Outcrop at the shoreline of Huvudet, southeastern part of Händelöp. Park at the harbor.
Time should be taken to observe the many details.
This outcrop gives an excellent example on the effect of mafic magma spreading and intruding
anatectic granitoids along their foliation. It shows disrupted amphibolitic dikes in a granodiorite (cf. fig. 4.9a).
The granodiorite is massive and irregularly grained. According to a description by v. Drachenfels (2004),
the granodiorite consists of coarse-grained hornblende and feldspar within a fine-grained matrix
of recrystallized quartz and feldspars, green hornblende and biotite. The hornblende grains are
hypideomorphic to idiomorphic in shape and contain inclusions of muscovite and zircon.
The main components are hornblende, plagioclase (mostly saussuritized and sericitized) and chlorite.
Muscovite, apatite and ore minerals occur in minor amounts (v. Drachenfels 2004).
Some of the amphibolite fragments are of angular shape, and mostly in sharp contact with the surrounding
rock (cf. fig 4.9a-c). The grain size increases from the contact zones to the center of the fragments.
Partly extremely fine-grained “chilled margins” are developed. Some dikes show a ductile boudinage
fabric, i.e., they probably have been deformed by granitic magma shortly after emplacement. Small
scaled late magmatic coarse-grained veins intruded the mafic dikes, forming an irregular network of agmatic
brecciation (cf. fig. 4.9b). Sometimes the borders of these mafic dikes and also restites of schlieren shape,
which are mostly aligned parallel to the foliation of the granites (cf. fig. 4.9d), are diffuse. Fig 4.9c shows
a partial view of an amphibolitic dike which has been affected by dextral shearing. These fault zones
are partly filled with greenschist facies minerals, possibly epidote and/or pumpellyte. The NW-SE striking
direction and the dextral sense of shear point to a coherence with the LLDZ.
Kresten, P., 1972. Der basische Magmatismus und seine Stellung in der geologischen Entwicklung
des Västervik-Gebietes, Südostschweden, GFF, 94, 91-109.