ig2I. Xo. 8. ox THE ECLOGITES OF NORWAY. 63 



the lens-form at the ends of the lenses, though I can no more state that 

 this structure would have been cut off. Further observation with special 

 attention paid to this point, could perhaps give full elucidation. 



The markedly banded eclogite near Aaland, Bryggen, builds up a 

 little peninsula, and the ends are not exposed. The series of bands, on 

 the southern side, begins with alternating garnet- and pyroxene-rich bands, 

 a few cm thick, whereafter follow amphibole-eclogite and more massive 

 varieties of pyroxene-eclogite. The lens, as a whole, has an unsymmetric 

 structure. 



A lens of banded eclogite on Aasnaes near Bryggen is 15 meters 

 broad and apparently very long, only a section on the shore being exposed. 

 The individual bands, many of which are almost monomineralic, are but 

 one or two centimeters thick. Somewhat broader bands of amphibole-eclogite 

 occur on the northern salband, giving the occurrence an unsymmetric ap- 

 pearance. 



H. Reusch (op. cit. 1877) described a large outcrop of banded eclogite 

 near Sondre \'artdal. Xo concentric arrangement of the bands has been 

 mentioned. Xor have I found any such note in the literature concerning 

 very similar banded eclogites in igneous gneiss in other lands. 



Many small inclusions, have an unsvmmetric structure. Most illustrative 

 is the occurrence of eclogite-pegmatite at Gryting\aag Ip. 49I. This inclusion, 

 showing a part of a large pegmatitic dike and a portion of its country- 

 rock on the one side, can hardly be understood in any other way than as 

 a fragment derived from a formerly consolidated complex. 



Many inclusions, moreover, show quite irregular forms. 



In this respect the inclusions of eclogite are similar to the "dark in- 

 clusions" in the Archaean granites and granite-gneisses, and both must be 

 regarded as genetically analogous. 



There is, on the other hand, full evidence that the eclogite has con- 

 solidated under similar stress conditions as the gneiss: We must remember 

 the very existence of banded structure apparently originated by fractional 

 crystallization during fluctuation under stress, just as did the analogous 

 band and vein structure in the gneiss itself This band structure, in the 

 eclogites, gradually passes over into a foliation by parallel arrangement ot 

 the crystals, and further into a protoclastic structure from which a further 

 step leads into a true eclogite-mylonite. The banding and foliation is al- 

 ways conformable to the strike of the adjacent gneiss. 



But along-side with this apparent connection between the lenses and 

 their country-rock, the former often prove not to have been originated in 

 situ: Perfectlv non-foliated eclogite may be found enclosed in the ultimately 

 stretched out gneiss, and inclusions of eclogite of quite different structure 

 may be found near one another. 



The field-evidence so far gathered goes to favour the 

 opinion that the inclusions of eclogite are no segregations 



