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(quebrada) de Vermellon at the foot of the table land of Ibague Viejo is filed; but they. know the vein also from which the torrent appears to have detached these fragments, and which traverses the small ravin of Santa Ana. Near the village of Azogue to the North-west of Cuenca, the mercury is found, as in the department of Mont-Tonnerre, in a formation of quartz-freestone with argillaceous cement. This freestone is nearly 1400 metres * in thickness, and contains fossil wood † and asphaltos . In the mountains of Guazun and Upar, situated to the North-east of Azogue, a vein of cinnabar traverses beds of clay filled with calcareous spar, and contained in free-stone. We discover there the remains of an old gallery of 120 metres in length, § and 11 pits very close to one another. It is believed in the country that this mine was wrought before Huancavelica, and that it was the dis

* 4592 feet. Trans.

+ I found beautiful pieces of 14 decimetres (4£ feet English) in length at Silcai-Yacu between Delec and Cuenca.

$ At Porche and the Western declivity of the mountains of Coxitambo, I was singularly struck with the geological relations between the freestone formation of Cuenca and Azogue and the freestone of the mines of Wolfstein and Münsterrappel which I visited in 1790, and which contain also cinnabar, fossil wood, and petrole.

393 feet Trans.

covery of the latter, which was the occasion of its abandonment. The learned experiments of Don Pedro Garcia, and the works executed by M. Vallejos the intendant of Cuenca in 1792, have not proved that the vein of cinnabar of Guazun, may be successfully wrought. At five leagues distance from the town of Popayan, to the North-west near Zeguengue there is a ravin which is called the mercury ravin (quebrada del azogue) without the origin of the name being known.

In Peru, cinnabar is found near Valdivui in the province of Pataz, between the eastern bank of the Marañon and the missions of Guailillas; at the foot of the great Nevado de Pelayato, in the province of Conchucos, to the east of Santa ; at the baths of Jesus in the province of Guamalies to the Southeast of Guacarachuco; near Huancavelica in the intendancy of that name; and near Guaraz in the province of Guailas. From the account books found in the provincial treasury of the town of Chachapoyas (between the Rio Sonche and the Rio Utcubamba) it appears that at the beginning of the conquest, -mercury. mines were wrought in the moderately elevated mountains which extend from Pongo de Manseriche to near Caxamarquillo and the Rio Huallaga ; but from the information which I obtained during my stay in the province of Jaen, the place where these mines were situated is at present totally unknown. The veins of cinnabar of Guaraz.were worked with some degree of success in 1802. There was extracted as much as 84 pounds of mercury from a mass of minerals of 1500 pounds weight.

The famous mine of Huancavelica, as to the state of which so many false ideas have been disseminated, is in the mountain of Santa Barbara, to the south of the town of Huancavelica, at a horizontal distance of 2772 varas (or 2319 metres*). The height of the town above the level of the sea, is according to Le Gentilt 3752 metres (1925 toises) 1. If we add to this the 802 varas, which the summit of the mountain of Santa Barbara, is higher than the level of the streets of Huancavelica, we shall find the absolute height of this * 7606 feet. Trans.

+ This height is calculated agreeably to the formula of M. La Place, supposing a temperature of 10 centigrade degrees (50° Fahr.). According to Le Gentil, (Voyage aux Indes, T. i. p. 76.) the mean height of the barometer at the town of Huancavellca iš 1880. 111.5. In the manuscript of Mothes, this height is estimated at 18po. 7'i. which would give only 1814 toises, or 3535 metres of absolute elevation. (11,596'feet. Trans.) The great square of the town of Micuipampa, where I found the barometer 18po. 411.7, would then be 84 metres (275 feet. Trans.) higher than the level of the streets of Huancavelica, (Recueil d'Observations Astronomiques, Vol. i. p. 316.)

$ 12,308 feet. Trans.

mountain 4422 metres*. The discovery of the great mercury mine, is generally attributed to the Indian Gonzalo Abincopa or Navimcopa; but it is certain that it goes back to a period long before 1567, since the Incas made use of cinnabar in painting themselves, and procured it from the mountains of Palcas. The working of the mine of the Cerro de Santa Barbara on account of the Crown, began however only in the month of September, 1570, nearly the same year in which Fernandez de Velasco introduced the Mexican amalgamation into Peru.

Mercury is found in the environs of the town of Huancavelica, in two very different manners, in heds and in veins. In the great mine of Santa Barbara, the cinnabar is contained in a bed of quartz freestone of nearly 400 metres in thickness, and in a direction of hor. 10–11

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* 14,506 feet. Trans. This measurement agrees very well with the assertion of Ulloa, who relates that he saw the barometer remain at the bottom of the mine of Hoyo Negro at 1700. 2li. 2; from which we may conclude that the bottom of the mine was then 2159 toises, or 4208 metres of elevation above the level of the ocean (13,805 feet. Trans.). (Ulloa, Noticias Americanas, p. 279.) In this pit then the miners wrought in a point which is 500 metres (1640 feet), higher than the summit of the Peak of Teneriffe. In the Cerro de Hualgayoc, I have seen galleries of which the absolute height exceeded 4050 metres (13,287 feet. Trans.).

of the German compass, with an inclination of 64° towards the west. This freestone, analogous to that of the environs of Paris, and the mountains of Aroma and Cascas, in Peru, resembles pure quartz. The most part of the specimens which I examined in the geologia cal cabinet of the Baron de Nordenflycht, exhibit very little clayey cement. The quartz rock which contains the mercury minerals, forms a bed in a calcareous brescia, from which it is only separated in its wall and its roof, by a very thin stratum of slate clay (schieferthon), which has been frequently confounded with primitive slate. The brescia is covered with a formation of secondary limestone, and the fragments of compact limestone contained in the brescia, seem to indicate that the whole mass of the mountain of Santa Barbara itself reposes on alpine limestome rock. This last rock (alpenkalkstein), is in fact discovered - on the eastern slope of the mountain near

Acobamba and Sillacasa. It is still found at very considerable elevations, and is of a blueish grey, and traversed by a great number of small veins of calcareous spar. Ulloa observed there in 1761 petrified shells*, at a height of more

mass

* We also found them on the ridge of the Andes, near Montan and Micuipampa; Geographie des Plantes, p. 127. See, as to the Pelasgic shells observed at great heights in Europe and America, Faujas de Saint-Fond, Essai de Geologie, T. ii. p. 61–69.

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