Dimensional grain orientation studies of turbidite graywackes.

Abstract

This study describes the analysis of orientation measurements of elongated quarts grains in graywackes of turbidite nature of the Normanskill formation of New York and the Quebec Group of Quebec. Definite relationships are demonstrated between the direction of flow, as indicated by the measurement of the flute casts, and the preferred orientation direction of the sand grains. Dimensional orientation analysis of sand grains in thin section can be used to determine the transport direction of the turbidity current where this can not be determined by other means. Size and shape analysis of quartz grains in thin section might be biased depending on how the thin section is cut with respect to the fabric of the rock.