Professor T. G. Bonney — On Rocks from Ararat. 53 



indebted for information about the geology of Asia Minor, ascended 

 Ararat on July 29, 1845,^ and Dr. F. JBecke - has described the 

 microscopic structure of three specimens which he brought down. 

 One is from the summit, another from a parasitic cone, Takjaltu, 

 on the south-east slope, and a third from the same slope of Little 

 Ararat. Mr. Lynch's collection, as will be seen, is a much larger 

 one, so that it gives a more complete idea of the materials of the 

 mountain. 



The volcanic mass of Ararat, a natural monument to mark the 

 place where three empires meet, rises at one end of the Aghri Dagh 

 range from a rudely elliptical base measuring about 28 miles from 

 N.W. to S.E. by 23 miles in the transverse direction. The mountain 

 viewed from the north, where it is seen towering up to some 

 14,000 feet above the Araxes valley, shows a long ridge, its 

 eastern end crowned by the fairly steep cone of Little Ararat 

 (12,840 feet), from which it descends to about 9,000 feet, and then 

 rises, at first gently, afterwards more sharply, to the snowy pyramid 

 of Great Ararat (16,916 feet).^ On its northern side a chasm or 

 glen runs up towards the summit into the heart of the mountain. 

 This also was visited by Mr. Lynch, who informs us that in 1840 

 it was to some extent modified by an earthquake. 



Great Ararat. 



In his ascent of Ararat he encamped first at a height of about 

 7,500 feet in an upland valley on the northern side of the depression 

 (about 8,800 feet) between Little and Great Ararat, and for the 

 second night on the south-eastern side of the latter, at an elevation 

 of 12,194 feet. A specimen marked Great Ararat Camp (A) is 

 a dark-grey rock containing numerous whitish felspar crystals (up 

 to about 0-1 inch in diameter) and some minute vesicles. Micro- 

 scopic examination shows a base consisting of a light-brown glass 

 crowded with minute prismatic microliths and speckled with 

 opacite. In this ground-mass are scattered grains of hematite or 

 magnetite and crystals of plagioclase felspar.* The latter frequently 

 contain numerous glass enclosures with vacuoles, which not seldom 

 are crowded in an outer zone of the crystals. Pyroxene also occurs, 

 and although the grains of it have a general resemblance, there is 

 probably more than one species present. Some exhibit slight 

 pleochroism and straight extinction, indicating a mineral akin to 



1 For early ascents of Ararat, see Alpine Journal, vol. viii, p. 213. 



^ H. Abich: " Geologische Forschungen in den kaukasischen Landern," iii, 102. 

 A general description of the chief varieties is given by Dr. Parrot, who made the 

 first ascent in 1829 ("Journey to Ararat," p. 198, n.d.). 



3 This is the height given by Mr. Lynch; other authorities make it 17,100 feet. 

 The snow-line in Summer is about 13,500 feet. 



* I prefer to leave this indefinite name in all these rock-specimens. Many of the 

 crystals are not fitted for measurement by reason of enclosures, etc. Others give 

 indefinite results, but in most of the specimens 1 have identified labradorite, and 

 more than one species is present, the microliths agreeing better with oHgoclase. 

 I have thought it needless to note the variations in size. The largest (in B, b, 1) is 

 about -08 inch long, but they commonly range from about '06 inch downwards, the 

 pyroxenes running a little smaller. 



