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Showing papers on "Phenocryst published in 2017"


Journal ArticleDOI
TL;DR: In this paper, the authors developed parameterized lattice strain models for the partitioning of monovalent (Na, K, Li), divalent (Ca, Mg, Ba, Sr, Ra) and trivalent (REE and Y) cations between plagioclase and silicate melt.

99 citations


Journal ArticleDOI
TL;DR: In this article, trace element data for olivines from the Karoo CFB Tuli and Mwenezi picrites and the Etendeka CFB Horingbaai/LTZ-L type picrites, all of which erupted in regions of thickened (>90 km) lithosphere in southern Africa.

88 citations


Journal ArticleDOI
TL;DR: In this article, a detailed petrographic and geochemical study of a hypabyssal sample (BK) from the Bultfontein kimberlite (Kimberley, South Africa) is presented.

83 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigate the mineralogical variability of silicates in Mercury's crust using crystallization experiments on magmas with compositions and under reducing conditions expected for Mercury, and find a common crystallization sequence consisting of olivine, plagioclase, pyroxenes and tridymite for all magmas tested.
Abstract: NASA’s MESSENGER spacecraft has revealed geochemical diversity across Mercury’s volcanic crust. Near-infrared to ultraviolet spectra and images have provided evidence for the Fe2+-poor nature of silicate minerals, magnesium sulfide minerals in hollows and a darkening component attributed to graphite, but existing spectral data is insufficient to build a mineralogical map for the planet. Here we investigate the mineralogical variability of silicates in Mercury’s crust using crystallization experiments on magmas with compositions and under reducing conditions expected for Mercury. We find a common crystallization sequence consisting of olivine, plagioclase, pyroxenes and tridymite for all magmas tested. Depending on the cooling rate, we suggest that lavas on Mercury are either fully crystallized or made of a glassy matrix with phenocrysts. Combining the experimental results with geochemical mapping, we can identify several mineralogical provinces: the Northern Volcanic Plains and Smooth Plains, dominated by plagioclase, the High-Mg province, strongly dominated by forsterite, and the Intermediate Plains, comprised of forsterite, plagioclase and enstatite. This implies a temporal evolution of the mineralogy from the oldest lavas, dominated by mafic minerals, to the youngest lavas, dominated by plagioclase, consistent with progressive shallowing and decreasing degree of mantle melting over time. The MESSENGER spacecraft has revealed geochemical diversity across Mercury’s surface. Magma crystallization experiments suggest a crustal mineralogy consistent with a transition towards shallower and cooler mantle melting conditions.

74 citations


Journal ArticleDOI
TL;DR: In this paper, the authors compared mid-Cretaceous porphyry and iron oxide copper-gold (IOCG) deposits in the Mesozoic Coastal Cordillera of northern Chile.
Abstract: Porphyry Cu ± Mo ± Au and iron oxide copper-gold (IOCG) deposits share many similarities (e.g., Fe, Cu, and Au contents), but also have important differences (e.g., the predominance of sulfide minerals in porphyry deposits and iron oxides in IOCG deposits). Genetic comparisons are complicated by the broad definition of IOCG deposits; here we restrict our study to IOCG deposits that are related to igneous intrusive systems. In the Mesozoic Coastal Cordillera of northern Chile, both porphyry and IOCG deposits occur in close spatial and temporal proximity, offering the chance to examine what controls their different modes of formation. From detailed examination of the timing, geochemistry, and tectonic setting of associated igneous rocks, based on new and published data, we find that rocks associated with mid-Cretaceous IOCG deposits (~125–110 Ma) are largely indistinguishable from those associated with slightly earlier (>125 Ma) and later (<110 Ma) porphyry Cu ± Mo ± Au deposits. Magmas related to IOCG deposits were formed during a brief period of back-arc transtension in the mid-Cretaceous and are, on average, somewhat more mafic (dioritic), locally alkaline, and isotopically primitive compared to granodioritic magmas associated with porphyry deposits formed during normal contractional arc tectonics in the later Cretaceous. However, these compositional ranges overlap, and the differences are not clear enough to be diagnostic. We measured the SO3 content of igneous apatite from selected samples of these rocks to test the hypothesis that the difference in sulfur content of the ore deposits was due to differences in sulfur content of the associated magmas. Early igneous apatite crystals occurring as inclusions in silicate phenocrysts from the Carmen de Andacollo porphyry Cu-Au deposit (Re-Os molybdenite ages of 103.9 ± 0.5 Ma, 103.6 ± 0.5 Ma) are significantly richer in S (0.25 ± 0.17 wt % SO3, n = 69) than similar apatite crystals from two IOCG deposits (Candelaria, Casualidad) and a sample of regional mid-Cretaceous igneous rock from near Productora (0.04 ± 0.02 wt % SO3, n = 76). Using published partition coefficients for S between apatite and oxidized silicate melt, we semi-quantitatively estimate corresponding magmatic sulfur contents of ~0.02 wt % S in the Carmen de Andacollo magmas versus ~0.001 to 0.005 wt % S in the IOCG-associated magmas. This is an order of magnitude difference, and the opposite of what would be expected if the difference were due to bulk magma composition (sulfur solubility is generally higher in mafic magmas, whereas here the S content is higher in the more felsic porphyries). We conclude that the porphyry-forming magmas indeed had higher S contents than the IOCG-related magmas and suggest that these differences reflect different petrogenetic processes. During normal subduction, magmas derived from the metasomatized mantle wedge are hydrous, moderately oxidized, and S rich, and have the potential to generate S-rich porphyry-type deposits. In contrast, in back-arc extensional settings, upwelling asthenospheric melts carry a weaker subduction signature, including lower S contents. Interaction of these S-poor magmas with previously subduction modified upper plate lithosphere is more likely to give rise to S-poor IOCG deposits.

