366 SCIENCE PROGRESS 



products of the primary differentiation of an Urmagma, and 

 have themselves suffered a secondary differentiation, A final 

 phase was the injection of numerous varieties of aphte into the 

 consohdated mass. In form the intrusion is beheved to be 

 intermediate between a laccoHth and a bathoUth, and the act 

 of intrusion was intimately connected with the folding of the 

 adjacent strata. The description suggests a large type of 

 phacolith (Harker). The paper is further noteworthy for the 

 large number of analyses of gases included in the igneous rocks. 



One of the most important results of P. Eskola's detailed 

 memoir " On the Eclogites of Norway " {Vidensk. Selsk. Skr. 

 /. Math.-Nat. KL, Kristiania, 1921, No. 8, p. 118) is that the 

 eclogites found in the banded igneous gneisses are not segrega- 

 tions from the magma, but fragments detached from large 

 bodies of eclogite rock. They have, however, originated under 

 the same stress conditions as the gneiss, and show con- 

 sanguinity indicating genetic connection with the latter rock. 

 In bulk composition the eclogites are identical with the " dark 

 inclusions " so common in many granites and gneisses. The 

 banded eclogites in the olivine-rock of S^ndm^re are also of 

 igneous origin and are genetically connected with their country 

 rock. Both types are consanguineous with the labradorite 

 rocks common in the Bergen district. 



H. von Eckermann has completed an intensive study of the 

 rocks and minerals of Mansj^ Mountain (Helsingland, Sweden) 

 {Geol. Forcn. Stockholms Fork., 44, 1922, pp. 203-410). The 

 area consists of synclinally-folded crystalline limestones, 

 pyroxene-gneiss, and paragneisses, intruded by amphibolites. 

 There are also post-folding intrusions of magnesium- and iron- 

 rich peridotites, harzburgite, and eulysite. The contacts of 

 these ultrabasic rocks with the surrounding metamorphic 

 rocks is marked by metasomatic action resulting in the produc- 

 tion of various types of " skarn." The latest intrusion is a 

 highly alkaline microcline granite, whose pegmatites intrude 

 the crystalline limestone, and have caused the formation of 

 a wonderful series of contact minerals, including grossularite, 

 vesuvianite, chrondrodite, phlogopite, apatite, and wollas- 

 tonite, with many others. This has been accomplished through 

 the transfer of magnesia and alumina to the limestone by the 

 agency of halogen emanations. 



The pre-Devonian basement complex of central Spitsbergen, 

 described by the writer {Trans. Roy. Soc. Edinburgh, 63, pt. i, 

 1922, pp. 209-29), consists of a series of slates, quartzites, and 

 calcareous hornfels, having the same strike as, and lithologically 

 identical with, the type Hecla Hook rocks of Treurenberg Bay. 

 These are associated with a much more highly metamorphic 

 series consisting of paragneisses, garnetiferous-mica-schist, 



