Transactions . that view, the difficulty of explaining the absence ofpisolitic ore from any of the underlying bands yielding only bole andlithomarge is avoided. On the precipitation hypothesis it need only besupposed that if the lower beds, like the upper one, were submerged inwater, iron was present only during the deposition of the pisolitic oreaccompanying the upper bed, or it may be that then only were thenecessary organisms present to effect the precipitation. AGE OF THE DEPOSITS. Being inter-bedded with rocks of miocene age, it is certain that theseores are not older than middle Tertiary
Transactions . that view, the difficulty of explaining the absence ofpisolitic ore from any of the underlying bands yielding only bole andlithomarge is avoided. On the precipitation hypothesis it need only besupposed that if the lower beds, like the upper one, were submerged inwater, iron was present only during the deposition of the pisolitic oreaccompanying the upper bed, or it may be that then only were thenecessary organisms present to effect the precipitation. AGE OF THE DEPOSITS. Being inter-bedded with rocks of miocene age, it is certain that theseores are not older than middle Tertiary; nor can the pisolitic ore be younger,as it must have been formed contemporaneously with the rocks in whichit occurs. The bole and lithomarge may be much younger if they aremetamorphosed basalt, but the evidence afforded by the blended junctionof the pisolitic ore and bole suggests that these two beds, at any rate, i» illustrate MrrJ. D^KendaHs paper On t/w Iran Ores of Antrim. Fig. i^w?^ jpip^rr;; Sttrrian Cam7rj*ia7i
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