Metallogeny of the Zahedan-Nehbandan magmatic belt and implications to porphyry Cu exploration in southeastern Iran

2021 ◽  
Author(s):  
Majid Soleymani ◽  
Shojaeddin Niroomand ◽  
Abdorrahman Rajabi ◽  
Thomas Monecke ◽  
Soroush Modabberi
Keyword(s):  
Late Cretaceous ◽  
Igneous Rocks ◽  
Geochemical Composition ◽  
Porphyry Deposits ◽  
Epithermal Deposits ◽  
Porphyry Cu ◽  
Continental Block ◽  
Igneous Activity ◽  
Volcaniclastic Rocks ◽  
Alluvial Terraces

<p>The Late Cretaceous to Eocene Sistan suture zone in southeastern Iran separates the Lut continental block in the west from the Afghan continental block in the east. A major belt of Oligocene to Miocene igneous rocks occurs between the cities of Zahedan and Nehbandan, stretching for ~200 km from south to north parallel to the border with Pakistan and Afghanistan. Known porphyry Cu mineralization is associated with the intrusions and intrusive complexes at Kuh-e Janja (16.5+2.0 Ma), Kuh-e Seyasteragi (19.2+ 1.4 Ma), Kuh-e Assagie (27.5+2.0 Ma), and Kuh-e Lar (32.8+3.0 Ma).</p><p>Small intrusions and intrusive complexes in the Zahedan-Nehbandan magmatic belt are mostly intermediate to felsic in composition and have calc-alkaline or shoshonitic affinities. Associated volcanic and volcaniclastic rocks are common. The igneous rocks are hosted by deformed late Cretaceous to Eocene flysch sequences that formed in the Sefidabeh forearc basin developed during the subduction and closure of the Sistan ocean. The geochemical composition of the intrusive rocks and their ages suggest that igneous activity and related mineralization in the Zahedan-Nehbandan magmatic belt may have formed as a result of post-collisional processes. The locations of the intrusive centers in the Kuh-e Assagie and Kuh-e Lar may be controlled by strike-slip faults, which are major post-collisional structures.</p><p>The recent discovery of the Janja porphyry Cu-Au-Mo deposit below Quaternary alluvial terraces highlights the exploration potential of the Zahedan-Nehbandan magmatic belt. In addition to post-collisional porphyry deposits, other deposit types such as skarns, polymetallic veins, or epithermal deposits may be hidden below the regionally extensive Quaternary cover.</p>

scholarly journals Sm-Nd isochron ages of mafic igneous rocks from the Ryoke Belt, Southwest Japan: Remains of Jurassic igneous activity in a late Cretaceous granitic terrane.

1995 ◽  
Vol 29 (2) ◽  
pp. 123-135 ◽  
Author(s):  
Hiroo Kagami ◽  
Masaki Yuhara ◽  
Yoshiaki Tainosho ◽  
Shigeru Iizumi ◽  
Masaaki Owada ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Igneous Rocks ◽  
Southwest Japan ◽  
Igneous Activity

Dissimilar age and provenance of the Nindam and Jurutze volcaniclastic formations, Zanskar Gorge, Ladakh (India)

2021 ◽  
Author(s):  
Goran Andjic ◽  
Renjie Zhou ◽  
Tara N. Jonell ◽  
Jonathan C. Aitchison
Keyword(s):  
Detrital Zircon ◽  
Tectonic Evolution ◽  
Alternative Model ◽  
Early Eocene ◽  
Convergent Margins ◽  
Geochemical Composition ◽  
Age Gap ◽  
Volcaniclastic Rocks ◽  
Forearc Basins ◽  
Early Cenozoic

<p>Pre-early Eocene volcaniclastic rocks exposed in the Indus Suture Zone (Ladakh, India) are key to deciphering the complex magmatic and tectonic evolution of the convergent margins that existed between India and Eurasia. Several hypotheses exist regarding the provenance of the middle Cretaceous to early Cenozoic Jurutze and Nindam formations yet there is presently no consensus. Leading models propose that: (a) they were either formed in neighbouring sub-basins at one convergent margin consisting of the Kohistan-Ladakh-Dras arc; or (b) they became stratigraphically superposed after the collision between the Kohistan-Ladakh and Dras arcs. Here we present new U-Pb detrital zircon, major and trace element geochemical, and petrographic datasets from the Nindam and Jurutze formations that support a disparate provenance and thus necessitate an alternative model. The Jurutze Fm. has a geochemical composition typical of arcs built on continental crust, whereas the Nindam Fm. presents a geochemical signature compatible with that of an intraoceanic arc. The significant age gap between these formations (>20 m.y.) in the Zanskar Gorge further precludes the possibility that the Jurutze Fm. was deposited on top of the Nindam Fm. We propose that the Nindam and Jurutze formations were deposited in distinct forearc basins and explore scenarios for their formation at separate convergent margins, i.e. the separate Kohistan-Ladakh and Dras arcs, respectively.</p>

