. Annual Reports of the Department of the Interior for the Fiscal Year Ended June 30, 1900--Twenty-First Annual Report of the United States Geological Society. pping which has produced thebreccia has not been along the contact of the two formations. (Seep. 71.) Just over the sunmiit of the conglomerate bench which lies D. M. Mitchells place a hard baked conglomerate is foundwithin a few feet of the amygdaloid. l)ut here it is bleached almostto whiteness. (.Specimen -Hi;-5a.) Not far distant from this localityis a similar baked variety of the conglomerate, about 2~) paces fromthe neares
. Annual Reports of the Department of the Interior for the Fiscal Year Ended June 30, 1900--Twenty-First Annual Report of the United States Geological Society. pping which has produced thebreccia has not been along the contact of the two formations. (Seep. 71.) Just over the sunmiit of the conglomerate bench which lies D. M. Mitchells place a hard baked conglomerate is foundwithin a few feet of the amygdaloid. l)ut here it is bleached almostto whiteness. (.Specimen -Hi;-5a.) Not far distant from this localityis a similar baked variety of the conglomerate, about 2~) paces fromthe nearest exposure of the basalt, although, in view of the low dipsof the series, this mav represent but a few feet of actual distancefrom the former roof of basalt. The preservation of the conglomer-ate as a distinct ridge following the lower contact of the anteriorbasalt sheet with such persistence, though its beds are elsewhere onl\rarely exposed, is unquestionably connected with its induiation by thebasalt, which has thus not only prepared the conglomerate to resistthe forces of disintegration, but by forming a trough has preservedits own substance as CONTACT OF ANTERIOR BASALT WITH SHALES. 51 As already mentioned, the cong-lomerate which occupies the bed ofthe Pomperaug River below the dam at South Britain has the samecharacters as the basalt-contact variet}-, and its origin is believedto be the same, movement along a dislocation having removed thebasalt from view in a manner which will be subsequently explained(p. 89). To summarize the observations of the contact of the conglomerateand the anterior basalt sheet, it may be stated that this surface of con-tact seems to be somewhat irregular for shoit distances at least, cuttingacross the bedding of the conglomerate, and, further, that irregularfragments of the cong-lomerate have been incorporated in the basalt,and that the former is al)normally hard and sometimes abnormallywhite in the vicinit} of the latter. Contact of the
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