Wyniki badań geofizyczno-geologicznych w rejonie Suwałk

Abstract

Przedstawiono przebieg badań geologicznych w północno-wschodniej Polsce, które doprowadziły do odkrycia złóż rud żelaza, tytanu i wanadu, oraz wykazano przydatność metod geofizycznych w poszukiwaniach tych złóż. Podano charakterystykę mineralogiczną oraz geologiczną złóż: Krzemianka, Jeleniewo i Udryń.

THE RESULTS OF GEOPHYSICAL-GEOLOGICAL SURVEYS OF THE SUWŁKI REGION (NORTH-EASTERN POLAND)

The geophysical-geological surveys of north-eastern Poland were initiated in 1949. The results of regional geophysical mapping confirmed the need to initiate geological-drilling works by the Geological Institute in 1957. Semi-detailed and detailed magnetic and gravimetric surveys .of the area of the Suwałki basic massif appeared highly useful in prospecting and exploration of ilmenite-magnetite deposits. The results of magnetic surveys made it possible to differentiate areas of occurrence of depsits characterized by very high and high magnetization, i.e. ilmenite-magnetite ores and ore-bearing norites and anorthosites.

The correlation between ilmenite-magnetite deposit and the recorded local magnetic anomalies appeared to be high, despite of difficulties in interpretation of magnetic anomalies which are related to varying remnant magnetization of ore.

The Suwałki ores are related to anorthosites. The melt enriched in ore components and saturated with mineralizers has separated in result of differentiation. A few minernlization stages were differentiated. The melt of oxide ore with silicates and sulfides has been transported from deep parts of the massif to zones·of loosening, with a marked contribution of dynamic factor. Subsequently, concordant ore bodies have originated in norites and later, irregular ore bodies and veins in anorthosites. Four types of ore assemblages are recognized: anorthosite with magnetite and hemo-ilmenite, ore with magnetite rich in titanium (3.0 to 8.2% of TiO₂), ore with magnetite poor in titanium. (0.8 to 2.0% of TiO₂) and norite with magnetite containing from 0.4 to 0.9% of TiO₂ and occurring also in gabbrodiorites leuconorites and diorites of the Suwałki massif.

The deposits were discovered at Krzemianka, Jeleniewo and Udryń, in area of about 36 km² in NE part of the anorthosite massif. In the Krzemianka deposit, ore bodies are lenticular in shape, steeply inclined (at the angle of 45°) and 3 to 120 m thick. The majority (69%) of ore bodies of that deposit range from 3 to·11 m in thickness but the bulk of ore (66%) is connected with the thick bodies. Iron content of the ores ranges from 20 to 48%, and the average content of Fe in the deposit equals 27.9%, TiO₂ – 7.2%, and V₂O₅ – 0.3%. The Udryń and Jeleniewo deposits comprise ores of the same type.