526 Obituary — Charles Callaway. 



subsequent work. Below these shales he found a greenish sandstone, 

 which, by its fossil evidence and its geographic relations, he correlated 

 with the Hollybush Sandstone of the Malvern country, then supposed 

 to be of approximately Middle Cambrian age. 



Underlying this sandstone was the Wrekin Quartzite, believed by 

 the earlier geologists to have been metamorphosed by intrusive 

 greenstone forming the core of the Wrekin. Meanwhile Mr. Samuel 

 Allport had been working on the supposed irruptives, and by means 

 of the microscope — which he was one of the first to apply to rock- 

 structures — he proved them to be in the main of volcanic origin, 

 consisting of interbedded ashes and rhyolites. As these strata 

 underlay unconformably a quartzite which was not younger than 

 Middle Cambrian, their Pre-Cambrian age became a fair inference. 

 The subsequent demonstration by Professor Charles Lapworth of the 

 Lower Cambrian age of the Hollybush Sandstone converted the 

 inference into conclusive proof. 1 For this new Pre-Cambrian formation 

 the name ' Uriconian ' was proposed. 



The granite rocks of the Wrekin were seen to furnish water- worn 

 fragments to Uriconian conglomerates. Thus a second Pre-Cambrian 

 system was recognized. The Pre-Cambrian age of the Longmynd 

 Series also followed from the above discoveries, and the name of 

 ' Longmyndian ' was suggested for this great sedimentary formation. 



Dr. Callaway extended his researches to the complicated area of 

 Anglesey. He claimed to have proved, after work extending over 

 twenty years, that the Ordovician strata of Northern Anglesey lay in 

 a reflexed syncline, so that the rocks to the north could not be 

 Ordovician, and were probably Archaean ; that the crystallines of 

 Northern Anglesey were metamorphosed sediments, that the Grey 

 Gneiss of the southern district was a modified felsite, and that the 

 diorite of the central complex has been modified into an elliptical dome 

 of gneiss. In the Highlands of Scotland he took part in the work 

 which led to the abandonment of the Murchisonian hypothesis. His 

 researches were confirmatory of those of Nicol, but he found that the 

 "igneous rocks" of that author were usually the Hebridean gneiss 

 thrust over the Ordovician (Cambrian) strata by earth-movements — 

 the zone of thrust extending from Loch Erribol on the northern coast 

 to Ullapool. Certain problems in Ireland were investigated. The 

 supposed metamorphic granite of Donegal was shown to be intrusive 

 in the associated schists, the apparent bedding being the result of 

 pressure. In County Galway it was contended that the "meta- 

 morphosed conglomerates " and other alleged sediments were plutonic 

 rocks which had sometimes acquired parallel structures under earth- 

 pressures. The district south of Wexford, alleged to show the 



1 In December, 1891, Professor Charles Lapworth described a new species of 

 Olenellus which he dedicated to his friend, Mr. Charles Callaway, D.Sc, 

 F.G.S., "who was the first to detect organic remains in the Comley Sandstone, 

 and the first to demonstrate the presence of true Cambrian fossils in Shropshire 

 generally ; and whose original and sagacious inferences as to the probable 

 Pre-Cambrian age of the unconformably underlying rocks the discovery of 

 Olenellus places beyond much dispute " (p. 532. See Geol. Mag., December, 

 1891, pp. 529-36, Pis. XIV and XV). 



