The geodynamic setting of Dulan eclogite-type rutile deposits in the North Qaidam orogen, western China

Chen, Xin; Xu, Runsheng; Zheng, Youye; Gao, Shiqiang; Cai, Pengjie; Yu, Junzhen; Wang, Qimeng

doi:10.1016/j.oregeorev.2019.102936

Cited by 16 publications

(15 citation statements)

References 103 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Eclogite D16E has dark CL zircon cores with magmatic‐type trace‐element characteristics that yield a weighted mean age of 459.3 ± 4.2 Ma (Figure 4a,b; Table 2). This eclogite outcrops in the Shaliuhe area (SDB), where dark CL zircon cores from other eclogite samples have been analysed (Figure 1b; Chen, Schertl, et al, 2019; Chen, Xu, et al, 2019; Song et al, 2014a, 2019; G. Zhang et al, 2008). Our 459.3 ± 9.2 Ma age differs from the interpreted magmatic protolith ages of 516 ± 8 Ma, 446 ± 2 Ma and 443 ± 3 Ma reported from other eclogite samples in this locality (Chen et al, 2019,b; Song et al, 2014a, 2019; G. Zhang et al, 2008).…”

Section: Discussionmentioning

confidence: 98%

“…Dark CL zircon cores from samples D119 and D197 yield upper intercept ages of c .900 Ma (Figures 6d and 7b; Table 2). Dulan eclogite from other locations also yields Proterozoic zircon core ages: two eclogite samples from the central part of the Dulan area record protolith ages of 835–828 Ma (Yu, Zhang, Li, et al, 2013; J. X. Zhang et al, 2010) and three eclogite samples from the northern part of the Dulan area record variable protolith ages, spanning from 1.9 Ga, 845 Ma and 765–756 Ma (Chen, Xu, et al, 2019; Lu et al, 2018; Zhang, Chen, et al, 2017), all interpreted as the crystallization of magmatic intrusions in continental rocks. The dark CL cores found in our samples yield similar ages to the c .850–830 Ma ages interpreted as continental rifting during the breakup of Rodinia (Song et al, 2010; Xu et al, 2016; Yu, Zhang, Li, et al, 2013; J. X. Zhang et al, 2010, 2018).…”

Section: Discussionmentioning

confidence: 99%

“…Zircon U–Pb analyses from Dulan eclogite record ages of ca. 457–422 Ma (Chen, Schertl, et al, 2019; Chen, Xu, et al, 2019; Mattinson et al, 2006a; Ren et al, 2016; Song et al, 2006; Song et al, 2014a; Yu, Zhang, Li, et al, 2013; G. Zhang et al, 2008, 2009, 2014; J. X. Zhang et al, 2010). Three garnet–omphacite–whole‐rock Sm–Nd isochrons yield slightly older ages of ca.…”

Section: Geologic Settingmentioning

confidence: 99%

See 2 more Smart Citations

Protracted eclogite‐facies metamorphism of the Dulan area, North Qaidam ultrahigh‐pressure terrane: Insights on zircon growth during continental subduction and collision