68 citations


Journal ArticleDOI
TL;DR: In this article, the metal and sulfur content of an ore-related latite magma at Bingham Canyon and comparing it with that of intermediate magmas in several other arc magma systems is presented.
Abstract: Porphyry Cu deposits are commonly thought to have formed by magmas that were unusually rich in metal and/or sulfur. In this study, we test this assumption by reconstructing the metal and sulfur content of an ore-related latite magma at Bingham Canyon and comparing it with that of intermediate magmas in several other arc magma systems. The ore-related latite magma at Bingham Canyon records strong evidence for magma mixing and has a major to trace element composition that can successfully be modeled by a mixture of ~40 wt % mafic magma, which was similar to the most mafic rock found at Bingham Canyon (a melanephelinite containing 45 wt % SiO 2 ), and ~60 wt % felsic magma of rhyolitic composition. Based on the modal abundance of 0.19 ± 0.01 vol % sulfides and laser ablation-inductively coupled plasma-mass spectrometry analyses of unaltered sulfide inclusions preserved within hornblende and plagioclase phenocrysts, the latite magma contained 50 to 90 ppm Cu, 0.8 to 2.0 ppb Au, 2 to 3 ppm Mo, and ≥0.12 to 0.14 wt % S. Whole-rock and melt and sulfide inclusion data suggest that the bulk of copper and Au in the latite magma was derived from the mafic end member, whereas significant amounts of sulfur were also provided by the felsic end member. A rough, independent estimate of the amount of Cu present in the mixed magma can be obtained by taking the Cu content of mafic, sulfide-undersaturated silicate melt inclusions and multiplying it with the mass fraction of mafic magma involved in the magma mixing. Applying this latter approach to two other porphyry Cu-mineralized magma systems (Santa Rita, USA; Bajo de la Alumbrera, Argentina) and several modern arc magma systems suggests that ore-forming intermediate magmas in mineralized systems were not unusually Cu rich. Whether or not they were unusually sulfur rich could not be answered with the available data. If the sulfur contents of mineralizing magmas prove to be normal, then the most distinctive feature of fertile magma systems may be the formation of large, long-lived magma chambers at 5- to 15-km depth and the development of vent structures that enable focused fluid flow.

67 citations




Journal ArticleDOI
TL;DR: The authors analyzed whole rocks, minerals, and silicate melt inclusions from the co-genetic, ore-contemporaneous volcanic package (∼38 Ma) and showed that the latites were Cu rich, with Cu concentrations in the silicates melt reaching up to 300-400 ppm at about 60 wt% SiO2.

57 citations


Journal ArticleDOI
TL;DR: In this paper, micro X-ray absorption near-edge structure spectroscopy (μ-XANES) was used to determine the ratio of Fe(+3)/Fe^T between olivine phenocrysts and glass inclusions in eight 1959 scoria samples.

