CONTRIBUTIONS TO THE PETROGRAPHY OF JAVA 

 AND CELEBES 



JOSEPH P. IDDINGS and EDWARD W. MORLEY 



In a short visit to Java and Celebes in 1910 one of the authors 

 visited several localities in Java, the rocks of which have been 

 described by Verbeek,^ and also the region of the Pic de Maros 

 in Celebes, from which rocks were collected by Paul F. Sarasin 

 and subsequently were described by C. Schmidt.^ Part of the 

 material collected on this visit has been analyzed chemically by 

 the other author of this paper, and the analyses have been pub- 

 lished, for the most part, without special description in the second 

 volume of Igneous Rocks recently printed.^ It is the purpose of 

 this paper to call attention more specifically to the characters of 

 the rocks analyzed, and to point out certain chemical and mineral 

 relationships between the leucitic lavas of Mt. Mouriah in Java 

 and the shonkinites and nephelite syenites in the vicinity of the 

 Pic de Maros in Celebes. 



Mt. Mouriah in the Diapara Residency, northeast of Semarang, 

 on the north coast of Java has been described by Verbeek as an 

 extinct volcano, 1595 m. high, which has undergone extensive 

 erosion but still exhibits evidences of two large circular craters. 

 Associated with it are two smaller volcanoes of similar character, 

 Paliaian and Tillering. The rocks of these mountains are exclu- 

 sively leucitic, but some varieties are poor in leucite. Other leucitic 

 lavas occur in the small volcano Lourous, and the larger, much 

 eroded volcano Ringgit, in Besouki Residency in Eastern Java. 

 Leucitic rock, together with phonolites, also occurs on the island 



' R. D. M. Verbeek and R. Fennema, Java et Madoura, Amsterdam, 1896. 



2 P. and F. Sarasin, Insel Celebes; Anhang, Untersuchtmg einiger Gesteinssuiten. 

 Wiesbaden: C. Schmidt, 1901. 



3 J. P. Iddings, Igneous Rocks, II. New York, 19 13. 



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