Potassic and ultrapotassic rocks : Compositional characteristics, petrogenesis, and geologic significance

Peccerillo, A.

doi:10.18814/epiiugs/1992/v15i4/002

Cited by 68 publications

(25 citation statements)

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“…All the alkaline rocks are potassic, rarely highly potassic, and mainly intermediate silica-types, alkali granitic dyke excepted, and then they are believed derivative from a basic magma, probably a basanitic liquid, analogously to other world-wide occurrences and on the basis also of the trace element behavior ( [50] and therein references); [32][33][34]; clinopyroxene and calcic plagioclase are evolving by fractional crystallization of olivine during ascent to the present position.…”

Section: Discussionmentioning

confidence: 99%

Some Notes on the Lugiin Gol, Mushgai Khudag and Bayan Khoshuu Alkaline Complexes, Southern Mongolia

Baatar¹,

Gerel²,

Kynický³

et al. 2013

IJG

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Volcanic-plutonic alkaline complexes from Lugiin Gol, Mushgai Khudag and Bayan Khoshuu, southern Mongolia (244, 139 and 131 Ma, respectively) occur within grabens in E-W lineaments. They are represented by syenitic rock-types (silica undersaturated to slightly silica oversaturated) potassic rocks and are associated to stockworks of carbonatitic veins, dykes and so on. Geochemical characteristics and isotope systematics point to a veined mantle source particularly enriched in LILE and LREE. The carbonatitic veins show high contents of Ba, Sr, Th and REE and are suitable as potential ore deposits.

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Section: Discussionmentioning

confidence: 99%

Some Notes on the Lugiin Gol, Mushgai Khudag and Bayan Khoshuu Alkaline Complexes, Southern Mongolia

Baatar¹,

Gerel²,

Kynický³

et al. 2013

IJG

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“…Potassic rocks are found in several tectonic environments, such as cratons, post-collisional setting, and active orogenic belts and, to a lesser extent, oceanic intraplate settings [46] and have moderate abundances of LREE, LILE, and HFSE [47]. Shoshonitic rocks in particular are associated with many continental and oceanic arcs [48]. The tectonic affinities of ancient and altered/mineralized rocks can be investigated with the use of immobile trace elements.…”

Section: Tectonic Setting Of the Sungun Stock And Post-mineralizationmentioning

confidence: 99%

“…with many continental and oceanic arcs [48]. The tectonic affinities of ancient and altered/mineralized rocks can be investigated with the use of immobile trace elements.…”

Section: Tectonic Setting Of the Sungun Stock And Post-mineralizationmentioning

confidence: 99%

Post-Mineralization, Cogenetic Magmatism at the Sungun Cu-Mo Porphyry Deposit (Northwest Iran): Protracted Melting and Extraction in an Arc System

et al. 2018

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The Sungun porphyry ore deposit is located in Eastern Azarbaijan province, Northwestern Iran. The oldest intrusive pulse in the region is a quartz-monzonite pluton, which hosts the porphyry copper-molybdenum mineralization. The Sungun Copper Mine includes the mineralized Sungun porphyry as well as six groups of cross-cutting and lithologically distinct post-mineralization dykes. The composition of these dykes ranges from quartz diorite, gabbro, diorite, dacite, lamprophyre, and microdiorite. Quartz diorite and dacite dykes are the oldest and youngest dykes, respectively. Based on their cross-cutting relationships, the composition of the dykes tend to become more primitive through time. The dykes strike Northwest–Southeast with Southwest dip, sub-parallel to the reverse faults within the deposit area. The lamprophyric dykes range from phonotephrite, to trachybasalt, tephrite, and basanite. The quartz-monzonite porphyry (SP) and the post-mineralization dykes (DK1-DK3) have clear and distinct negative anomalies of Ti, Zr, P, Pr, Ce, and Nb, as well as positive anomalies of Cs, U, K, Pb, and Nd with respect to primitive mantle. Microdioritic dykes (MDI) show depletion of Ti, Nb, P, Ta, Th, Yb, and Zr, and enrichment of Cs, Ba, U, Pb, Nd. The similarities in trace element abundances and patterns in the porphyry and post-mineralization calc-alkaline dykes implies a single source and fractional crystallization as the main mechanism controlling magmatic evolution in a collisional environment. Lamprophyric dykes have enrichment of LREE and LILE and depletion of HREE and HFSE such as Ti, Nb, and Ta. The parent magma of the lamprophyric dykes (LAM) was likely derived by low degrees of melting of a garnet lherzolite mantle peridotite. The 87Sr/86Sr and 143Nd/144Nd ratios range from 0.704617 to 0.706464 and from 0.512648 to 0.512773 for the dykes suggesting that the parental magmas came from a progressively more enriched mantle. Isotope ratios of 87Sr/86Sr and 143Nd/144Nd support a cogenetic relationship of porphyry and calc-alkaline dykes, except for the microdiorite ones. A common primary melt underwent gravity differentiation in a deep magmatic chamber to form a dioritic magma. This subsequently migrated to shallower levels to evolve further and feed individual dyke groups into the Sungun porphyry.

