Beskrivning av och relationer mellan Karlshamnsgraniten och leukograniten i Blekinge

The Karlshamn-granite is a greyish red to reddish grey mediumgrained rock with considerable amounts of potash feldspar megacrysts. It covers large areas of Blekinge and northeastern Scania. The granite appears as post-orogenic intrusive granitoid plutonics of very varying size and is considered to belong to the youngest granitoids in this area. The matrix mineralogy has been studied and the main minerals are quartz, potash feldspar, plagioclase and biotite. As accessory minerals mainly amphibole, sphene, epidote, apatite and opaque minerals are found. This paper is a compilation of modern chemical analysis on Karlshamngranite from various sources, recalculated norms on a common basis, matrix mineralogy investigations and statistical calculations. The results are presented in various diagrams and tables. In the town of Ronneby the leucogranite is found as a red mediumgrained rocktype, at some places with a well developed structure pronounced by elongated quartz and feldspar grains. It crops out as smaller bodies from dm-large patches to 7-800 m large massives with sharp intrusive margins to the neighbouring Karlshamn granite. It consists to more than 95% of quartz, plagioclase and potassium feldspar and carries as accessorial minerals mainly biotite, opaque minerals and sphene. Chemical analysis has been done and the results are, together with the Karlshamn granite analysis, shown in different diagrams. In these diagrams, trends can be seen which can be interpreted as differentiation trends. If the leucogranite is an anatectic granite formed by partial melting of the Karlshamn granite or the end of a differentiating Karlshamn granite magma has been considered but this investigation has not led to a definit conclusion.