Jurassic–Cretaceous arc magmatism along the Shyok–Bangong Suture from NW Himalaya: Formation of the peri-Gondwana basement to the Ladakh Arc

2021 ◽  
pp. jgs2021-035
Author(s):  
Wanchese M. Saktura ◽  
Solomon Buckman ◽  
Allen P. Nutman ◽  
Renjie Zhou
Keyword(s):  
Late Cretaceous ◽  
Nw Himalaya ◽  
Content Type ◽  
Magmatic Arc ◽  
Basement Rocks ◽  
Ladakh Himalaya ◽  
Accreted Terranes ◽  
Volcaniclastic Rocks ◽  
Supplementary Material ◽  
Depositional Age

The Jurassic–Cretaceous Tsoltak Formation from the eastern borderlands of Ladakh Himalaya consists of conglomerates, sandstones and shales, and is intruded by norite sills. It is the oldest sequence of continent-derived sedimentary rocks within the Shyok Suture. It also represents a rare outcrop of the basement rocks to the voluminous Late Cretaceous–Eocene Ladakh Batholith. The Shyok Formation is a younger sequence of volcaniclastic rocks that overlie the Tsoltak Formation and record the Late Cretaceous closure of the Mesotethys Ocean. The petrogenesis of these formations, ophiolite-related harzburgites and norite sill is investigated through petrography, whole-rock geochemistry and U–Pb zircon geochronology. The youngest detrital zircon grains from the Tsoltak Formation indicate Early Cretaceous maximum depositional age and distinctly Gondwanan, Lhasa microcontinent-related provenance with no Eurasian input. The Shyok Formation has Late Cretaceous maximum depositional age and displays a distinct change in provenance to igneous detritus characteristic of the Jurassic–Cretaceous magmatic arc along the southern margin of Eurasia. This is interpreted as a sign of collision of the Lhasa microcontinent and the Shyok ophiolite with Eurasia along the once continuous Shyok–Bangong Suture. The accreted terranes became the new southernmost margin of Eurasia and the basement to the Trans-Himalayan Batholith associated with the India-Eurasia convergence.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5633162

Revised stratigraphy of the Mesozoic rocks of southern Cyprus

1980 ◽  
Vol 117 (6) ◽  
pp. 547-563 ◽  
Author(s):  
R. E. Swarbrick ◽  
A. H. F. Robertson
Keyword(s):  
Oceanic Crust ◽  
Continental Margin ◽  
Late Cretaceous ◽  
Sedimentary Cover ◽  
Igneous Rocks ◽  
Late Triassic ◽  
Metamorphic Rocks ◽  
Southern Cyprus

SummaryRecent resurgence of interest in the Mesozoic rocks of SW and southern Cyprus necessitates redefinition of the Mesozoic sedimentary and igneous rocks in line with modern stratigraphical convention. Two fundamentally different rocks associations are present, the Troodos Complex, not redefined, a portion of late Cretaceous oceanic crust, and the Mamonia Complex, the tectonically dismembered remnants of a Mesozoic continental margin. Based on earlier work, the Mamonia Complex is divided into two groups, each subdivided into a number of subsidiary formations and members. The Ayios Photios Group is wholly sedimentary, and records the evolution of a late Triassic to Cretaceous inactive continental margin. The Dhiarizos Group represents Triassic alkalic volcanism and sedimentation adjacent to a continental margin. Several other formations not included in the two groups comprise sedimentary mélange and metamorphic rocks. The Troodos Complex possesses an in situ late Cretaceous sedimentary cover which includes two formations of ferromanganiferous pelagic sediments, radiolarites and volcaniclastic sandstones. The overlying Cainozoic calcareous units are not redefined here.

Porphyry Cu-Au±Mo mineralization hosted by potassic igneous rocks: implications from the giant Peschanka porphyry deposit, Baimka Trend (North East Siberia, Russia)

2021 ◽  
pp. SP513-2020-178
Author(s):  
Andrey F. Chitalin ◽  
Ivan A. Baksheev ◽  
Yurii N. Nikolaev ◽  
Georgy T. Djedjeya ◽  
Yuliya N. Khabibullina ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Igneous Rocks ◽  
Oxidation States ◽  
Island Arcs ◽  
Porphyry Cu ◽  
North East ◽  
Average Grade ◽  
High K ◽  
High Oxidation ◽  
Other World