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“…Potassic igneous rocks include a variety of compositions ranging from shoshonites associated with calc‐alkaline volcanic rocks to ultrapotassic leucitites (Campbell et al, ; Foley & Peccerillo, ; Peccerillo, ). Potassic igneous rocks have been recognized as an important and integral component of magmatism at destructive continental margins (e.g., Abbasi, Manesh, Karimi, & Parfenova, ; Carr, ; Costa, Oliveira, & McNaughton, ; Ding et al, ; Foley & Peccerillo, ; Hari, Chalapathi, Vikas, & Guiting, ; Liu, Jiang, Jia, Zhao, & Zhou, ; Morrison, ; Nabatian et al, ; Orozco‐Garza, Dostal, Keppie, & Paz‐Moreno, ; Rao, Srivastava, Sinha, & Ravikant, ; Rios et al, ; Saunders, Tarney, & Weaver, ; Torabi, ; Yang et al, ).…”

Section: Introductionmentioning

confidence: 99%

“…The origin of potassic igneous rocks is controversial (Peccerillo, ). Generally, in a subduction system, these rocks are derived from the partial melting of mantle that is metasomatically modified by subduction‐related fluids (Aoki, Ishiwaka, & Kanisawa, ; Edgar & Arima, ; Foley & Peccerillo, ; Jiang et al, ; Morrison, ; Peccerillo, ), subducted oceanic crust (Shen, Shen, Liu, Li, & Zeng, ), subducted marine sediment (Liu et al, ; Mallik, Nelson, & Dasgupta, ; Miller, Schuster, Klötzli, Frank, & Purtscheller, ; Rogers, Hawkesworth, Parker, & Marsh, ; Woodhead, Hergt, Davidson, & Eggins, ), and the overlying mantle wedge (Bucholz, Jagoutz, Schmidt, & Sambuu, ; Ellam & Hawkesworth, ). The metasomatic hypothesis for the origin of shoshonites is consistent with the experimental work of Wyllie and Sekine (), who showed that potassic magmas can be produced by melting the hydrated mantle.…”

Section: Introductionmentioning

confidence: 99%

Potassic alkaline granitoid magmatism in the northern margin of the Tarim Craton: First evidence of a back‐arc extensional environment

Chen

Yang

2019

Geological Journal

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The tectonic setting of the northern Tarim Craton during the Palaeozoic is vital to our understanding of the subduction polarity of the paleo-oceanic plates in the Tianshan Orogen and the accretion history of the south-western Central Asian Orogenic Belt.We first identified granitoids intruding the Palaeoproterozoic metamorphic rocks in the Kurchu area in the northern Tarim Craton. The zircon LA-ICP-MS U-Pb dating of this rock indicates that its crystallization age is 418 Ma, highlighting a late Early Palaeozoic magmatic event. Compared with the contemporaneous granitoids in the southern margin of the Tarim Craton, the Kurchu granitoid has high K 2 O (6.17-7.25 wt.%) and high alkaline (Na 2 O + K 2 O = 9.48-10.56 wt.%) contents. The Rittmann index (σ) ranges from 3.53 to 5.68, and samples plot in the shoshonite series in the K 2 O-SiO 2 diagram, indicating that the rock is a potassic-alkaline granite (PAG). In addition, this granitoid shows high REE concentrations (264-817 ppm) with significant Eu anomalies and is depleted in Ba, Sr, Nb, Ta, Ti, and P but enriched in Zr and Hf. These geochemical characteristics and high ( 87 Sr/ 86 Sr) i (0.70857-0.70995) and low εNd(T) (−10.67 to −10.24) values of the Kurchu PAG indicate that this rock was derived from the partial melting of the crust. The diagenetic conditions of the Kurchu PAG are high temperatures, as recorded by higher zircon saturation temperatures (855-919°C), low diagenetic pressure, a less shallow emplacement depth recorded by lower Sr (<200 ppm) concentrations, and a low oxygen fugacity recorded by lower Eu* (0.17-0.89), higher Zr (>355 ppm) and Hf (>9.73 ppm) concentrations, and trace element contents of zircons. In various discrimination diagrams, all samples consistently plot in rift-related areas. These geochemical and diagenetic features suggest that this magmatic event probably occurred in a backarc environment. Therefore, there is back-arc basin occurring in the northern TarimCraton in the Early Palaeozoic, which provides strong evidence that this region was an active margin probably much earlier than Silurian, necessitating the southward subduction of the South Tianshan Ocean.

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Potassic and ultrapotassic rocks : Compositional characteristics, petrogenesis, and geologic significance

Cited by 68 publications

References 0 publications

Some Notes on the Lugiin Gol, Mushgai Khudag and Bayan Khoshuu Alkaline Complexes, Southern Mongolia

Some Notes on the Lugiin Gol, Mushgai Khudag and Bayan Khoshuu Alkaline Complexes, Southern Mongolia

Post-Mineralization, Cogenetic Magmatism at the Sungun Cu-Mo Porphyry Deposit (Northwest Iran): Protracted Melting and Extraction in an Arc System

Potassic alkaline granitoid magmatism in the northern margin of the Tarim Craton: First evidence of a back‐arc extensional environment

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