cross: lavas of hawaii 63 



essexose (II. 6.2.4), salemose (II.6.3.4), kilanose (III.5.2.4), camp- 

 tonose (III.5.3.4), ornose (III.5.3.5), auvergnose (III. 5.4.4-5), 

 uvaldose (IV.2 3 .1 2 .2), unnamed subrangs IV.3 4 .l3.2, and IV.3.1 2 .1, 

 wehrlose (IV.1 3 .1 2 .2). 



As to the distribution of the chemical types on different 

 islands it appears that the various volcanic centers are much alike 

 in their products. The collections are too meager and analyses 

 are too few to prove a definite peculiarity for any center. Neph- 

 elite-m^lilite basalts are known on three islands, Kauai, Oahu, 

 and Maui. Strongly feldspathic andesites occur on Oahu, Maui, 

 and Hawaii. Trachyte is known only on Hawaii. Kilauea, 

 the most juvenile volcano of the islands, has produced lavas 

 belonging to 6 different subrangs among the 17 rocks and analysed. 



Relations of Hawaiian lavas to the Atlantic and Pacific Kindred. — 

 Through the norms of the 36 analysed rocks of the islands a 

 search has been made for the rocks of the world most nearly 

 identical in chemical composition with each of the Hawaiian types. 

 Washington's tables have been most useful, but many newer 

 analyses have also been compared. For most of the Hawaiian 

 magmas strikingly similar counterparts have been found, tho in 

 some cases the correlated forms are not lavas. 



Looking first strictly at the geographic distribution of the simi- 

 lar rocks it is a striking fact that they occur almost all over the 

 world and no one province shows marked resemblance as a whole 

 to the Hawaiian group. It seems noteworthy that compara- 

 tively few of the magmas of Hawaiian volcanoes find their near- 

 est relatives in other islands of the Pacific. Few rocks of Tahiti, 

 Samoa, New Zealand, and Australia are closely comparable in 

 composition with types of the Hawaiian group. 



With respect to the assignment of the Hawaiian magmas to 

 the Atlantic or Pacific kindred, on composition alone, it certainly 

 appears that the strongest resemblance is to the Atlantic group, 

 yet many of the types have their analogues in the Pacific group. 

 The trachyte of Puu Waawaa on Hawaii is nearest to alkali 

 rocks of Cape Ann, Massachusetts, or of Norway; an andesitic 

 type of the Kohala Mountains, in Hawaii is very nearly identical 

 with an "augite andesite" of Pantellaria and an "akerite" of 

 Norway; two lavas of Kilauea may best be compared to basalts 



