Tim ing of ore min er al iza tion us ing ore min er al ogy and U-Pb dat ing, Iron Ox ide Cop per Gold Sin Quyen de posit, North Viet nam
Jadwiga PIECZONKA1, Chau Dinh NGUYEN1, Adam PIESTRZYÑSKI1, * and Phon Khanh LE2
1 AGH Uni ver sity of Sci ence and Tech nol ogy, Fac ulty of Ge ol ogy, Geo phys ics and En vi ron men tal Pro tec tion, Al. A. Mickiwicza 30, 30-059 Kraków, Po land
2 Ha noi Uni ver sity of Min ing and Ge ol ogy, Oil and Gas Fac ulty, Dong Ngac, Tu Liem, Ha noi, Viet nam
Pieczonka, J., Nguyen, C.D., Piestrzyñski, A., Le, P.K., 2019. Tim ing of ore min er al iza tion us ing ore min er al ogy and U-Pb dat - ing, Iron Ox ide Cop per Gold Sin Quyen de posit, North Viet nam. Geo log i cal Quar terly, 63 (4): 861–824, doi: 10.7306/gq.1507 As so ci ate Ed i tor: Jacek Szczepañski
Mag ne tite, py rite, pyrrhotite, chal co py rite and sphalerite are the ma jor min er als iden ti fied in the de posit, while il men ite, marcasite, ten nan tite, cubanite, ar seno py rite, ga lena, al la nite, chevkinite, ap a tite, Bi-na tive, bis muthi nite, electrum, na tive gold, and tellurides are the mi nor ones in the Iron Ox ide Cop per Gold (IOCG) Sin Quyen de posit. The REEs are hosted mostly by al la nite, and the mi nor min er als by chevkinite, monazite, ap a tite and uraninite. Based on chem i cal anal y ses and Raman spec tros copy, two va ri et ies of al la nite have been doc u mented: (1) with lower to tal REE con tents of 13–19 wt.%, and (2) with higher con tents of 20–23 wt.%. Uraninite from cop per-iron mas sive ores is inhomogeneous in both op ti cal prop er ties and chem i cal com po si tion. The con cen tra tions of ura nium and to tal rare earth el e ment ox ides (REOs) in the paragenetically ear lier uraninite are 84.55–85.96% and 1.9–8.0% on av er age, re spec tively, whereas in paragenetically later uraninite, the U and SREE2O3 con cen tra tions are 96.2–96.7% and 1.3–2.7% on av er age re spec tively. The tho rium con cen tra tion in both the early and late uraninites is very low (0.21–0.22% and 0.2 % on av er age). These are the high est REE con cen tra tions as com - pared with the known con cen tra tions of these el e ments in uraninite. Elec tron microprobe “chem i cal” dat ing of the uraninite yielded an age of 500 ±33 Ma (n = 35) for the paragenetically early uraninite, and an age of 73 ±15 Ma (n = 6) for the paragenetically later ones. The min er als of the older age, which is in ter preted as the pri mary ore min er al iza tion stage, cor re - spond in age with a range of de pos its along the East Gond wana mar gin. The mea sured d34S of sul phide min er als from –2.78 to +8.65‰ sug gests hy dro ther mal or i gin of fluid that was re spon si ble for trans por ta tion and crys tal li za tion.
Key words: IOCG de posit, uraninite dat ing, min eral stages, geo chem is try.
INTRODUCTION
The Sin Quyen de posit is the larg est IOCG de posit in Viet - nam (Pham et al., 2011; Zhao and Zhou, 2011). The fol low ing re serves were cal cu lated dur ing the ex plo ra tion stage:
550,000 t of Cu, 334,000 t REE, 843,000 t S, 34.7 t Ag, and 25.3 t Au (ESCAP, 1990). Since 2006, this de posit has been ex ploited as an open-pit mine. Each year, six mil lion cu bic metres of host rocks and one mil lion tonnes of ore are ex ca - vated, and the an nual av er age pro duc tion of the me tal lic cop - per is 12,000 tonnes (Le et al., 2015). In the de posit, the cop per con cen tra tions range from 0.55 to 1.93%, and the iron con tent
is rang ing from a few to some tens of percents. The to tal con - cen tra tions of rare earth el e ments range from 12 ppm to more than 5.400 ppm; how ever, 0.7% of REE was used for re serve cal cu la tion (ESCAP, 1990). The REE are not re cov ered from the de posit. The max i mum con cen tra tion of the sum of the REE mea sured in the waste sam ple was 0.54%.
The IOCG de pos its are well-known around the world (Hitzman, 2000; Corriveau et al., 2007), but the stud ied de posit is a spe cific va ri ety in which both cop per with gold and mag ne - tite rich ore are of eco nomic im por tance. Due to ev i dence of for - ma tions of both magmatism and meta mor phism orig i nat ing in the de posit re gion, the or i gin of this de posit is still dis cussed (Ta, 1975; McLean, 2001; Tran, 2007; Ishi hara et al., 2011;
Pham et al., 2011; Pieczonka et al., 2015; Li and Zhou, 2018a, b; Li et al., 2018).
The pa per pres ents the re sults of de ter mi na tion of the ab so - lute age of uraninite by the U-Pb method CHIME (The Chem i cal Th-U-Pb Isoch rone Method) and in ves ti ga tion of Cu, Fe, Ag, Au, U and REE min er als of some sam ples col lected in site.
