Interstellar polarization at high galactic latitudes from distant stars. VI. Extended polarization map and connection with the local spiral structure. We present new interstellar polarization measurements for 116 stars athigh galactic latitudes. Our data show that Markkanen's cloud -- themain polarization structure seen in the North Galactic Pole area (b >75 degr) extends further towards lower latitudes. Especially, we havefound a new dust formation in the area 35 degr < l < 45 degr, 57degr < b < 63 degr. Interstellar polarization in this part of thesky peaks at 0.7%, which gives a lower limit to the extinctionAV > 0.23m. Polarization vectors in this cloud are verywell aligned along the direction of l = 50 degr. On the IRAS 100 micronmap this dust structure shows up as a bright emission area. We discussthe new polarization map extending from circumpolar to lower latitudesand point out features which suggest that Markkanen's cloud may be apart of the dust lane in the inner edge of the local spiral or spur.
