stage of geologic time in the Upper Orodovician (above Upper Caradocian, below Llandoverian of Silurian).
References in periodicals archive ?
1984) attributed an Ashgillian or younger age to this series because of the absence of acidic volcanic rocks interbedded in the series.
The lithological variation, a great number of lithostratigraphical units and uneven palaeontological data have complicated the correlation and compilation of models of basin development during the middle Ashgillian Pirgu time.
This unconformity corresponds to the eustatic fall in sea level associated with the terminal Ashgillian event (Berry and Boucot, 1973).
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.
39-41) from the Rawtheyan (beds 5a), Oslo Region, Norway; the North American species Grewingkia callahanensis Elias, 1984 from the Ashgillian, eastern Klamath Mountains, California; Grewingkia penobscotensis Elias, 1982 from the Ashgillian, County of Maine.
The first tract contains the oldest part of the Late Ordovician-Devonian sequence and comprises Ashgillian to possibly Llandoverian volcanic, clastic sedimentary and carbonate rocks (the Goss Point and Simpsons Island formations as defined by McLeod (1995)).