Tectonically deformed pillow lava as an indicator of bedding and way-up

Often the outlines of tectonically deformed lava pillows cannot be used to give directly the true bedding and way-up directions. Where the pillows are strained homogeneously, with moderate total strains, certain procedures allow the determination of the true bedding and way-up directions. Where the strain history has been coaxial, these are: the use of pillows fortuitously parallel with a principal extension direction and graphical restoration of pre-tectonic pillow shapes to fix true bedding directions. Furthermore, use may be made of special pillow shapes with flat bases or multiple cusps, even where the strain history has been noncoaxial. With total strain ratios > 4.5, heterogeneous strain often occurs and it may not be possible to determine the true bedding and way-up directions.