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The more common zeolites from the Triassic basalts of Nova Scotia were studied by single crystal photography and diffractometry techniques. These included analcite, apophyllite, chabasite (including the variety "acadialite"), gmelinite, laumontite, mordenite, natrolite, stilbite, thomsonite, and other minerals occurring as intergrowths.
Buerger precession photos were taken and cell parameters calculated directly. These parameters were processed by an IBM 1620 electronic computer to calculate all possible lines and indices which could occur in the respective diffractograms. Results were compared with experimentally obtained diffractograms, and tabulations were made of actual "d" spacings so obtained against tentative indices. Cell parameters were then re-calculated with greater precision from the indexed diffractograms.
A sequence of crystallization, related to the stratigraphy of the basalts, was tentatively formulated from field observations to be as follows: silica acting as a base, with chabasite and gmelinite as the first zeolites, followed by stilbite, heulandite, laumontite, apophyllite, analcite, thomsonite, and finally natrolite (with mesolite intergrowths).
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