54 citations


Journal ArticleDOI
01 Sep 2017-Lithos
TL;DR: In 2014, after 19 years of quiescence, Fogo volcano (Cape Verde Archipelago) experienced a new eruption, with the vents located 200 m from those of the 1995 and 1951 eruptions, and less than 2000 m from the 1951 event as mentioned in this paper, which offered a unique opportunity to investigate the existence of small-scale mantle heterogeneity and the short-term compositional evolution of magmas erupted by a very active oceanic volcano like Fogo.

Journal ArticleDOI
TL;DR: In this article, the authors examined primary fluid/melt inclusions in chromite, perovskite and apatite containing a diversity of daughter phases and found that the primary inclusions represent remnants of fluid(s)/melt(s) trapped during crystallisation of the host minerals.

Journal ArticleDOI
TL;DR: A mineralogical study of the hypabyssal facies, late Cretaceous macrocrystic pulse of TK1 intrusion and the Mesoproterozoic aphanitic pulse of the TK4 intrusion in the Wajrakarur Kimberlite Field of southern India has been conducted by as mentioned in this paper.

Journal ArticleDOI
TL;DR: Comparison of experimental and natural (lava, xenolith) mafic mineral composition reveals that whereas olivine in lavas is predominantly primocrysts precipitated at low-pressure, pyroxenes and spinel are predominantly xenocrysts formed by disaggregation of plutonic mushes, overall, St. Kitts xenoliths and lavas testify to mid-crustal differentiation of low-MgO basalt and basaltic andesite magmas within
Abstract: St. Kitts lies in the northern Lesser Antilles, a subduction-related intraoceanic volcanic arc known for its magmatic diversity and unusually abundant cognate xenoliths. We combine the geochemistry of xenoliths, melt inclusions and lavas with high pressure–temperature experiments to explore magma differentiation processes beneath St. Kitts. Lavas range from basalt to rhyolite, with predominant andesites and basaltic andesites. Xenoliths, dominated by calcic plagioclase and amphibole, typically in reaction relationship with pyroxenes and olivine, can be divided into plutonic and cumulate varieties based on mineral textures and compositions. Cumulate varieties, formed primarily by the accumulation of liquidus phases, comprise ensembles that represent instantaneous solid compositions from one or more magma batches; plutonic varieties have mineralogy and textures consistent with protracted solidification of magmatic mush. Mineral chemistry in lavas and xenoliths is subtly different. For example, plagioclase with unusually high anorthite content (An≤100) occurs in some plutonic xenoliths, whereas the most calcic plagioclase in cumulate xenoliths and lavas are An97 and An95, respectively. Fluid-saturated, equilibrium crystallisation experiments were performed on a St. Kitts basaltic andesite, with three different fluid compositions (XH2O = 1.0, 0.66 and 0.33) at 2.4 kbar, 950–1025 °C, and fO2 = NNO − 0.6 to NNO + 1.2 log units. Experiments reproduce lava liquid lines of descent and many xenolith assemblages, but fail to match xenolith and lava phenocryst mineral compositions, notably the very An-rich plagioclase. The strong positive correlation between experimentally determined plagioclase-melt KdCa–Na and dissolved H2O in the melt, together with the occurrence of Al-rich mafic lavas, suggests that parental magmas were water-rich (> 9 wt% H2O) basaltic andesites that crystallised over a wide pressure range (1.5–6 kbar). Comparison of experimental and natural (lava, xenolith) mafic mineral composition reveals that whereas olivine in lavas is predominantly primocrysts precipitated at low-pressure, pyroxenes and spinel are predominantly xenocrysts formed by disaggregation of plutonic mushes. Overall, St. Kitts xenoliths and lavas testify to mid-crustal differentiation of low-MgO basalt and basaltic andesite magmas within a trans-crustal, magmatic mush system. Lower crustal ultramafic cumulates that relate parental low-MgO basalts to primary, mantle -derived melts are absent on St. Kitts.

Journal ArticleDOI
TL;DR: In this paper, petrology and geochemistry of two undeformed and unmetamorphosed lamprophyre dykes from the Mudigubba area located immediately towards the western margin of the Paleo-Mesoproterozoic Cuddapah basin from this craton are reported.

