438 M. Abicli on Fulgurites in the Andesite of the Lesser Ararat. 



on the horizon of permanent snow, and stretching downward in a 

 N. 35° E. direction. Its component rock is alight-coloured pho- 

 nolite-like,fine-grained trachyte, separating into sonorous laminae, 

 quite different from the dark-coloured doleritic lava covering 

 the mountain -slopes. A similar ridge, at some distance from 

 the first, and somewhat diverging from it, runs from the top 

 ridge of the Ararat down to the lower region. These ridges are 

 undoubtedly the upheaved margins of the powerful fissures tra- 

 versing the foundations of the Ararat mass, probably coeval with 

 its last great upheaval, and antecedent to the great effusion of 

 lava attending it. The whole structure of the Ararat slope con- 

 firms this view. From the Goelldag (11,340 Paris feet above 

 the sea-level) the eye looks down into the broad, valley-like space 

 between the two rocky ridges, which converge upwards and at a 

 short distance towards a third ridge. In this place the dolerite 

 is covered by glacier- detritus; and a large current of lava, de- 

 scending in a south-west direction, having advanced in the 

 form of a wall on the plain of Bajazid, had evidently found here 

 a fissure or excavated bed. Another current of lava, reaching 

 the plain in the direction towards Bajazid, seems to have also 

 broken out alongside of this second rocky ridge. The only traces 

 left by lightning in these regions are isolated traces of fusion 

 and perforations of trachyte plates. No such traces had been 

 ascertained on the north side of the Ararat. 



Isolated fulgurites occur on the Parlydag (" Mountain of 

 Lightning ;; in the Tartar language), an extensive trachyto- 

 porphyritic system, dominating the plateau of Sinak, on the 

 nitrachytic top of the Magaz*, and on the highest top of the 

 Sahand near Tawris (Adherbeidjan) at an altitude of 11,600 

 Paris feet. The light-coloured vitreous and lithoid rhyolites, 

 forming the prominent tops of the Agdag and Boosdag moun- 

 tain-systems (11,168 and 10,726 Paris feet above the sea-level), 

 offered no traces of fulgurites ; nor did the crater-margin of the 

 great eruptive trachytic system of the Ischichlydag (9740 feet), 

 or the Tardourek, a llatly vaulted cone south-west of the Ararat 

 behind Bajazid. 



All these details are necessary for demonstrating the frequence 

 of thunderstorms in the region of the Lesser Ararat, and the 

 very frequent and intense action of lightning perceptible on its 

 summit, to be facts depending not only on general physico- 

 geographical circumstances, but still more on the situation of 

 this mountain-system relative to the plain of the Araxes and to 

 the Great Ararat. 



* Altitudes measured by M. Abicli : — plateau of the Sinak, 7382 Paris 

 feet ; uppermost peak of Parlydag, 6'887feet. Uppermost peak of the Magaz 

 (Imperial Russian Staff-Corps), 12,6 10 Paris feet. 