AbstractPorphyry Cu-Au±Mo mineralization at Peschanka is hosted by monzodiorite and monzonite intrusions with high-K calc-alkaline to shoshonitic compositions and dated at about 144.1±1.5 Ma, using U/Pb zircon ages. The Cretaceous intrusions are emplaced in a melange of Cretaceous island arcs, a tectonic setting comparable to other world-class porphyry Cu-Au deposits, such as Oyu Tolgoi, Mongolia, and Pebble, Alaska.Abundant primary magnetite contents of the Peschanka intrusions, as well as numerous gypsum and anhydrite veins, reflect the high oxidation states of their parental magmas. This mineralogical interpretation is confirmed by high whole-rock Fe2O3/FeO ratios and high V/Sc ratios of the rocks of up to 1.27 and up to 21.9, respectively. The whole-rock Eu/Eu& ratios of the Peschanka intrusions are ≥1 which is also typical for potassic igneous rocks with high oxidation states. Abundant amphibole and biotite phenocrysts of the intrusions as well as their high whole-rock Sr/Y ratios of up to 225 document significantly high H2O contents of the high-K magmas.Peschanka contains a resource of >9.5 Mt of copper at an average grade of 0.43 wt% and 16.5 Moz of gold at a high average grade of 0.23 g/t and, thus, representing one of the largest undeveloped greenfield copper projects worldwide. The vicinity of Peschanka still offers significant brownfields exploration potential.The hypogene vein-related and disseminated Cu-Au±Mo sulfide mineralization at Peschanka is structurally-controlled by significant NE-trending strike-slips that acted as the conduits for the hydrothermal fluids. The central part of the orebody consists of high-grade N-S trending sheeted quartz-bornite veining with unusually high vein densities. The highest Cu and Au grades are directly correlated with high vein densities.Peschanka is defined by distinct hydrothermal alteration zones including potassic, phyllic, propylitic and argillic assemblages, but a distinct lack of advanced argillic alteration. The mineralization itself is also zoned ranging from a central Mo-Cpy-Bn sulfide assemblage to a peripheral Py-Mt-dominated zone (“pyrite-shell”). Late-stage polymetallic assemblages overprint and surround the main stockwork zone.

Using Mineral Chemistry to Aid Exploration: A Case Study from the Resolution Porphyry Cu-Mo Deposit, Arizona

2020 ◽  
Vol 115 (4) ◽  
pp. 813-840 ◽  
Author(s):  
David R. Cooke ◽  
Jamie J. Wilkinson ◽  
Mike Baker ◽  
Paul Agnew ◽  
Josh Phillips ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Mineral Chemistry ◽  
Three Dimensions ◽  
Temperature Sensitive ◽  
Blind Test ◽  
Inductively Coupled ◽  
Porphyry Cu ◽  
The North ◽  
Icp Ms ◽  
Volcaniclastic Rocks

Abstract The giant, high-grade Resolution porphyry Cu-Mo deposit in the Superior district of Arizona is hosted in Proterozoic and Paleozoic basement and in an overlying Cretaceous volcaniclastic breccia and sandstone package. Resolution has a central domain of potassic alteration that extends more than 1 km outboard of the ore zone, overlapping with a propylitic halo characterized by epidote, chlorite, and pyrite that is particularly well developed in the Laramide volcaniclastic rocks and Proterozoic dolerite sills. The potassic and propylitic assemblages were overprinted in the upper parts of the deposit by intense phyllic and advanced argillic alteration. The district was disrupted by Tertiary Basin and Range extension, and the fault block containing Resolution and its Cretaceous host succession was buried under thick mid-Miocene dacitic volcanic cover, obscuring the geologic, geophysical, and geochemical footprint of the deposit. To test the potential of propylitic mineral chemistry analyses to aid in the detection of concealed porphyry deposits, a blind test was conducted using a suite of epidote-chlorite ± pyrite-altered Laramide volcaniclastic rocks and Proterozoic dolerites collected from the propylitic halo, with samples taken from two domains located to the north and south and above the Resolution ore zone. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data of epidote provided indications of deposit fertility and proximity. Competition for chalcophile elements (As, Sb, Pb) between coexisting pyrite and epidote grains led to a subdued As-Sb fertility response in epidote, consistent with epidote collected between 0.7 and 1.5 km from the center of a large porphyry deposit. Temperature-sensitive trace elements in chlorite provided coherent spatial zonation patterns, implying a heat source centered at depth between the two sample clusters, and application of chlorite proximitor calculations based on LA-ICP-MS analyses provided a precisely defined drill target in this location in three dimensions. Drilling of this target would have resulted in the discovery of Resolution, confirming that epidote and chlorite mineral chemistry can potentially add value to porphyry exploration under cover.

Mid–Late Cretaceous igneous activity in South China: the Qianjia example, Hainan Island

2017 ◽  
Vol 60 (11-14) ◽  
pp. 1665-1683 ◽  
Author(s):  
Sai-Jun Sun ◽  
Li-Peng Zhang ◽  
Rong-Qing Zhang ◽  
Xing Ding ◽  
Hong-Li Zhu ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
South China ◽  
Hainan Island ◽  
Igneous Activity
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