Journal ArticleDOI
TL;DR: In this article, the authors presented the mineralogical (olivine, Cr-spinel, orthopyroxene), geochemical (trace elements and Sr-Nd-Hf-Pb isotopes) and olivine-hosted melt inclusion compositional characteristics of a single primitive (16-wt% MgO), high-Ti (2.5", high-MgO2), with high-Olivine (up to 91-mol% Fo) from the Letaba Formation in the ~ 180-Ma Karoo LIP (

Journal ArticleDOI
TL;DR: Olivine-hosted inclusions of silicate and sulfide melts, Cr-spinel and pyroxene were studied to estimate magma composition, temperature, pressure, and fO2 at the onset and during the silicate-sulfide immiscibility in modern arc basalt from Tolbachik volcano, Kamchatka arc.

Journal ArticleDOI
01 Nov 2017-Lithos
TL;DR: In this paper, minor and trace element composition in olivines from the type aillikites from Aillik Bay in Labrador, Canada was analyzed and the olivine phenocryst compositions were interpreted to result from phlogopite and not high modal pyroxene in the source.

Journal ArticleDOI
TL;DR: In this article, a three-way integrated method, linking systems analysis of crystals, a time-integrated study of zoned olivine populations, and a forward-modeling approach using thermodynamic calculations was applied to reconstruct the timing and chronology of melt and crystal transfer prior to and during the 1669 flank eruption of Mt Etna.
Abstract: The 1669 eruption of Mt Etna was one of the most voluminous and devastating of its flank eruptions in historical times. Despite a large body of relevant research, knowledge of the timing and duration of magma transfer and magma recharge through the internal plumbing system preceding and during the eruption is still limited. To address that lack of knowledge, we apply a three-way integrated method, linking systems analysis of crystals, a time-integrated study of zoned olivine populations, and a forward-modelling approach using thermodynamic calculations. Analysis of 202 olivine crystals erupted during the initial (pre-March 20, i.e. SET1) and the final (post-March 20;i.e. SET2 and MtRs) stages of the eruption reveals the existence of three magmatic environments (MEs) in which the majority of the olivine cores [M-1 (= Fo(75-78))] and rims [i.e. M-5 (= Fo(51-59)) and M-3 (= Fo(65-69))] formed. Application of the rhyolite-MELTS software allowed us to constrain the key intensive variables associated with these MEs. We find that temperature, water content and oxidation state vary between these MEs. Application of diffusion modelling to the zoned olivine crystals allowed us to reconstruct the timing and chronology of melt and crystal transfer prior to and during the 1669 flank eruption. We find that, following the formation of the olivine cores [M-1 (= Fo(75-78))], the reservoir M-1 was intruded by batches of more evolved, degassed and possibly aphyric M-5-type magma, commencing 1 center dot 5 years prior to eruptive activity. This is the origin of the SET1 olivine rims (i.e. Fo(51-59)). In the months prior to eruption, timescale data show that recharge activity along the newly established pathway M-1-M-5 increased notably. Starting in November 1668, only a few weeks after the first intrusive episode into the M-1 reservoir, a second pulse of magma injections (M-3-type magma) occurred and a new pathway M-1-M-3 opened;this is how the SET2 olivine rims (i.e. Fo(65-69)) formed. For several weeks a bifurcated transport system with two dominant magma pathways developed along M-1-M-5 and M-1-M-3 dyke injections. Accompanied by vigorous seismicity, in the days immediately before eruption the local magma transfer dynamics changed and the M-1-M-5 recharge activity slowed down, as shown by a relative lack of crystals recording shorter timescales. M-1-M-3 recharge, however, remained high and persisted following the eruption onset on March 11, during which the SET1 lavas were drained. We propose that the change of the local magma transfer dynamics might be linked to changes in the local stress field brought on during eruption. This may potentially have been due to repeated dyke injections into Etna's shallow plumbing system disrupting the early M-1-M-5 pathway and at the same time stabilizing the M-1-M-3 route as a dominant feeder. This transfer of system feeding would reproduce the observed syn-eruptive recharge and mixing in the weeks following eruption onset, culminating in the eruption of the later SET2 lavas.

Journal ArticleDOI
TL;DR: Huili leucogranite has been identified petrologically as highly fractionated granite near Huili in the Jiaobei Terrane of the North China Craton as discussed by the authors.

