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VOLCANOES OF THE LOWER OLD RED SANDSTONE book v 
of Fife and the Lothians may still be read with pleasure and instruction.^ 
Bond had indicated roughly on the little sketch-map accompanying his 
Fssai the chief bands of his felspathic and trappean rocks of the Old 
Bed Sandstone, but their position and limits were more precisely defined in 
MaccuLloch’s "Geological Map of Scotland,” which was published in 1840, 
five years after the sudden and tragic death of its author. The observers 
who have more recently studied these rocks have l)een chiefly members of 
the Geological Survey, and to some of the more important results obtained 
by them I shall refer in the sequel. 
For many years I have devoted much time to the investigation of the 
Old Bed Sandstone and its volcanic rocks. In the year 1859 I ascertained 
tlie existence of the great hiatus between the Lower and Upper divisions 
of the system." A first sketch of the volcanic history of the Old Bed 
Sandstone was given by me in 1861,® which was subsequently enlarged and 
filled in with more detail in 1879.'* But it was not until 1892 that I 
published a somewhat detailed outline of the whole subject, tracing the 
history of volcanic action during the period of the Old Bed Sandstone, the 
distribution of the volcanoes, and the character of the materials erupted by 
tliem.® This outline I now proceed to amplify, filling in details that were 
necessarily omitted before, though there are still several districts regard- 
ing which information is scanty. 
In arranging the treatment of the subject I shall divide the record into 
two main sections, the first and much the more important being devoted to 
the Lower and the second to the Upper Old Bed Sandstone. In the first 
of these divisions it will be convenient to begin by taking note of the 
distribution of tbe va,rious districts over winch the geological evidence is 
spread. We may then proceed to consider the general character of the 
volcanic rocks and the manner in which they are arranged in the strati- 
graphy of the country, taking in consecutive order (1) the superficial lavas 
and tufts; (2) the vents; (3) the dykes and sills. From these general 
considerations we may pass to the detailed history of events in each of the 
separate volcanic areas, and thus obtain, as far as the evidence at present 
permits, a broad view of the progress of volcanic action during the time of 
the Lower Old Bed Sandstone in Britain. 
' Geology of Fife and the Lothians, 18-39. More detailed reference will be made in later 
jiagc.s to this classic. 
2 “On the Old Red Sandstone of the South of Scotland,” Quart. Journ. Oeol. Soc. xvi. 
(1860), p. 312. 
“ “ On the Chronology of the Trap-Rooks of Scotland," Trans. Roy. Soc. Edin. vol. xxii. 
(1861), p. 63. 
■* Article “Geology,” in Ninth Edition of the Encyclopccdia Britannica, vol. x. (1879), p. 343. 
Reprinted in my Text-Book of Geology, of which the first edition appeared in 1882. 
® “ I’residential Address to the Geological Society,” Quart. Joum. Geol. Soc. vol. xlviii. 
(1892). 
