Biemsderfer plotter for field recording of structural measurements on equal area nets

The Biemsderfer plotter is a pie-shaped template anchored by a thumb-tack at the center of an equal area net. A 90° angle between its two arms allows one side to be laid parallel to the strike of a plane while the pole is plotted as a dot along the other arm. Variations for use with lineations are equally simple. Its chief virtue is field-friendly ease of producing hard-copy equal area plots while the geologist is still able to make further observations on the outcrop about each data class. These plotters may be low-tech tools but their use with some of the strategies described commonly produces a quantum leap in the quality of recognition and recording of field structural data.