1901, Smithsonian Institution, Board of Regents, Annual Report of the Board of Regents of the Smithsonian Institution, Appears to be a fine-grained dioritic dyke rock, but is too dirty and stained to be satisfactorily examined.
1983, B. Simpson, Rock & Minerals, If the dyke is of great thickness the centre may be coarsely crystalline as a deep-seated plutonic rock and this makes it difficult to distinguish a dyke rock in hand specimen.
2017, Chris Pellant, Helen Pellant, Geological Structures - An Introductory Field Guide, As a dyke is made of igneous rock, it is usually possible to date it by radiometric dating methods, which give an absolute age for the dyke rock.