* Corresponding author, e-mail: piestrz@agh.edu.pl
Received: January 22, 2019; accepted: October 11, 2019; first published online: December 30, 2019
OUTLINE OF REGIONAL GEOLOGY
Geo log i cally, the ter ri tory of North Viet nam is di vided by the Red River (Song Hong, and Song Chay) fault sys tem into the Indochina Block in the west and the South China Block in the east (Fig. 1). North-east Viet nam is com posed mainly of De vo nian terrigenous car bon ate suits in clud ing shale, black argillite, clayish lime stone and mar ble (Pham et al., 2011), which are a part of the South China Block (Fig. 1). North-west Viet nam is built of Paleoproterozoic to Neoproterozoic terrigenous sed i ments interbedded with mi nor car bon ate and vol ca nic rocks form ing the Indochina Block (Fig. 1; Phan, 2015). In North Viet nam the Phan Si Pan and Day Nui Con Voi belts con sti tute parts of the Red River shear zone (Tapponnier et al., 1990; Leloup et al., 2007). The Pan Si Pan belt is a high-grade meta mor phic com plex in clud ing the Suoi Chieng, Sin Quyen and Cam Duong for ma tions. The Suoi Chieng for - ma tion is com posed of Paleoprotezoic bi o tite schist, am phi bo - lite and terrige nous sed i ments. The for ma tion is con form ably cov ered by the Sin Quyen for ma tion with Paleo pro terozoic to Neopro terozoic terrigenous sed i ments inter bedded with mi nor car bon ate and vol ca nic for ma tions. Ac cord ing to the min eral com po si tion, the Sin Quyen for ma tion is di vided into up per and lower units. In the up per unit (Sq1), quartz (50%), graph ite (15%), mus co vite (12%) and bi o tite (10%) are the ma jor min - er als, while plagioclase, tour ma line, gar net are sillimanite are mi nor ones. The lower unit (Sq2) con sists chiefly of plagioclase (61%), quartz (21%) and bi o tite (15%) as ma jor min er als, and ap a tite, sphene, cal cite and gar net as ac ces - sory min er als (Ta, 1975; McLean, 2001). The Cam Duong for -
ma tion is com posed of Pa leo zoic suits con tain ing quartz, seri - cite, graph ite, car bon ate and bi o tite. The for ma tion ex tends in the NW–SE di rec tion from 280 to 320° and dips at 20 to 70°
(Ta, 1975). In the north-west, the Pan Si Pan belt com plex is in truded by Neoprotezoic and Up per Perm ian and Lower Tri - as sic ig ne ous rocks. The Day Nui Con Voi belt is com posed of lime stone, mafic olistoliths and mud stone ma trix with slumped beds sug gest ing grav ity-driven cha otic sed i men ta tion (Faure et al., 2014). The Sin Quyen cop per de posit, nearly 2 km2 in area, is lo cated 300 km NW of Ha noi, close to the China bor - der. This de posit is com posed of 17 ore bod ies with an av er - age grade of 0.91 wt.% Cu, 0.7 wt.% LREE (La, Ce, Pr and Nd) and 0.44 ppm Au; the to tal ex pected Cu re source is 550,000 tons (Ta, 1975; McLean, 2001). The ore bod ies oc cur as lens, up to tens of metres thick and a few hun dred metres long, trending NW–SE and dip ping nearly ver ti cally (70–80°) (Fig.
2). The Cop per Sin Quyen de posit has been ex ploited since 2006 (Phan, 2015). The main ore min er als are mag ne tite, py - rite, pyrrhotite, chal co py rite, al la nite and some mi nor min er als:
il men ite, marcasite, sphalerite, ten nan tite, cuba nite, ar seno - py rite, ga lena, na tive bis muth, bis muthi nite, electrum, na tive gold, and tellurobismuthite.
METHODS
Forty-four sam ples were col lected from the de posit, three from waste and two from cop per and iron con cen trate; the sam - pling places are shown in Fig ure 3. All sam ples were stud ied in de tail us ing an op ti cal mi cro scope both in trans mit ted and re - flected light. Based on this in ves ti ga tion, some sam ples were
Fig. 1. Geo log i cal sketch-map of North Viet nam with the lo ca tion of the Sin Quyen de posit (af ter McLean, 2001, mod i fied)
se lected for the bulk chem i cal anal y ses and EDS and WDS mea sure ments (Ta ble 1).
The bulk chem i cal anal y ses of the waste, con cen trates and solid sam ples were car ried out at ACME Lab o ra to ries in Van cou - ver Can ada, us ing the AQ251 method. The sam ple of 0.5 g was di gested in aqua regia at 90°C, fol lowed by an ICP-MS pro ce - dure. An a lyt i cal un cer tain ties are 5% of the mea sured value for most an a lysed el e ments. De tec tion lim its for REE vary from 0.02 to 0.5 ppm, and for U and Th are equal to 0.1 ppm, and are stan - dard for the AQ251-type anal y ses (ACME, www.acmelab.com).
Elec tron microprobe mea sure ments were car ried out in the Crit i cal El e ment Lab o ra tory of the AGH-UST Uni ver sity in
Kraków. The fol low ing stan dards and mea sure ment lines have been used: SiKa (al bite), AlKa (kyan ite), SKa (anhydrite), UMb (UO2), YLa (YPO4), PKa (YPO4), ScKa (100%), TiKa (rutile), CeLa (CePO4), LaLa (LaPO4), ThMa (ThO2), CaKa (wolla stonite), PrLb (PrPO4), TbLa (TbPO4), DyLa (DyPO4), ErLa (DyPO4), LuLa (LuPO4), GdLb (GdPO4), PbMa (croco - ite), NdLa (NdPO4), SmLa (SmPO4), EuLb (EuPO4), TmLa (TmPO4), YbLa (YbPO4), HoLb (HoPO4), AsLa (InAs). Over - lap cor rec tion of Nd-Ce, Sm-Ce, Lu-Dy, Dy-Eu, U-Th, Tm-Sm and Gd-Ho were im ple mented us ing the method de scribed by Pyle et al. (2002).
The fol low ing con di tions were im ple mented for WDS mea - sure ments: ac cel er at ing volt age 15 kV, probe cur rent 40 nA, fo - cused elec tron beam di am e ter 3 mm; count ing times peak/back - ground (in sec.) were as fol lows: Si 10/5, Al 10/5, S 20/10, REE 45/15, P 20/10, Ti 20/10, Ca 20/10, V 10/5, Fe 20/10 and As 20/10. For better sta tis tics of mea sure ments and to re duce the de tec tion limit, the fol low ing peak/back ground con di tions (in sec.) were used: U 120/60, Pb 180/90, Th 120/60. Orig i nal Jeol ZAF pro ce dures were used for the fi nal cor rec tion of all mea - sured el e ments. Monazite crys tal TS-Mnz (894.8 ±5.3 Ma) was used as a ref er ence ma te rial for microprobe stan dard iza tion (Budzyñ et al., 2017).
The anal y ses of d34S in seven min eral sep a rates of chal co - py rite, pyrrhotite and mixed chal co py rite-pyrrhotite were un der - taken at Maria Cu rie-Sk³odowska Uni ver sity (UMCS) in Lublin, Po land. Prior to d34S anal y sis, ~0.5 g of sep a rate was sep a rated from the mas sive sul phide ore, dried at 90°C, pow dered to the 100–200 mm and ho mog e nized. A small aliquot of this min eral sep a rate was ana lysed us ing an el e ment analyser at tached to an Iso tope Rel a tive Mass Spec trom e ter (IRMS) (Pearson Jr.
and Rightmire, 1980), with re sults re ported rel a tive to Vi enna Can yon Diablo Troilite (V-CDT). The 1d pre ci sion is ±0.2‰.
