. Transactions. he in-D. eluded schists and limestones, Dr. Spencer° favors the view that the ores were original?^ members of the schist and limestone seriesg and that they have been torn off withS varying amounts of their old associatedstrata and floated upward as includedmasses in the porphyry. The great slabsor masses of ore are often cracked apartand separated by dikes of porphyry whichare regarded as the same rock with thegeneral inclosing walls. ^ Several cross-sections assembled and reproduced here inFigs. 3, 4, 5 and 6, on a reduced scale arepp\5 given in support of the view. One of ^d
. Transactions. he in-D. eluded schists and limestones, Dr. Spencer° favors the view that the ores were original?^ members of the schist and limestone seriesg and that they have been torn off withS varying amounts of their old associatedstrata and floated upward as includedmasses in the porphyry. The great slabsor masses of ore are often cracked apartand separated by dikes of porphyry whichare regarded as the same rock with thegeneral inclosing walls. ^ Several cross-sections assembled and reproduced here inFigs. 3, 4, 5 and 6, on a reduced scale arepp\5 given in support of the view. One of ^dcc 8 In Trans., xlii, 167, 168 (1911), two pano- ramic views appear accompanj^ing some notesincidental to the Canal Zone excursion. CS bcS.^ ^ o ^.2 exd >, fl cd ^i -^-^ 9 JAMES F. KEMP these with a quotation appears also in J. E. Spurrs Geology Applied toMining, p. 118 (1907) where it is more generally accessible than in theoriginal paper. In reading Dr. Spencers description one must bear in mind that the.
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
