H. 8. Washington — Basalts of Kula. 115 



largest running north to the Hermos River, a distance of about 

 10 km . A few smaller third period cones are to be found in 

 the basin, and the Turks call the whole field of cones and 

 black lava Janyk Task, Burnt Rock. 



As to the date of their eruption we know nothing, histori- 

 cally or traditionally ; but as is evident from their i'resh and 

 unaltered state, it must have been within historical, or very 

 recent quaternary, times. For the ancient description of the 

 district the reader is referred to Strabo,* and of the very 

 scanty modern notices the best are those of Hamilton, f Hamil- 

 ton and Strickland,^: and Tc hi hatch efi.§ 



The lavas of both the second and third period outflows are 

 to be classed as hornblende-plagioclase basalts, distinguished by 

 the constant presence and great relative quantity of the horn- 

 blende, its peculiar magmatic alteration, the small quantity of 

 both plagioclase and olivine, and the large amount of glass 

 basis. They form a distinct (and. in some points new) type of 

 the group, so much so as to be worthy of a distinctive name, 

 that selected being Kulaite, the definition and characteristics 

 of which being given later. They are all very fine grained 

 compact rocks, gray or iron-black in color, and of low specific 

 gravity. Hornblende, presenting the usual features of basaltic 

 hornblende, olivine and augite, are visible megascopically, as 

 porphyritical crystals. Occasional enclosed fragments of 

 quartz, clear and with the usual fringe of augite needles, are 

 to be found, some reaching a diameter of several centimeters. 

 These are most certainly foreign enclosures. || The lava — 

 especially of the third period — is vesicular and in some of the 

 outflows shows a decided columnar structure, in one place on 

 the Hermos River the columns attaining a length of six 

 meters. 



An interesting mineralogical feature of two of the Kula 

 Devlit streams is the presence of leucite in small characteristic 

 crystals. This is only the second time that it has been ob- 

 served in Asia Minor, Lacroix^f having found, it in rocks from 

 Trebizonde. These leucitic basalts seems to have their con- 

 tinuation in Persia. It is also to be noted that this is the first 

 recorded case of its occurrence in hornblende basalts; nephe- 

 line, which is a very frequent constituent, not having been 

 here observed. 



* Geography, xiii, 411. 



f Researches in Asia Minor, etc. London, 1842, i, 136-140, ii, 130-150. 



i Trans. Geol. Soc, 2d Ser., vi. 81. 



§ Asie Mineure, Pt. IV", Geoiogie. Paris, 1867, I, 7. 



|| Throughout the paper the word " enclosure " is used for such foreign masses 

 accidentally enclosed in the lava stream, while "inclusion" is reserved for crys- 

 tals, etc., structurally included in the other component minerals. 



TfBull. Soc. Geol. de France, xix, 1891, 732. 