Hernández‐Uribe

Mattinson

Regel

et al. 2023

Journal Metamorphic Geology

View full text Add to dashboard Cite

Continental subduction and collision are recorded by ultrahigh-pressure (UHP) terranes; UHP terranes that form at early stages of an orogeny tend to be small and experience short residence at eclogite-facies depths, whereas terranes that form at mature stages of an orogeny tend to be larger and experience longer residence at these depths, but accurately determining eclogitefacies residence time requires a large geochronologic dataset tied to metamorphic conditions (via trace elements and/or inclusions). In the Dulan area, North Qaidam UHP terrane, China, it remains unclear whether the terrane experienced a long residence at eclogite-facies depths, marking the mature stage of an orogeny or two distinct (ultra)high pressure ([U]HP) events (with short residence times), interpreted as the transition from oceanic subduction to continental collision, where one (U)HP event is related to the former and second (U)HP event to the latter. To address this issue, we report new zircon U-Pb ages and trace-element data from eclogite and host paragneiss from the Dulan area and show that this terrane records $42 Myr of eclogite-facies metamorphism at (U)HP conditions, similar to other large UHP terranes. Zircon from 11 eclogite and 2 gneiss samples yields weighted mean ages of 463-425 Ma, flat heavy rare earth element (HREE) patterns without negative Eu anomalies, and eclogitic mineral inclusions, indicating eclogite-facies conditions. Paragneiss metamorphic ages overlap with ages from eclogite but are generally younger, suggesting that a lack of internally generated fluids may have inhibited zircon growth and/or recrystallization until early decompression and white mica consumption in felsic gneiss generated fluids; thus, we interpret that these felsic rocks record the later stages of continental collision. Dataset patterns from all new and previously published analyses for the Dulan area (34 eclogite and 14 gneiss) suggest that metamorphic zircon in eclogite records prograde, peak and possibly early retrograde conditions, in contrast to the prediction from mass balance models that metamorphic zircon should only grow during exhumation and cooling. We reconcile our observations with these model predictions by recognizing that differential solubility can lead to

show abstract

Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

Section: Geologic Settingmentioning

confidence: 99%

See 1 more Smart Citation

Protracted eclogite‐facies metamorphism of the Dulan area, North Qaidam ultrahigh‐pressure terrane: Insights on zircon growth during continental subduction and collision

Hernández‐Uribe

Mattinson

Regel

et al. 2023

Journal Metamorphic Geology

View full text Add to dashboard Cite

show abstract

“…Data from sedimentary rocks are from Menderes massif [70] and Capricorn orogen belt [95]. The metamorphic deposit includes Dulan eclogite-type rutile [9].…”

Section: Implications For Mineralization Potential and Explorationmentioning

confidence: 99%

“…It is also found in hydrothermal ore systems, such as porphyry Cu or Cu-Au, Carlin-type Au, and orogenic Au deposits [5][6][7]. Trace element compositions of different genetic rutile can provide insights into potential sources and evolution of rocks, as well as information for ore genesis [8,9]. Rutile is also evaluated as a powerful tool for detecting mineralization systems with its distinct grain structure (i.e., size and aspect ratio) and abundance of V, W, Sn, and Nb [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Rutile and Chlorite Geochemistry Constraints on the Formation of the Tuwu Porphyry Cu Deposit, Eastern Tianshan and Its Exploration Significance

et al. 2021

View full text Add to dashboard Cite

The chemical composition of rutile has been used as an indicator in magmatic and metamorphic-related diagenetic systems, but rarely in porphyry-style ore systems. The Tuwu deposit (557 Mt at 0.58% Cu) is a large porphyry-style Cu mineralization in Eastern Tianshan, Xinjiang, with typical disseminated, stockwork mineralized veins hosted in tonalite and diorite porphyry, and to a lesser extent in volcanic rocks of the Qi’eshan Group. We first present determination of rutile minerals coupled with chlorite identified in mineralized porphyries from Tuwu to reveal their geochemical features, thus providing new insights into the ore-forming processes and metal exploration. Petrographic and BSE observations show that the rutile generally occurs as large crystals (30 to 80 µm), in association with hydrothermal quartz, chlorite, pyrite, and chalcopyrite. The rutile grains display V, Fe, and Sn enrichment and flat LREE-MREE patterns, indicating a hydrothermal origin. Titanium in rutile (TiO2) is suggested to be sourced from the breakdown and re-equilibration of primary magmatic biotite and Ti-magnetite, and substituted by Sn4+, high field strength elements (HFSE; e.g., Zr4+ and Hf4+), and minor Mo4+ under hydrothermal conditions. The extremely low Mo values (average 30 ppm) in rutile may be due to rutile formation postdating that of Mo sulfides (MoS2) formation in hydrothermal fluids. Chlorite analyses imply that the ore-forming fluids of the main stage were weakly oxidized (logfO2 = −28.5 to −22.1) and of intermediate temperatures (308 to 372 °C), consistent with previous fluid inclusion studies. In addition, Zr-in-rutile geothermometer yields overestimated temperatures (>430 °C) as excess Zr is incorporated into rutile, which is likely caused by fast crystal growth or post crystallization modification by F-Cl-bearing fluid. Thus, application of this geothermometer to magmatic-hydrothermal ore systems is questionable. Based on the comparison of rutile characteristics of porphyry Cu with other types of ore deposits and barren rocks, we suggest that porphyry Cu-related rutile typically has larger grain size, is enriched in V (average 3408 ppm, compared to <1500 ppm of barren rocks) and to a lesser extent in W and Sn (average 121 and 196 ppm, respectively), and has elevated Cr + V/Nb + Ta ratios. These distinctive signatures can be used as critical indicators of porphyry-style Cu mineralization and may serve as a valuable tool in mineral exploration.

