464 BUTE. GEOLOGY. 



minately, and in a disorderly manner. They present but 

 few of the occasional substances or more limited beds 

 which occur so abundantly in that island ; yet different 

 varieties of coloured shales passing into iron stones, 

 are to be observed in some places. 



On the shore between Ascog and Rothsay, fragments 

 of an irregular bed of limestone are found in the con- 

 glomerate. This is of a mottled grey colour, and at its 

 boundaries graduates into the. contiguous rock ; in- 

 volving fragments of the several substances that are 

 imbedded in this stratum. Similar appearance's are very 

 common in Arran. I may conclude the subject of the 

 red sandstone by remarking, that where it gives passage 

 to trap veins it often assumes the same colour as the 

 vein ; a phenomenon also of frequent occurrence in that 

 island. 



The other appearances of limestone in Bute are scanty. 

 A small portion of a bed is visible between Scalspie 

 and Kilmory ; imagined by the natives to be a portion 

 of that which appears above Kilchattan bay, and which 

 is the only conspicuous mass in the island. This latter 

 bed seems to lie above all the sandstone strata at this 

 place, and to be the rock immediately in contact with 

 the superincumbent trap. It is traversed by trap veins, 

 which appear to have their origin in the great body 

 of that substance ; and from this cause probably, the 

 disposition of its beds is disturbed, although the general 

 bearing of the whole is sufficiently regular. It does 

 not contain any organic remains that I could discover; 

 although they may still exist, since they are found in 

 some of the limestones of Arran that are similarly 

 .situated. The colour is a pale blueish grey and the 

 fracture earthy, where it is most simple and has under- 

 gone the least apparent disturbance. In most places 

 however, the shales, with which this limestone is in 

 other cases regularly interstratined, are twisted about 

 and irregularly mingled throughout the whole mass ; 

 i 



