New Results of Polymetallic, Pge and Ree Mineralization Research in the Suwałki Anorthosite Massif (Ne Poland)

Abstract

Suwałki Anortosite Massif (SAM) occurs in the crystalline basement of NE Poland within 200 km of the magmatic, Mesoproterozoic AMCG (anorthosite–mangerite–charnockite–granite) rock suite terrane called the Mazury Complex. SAM was discovered as a result of the drilling research of the prominent negative magnetic and gravimetric anomalies. There is an extensive negative anomaly of both potential fields related to the anorthosite massif. Gravimetric anomaly is surrounded by the bands of positive anomalies caused by rocks with elevated densities, such as granitoids, monzondiorites and granodiorites. A negative magnetic anomaly is surrounded by the bands of positive anomalies with significant amplitudes, particularly strongly marked from the south, west and north. Positive magnetic anomalies are associated with the presence of rocks with proven strong magnetic susceptibility due to the content of ferrolites (ilmenite-magnetite rocks) with accompanying Fe-Cu-Ni-Co sulphide mineralization. Fe-Ti-(V) ore deposits in the SAM were discovered in the early 1960s, in the region of Krzemianka and Udryn, but also Jeleniewo and Jezioro Okrągłe, under a thick overburden of Phanerozoic sedimentary rocks within small positive magnetic anomalies. These deposits were documented in about 100 deep boreholes to a depth of 2300 m, and the resources in C1 + C2 category were estimated for about 1.5 billion tons of titanium-magnetite ores with vanadium, mainly in the Krzemianka and Udryn ore fields. The model age obtained by the Re-Os NTIMS method for Fe-Ti-V ores and sulphides from the Krzemianka and Jezioro Okrągłe ore deposits was 1559 ±37 Ma with an initial ratio of 187Os/188Os = 1.16 ±0.06. This age was recognized as the age of the entire Suwałki Massif. Despite many years of research, the deep structure and the form of the massif has not been fully recognized. At present, geophysical and geological 3D modelling of borehole data is carried out using the OasisMontaj (Geosoft) software package. The 3D model is generated in the GeoModeller 3D application (Intrepid Geophysics) in order to recognize the geological correctness and interpretation of magnetic-gravity anomalies of the whole massif and its cover.

Vanadium and Cobalt Occurrence in the Fe-Ti-V Oxide Deposits Related to Mesoproterozoic AMCG Complex in NE Poland

“…They are classified as sub-economic on account of their low metal contents, especially of vanadium (0.26-0.31% V 2 O 5 on average) and because of their occurrence at a depth exceeding 300 m [31]. However, the Fe-Ti-V mineralization contains lower contents of Fe-Cu-Ni-Co sulphides (1-3% by rock volume) and some amounts of REE carbonates and other trace elements [32][33][34][35][36]. The obtained Re-Os model age for pyrite, pyrrhotite and magnetite is 1536 ± 67 million years [37,38].…”

“…In addition, there was significant (>400×) enrichment in the REE (especially in Ce, La and Nd) in three mineralized samples from the Udryn deposit. The REE concentrations in these three samples were elevated (ΣREE = 0.1%) and associated with enrichments in P 2 O 5 , CaO, and MgO, as well as to the presence of carbonatites related to Variscan alkaline magmatism [32,34]. REEs spanned a relatively large interval of concentrations, which can be explained partly by fractional crystallization and partly by the varying amounts of apatite crystallized from trapped liquid (these samples had the highest REE and P 2 O 5 contents).…”

Internal structure of the buried Suwałki Anorthosite Massif (East European Craton, NE Poland) based on borehole, magnetic and gravity data combined with new petrological results

“…The Fe-Ti-V large ore de pos its of the Krzemianka (K) and Udryn (U) ore fields and two other smaller bod ies, Jeleniewo (J), Jezioro Okr¹g³e (JO; Fig. 1B), con cen trated in the mar ginal parts of the mas sif, have been doc u mented within anorthosites, norites, and gabbronorites (Wiszniewska, 1998a(Wiszniewska, , 2002Wiszniewska et al, 2018). Titanomagnetite, il men ite and Fe-Cu-Co-Ni sulphides are the main ore min er als in the host rocks.…”

“…Var i ous geo log i cal maps of the SAM (Kubicki and Ryka, 1982;Juskowiak, 1998;Wiszniewska, 2002;Cymerman, 2014;Krzemiñska et al, 2017) have been made based mainly on the re sults of geo phys i cal re search, pri mar ily mag netic data anal yses in te grated with bore hole data. Most of the SAM area was not rec og nized by bore holes, be cause geo log i cal in ves ti ga tions were fo cused on pros pect ing for mag ne tite-il men ite ore de posits (Wiszniewska et al, 2018). There fore, the geo log i cal map of the SAM, be yond well iden ti fied ar eas of the Krzemianka and Udryn de pos its, re mains ten ta tive.…”

“…Be ing a po ten tial site of ore de pos its, the SAM has long been stud ied geophysically, pet ro log i cally and struc tur ally (e.g., Kurbiel et al, 1979;Cieoela and Wybraniec, 1998;Juskowiak, 1998;Cymerman, 2014). De spite pre vi ous geo phys i cal and geo log i cal stud ies (Wybraniec et al, 1993;Ryka and Podemski, 1998;Wiszniewska, 2002;Wiszniewska et al, 2002Wiszniewska et al, , 2018 the com po si tion and deep struc ture of the mas sif are still not well un der stood. The ear lier geo phys i cal in ter pre tations were mainly used for prac ti cal pur poses re lated to the large Fe-Ti-V min eral con cen tra tions, and not for fun da men tal stud ies of vari a tion in the in ter nal struc ture of the SAM.…”