| 释义 |
sillar Geol.|siːlˈjɑː(r)|
[Sp.]
An ignimbrite or volcanic tuff that has not become indurated by welding.
1948C. N. Fenner in Bull. Geol. Soc. Amer. LIX. 883 There has been a tendency to call all such deposits ‘welded tuffs’... For those in which induration is primarily the result of recrystallization, and for those in which the fragments have little cohesion, another term is desirable. The local term ‘sillar’.., commonly used in the Arequipa region [in Peru], has been applied in the present paper. Ibid. 887 These occurrences of both white and salmon sillar contain scattered inclusions of white pumice. 1965F. H. Hatch et al. Petrol. Sedimentary Rocks (ed. 4) xv. 322 Both sillars and welded tuffs frequently exhibit columnar jointing, somewhat akin to that in lava flows proper. 1978Nature 24 Aug. 750/1 In the outcrops visited, two distinct flow units, each up to 30 m thick, were consistently present, both exhibiting the properties of classic sillar. |