Journal ArticleDOI
TL;DR: The Porcellanite Formation in the basal Semri Group of the Proterozoic Vindhyan Supergroup, exposed along the Son River Valley, India, primarily consists of intercalated silicified felsic tuff beds (porcellanites), rhyolitic breccia, and shale as mentioned in this paper.
Abstract: The Porcellanite Formation in the basal Semri Group of the Proterozoic Vindhyan Supergroup, exposed along the Son River Valley, India, primarily consists of intercalated silicified felsic tuff beds (porcellanite), rhyolitic breccia, and shale. Lensoid patches of very coarse-grained rhyolite occur in a stretch of about 10 km near the eastern end of the valley. These are newly interpreted as rhyolite flows, with flow structures including aligned volcanic fragments and phenocrysts, a few of which are ∼10-cm-long feldspars. Microphenocrysts consist of fragments of patchy perthite and quartz, with subordinate Fe-oxide minerals set in a very fine-grained groundmass of quartz and feldspar. Volcanic rock fragments and fiamme are common. Bulk chemical compositions of nine samples also identify them as rhyolite (SiO2 = 75.24%; Na2O + K2O = 7.06%, CaO = 1.66%). Rare earth element distribution is typical of granitic rocks, with a negative Eu anomaly of 0.57. The samples are enriched in U, Th, La, and Rb and d...

Journal ArticleDOI
TL;DR: Early rhyolite (ER) is a type of rhyolite tuff that is known to have a high fraction of the phenocryst contents from 0 to 2.5% as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this article, the authors present new geochronological, geochemical, isotopic and mineralogical data for both economically mineralized and barren porphyritic intrusions from the Duobuza and Naruo porphyry Cu-Au deposits.

Journal ArticleDOI
TL;DR: In this article, phase equilibria experiments have been performed on a Tungurahua andesite (Ecuador) to shed light on the magmatic conditions that lead to the July-August 2006 eruptions and the parameters that controlled the eruptive dynamics.
Abstract: Understanding the plumbing system structure below volcanoes and the storage conditions (temperature, pressure, volatile content and oxygen fugacity) of erupted magmas is of paramount importance for eruption forecasting and understanding of the factors controlling eruptive dynamics. Phase equilibria experiments have been performed on a Tungurahua andesite (Ecuador) to shed light on the magmatic conditions that lead to the July-August 2006 eruptions and the parameters that controlled the eruptive dynamics. Crystallization experiments were performed on a representative August 2006 mafic andesite product between 950-1025oC, at 100, 200 and 400 MPa and NNO+1 and +2, and water mole fractions in the fluid (XH2O) from 0.3 to 1 (water-saturation). Comparison of the natural phenocryst assemblage, proportions and phenocryst compositions with our experimental data indicates that the natural andesite experienced two levels of ponding prior to the eruption. During the first step, the magma was stored at 400 MPa (15-16 km), 1000oC, and contained ca. 6 wt % dissolved H2O. In the second step, the magma rose to a confining pressure of 200 MPa (8-10 km), where subsequent cooling (down to 975oC) and water-degassing of the magma led to the crystallization of reversely zoned rims on pre-existing phenocrysts. The combination of these processes induced oxidation of the system and overpressure of the reservoir, triggering the July 2006 eruption. The injection of a new, hot, volatile-rich andesitic magma from 15-16 km into the 200 MPa reservoir shortly before the eruption, was responsible for the August 2006 explosive event. Our results highlight the complexity of the Tungurahua plumbing system in which different magmatic reservoirs can co-exist and interact in time and are the main controlling factors of the eruptive dynamics.

