English edit

Etymology edit

Coined by English geologist Alfred Harker in 1909 as phacolite, from phaco- (lens) +‎ -lite or -lith (rock).[1]

Noun edit

phacolith (plural phacoliths)

  1. (geology) A lens-shaped mass that occurs in an anticlinal crest or synclinal trough.
    • 1947, Virgil Everett Barnes, Raymond Fillmore Dawson, George Ashworth Parkinson, Building Stones of Central Texas - Volume 19, page 21:
      This body is a phacolith intruded along the gneiss-schist boundary in the trough of a syncline that plunges 16° southeast.
    • 1964, Geological Survey Professional Paper, volume 501, page A-81:
      This bedding forms a distinctive stratigraphic sequence that may be traced from phacolith to phacolith throughout an area of 1,200 square miles.
    • 2007, Richard Huggett, Fundamentals of Geomorphology, page 120:
      Corndon Hill, which lies east of Montgomery in Powys, Wales, is a circular phacolith made of Ordovician dolerite (Figure 5.3b).

References edit

  1. ^ Alfred Harker (1909) The Natural History of Igneous Rocks, Macmillan, →OCLC, page 77