Humboldt, F.A. v. (1797). "Ueber die merkwürdige magnetische Polarität einer Gebirgskuppe von Serpentinstein" [About the strange magnetic polarity of a mountain peak of serpentine]. Neues Journal der Physik (in German). 4: 136–140. On pp. 136-137 Humboldt found that a peak in the Oberpfalz mountains was magnetic. On p. 138, Humboldt noted that a mountain peak in the Harz Mountains — specifically, the Schuarcher (the snorer) — also showed magnetization. He attributed the magnetization to lightning strikes. From p. 138: "Bey den Schuarchern ist es […] nicht unwahrscheinlich, daß ein Blitzstrahl in dem Granit jenen magnetischen Streifen hervorgebracht habe, […] " (In the case of the Schuarcher […] it's not improbable that a bolt of lightning produced in the granite that magnetic streak, […] ) Humboldt thought that this explanation was even more likely in the case of peak in the Oberpfalz because even fragments of the rock were magnetized: "Nicht bloß das anstehende Gestein, sondern auch jedes noch so klein abgeschlagene Stück hat seine beiden Pole, seine eigene magnetische Achse." (Not just the outcrop but also every chip, however small, has both [magnetic] poles, its own magnetic axis.)
Herries, A. I. R.; Adams, J. W.; Kuykendall, K. L.; Shaw, J. (2006). "Speleology and magnetobiostratigraphic chronology of the GD 2 locality of the Gondolin hominin-bearing paleocave deposits, North West Province, South Africa". Journal of Human Evolution. 51 (6): 617–31. Bibcode:2006JHumE..51..617H. doi:10.1016/j.jhevol.2006.07.007. PMID16949648.
Herries, A. I. R.; Adams, J. W.; Kuykendall, K. L.; Shaw, J. (2006). "Speleology and magnetobiostratigraphic chronology of the GD 2 locality of the Gondolin hominin-bearing paleocave deposits, North West Province, South Africa". Journal of Human Evolution. 51 (6): 617–31. Bibcode:2006JHumE..51..617H. doi:10.1016/j.jhevol.2006.07.007. PMID16949648.
Herries, A. I. R.; Adams, J. W.; Kuykendall, K. L.; Shaw, J. (2006). "Speleology and magnetobiostratigraphic chronology of the GD 2 locality of the Gondolin hominin-bearing paleocave deposits, North West Province, South Africa". Journal of Human Evolution. 51 (6): 617–31. Bibcode:2006JHumE..51..617H. doi:10.1016/j.jhevol.2006.07.007. PMID16949648.
W. Jacquelyne, Kious; Robert I., Tilling (2001). "Developing the theory". This dynamic earth: the story of plate tectonics (online edition version 1.20). Washington, D.C.: U.S. Geological Survey. ISBN0-16-048220-8. Retrieved 6 November 2016.