Fig. 2. The view of the main mag ne tite ore body in the Sin Quyen de posit (phot. 2015, look ing NW)
Fig. 3. Lo ca tion of col lected sam ples on the Google map
RESULTS AND DISCUSSION
GEOCHEMISTRY OF HOST ROCKS, ORE, CONCENTRATES AND WASTES
Based on mi cros copy of ore sam ples, mag ne tite, py rite, pyrrhotite, chal co py rite, sphalerite are ma jor min er als and il - men ite, marcasite, ten nan tite, cubanite, ar seno py rite, ga lena, Bi-na tive, bis muthi nite, electrum, na tive gold, and tellurides are mi nor ones. All the above-men tioned min er als are char ac ter is - tic for ores oc cur ring in the skarn zone. The cop per con tent ranges from tens of ppm to the level above 1.0 wt.%, with an av - er age of 0.3 wt.%; the iron con tent reaches 40 wt.%. The pre - cious met als are highly vari able, the gold con cen tra tions in ore sam ples range from 3 to 2.360 ppb with an av er age of 482 ppb, and the sil ver con cen tra tions range from 8 to 1.850 ppb with an av er age of 422 ppb (Ap pen dix 1A*). The av er age val ues of these met als are a few hun dred times larger than those in the Earth’s crust. The ex tra-high con cen tra tions of Au (6.500 ppb), Ag (31.000 ppb), Zn, Co, Se and Te are ob served in the cop per con cen trate (Ap pen dix 1A). High Ag and Au con tents are com - monly as so ci ated with the high cop per con tent, sug gest ing an as so ci a tion with chal co py rite. In some Au-Ag-rich sam ples (e.g., W-36), el e vated con cen tra tions of ura nium and tho rium are also re ported, as also noted by McLean (2001) and Gaskov et al. (2012). Sam ple W-25 shows a rel a tively high con cen tra - tion of ni o bium (227 ppm), sam ple W-18 and the Fe-con cen - trate (sam ple W-37) have en rich ments in va na dium (123 and 219 ppm, re spec tively).
The sam ples are char ac ter ized by low con cen tra tions of Ti (Ap pen dix 1A), which is typ i cal for the IOCG de pos its (Dupuis
and Beaudoin, 2011; Fengli et al., 2014; Chen et al., 2015). The max i mum con cen tra tions of REE, up to 5.470 ppm, were found in tail ing sam ples (W-39, W-40, and W-44; Ap pen dix 1B). The REE oc cur mostly in min er als of the al la nite group (Pieczonka et al., 2017). In some pol ished sec tions pre pared from the ore, the con cen tra tion of al la nite reaches 1 to 5% by vol ume (e.g., sam ple No. 3). The high est ura nium con cen tra tions (56 ppm) were found in sam ple W-18 col lected at the site dis play ing the high est in ten sity of gamma-ray ra di a tion in the ore bod ies, which is typ i cal of mas sive Cu-Fe ore (Nguyen et al., 2016). The el e vated amounts of U and Th are noted also in the waste sam - ples (W-39, W-40 and W-44; Ap pen dix 1A) and are re lated to the uraninite and al la nite groups.
ORE MINERALS DESCRIPTION
Sev eral types of ore are rec og nized in the de posit:
–mas sive cop per ore, –mas sive iron ore, –mixed Fe-Cu ore, –dis persed ores,
–vein-type ore and supergene weath ered ore (Fig. 4).
All ore types are char ac ter ized by dif fer ent ore min eral as - sem blages. Based on the space dis tri bu tion of the ma jor min er - als within the de posit, Gaskov et al. (2012) di vided the de posit into two zones. In the first zone, lo cated in the cen tral and east ern part of the de posit, py rite, pyrrhotite and chal co py rite are dom i - nant, while in the sec ond, west ern zone – chal co py rite and mag - ne tite are the pre vail ing ore min er als. Ma jor ore min er als in clude mag ne tite, py rite, pyrrhotite, chal co py rite and al la nite; mi nor and
T a b l e 1 The list of sam ples used for de tailed in ves ti ga tions
Sam ple Lo ca tion Type of rocks Re marks
W-3 open pit Fe-Cu ore with al la nite min er al ogy, WDS, Raman spectroscopy
W-5 open pit mag ne tite-cop per ore min er al ogy, WDS, age determina tion
W-7 open pit mas sive cop per ore chal co py rite, d34S
W-15 open pit dis persed – lam i nated Cu ore min er al ogy, bulk chem. analysis W-18 open pit mas sive Cu ore, chalcopy rite min er al ogy, bulk chem. analysis W-25 open pit epidote- am phi bo lite rock min er al ogy, bulk chem. analysis
W-31 open pit skarn min er al ogy, bulk chem. analysis
W-31a open pit gar net skarn min er al ogy, bulk chem. analysis
W-33 open pit dis sem i nated/mas sive ore chal co py rite, pyrrhotite, d34S W-36 floa ta tion plant cop per con cen trate min er al ogy, bulk chem. analysis
W-37 lo cal stor age iron con cen trate min er al ogy, bulk chem. analysis
W-39 lower tail ing waste I min er al ogy, bulk chem. analysis
W-40 lower tail ing waste II min er al ogy, bulk chem. analysis
W-44 pipe line trans port ing
waste waste outflowing from the pipe min er al ogy, bulk chem. analysis
Lo ca tion of sam ples is shown in Fig ure 3
* Sup ple men tary data as so ci ated with this ar ti cle can be found, in the on line ver sion, at doi: 10.7306/gq.1507
trace min er als in clude il men ite, marcasite, sphale rite, ten nan tite, cubanite, ar seno py rite, ga lena, uraninite, na tive Bi, bis muthi nite, electrum, na tive gold and tellurobismuthite (Figs. 5 and 6). In mag ne tite-dom i nant ores, chal co py rite is very com mon, while in mas sive cop per ore, mag ne tite and pyrrhotite are ma jor as so ci - ated min er als. Electrum was rec og nized in mas sive sul phide ores as 1–5 mm thick veinlets and as 5–100 mm in clu sions and veinlets ran domly dis trib uted in py rite and chal co py rite (Figs. 5C and 7). EDS mea sure ments in di cate an av er age com po si tion of 75.72% Au and 24.28% Ag, which con firmed mi cro scopic ob ser - va tion and the pres ence of electrum. Us ing the same meth ods, a Bi-S and Bi-Te min eral as so ci a tion was doc u mented (Fig. 5D).
This as so ci a tion is com posed of tellurobismuthite, con tain ing 87.62 wt.% of Bi and 21.38 wt.% of Te (EDS com po si tion), and bis muthi nite (Fig. 5D).
SULPHUR ISOTOPES
Sul phur iso topes of se lected sulphides from mas sive and dis sem i nated types of ore have been ana lysed. The value of d34S var ies from –2.78 to +8.65‰ (Ta ble 2). Sim i lar val ues of
d34S are noted in pub li ca tion by Li and Zhou (2018b) and Li et al.