Journal ArticleDOI
TL;DR: In this article, the authors focus on the 28.7 Ma Masonic Park Tuff, a dacitic ignimbrite with an estimated erupted volume of ~500 km3 and an average of 45% crystals.
Abstract: Determining the mechanisms involved in generating large-volume eruptions (>100 km3) of silicic magma with crystallinities approaching rheological lock-up (~50 vol% crystals) remains a challenge for volcanologists. The Cenozoic Southern Rocky Mountain volcanic field, in Colorado and northernmost New Mexico, USA, produced ten such crystal-rich ignimbrites within 3 m.y. This work focuses on the 28.7 Ma Masonic Park Tuff, a dacitic (~62–65 wt% SiO2) ignimbrite with an estimated erupted volume of ~500 km3 and an average of ~45 vol% crystals. Near-absence of quartz, titanite, and sanidine, pronounced An-rich spikes near the rims of plagioclase, and reverse zoning in clinopyroxene record the reheating (from ~750 to >800 °C) of an upper crustal mush in response to hotter recharge from below. Zircon U–Pb ages suggest prolonged magmatic residence, while Yb/Dy vs temperature trends indicate co-crystallization with titanite which was later resorbed. High Sr, Ba, and Ti concentrations in plagioclase microlites and phenocryst rims require in-situ feldspar melting and concurrent, but limited, mass addition provided by the recharge, likely in the form of a melt-gas mixture. The larger Fish Canyon Tuff, which erupted from the same location ~0.7 m.y. later, also underwent pre-eruptive reheating and partial melting of quartz, titanite, and feldspars in a long-lived upper crustal mush following the underplating of hotter magma. The Fish Canyon Tuff, however, records cooler pre-eruptive temperatures (~710–760 °C) and a mineral assemblage indicative of higher magmatic water contents (abundant resorbed sanidine and quartz, euhedral amphibole and titanite, and absence of pyroxene). These similar pre-eruptive mush-reactivation histories, despite differing mineral assemblages and pre-eruptive temperatures, indicate that thermal rejuvenation is a key step in the eruption of crystal-rich silicic volcanics over a wide range of conditions.

Journal ArticleDOI
TL;DR: In this article, the authors identified expressions of effusive deposits in silicic units from the Parana Magmatic Province outcropping in a key area in south Brazil where three units with different compositions occur (Caxias do Sul dacites, CSd, Barros Cassal andesites, BCs, and Santa Maria rhyolites, SMr).

Journal ArticleDOI
01 Feb 2017-Lithos
TL;DR: The dykes are vaugnerite and syenite in compositions and contain talc pseudomorphs after olivine within a fine-grained matrix that consists of K-feldspar, phlogopite with small amounts of clinopyroxene and accessory quartz, apatite, titanite and sulphides of Fe, Cu, Ni as mentioned in this paper.

Journal ArticleDOI
01 Oct 2017-Lithos
TL;DR: In this paper, the authors employed principal component analysis (PCA) to evaluate the compositional variations of volcanic rocks from the Sengan volcanic cluster of the Northeastern Japan Arc.

Journal ArticleDOI
TL;DR: The lamprophyre dykes are minettes composed of phlogopite, sanidine and calcite as discussed by the authors, and they are characterized by fractionated rare earth element patterns, radiogenic Sr and unradiogenic Nd isotope compositions.
Abstract: Abundant lamprophyre dykes occur near the northern margin of the North China Craton and offer a unique opportunity to study the nature of the mantle source. The dykes are minettes composed of phlogopite, sanidine and calcite. 40 Ar/ 39 Ar dating yields ages of 234 ± 2 and 222 ± 6 Ma. The lamprophyres are near-primary, mantle-derived ultrapotassic melts, having low SiO 2 (31.0 – 41.5 wt%) and high K 2 O (4.40 – 7.12 wt%) contents, high Mg# (62 – 84) and high contents of compatible elements. They are characterized by fractionated rare earth element patterns, radiogenic Sr and unradiogenic Nd isotope compositions ( 87 Sr/ 86 Sr i = 0.7070 – 0.7075; e Nd ( t ) = −12.8 to −9.2). A small amount of mafic crustal rocks ( 187 Os/ 188 Os i ratios of 0.4548 – 0.8068. These data suggest that the lamprophyres originated from a low degree of partial melting of an enriched subcontinental lithospheric mantle source with abundant phlogopite, clinopyroxene and carbonate. The source has been metasomatized by carbonate- and potassium-rich fluids derived from carbonated sediments recycled via subduction of Palaeo-Mongolian oceanic slab beneath the North China Craton. Supplementary material: Microprobe analyses of biotite, feldspar and carbonate, 40 Ar– 39 Ar analytical data, and 36 Ar/ 40 Ar v. 39 Ar/ 40 Ar inverse isochron diagrams for phlogopite phenocrysts and groundmass from the Datong lamprophyres are available at https://doi.org/10.6084/m9.figshare.c.3574265.

Journal ArticleDOI
TL;DR: In this article, the authors classified Northwest Africa (NWA) 7320 as a gabbroic shergottite, the second to be recognized in the martian meteorite record.