Transactions of the Royal Society of Edinburgh . a Fig. 3.—Ground plan of volcanic vents. teristic forms of vents. Some of the eccentricities of outline no doubt arosefrom the irregular way inwhich the rocks throughwhich an orifice was drilledyielded to the forces ofexplosion. This is oftenwell shown by the veinsand nests of tuff or ag-glomerate which have beenforced into the rents orsinuosities of the other cases, however,it is probable that whatappears now as onevolcanic neck, was theresult of a shifting of theactual funnel of discharge,. Fig 4.—Plan of volcanic necks at Kellie L
Transactions of the Royal Society of Edinburgh . a Fig. 3.—Ground plan of volcanic vents. teristic forms of vents. Some of the eccentricities of outline no doubt arosefrom the irregular way inwhich the rocks throughwhich an orifice was drilledyielded to the forces ofexplosion. This is oftenwell shown by the veinsand nests of tuff or ag-glomerate which have beenforced into the rents orsinuosities of the other cases, however,it is probable that whatappears now as onevolcanic neck, was theresult of a shifting of theactual funnel of discharge,. Fig 4.—Plan of volcanic necks at Kellie Law, east of Fife. 1, Kellie Law(tuff); 2, Carnbee Law (tutf) ; 3, 4, 5, small tuff necks; BB, basaltdykes and sheets ; cc, coal-seams ; I, limestone ; /, fault. The arrowsmark the clip of the strata through which the necks have been drilled. so that the neck really represents several closely adjacent vents. Thenecks at Kellie Law (fig. 4) show this arrangement veryclearly. The Law itself (1) probably consists of twocontiguous vents, while a third (2) forms a smaller coneimmediately to the east. This slight lateral displace-ment of the vent has been noticed at many Tertiaryand recent volcanic orifices. In the island or peninsulaof Volcanello, for example, I observed three cratersindicative of successive shiftings of the vent, the mostperfect crater marking the latest and diminishing phase ^vl^u^Sl^of the volcanic activity. The cones at Kellie LaAv may point to a similarseries of events*
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