(2018). Such val ues might sug gest post-mag matic hy dro ther - mal or i gin of sul phur which was trans ported by flu ids re spon si - ble for crys tal li za tion of the ore min eral as sem blage (Thode, 1991). The mas sive cop per ore is com posed of chal co py rite, pyrrhotite, cubanite, mag ne tite, py rite and al la nite (as ma jor com po nents), ar seno py rite, sphalerite, ten nan tite and marca - site (as mi nor min er als), and traces of ga lena and a Bi-Te-pre - cious metal as so ci a tion. The pres ence of exolutions of sphale - rite stars in chal co py rite sug gests high tem per a ture of sul phide crys tal li za tion, but not higher than 500°C (Sugaki et al., 1987). It de pends on tem per a ture, pres sure and Zn con cen tra tion in chal co py rite (Sugaki et al., 1987). The mas sive iron ore is com - posed of mag ne tite, al la nite, pyrrhotite, mi nor py rite, chal co py - rite and cubanite, and traces of uraninites. The mixed Fe-Cu ores are rep re sented by both as so ci a tions men tioned above.
Other types of min er al iza tion are mi nor in the de posit. Ex cept Cu sulphides, more im por tant min er als are rep re sented by allanites and uraninite, which are im por tant car ri ers of the REE, U and Th.
Fig. 4. Dif fer ent ore types
URANINITE
Uraninite was de scribed by McLean (2001), but no spe cial at ten tion was paid to it in that pub li ca tion. Uraninite was thor - oughly de scribed in the pro ject grant No. 01/2012/HD- HTQTSP, be cause the iden ti fi ca tion of ra dio ac tive ma te ri als was one of its ma jor aims. Uraninite crys tals have been found in the mag ne tite sul phide mas sive ores (Fig. 6). The crys tals of uraninites are up to 150 mm in size and are mostly intergrown with mag ne tite and sul phide min er als. Some euhedral crys tals have been found as in clu sions in mag ne tite and sil i cate min er - als ma trix, e.g. bi o tite. These re la tion ships are good in di ca tions that uraninite crys tal lized si mul ta neously with mag ne tite within the ore. The uraninites are inhomogeneous es pe cially in high mag ni fi ca tion un der op ti cal mi cro scope. The inhomogeneity
ap pears in slight col our tint changes, re flec tivity and in ter nal re - flec tions. This inhomogeneity was vis i ble in both WDS anal y sis (Ap pen dix 2) and BSE im age (Fig. 8).
The com po si tion of uraninite is vari able, par tic u larly with re - spect to both rare earth el e ment ox ides (REEOs) and PbO. The high Pb-bear ing uraninite (5.0–6.8 wt.% PbO) tends to have also higher REEOs (1.9–8.0 wt.%), whereas in the low Pb- uraninite (0.54–1.06 wt.% PbO) there is lower to tal REEOs (1.3–2.7 wt.%). The uraninites with a high con cen tra tion of REEOs and high PbO reach ing 8 wt.% (Ap pen dix 2) are clas si - fied as older. These uraninites can be re lated to base ment flu - ids (Alexandre et al., 2015). The con cen tra tion of Pb in the host rocks and ore is very low (4.32 ppm), while in the waste it is only 4.83 ppm; even in the cop per sul phide con cen trate it is also low – 40.8 ppm (Ap pen dix 1A). Such low Pb in all de posit ma te ri als Fig. 5. Mi cro pho to graphs of prin ci pal ore min er als
A – inter growth of al la nite (all) with mag ne tite (mgt), white – sulphides, re flected light; B – inter growth of al la nite (all) with chal co py rite (cpy), re flected light; C – po si tion of gold (Au) with py rite (py), re flected light; D – Bi-Te as - sem blage (Bi-Te – tellurobismuthite, bsm – bis muthi nite), pale yel low – chal co py rite, re flected light
T a b l e 2 ä34S data of the se lected sul phide min er als from the Sin-Quyen de posit (UMCS Lublin Lab.)
Sam ple Min er als Type of ore d34S‰
W-18 chal co py rite brec cia ce ment +8.65
W-33 chal co py rite, pyrrhotite dis sem i nated ore +3.06
W-31 chal co py rite, pyrrhotite dis sem i nated ore +2.57
W-15 pyrrhotite mas sive ore +8.27
W-7 pyrrhotite mas sive ore -2.78
W-18 chal co py rite mas sive ore +0.93
W-33 chal co py rite (75%), pyrrhotite mas sive ore +2.57
Fig. 6. Mi cro pho to graphs of uraninite ag gre gates
A – inter growth of uraninite (U) with mag ne tite (mgt) and chal co py rite (cpy), re flected light; B – inter growth of uraninite (U) with mag ne tite (mgt) and chal co py rite (cpy), re flected light; C – inter growth of uraninite (U) I and II with mag ne tite (mgt) and chal co py rite (cpy); al la nite (all), re flected light; D – inter growth of two dif fer ent uraninites UI and UII with mag ne tite (mgt), re flected light; E – a small uraninite crys tal (U) in sil - ica ma trix, po – pyrrhotite, cpy – chal co py rite, re flected light; F – inter growth of uraninite (U) with mag ne tite (mgt) and youn ger chal co py rite II (cpy), re flected light
in di cates the lack of Pb leach ing. There fore, the Pb level re la - tion in the de posit is dif fer ent from the model de scribed by Janeczek and Ew ing (1995), in which ther mal re gional ac tiv ity can leach Pb from the uraninites. In the pa per, uraninite grains char ac ter ized by dif fer ent con tents of REE and tex tural re la tion - ship have been clas si fied into two dif fer ent stages (Ta ble 3 and Fig. 8). The ar gu men ta tion can sup port that the ab so lute age pre sented in this work seems to be re al is tic, and the youn ger uraninite show only the last hy dro ther mal event re lated to tec - tonic or young vol ca nism which is doc u mented in the area.
There fore un cer tainty of age de ter mi na tion can be larger (Ap - pen dix 2, Fig. 9). The low-Pb, and low REE con tents in uraninite could be a re sult of recrystallization of the high-Pb, high-REE uraninite, as shown in BSE im ages (Fig. 8).
Such min er als as chevkinite, aeschynite, bastnäsite and fluorapatite are rare in the ores, and their in flu ence on the to tal vol ume of REE in the de posit is low. The rock-form ing min er als con tain some REE but be low the level of WDS mea sure ments.
