KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 29. \:<» 4. 12] 



intrusive granites, the < |u<^t i« »n as tö the origin of the Vestanå amphibolites of Mm- greal 

 bed seems in lic settled. 



With those amphibolites occurring al the top of the gneiss formation the numerous 

 amphibolites in various horizons in the gneiss formation itself closelj agree. Thej generally 

 occur as »layers», bul in the liills »Grödby Hallar», that rise from the plain through the 

 cretaceous strata as shown on the southern pari of the map, a dyke of amphibolite cuts 

 through the bedding of the dense fine-grained gneiss. The rock of the dyke is macro- 

 scopically much more finely grained al the contact tha.n in the middle, the hornblende 

 and plagioclase of the middle zone occurring as aggregates, and consequently an original 

 åifference of grain has been preserved though the rock is now a completely recrystallized 

 ööntact-amphibolite of the type described. 



The amphibolites of this part of the district consequently are considered as derived 

 from massive diabases, and of tbem one al least is a dyke cutting through the bedding of 

 I lic sediments which are now transformed into »-neiss, the others are sheets or sills intru- 

 ded between the strata. The great hed. occurring at the juncture between the tAvo sedi- 

 mentary formations, el' which at leasl the upper is a shore-deposit, is probably not in- 

 trusive, but either a layer of diabase-tuff er a. flow of diabase. 



In the north western parts of the district, where the tectonic movements have been 

 more pronounced, the representatives of the amphibolites described above are, as before 

 mentioned, quite different; they are free from hornblende, but rich on chlorite and epi- 

 dote. Examples which might be mentioned occur east of Lake Vielången, Jemshög parish, 

 and east of Kastagropen, V ånga parish. — These probably were contact-amphibolites be- 

 fore being altered by pressure. 



In the granite-gneiss district of the south-western part of the region there also occur 

 amphibolites of the contact type, somewhat crushed. — At Hjerthall, near Sölvesborg, an 

 epidote-amphibolite was observed. — In the amphibolite band southwest from Arkelstorp 

 railway station, there occurs, besides the cominon amphibolite, a homblendite, composed of 

 green hornblende with borders of tremolite, in which needles of rutile occur; a little chlo- 

 rite filling the space between the grains. This homblendite may be perhaps an altered 

 pyroxenite. 



Consequently, in the region stuclied no unaltered diabases or gabbros or diorites 

 older than the granites or o l der than the folding of the strata are found. Ön the other 

 hand numerous dykes of unaltered diabases and norites occur, cutting the granites and 

 showing themselves to be younger than the folding. 



The gneiss series. 



Conförmably underlying the quartzite and amphibolite beds the series of gneisses 

 occur. It commences with dense fine-grained gneiss 1 and this passes gradually and slowly 



1 For the widely spread gneisses with maeroscopically dense texture in Sweden the term »hälleflintgneis» 

 is usert hy the Geol. Survey. By some authors it was named »eurite» or »leptite» or »granulite». — In German 

 nomenclature most of its varieties would he called »dichter Gneiss» and, its chief feature being the dense texture, 

 I have here used the name »dense fine-grained gneiss». 



K. Sv. Vet. Ålad. ITamll. Baiid 29. N : o 4. 16 



