Approach outcrop via E33 from Gunnebo to Ankarsrum immediately west of lake Långsjön. Parking
on a lane entry. This outcrop has many details to detect.
The main point of interest in this outcrop is a ductile shear zone which separates a porphyritic granite from
a granodiorite. It strikes nearly in a N-S direction and has a maximum extension of 1.5 2 m (cf. fig. 4.13a).
The porphyric granite east of the shear zone is red-gray in color with the main components consisting of quartz,
K-feldspars and plagioclase, as well as hornblende and biotite. The extremely coarse-grained K-feldspar causes
the porphyric fabric. The granodiorite generally is a medium- to dark-gray colored, fine- to medium-grained
rock and is located west of the shear zone. Only close to the shear zone does the granodiorite show an area
of porphyroblastic growth of K-feldspar clasts. According to Ondrasina (2003), the granodiorite contains a proportion
of mafic minerals, like hornblende and biotite, of about 25 vol.%. Leucocratic components are mainly quartz,
plagioclase and in parts K-feldspar. Some quartz grains occur as blue quartz (cf. fig. 4.13e).
Macroscopically the transition between the porphyric granite and the shear zone is more striking than between
the latter and the granodiorite. The ductilely sheared area is quite narrow, but the surrounding rocks are
affected up to several meter to both sides with smooth transitions. The mylonitic area is in dark color and
consists of interbedded light-, medium-, dark-brown, red and green colored bands (cf. fig. 4.13b-c). The
mylonite layers are generally finer-grained than the surrounding rocks, even of ultramylonitic shape in the
center. Fig. 4.13f shows a partial view of a thin section from epidote- and chlorite-rich mylonitic layers. These
layers occur as a coating on several joints. To the W of the mylonite zone porphyroblastic growth
of K-feldspars occurred quite similar to location no. 04 at Hallmare (cf. fig 4.13d and loc. 04).