Uraninites rep re sent ing the fi nal al ter ation stage show vari - able ages (Ap pen dix 2, Fig. 9). REE con cen tra tions in young uraninite are rel a tively high com pared to that in other ex am ples of nat u ral uraninite de scribed by Alexandre et al. (2015). The Fig. 7. BSE im age show ing po si tion of electrum (Au)
in re la tion to py rite (py) and chal co py rite (cpy)
Fig. 8. BSE im ages show ing lo ca tion of WDS quan ti ta tive anal y ses within the uraninite grains and points of ab so lute age de ter mi na tions (+): A–I sep a rate grains of uraninite, sam ples Nos. 3 and 5
1 – af ter Gaskov et al. (2012); 2 – af ter Li et al. (2018); min er als in bold were de scribed by the au thors
T a b l e 3 Tim ing of ore min er al iza tion in the Sin Quyen de posit (partly af ter Ta, 1975; McLean, 2001; Li et al., 2018)
level of REE con cen tra tion in the Sin Quyen uraninites can be com pared to the in tru sion re lated U-de posit (Cuney and Kyser, 2008). High REE con cen tra tion is also re ported from un con - formity-type min er al iza tion (Alexandre et al., 2015). The yt trium con tent in the ana lysed uraninite var ies from 0.79 to 2.37 wt.%
with an av er age of 1.46 wt.%. The range of Y con firms also an in tru sion re la tion ship (Alexandre et al., 2015). The pres ence of REEs in the uraninite sug gests that U and REEs were de pos - ited si mul ta neously dur ing the ore-form ing pro cess.
The av er age chondrite-nor mal ized curve of REE con cen - tra tion of older uraninite tends to have weak pos i tive Eu and Lu anom a lies (Fig. 10). The REE av er age spec tra of young ura - ninite show four anom a lies in clud ing La, Pr, Eu and Lu (Fig. 11).
The vari a tions of REE amounts are typ i cal in U de pos its as a re - sult of tem per a ture dif fer ences (Mercadier et al., 2011). In gen - eral, the shape of the av er age chondrite-nor mal ized curve of REE con cen tra tion in old uraninite is sim i lar to spec tra of
synmetamorphic U de posit (e.g., Kawanga, Bot swana; Mista - misk in Can ada; Mercadier et al., 2011). This nor mal ized con - cen tra tion curve is sig nif i cantly dif fers in shape from the REE con cen tra tion chondrite-nor mal ized curve for al la nite, gar net and zir con, pre sented in the pub li ca tion by Li et al. (2018).
These dif fer ences sug gested that uraninites were pre cip i tated dur ing the other stage in com par i son with the men tioned min er - als, which is in good agree ment with mi cro scopic ob ser va tion (e.g., Fig. 6D). A neg a tive Eu anom aly in the chondrite-nor mal - ized curve ap pears only in vein-type and in tru sive U de pos its (Mercadier et al., 2011). The REE chondrite-nor mal ized curve in uraninite for the IOCG de posit is char ac ter ized by a small vari a tion in REE con cen tra tion with a small pos i tive Eu anom aly (Fig. 12). It can be ex plained by dif fer ent ionic REE ra dii. The only in ter me di ate REE mem bers have ra dii of 1.06 , which is sim i lar to ura nium (1.08 ). The Eu con cen tra tion anom a lies can also be ex plained by the charge com pen sa tion, which is Fig. 9A – ages de ter mined for old uraninites; B – ages de ter mined
for young uraninites
better for two-va lence cat ions (e.g., Eu+2), and by the con struc - tion of the outer elec tron band. Based on it, the shape of the av - er age curve of old uraninite would be very eas ily ex plained (Figs. 10 and 11).
TIMING OF ORE MINERALIZATION
As dis cussed above, elec tron microprobe anal y ses and BSE im ages in di cate two compositionally dif fer ent gen er a tions of uraninite at the Sin Quyen de posit. More over, the com po si tion of the two gen er a tions is rel a tively con stant (Ap pen dix 2). As vir tu - ally all Pb in uraninite is pro duced by the ra dio genic de cay of U and Th, the con sis tency in the com po si tion of the two gen er a - tions of uraninite of fers the op por tu nity to de ter mine the age of uraninite de po si tion and the for ma tion of the Sin Quyen de posit.
Over the last two de cades, tech niques have been de vel - oped to al low de ter min ing an age of U-Th-rich min er als such as uraninite and monazite, in clud ing ion microprobe anal y sis.
Chem i cal dat ing as sumes all Pb in the ana lysed U-Th-rich min - eral formed by ra dio genic de cay, with no geogenic Pb (Kempe, 2003). Us ing the elec tron microprobe data and the orig i nal Jeol soft ware, ab so lute age of uraninite was cal cu lated. The Pb-rich uraninite yields ages of 430 to 575 Ma with a mean weighted age of 500 ±33 Ma (n = 33) (Ap pen dix 2, Figs. 8 and 9A). As these uraninite grains are intergrown closely with mag ne tite and chal co py rite, it is in ter preted as the same stage of IOCG min er - al iza tion at Sin Quyen (Ta ble 3).
The Pb-poor uraninite yields an age of 42–83 Ma (n = 6) (Ap pen dix 2, Figs. 8 and 9B), which is in ter preted as a recrystallization time; dur ing the pe riod the young hy dro ther mal event was tak ing place. Uraninite is com monly recrystallized fol low ing ini tial for ma tion, re sult ing in a long tail of youn ger ages Fig. 10. Chondrite-nor mal ized pat terns of REE con cen tra tion
(max., min. and av er age for n = 33) in old uraninite
Fig. 11. Chondrite-nor mal ized pat terns of REE con cen tra tion (max., min. and av er age for n = 6) in young uraninite
that have un cer tain geo log i cal mean ing (Mercadier et al., 2011). The age of ~42 Ma, as de ter mined from the low-Pb uraninite, cor re sponds to the fi nal changes ob served in the ore.
Re cently (2018), two pub li ca tions de scrib ing the tim ing of min er al iza tion in the Sin Quyen de posit have ap peared (Li et al., 2018; Li and Zhou, 2018b), both us ing zir con and monazite.
These two pub li ca tions al low better un der stand ing of the whole range of de vel op ment of ore min er als. The ox y gen iso topes de - scribed by Li and Zhou (2018b) show dif fer ent ge netic po si tions of both these min er als, which is in good agree ment with crys tal pa ram e ters of zir con, e.g. elon ga tion l/h close to 1.5. Such zir - con crys tal elon ga tion is rather typ i cal for meta mor phic rocks, which are the host rocks for the Fe-Cu ores. The first stage of min er al iza tion is re lated to the so dium al ter ation dated at 841–836 Ma (Li et al., 2018; Li and Zhou, 2018b; Ta ble 3). The d18O val ues of zir con are higher than those pre sented in mag - ne tite (Li and Zhou, 2018b), which in our opin ion ex clude si mul -
ta neous crys tal li za tion of these min er als. Mea sure ment of fluid in clu sions shows high tem per a ture above 500°C (Li and Zhou, 2018b), which may sug gest par tic i pa tion of meta mor phic or mag matic flu ids (Tay lor, 1974). Al ter ation of uraninite grains doc u mented by WDS quan ti ta tive mea sure ments (Ap pen dix 2, Fig. 8) and BSE im ages show ing well-vis i ble al ter ation of uraninite grains (Fig. 8) sug gests the pres ence of at least two im por tant stages, which are good doc u mented by the uraninite age dat ing and fit well to the geo log i cal phe nom ena (Anczkie - wicz et al., 2000; ¯elaŸniewicz et al., 2013).
