Lichen weathering of rock‐forming minerals: application of scanning electron microscopy and microprobe analysis

SUMMARY Using the scanning electron microscope with microprobe analysis, observations have been made on the weathering of rock‐forming minerals—feldspars, ferromagnesian minerals, quartz and serpentine—principally by crustose lichens. A variety of phenomena can be recognized, namely, etching patterns, decomposition features and secondary products which can be related to differences in mineral structure and composition. Such weathering has been proved to involve the chelating effects of oxalic acid in certain lichens, although lichen acids could also be implicated.