Annual report . garnets have been developed. The fragments vary from microscopic in size tothose which are eighteen inches or more in diameter. The outlines are angular, sub-angular or round, Fig. 30. They consist of felsite or rhyolite, devitrified glass showingflow textures, amygdaloid, fine-grained acid porphyries, quartz, feldspar, crystallinelimestone, slate, fine-grained greywacke or quartzite, and chert; sericite, calcite, garnetand biotite have been developed as secondary minerals. While some of the fragmental material is agglomeratic in character, other partsare more like normal congl
Annual report . garnets have been developed. The fragments vary from microscopic in size tothose which are eighteen inches or more in diameter. The outlines are angular, sub-angular or round, Fig. 30. They consist of felsite or rhyolite, devitrified glass showingflow textures, amygdaloid, fine-grained acid porphyries, quartz, feldspar, crystallinelimestone, slate, fine-grained greywacke or quartzite, and chert; sericite, calcite, garnetand biotite have been developed as secondary minerals. While some of the fragmental material is agglomeratic in character, other partsare more like normal conglomerate or agglomerate that has been worked over by chemical composition of some of the crystalline limestone fragments, obtained fromthe hill north of the village of Madoc, is shown in the following table: No. CaO. MgO. Loss on ignition. Insoluble. 1. 2. 3. .76 4. .95 * Geology of Canada, 1863, pp. 32-33. 66 Bureau of Mines No. 4. Hitr. 30. AKirlomcratc. IWadoc village, Hastings count) 1913 The Pre=Cambrian Geology of Southeastern Ontario 67 The varieties of these rocks, here grouped together, although differing widely inorigin, have not been separated on the geological map. Examples of the agglomerateand tuff are exposed two or three hundred yards northeast of the Catholic autoclastic rock, or crush-breccia, may be seen at the edge of the creek southwestof the Catholic cemetery, while felsite intrusions, holding fragments of the countryrock, occur a few hundred yards east of the Grand Trunk railway station, and just tothe south of the hematite pit on lot 5, in the sixth concession of Madoc. The felsitedikes near the Grand Trunk station contain fragments of crystalline limestone. Thefragmental rocks exposed on the hill north of the town also contain many limestonefragments. Outside of the places mentioned in the preceding paragraph, felsite occurs, as willbe seen from the map, on lots
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