The de ter mi na tion of ab so lute age (Ap pen dix 2, Fig. 8) pro - vides new con straints on min eral tim ing (Ta ble 3), and en ables a better un der stand ing of the min eral paragenesis pre sented by Ta (1975) and McLean (2001). Three stages of mag ne tite+sul phide for ma tion have been rec og nized. The first two are the main stages. Ac cord ing to min er al og i cal stud ies, most ores were pre - cip i tated dur ing the skarn-metasomatic stage, which is the first Fig. 12. Chondrite-nor mal ized pat terns of REE con cen tra tion
in old uraninites and allanites, based on WDS quan ti ta tive mea sure ments
Fig. 13. Re la tion of U and Th with SREE in rock, ore, con cen trate and waste sam ples, based on bulk chem i cal anal y ses (ACME)
stage (Ta, 1975; McLean, 2001). As the Pb- and REE-rich uraninite crys tal lized to gether with mag ne tite and al la nite fol - lowed by mas sive chal co py rite, pyrrho tite, py rite and cubanite, and is char ac ter ized by high con cen tra tion of REEs, this uraninite is in ter preted to be formed dur ing the early stage of de - po si tion (Ta ble 3). This is also sup ported by the pos i tive cor re la - tion be tween U-Th and REE (Fig. 13). The hy dro ther mal stage, as de scribed by Ta (1975) and McLean (2001) as a ma jor sul - phide crys tal li za tion stage, is in ter preted here as a con tin u a tion of the first metasomatic stage. De ter mi na tion of sul phide tem per - a ture crys tal li za tion is dif fi cult and re quires fur ther study. The pres ence of sphalerite star exsolution in chal co py rite sug gests tem per a ture of sul phide crys tal li za tion in the range of 300–500°C (Sugaki et al., 1987; Krismer et al., 2011). This tem per a ture is re - al is tic for the min eral as sem blage de scribed in this work. These stages are re lated to two calk-al ka line granitoids: Po Sen prob a - bly of Pre cam brian age (Bui et al., 2004) and Muong Hum of Paleogene age dated with K-Ar at 30–36 Ma (Hayashi et al., 2009). The Lower Pa leo zoic age of the Song Chay batholith is also sug gested by ¯elaŸniewicz et al. (2013), which fits very well to the first stage of ore min er al iza tion. The age of 35 Ma (Ap pen - dix 2) for the fi nal cool ing is pro posed by Vi ola and Anczkiewicz (2009). ¯elaŸniewicz et al. (2013) also de scribed two types of young gran ite, both of Paleogene age: calk-al ka line I-type and sub-al ka line A-type. Both types can be re spon si ble for the last stage of ore trans for ma tion. Crys tal li za tion of uraninites was prob a bly shifted in time in re la tion to al la nite. Based on the shape of an av er age chondrite-nor mal ized pat tern of REE in both al la - nite and uraninite (Fig. 12), it can be pointed out that uraninite crys tals are gen er ally youn ger (Ta ble 3).
The youn ger hy dro ther mal stage over printed the older one, brought recrystallization of uraninite, and may have in tro duced el e ments such as Pb, Au, Ag, Se, Bi and Te. This is con firmed by struc tures and tex tures of this as sem blage (e.g., Figs. 5 and 7). The youn gest stage (Ta ble 3) was de vel oped dur ing weath - er ing re spon si ble for ox i da tion of some sulphides in the sur face en vi ron ment. The zone of ox i da tion reached prob a bly 100 metres be low the sur face, be cause of ver ti cal po si tion of both rocks and ore.
CONCLUSIONS
Low-grade ura nium con cen tra tions have been doc u mented in the de posit. The study of Pieczonka et al. (2015) shows that
two dif fer ent min eral groups are re spon si ble for ura nium con - cen tra tion: allanites and uraninites. In that work, en rich ment in U was con firmed by us ing both field and lab o ra tory mea sure - ments. The first group in cludes two min er als from the al la nite group, and prob a bly monazites (Ishi hara et al., 2011); how ever, be cause of in ad e quate rel a tively higher de tec tion lim its of both EDS and WDS anal y ses and low con cen tra tion of this el e ment, it is dif fi cult to pre cisely de ter mine the quan ti ta tive con tent of ura nium in these min er als. The pres ence of uraninite in the as - so ci a tion of mag ne tite-sul phide ores, ac com pa nied by al la nite, was doc u mented in the de posit. The dif fer ences in REE and ura nium con cen tra tions are shown by bulk chem i cal anal y ses (Ap pen dix 1) of sam ples col lected from both a waste pond and the de posit. In the case of the Sin Quyen de posit, the rel a tively high con cen tra tion of U and REE in the waste sug gests co ex is - tence of all these el e ments in allanites (Ap pen dix 1A, B) and uraninite (Ap pen dix 2); how ever, the re sults from sam ple W-18 show an other pos si bil ity. In this sam ple, the high con cen tra tion of ura nium (56.51 ppm; Ap pen dix 1A, B) cor re sponds with low con cen tra tion of REE (242.33 ppm; Ap pen dix 2). It can be sug - gested that mostly ura nium ox ides are re spon si ble for ura nium con cen tra tion in the de posit.
In this work, three stages of min er al iza tion have been doc u - mented in the de posit that con sists of cop per ores con tain ing some gold-sil ver en rich ment. In the pre vi ous works (Li et al., 2018; Li and Zhou, 2018b), a high-tem per a ture Na-al ter ation stage 841–836 Ma was doc u mented.
The ma jor stage is skarn-metasomatic (Ta ble 3), which de - vel oped in the Late Pre cam brian and Early Cam brian (575–435 Ma). The youn ger stage (Ta ble 3) is doc u mented by uraninite II and oc curred dur ing Late Cre ta ceous-Paleocene times (83–42 Ma); how ever, ac cord ing to the data of fis sion -track anal y ses by Anczkiewicz et al. (2000), the last duc tile de for ma - tion within the Red River Fault Zone took place ~25 Ma.
The mag ne tite ore ex tracted and the mag ne tite con cen trate re ceived are strongly con tam i nated with high con cen tra tion of sul phur, dis qual i fy ing it as a mar ket prod uct.
Ac knowl edge ment. The au thors are grate ful to G. Kozub and A. W³odek from Crit i cal El e ments Lab. Fac ulty of Ge ol ogy, Geo phys ics and En vi ron men tal Pro tec tion UST -AGH Kraków for the WDS anal y ses, and to T. Æwiertnia for prep a ra tion of graphics. The au thors are also grate ful to UST-AGH Kraków for fi nan cial sup port, grants Nos. 11.11.140.161 and 11.11.140.645, and Uni ver sity of Min ing and Ge ol ogy (UMG), Ha noi, Viet nam, grant No. 01/2012/HD -HTQTSP.
