Saturday, March 18, 2006

Glossary: Magnetic Mountain

In the lore of the cosmic mountain and axis mundi we find repeatedly the theme of the "Magnetic Mountain" or the "Magnetic Isles." Other names include "Loadstone Mountain" and the "Great Loadstone."

Myths of the "whirling mountain" like Mount Mandara in the Sea of Milk may be related to the magnetic mountain theme where a whirling motion is also described.

Given the idea of magnetism and a whirling geography, late medieval writers in Europe naturally equated the Magnetic Mountain with the North Pole. However, the early references to this mysterious mountain place it instead in the "Indies."

Pliny mentions a magnetic mountain in this region during the first century. In the second century, Ptolemy identifies the ten magnetic isles of Maniolae in the Gangetic Gulf between Sri Lanka and the Malay Peninsula, where ships built with or carrying iron dare not approach.

Two centuries later we find in the Chinese text Nan Zhou Yi Wu Zhi, the mention of a similar place where only wood joint vessels should venture located in the extreme southern ocean off the coast of Tongking or Cochin-China (Giaochi). Muslim geographers like Kazwini and Idrisi mention the Loadstone Mountain and it is found in the tales of the Arabian Nights. In all cases, the geologic anomaly occurs in the "Far East" rather than in the North.

Roman de Ogier le Danois of the 14th century locates the Great Loadstone in Avalon "not far on this side of the terrestrial paradise, whither were rapt in a flame of fire Enock and Helios." Ogier is shipwrecked there after the iron nails and bolts of his vessel are pulled out by the areas's magnetic forces, and it is there he encounters Morgan le Fay. He also meets the fire-breathing fairy horse Papillon "famed for his skill and wisdom" with whom he returns to France from the Indies.

During the same century, John of Mandeville places the 'Adamant Islands' where ships use wooden pegs rather than iron nails in the eastern kingdom of Prester John.

Esoteric meaning

While the references to magnetic mountains or isles may be only an explanation of the wooden joint ships of the Indian Ocean, the theme often took on deeper meanings.

Arabic literature like the One Thousand and One Nights tell of a brazen/bronze horseman and brazen horse on the black, whirling Magnetic Mountain (The Story of the Third Kalendar). On the chest of the brazen horseman is a tablet of lead with mystical engraved names and talismans. A king is requested to climb the mountain and shoot the rider off the horse with his own lead arrows after which the sea will rise and engulf the mountain. After that the king was told he would be rescued by a man in a boat.

When the king accomplishes the tasks and shoots the brazen rider off his brass horse, the sea rises and swallows the mountain rendering it harmless to passing ships. In the approaching boat is a brazen man with a lead tablet on his chest engraved with names and talismans. The man rescues him and takes him back to his kingdom.

Medieval tales of Virgil the Magician, starting in Norman times, mention both the Magnetic Mountain and the brazen or bronze horse and horseman but in separate legends. Here the brazen horseman points with his brass lance toward the enemies of his kingdom.

Similar legends were told about the brass or bronze horseman mounted on the top of the Palace of the Green Dome of Caliph Mansur, the father of Harun al Rashid. In 1038, Khatib mentions this brass statue magically pointing toward the direction of impending attacks on the Caliphate. A similar brazen horseman was said to be found in Granada, Spain at the Hill of the Albaycin during Moorish rule.

The black mountain of the Arab tales was transferred as the Rupes Nigra in late medieval Europe to the North Pole. Eden also was moved to this location in this school of thinking playing on old legends of northernly or northwesternly journeys to the lush paradisical lands of Hyperborea and Avalon. There, people could frolic au naturel throughout the year. A type of supernatural explanation sometimes based on the magnetism of the Rupes Nigra itself explains the unusual suggested warmth in the polar region.

Taking the concept of the Great Loadstone to new heights, William Gilbert in his 1600 book De Magnete proposed a "magnetic philosophy" that ascribes an animistic spirit in all things to geomagnetism. One of the greatest proponents of this philosophy was Athanasius Kircher. A scientist, orientalist and occultist, Kircher spent years researching subterranean forces including the volcanoes of Etna, Stromboli and Vesuvius. He was even lowered into the crater of the latter volcano to study its dimensions. Kircher's two-volume Mundus Subterraneus was exceptionally highly regarded during his time.

Pinatubo and Magnetism

The Zambales (Sambal) range, where Mt. Pinatubo is found, is home to one of the world's major and best preserved ophiolites. An ophiolite is a geological formation that causes magnetic anomalies creating its own magnetic and gravity fields.

Most ophiolites have been broken into many parts by ocean action, but the Zambales ophiolite is a massive intact formation measuring 150 kilometers long and 40 kilometers wide. This area has long been known for its remarkably pure magnetic iron ores containing 75 to 80 percent metal.

Aside from the magnetism of the ophiolite and magnetic iron deposits, Zambales also contains large amounts of magnetic lahar deposited after Pinatubo's last eruption. Pinatubo is described, by Imai et al., as an "east-dipping subduction of the Eurasian plate at the Manila Trench." The Zambales Ophiolite acts as its basement rock.

Pinatubo magnetic dacite pumices are divided into strongly magnetic types known as ferromagnetic, and weakly magnetic types known as antiferromagnetic.

Most of the pumice and lithic deposits of Pinatubo have reversed magnetism with respect to the geomagnetic field direction. Some ancient stone deposits, however, have scattered natural remanent magnetization.

Paul Kekai Manansala


Beard, Charles R. Luck and Talismans: A Chapter of Popular Superstition, Kessinger Publishing, 2004.

Bina, M., J. C. Tanguy, V. Hoffmann, M. Prévot, E. L. Listanco, R. Keller, K. Th. Fehr, A. T. Goguitchaïchvili & R. S. Punongbayan. "A detailed magnetic and mineralogical study of self-reversed dacitic pumices from the 1991 Pinatubo eruption (Philippines)," Geophysical Journal International, Volume 138, July 1999, p. 159.

Dimalanta, C.B., Yumul,G.P.,Jr., De Jesus, J.V. and Faustino, D.V., 1999. Magnetic and gravity fields in southern Zambales: Implications on the evolution of the Zambales Ophiolite Complex, Luzon, Philippines. Geol. Soc. Malaysia Bull. 43, 537-543.

Imai,Akira, Eddie L. Listanco, and Toshitsugu Fujii. "Highly Oxidized and Sulfur-Rich Dacitic Magma of Mount Pinatubo: Implication for Metallogenesis of Porphyry Copper Mineralization in the Western Luzon Arc," FIRE and MUD: Eruptions and Lahars of Mount Pinatubo, Philippines,, 1999.