show abstract

The giant ShangzhuangREE‐rich apatite deposit, western China: Genesis by ultramafic magma differentiation

Wang¹,

Chen

Wan-wen³

et al. 2023

Geological Journal

Self Cite

View full text Add to dashboard Cite

The origin of giant rare earth element (REE)‐rich phosphorus deposits related to ultramafic rocks is unclear. To characterize the genetic linkage between ultramafic rocks and P–REE mineralization, we investigated the whole‐rock geochemistry, geochronology and Hf isotopic compositions, along with previously published data of barren and ore‐bearing clinopyroxenites from the giant Shangzhuang REE‐rich apatite deposit (containing about 51.1 million tonnes of P2O5 and 157,400 tonnes of REEs) in the Lajishan suture, Western China. The P–REE ores and barren biotite clinopyroxenites are composed predominantly of clinopyroxene and biotite, with high levels of apatite, amphibole, allanite, sulfide and oxide minerals in the ore‐bearing samples. Zircon and allanite U–Pb ages for the barren and ore‐bearing clinopyroxenites indicate they were formed between 467 and 465 Ma. The barren and ore‐bearing samples are characterized by high CaO and low SiO2 contents, as well as similar Hf isotope ratios (εHf[t]: +3.4 to +7.7), indicating that they represent an ultramafic magma system and have been derived from a similar source. They are enriched in light REEs and depleted in Nb–Ta–Zr–Hf–Ti, similar to arc‐related lavas found worldwide. The weakly evolved barren samples have high Ba/La, Rb/Y and Dy/Yb values, and their ages are coeval with calc‐alkaline granitic plutons in the belt, which postdate the formation of the Lajishan ophiolite by ~30 myr. This suggests that the primary magma originated from garnet peridotite mantle modified by subducted Proto‐Tethys oceanic crust‐derived fluids in an arc setting. The presence of apatite intergrowth with cumulus clinopyroxene without alteration features indicates that the deposit has a magmatic origin. The ore‐bearing clinopyroxenite contains higher contents of P, REEs, and high‐field‐strength elements than the barren clinopyroxenite, which could be attributed to the in situ accumulation of apatite and allanite in the residual magma. Thus, the formation of the P‐dominated orebodies results from phosphate saturation due to the extensive fractionation crystallization of clinopyroxene and biotite during magmatic evolution. REEs were primarily enriched in the late‐stage melt, which was compatible with apatite and allanite. We propose that the formation of the Shangzhuang REE‐rich apatite deposit can be attributed to a simple differentiation of ultramafic melts in an evolved magmatic system.

show abstract

The geodynamic setting of Dulan eclogite-type rutile deposits in the North Qaidam orogen, western China

Cited by 16 publications

References 103 publications

Protracted eclogite‐facies metamorphism of the Dulan area, North Qaidam ultrahigh‐pressure terrane: Insights on zircon growth during continental subduction and collision

Protracted eclogite‐facies metamorphism of the Dulan area, North Qaidam ultrahigh‐pressure terrane: Insights on zircon growth during continental subduction and collision

Rutile and Chlorite Geochemistry Constraints on the Formation of the Tuwu Porphyry Cu Deposit, Eastern Tianshan and Its Exploration Significance

The giant ShangzhuangREE‐rich apatite deposit, western China: Genesis by ultramafic magma differentiation

Contact Info

Product

Resources

About