REFERENCES
Alexandre, P., Kyser, K., Layton-Matthews, D., Joy, B., 2015.
Chem i cal com po si tions of nat u ral uraninite. The Ca na dian Min - er al o gist, 53: 595–622.
Anczkiewicz, R., Vi ola, G., Müntener, O., Thirwall, M.F., Villa, I.M., Cuong, N.Q., 2000. Evo lu tion of the Red River Shear Zone de duced from struc tural and fis sion track stud ies of the Day Nui Con Voi mas sif in North Viet nam. Min er al og i cal So ci ety of Po - land-Spe cial Pa pers, 17: 108–110.
Budzyñ, B., Yi, K., Lee, S., Kusiak, M.A., Kozub-Budzyñ, G., W³odek, A., Koneèny, P., Rzepa, G., 2017. Two Mad a gas car monazite crys tals as po ten tial ref er ence ma te ri als for U-Pb microanalysis. Mineralogia – Spe cial Pa pers, 47: 46.
Bui, P.M., Nguyen, V.H., Phan, V.K., Tran, D.T., 2004. Ge ol ogy and Min eral Re sources of Kim Binh-Lao Cai Sheet, Scale
1:200,000. Gen eral De part ment of Ge ol ogy and Min er als of Viet nam.
Chen, W.T., Zhou, M.F., Gao, J.F., Hu, R., 2015. Geo chem is try of mag ne tite from Pro tero zoic Fe-Cu de pos its in the Kangdian met al lo gen ic prov ince, SW China. Mineralium Deposita, 50:
795–809.
Corriveau, L.L., Ootes, H., Mumin, V., Jack son, V., Bennet, J.F., Cremer, J.F., McMartin, I., 2007. Al ter ation vectoring to IOCG (U) de pos its in fron tier vol cano-plutonic ter rain, Can ada. In: Pro - ceed ings Ex plo ra tion ’07, Fifth Decenniak In ter na tional Con fer - ence on Min eral Ex plo ra tion: 1171–1177.
Cuney, M., Kyser, T.K., 2008. Re cent and not-so-re cent de vel op - ments in ura nium de pos its and im pli ca tions for ex plo ra tion. Min - er al og i cal As so ci a tion of Can ada Short Course Se ries, 39.
Dupuis, C., Beaudoin, G., 2011. Discriminant di a grams for iron ox - ide trace el e ment fin ger print ing of min eral de posit types.
Mineralium Deposita, 46: 319–335.
ESCAP, 1990. Re port of Eco nomic and So cial Com mis sion for Asia and the Pa cific, 1990.
Faure, M., Lepvrier, C., Vuong, N.V., Tich, V.V., Lin, W., Chen, Z., 2014. The South China block-Indochina col li sion: where, when, and how? Jour nal of Asian Earth Sci ences, 79: 260–274.
Fengli, Y., Yafei, W., Shunfu, L., Xiaofen, L., Pengfei, G., Jiannian, Z., 2014. Com par i sons be tween the Zhuchong Fe-Cu De posit in Anqing and the IOCG-type De pos its. Acta Geologica Sinica, 88: 403–404.
Gaskov, I.V., Tran, T.A., Tran, T.H., Pham, T.D., Nevolko, P.A., Pham, N.C., 2012. The Sin Quyen Cu-Fe-Au-REE de posit (north ern Viet nam) com po si tion and for ma tion con di tions. Rus - sian Ge ol ogy and Geo phys ics, 52: 442–456.
Hayashi, T., Machida, S., Fukusawa, H., Takahashi, K., Nguyen, B.M., Ninh, Q.T., Tran, V.M., Nguyen, D.T., 2009. Age of carbonatite and alkalian magmatism in North Viet nam and its rare earth min er al iza tion. Ab stract with Pro grams 59th An nual Meet ing Sym po sium: Ge ol ogy and Min eral Re sources of Viet - nam and Sur round ing Re gion: 21.
Hitzman, M.W., 2000. Iron ox ide-Cu Au de pos its: what, where, when, and why. In: Hy dro ther mal Iron Ox ide Cop per Gold and Re lated De pos its: a Global Per spec tive (ed. T.M. Por ter): 9–25.
PGC Pub lish ing, Adelaide.
Ishi hara, S., Hideo, H., Mihoko, H., Pham, N.C., Pham, T.D., Tran, T.A., 2011. Min er al og i cal and chem i cal char ac ter is tics of the al - la nite-rich cop per and iron ores from the Sin Quyen mine, north - ern Viet nam. Bul le tin of the Geo log i cal Sur vey of Ja pan, 62:
197–209.
Janeczek, J., Ew ing, R.C., 1995. Mech a nisms of lead re lease from uraninite in the nat u ral fis sion re ac tors in Ga bon. Geochimica et Cosmochimica Acta, 59: 1917–1931.
Kempe, U., 2003. Pre cise elec tron microprobe age de ter mi na tion in al tered uraninite: con se quences on the in tru sions age and met - al lo gen ic sig nif i cance of the Kirschberg gran ite (Erzgebirge:
Ger many). Con tri bu tion to Min er al ogy and Pe trol ogy, 45:
107–118.
Krismer, M., Vavtar, F., Tropper, P., Sartory, B., Kaindal, R., 2011.
Min er al ogy, min eral chem is try and pe trol ogy of the Ag-bear ing Cu-Fe-Pb-Zn sul phide mineralizations of the Pfunderere Berg (South Tyrol, It aly). Aus tra lian Jour nal of Earth Sci ence, 104:
36–48.
Le, K.P., Nguyen, T.S., Tran, T.N., Lai, M.G., Piestrzynski, A., Pieczonka, J., Jodlowski, P., Nguyen, D.C., Nguyen, V.L., Nguyen, V.N., Do, T.H.T., 2015a. Re search ing the pro ce dures for sur vey and as sess ment of the ra dio ac tive en vi ron men tal im - pacts due to min ing and pro cess ing ores at the Sing Quyen coo - per mine, Lao Cai prov ince. Ma te ri als of the 2-nd In ter na tional Con fer ence Sci en tific-Re search Co op er a tion be tween Viet nam and Po land in Earth Sci ences, 4–6: 359–369.
Le, K.P., Nguyen, T.S., Piestrzyñski, A., Pieczonka, J., Jod³owski, P., Nguyen, D.C., Nguyen, V. L., Nguyen, V.N., Do, T.H.T., 2015b. Ex pan sion char ac ter is tics of the ra dio ac tive ma - te ri als due to the en rich ment and melt ing the cop per al loys at the IOCG Sin Quyen de posit (in Viet nam ese). Ma te ri als of the Na tional Con fer ence on the oc ca sion of the 70th An ni ver sary Ha noi: 253–261.
