Cu3(As,Sb)S4 minerals from the Baia Mare metallogenic district, Eastern Carpathians, Romania – a case study from the Cisma ore deposit

Abstract

2 Vic tor Gorduza County Min er al og i cal Mu seum of Baia Mare, 8 Traian bou le vard, 430212 Baia Mare, Ro ma nia Kovács, R., Tãmaê, C.G., 2020. Cu 3 (As,Sb)S 4 min er als from the Baia Mare met al lo gen ic dis trict, East ern Carpathians, Roma nia -a case study from the Cisma ore de posit. Geo log i cal Quar terly, 64 (2): 263-274, doi: 10.7306/gq.1529 As so ci ate Ed i tor: S³awomir OszczepalskiThe oc cur rence of Cu 3 (As,Sb)S 4 min er als, i.e. the en ar gite and luzonite-famatinite se ries, is poorly known in the Neo gene Baia Mare met al lo gen ic dis trict, NW Ro ma nia, with few re cords and no an a lyt i cal data. This study pro vides the first EPMA and XRD data on en ar gite/luzonite from the Baia Mare met al lo gen ic dis trict, i.e. the Cisma ore de posit from the Bãiuï met allo gen ic field, and the Herja ore de posit. Vein-type ore bod ies bear ing Cu 3 (As,Sb)S 4 min er als from Cisma are hosted by Paleocene-Eocene flysch suc ces sions, while the host rock of the en ar gite-bear ing ore from Herja is un known. The en ar gite and luzonite-famatinite se ries are known as "ex otic" in low sulphidation epi ther mal ore de pos its, "typ i cal" in high sulphidation epi ther mal de pos its in as so ci a tion with ten nan tite, and "some times com mon" in small amounts in in ter me di ate sulphidation epi ther mal ore de pos its. The oc cur rence of en ar gite/luzonite in the Baia Mare dis trict sug gests the need to up date the met allo gen ic in ter pre ta tion for sev eral ore de pos its, partly at the dis trict scale in re la tion to other ore de posit/min er al ogy fea tures, e.g. vug gy sil ica, hypogene argillic al ter ation.

Sphalerite Composition in Low- and Intermediate-Sulfidation Epithermal Ore Bodies from the Roșia Montană Au-Ag Ore Deposit, Apuseni Mountains, Romania

“…The clear separation of the Mn-rich and the Fe-rich compositional trends with a gap of the values distribution between the maximum and minimum ranges confirms the partitioning between Fe and Mn in sphalerite as stated by [50]. The new data for the Ros , ia Montană ore deposit and the published EPMA data on sphalerite from the LS, IS, and HS ore deposits in the Apuseni Mountains (Table S1supplementary material) [6,35,46,47] and the Baia Mare district (Table S2-supplementary material) [46,[48][49][50][51][52][53][67][68][69][70] suggest the existence of two major trends of the Fe-Mn ratio (Figure 7), (i.e., 9i) the Mn-rich trend and (ii) the Fe-rich trend.…”

“…The analyzed sphalerite from Ros , ia Montană was Mn-bearing (Mn > 1 wt%) and showed a constant low Cd content (0.13-0.16 wt% in Ag-free sphalerite) and Mn values approximately one order of magnitude greater than the Fe values (Table 2 and Figure 7). supplementary material) [6,35,46,47] and the Baia Mare district (Table S2supplementary material) [46,[48][49][50][51][52][53][67][68][69][70] suggest the existence of two major trends of the Fe-Mn ratio (Figure 7), (i.e., 9i) the Mn-rich trend and (ii) the Fe-rich trend. The Fe content was usually <1 wt% in the Mn-rich trend, and the Mn content was <0.75 wt% in the Fe-rich trend (Figure 7).…”

“…The dataset used by the present study also includes EPMA results on sphalerite from the Ros , ia Montană ore deposit previously published by [6,23,35,46,47]. Additional microchemical data on sphalerite from the Cisma [48,49], Cavnic [50], Herja [51][52][53], and Toroioaga [46,53] ore deposits from the Baia Mare ore district (NW Romania) were also used.…”