Annual report of the State Mineralogist for the year ending ... . nsformation of the original surface, andthe extent of the cutting and filling of the three periods (see Fig 5).The surfaces marked 1 are sections of the gravel deposits of the firstperiod, and those marked 2 are sections of the volcanic cement depositsof the second period. Distinctive Features.—From the frequent displacement of the streamsduring the second period, there have arisen various complications in thechannel systems. Although the mining developments are extensive inportions of the district, it still remains a difficult
Annual report of the State Mineralogist for the year ending ... . nsformation of the original surface, andthe extent of the cutting and filling of the three periods (see Fig 5).The surfaces marked 1 are sections of the gravel deposits of the firstperiod, and those marked 2 are sections of the volcanic cement depositsof the second period. Distinctive Features.—From the frequent displacement of the streamsduring the second period, there have arisen various complications in thechannel systems. Although the mining developments are extensive inportions of the district, it still remains a difficult matter to separate thechannel systems of the second period, and it is not always easy to dis-tinguish between those of the first and second periods. In a general way, it may be said that the channels of the second period ?In this article bedrock gravel means gravel composed of bedrock material;cement, volcanic cement; volcanic gravel, gravel composed of volcanic rocks morerecent than the channel systems of the first period. t See Appendix B to this Ficp. 4000 r- ::=^\ 3000 2000 J000 CLOSE OF FIRST PERIOD Jvs5
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Keywords: ., bookcentury1800, booksubjectgeology, booksubjectminesandmineralr