Leloup, P.H., Tapponnier, P., Lacassin, R., 2007. Dis cus sion on the role of the Red River shear zone, Yunan and Viet nam in the con ti nen tal ex tru sion of SE Asia. Jour nal of the Geo log i cal So ci - ety of Lon don, 164: 1253–1260.
Li, X.C., Zhou, M.F., 2018a. Hy dro ther mal al ter ation of monatzite-(Ce) and chevkinite-(Ce) from the Sin Quyen Fe-Cu-LREE-Au de posit, north west ern Viet nam. Amer i can Min - er al o gist, 102: 1525–1541.
Li, X.C., Zhou, M.F., 2018b. The na ture and or i gin of hy dro ther mal REE min er al iza tion in the Sin Quyen de posit, North west ern Viet nam. Eco nomic Ge ol ogy, 113: 645–673.
Li, X.C., Zhou, M.F., Chen, W.T., Zhao, X.F., Tran, M.D., 2018. Ura - nium-lead dat ing of hy dro ther mal zir con and monazite from the
Sin Quyen Fe-Cu REE-Au-(U) de posit, north west ern Viet nam.
Mineralium Deposita, 53: 399–416.
McLean, R.N., 2001. The Sin Quyen iron ox ide-cop per-gold-rare earth ox ide min er al iza tion of North Viet nam. In: Hy dro ther mal iron ox ide cop per-gold and re lated de pos its: a global per spec - tive 2 (ed. T.M. Por ter): 293–301. PGC Pub lish ing, Adelaide.
Mercadier, J., Cuney, M., Lach, P., Boiron, M.C., Bonioure, J., Rich ard, A., Leisen, M., Kister, P., 2011. Or i gin of ura nium de - pos its re vealed by their rare earth el e ment sig na ture. Terra Nova, 23: 264–269.
Nguyen, D.C., Le, K.P., Jod³owski, P., Pieczonka, J., Piestrzyñ - ski, A., Duong, V.H., Nowak, J., 2016. Nat u ral Ra dio ac tiv ity at the Sin Quyen iron ox ide cop per gold de posit in North Viet nam.
Acta Geophysica, 64: 2305–2321.
Pearson, F.J., Rightmire, C.T., 1980. Sul phur and ox y gen iso topes in aque ous sul phur com pounds. In: The Ter res trial En vi ron ment (eds. P. Fritz and J.Ch. Fontes): 227–258. Elsevier, Am ster dam.
Pham, N.C., Ishiyama, D., Tran, T.A., Sera, K., 2011. Min er al og i cal and geo chem i cal char ac ter is tics of rare met als bear ing Na Bop, Lung Hoai, Nason and Sin Quyen Base metal de pos its, North - ern Viet nam. NMCC An nual Re port, 18: 49–55.
Phan, T.H., 2015. The Ngoi Chi For ma tion in the Phan Si Pan area of north west Viet nam re vealed by zir con U-Pb age and Hf iso - tope com po si tion. Acta Geoscientica Sinica, 36: 755–760.
Pieczonka, J., Piestrzyñski, A., Le, K.P., Nguyen, D.C., Jod³o - wski, P., 2015. Rare Earth, ra dio ac tive and se lected el e ments in the iron ox ide cop per gold Sin Quyen de posit in North Viet nam.
In: Viet-Pol 2015 sec ond in ter na tional con fer ence on sci en tific re search co op er a tion be tween Viet nam and Po land in Earth Sci - ences: 331–353.
Pieczonka, J., Piestrzyñski, A., Nguyen, D.C., Le, K.P., Hao, D.V., 2017. IOCG Sin-Quyen de posit, Lao Cai, N-Viet nam. Min eral re - sources to dis cover. Pro ceed ings, 14th Bi en nial SGA Meet ing, Que bec, Can ada: 955–959.
Pyle, J.M., Spear, F.S., Wark, D.A., 2002. Elec tron microprobe anal y sis of REE in ap a tite, monazite and xeno time: pro to cols and pit falls. Re views in Min er al ogy and Geo chem is try, 48:
337–362.
Sugaki, A., Kitakaze, A., Kojima, S., 1987. Bulk com po si tion of in ti - mate inter growth of chal co py rite and sphalerite and their ge netic im pli ca tions. Mineralium Deposita, 22: 26–32.
Ta, V.D., 1975. Re port of geo log i cal sur veys and their re sults per - formed at the IOCG Sin Quyen de posit in Lao Cai, North Viet - nam. Main De part ment of Ge ol ogy of Viet nam (in Viet nam ese):
318.
Tapponnier, P., Lacassin, R., Leloup, H., Scharer, U., Zhong, D., Liu, X., Ji, S., Zhang, L., Zhong, J., 1990. The Ailaoshan-Red river meta mor phic belt: Ter tiary left-lat eral shear be tween Indochina and South China. Na ture, 343: 431–437.
Tay lor, H.P., 1974. The ap pli ca tion of ox y gen and hy dro gen iso - topes stud ies to prob lem of hy dro ther mal al ter ation and ore de - po si tion. Eco nomic Ge ol ogy, 69: 843–883.
Thode, H.G., 1991. Sul phur iso topes in na ture and the en vi ron - ment: an over view. In: Sta ble Iso topes in the As sess ment of Nat - u ral and Anthropogenic Sul phur in the En vi ron ment (ed. H.R.
Krouse and V.A. Grinenko): 1–26. John Wiley and Sons Lid.
Tran, T.H., 2007. Inplate magmatism in North ern Viet nam and its metallogeny. Sc.D. the sis, IGM SO RAN, Novosibirsk.
Vi ola, G., Anczkiewicz, R., 2009. Ex hu ma tion his tory of the Red River shear zone in north ern Viet nam: new in sights zir con and ap a tite fis sion-track anal y sis (in Viet nam ese). In: Dianamic Geolog, Kainozoi N-Viet nam (eds. T.Y. Nguyen, A. Tokarski, T.H. Tran, A. Zuchie wicz, T.A. Tran, A. Œwierczewska and Q.C.
Nguyen): 150–164.
Zhao, X.F., Zhou, M.F., 2011. Fe-Cu de pos its in the Kangdian re - gion, SW China: a Pro tero zoic IOCG (iron-ox ide-cop per-gold) met al lo gen ic prov ince. Mineralium Deposita, 46: 731–747.
¯elaŸniewicz, A., Tran, T.H., Larionov, A.N., 2013. The sig nif i - cance of geo log i cal and zir con age data de rived from the wall rocks of the Ailao Shan-Red River Shear Zone, NW Viet nam.
Jour nal of Geodynamics, 69: 122–139.
