Inclined pipe vesicles as indicators of flow direction in basalts: A critical appraisal

摘要: Inclined pipe vesicles and stretched near the base of basalt flows have long been regarded as reliable flow-direction indicators. However, attempts to use such structures in Santa Rosa Basalt Southern California determine regional flow patterns, paleoslope, source eruption yielded inconclusive contradictory results. Orientations 1070 at 37 localities were obtained directions inclination from vertical plotted on circular histograms. At any specific locality vesicle orientations typically are normally distributed through a 40–60 degree sector. Commonly pronounced maximum lies within 20–40 Even having bimodal or trimodal distribution most plot 90