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The GEOROC database includes helpful compilations of mineral compositions aggregated from measurements reported in decades worth of publications, but it can be challenging to consistently filter mislabeled, inaccurate, or incomplete mineral compositions. MIST (Mineral Identification by Stoichiometry) is a stoichiometry-based computational algorithm that identifies geochemical observations with normalized elemental ratios matching natural minerals. The stoichiometric filters that were manually coded in MIST for over 240 mineral species are based on reported mineral formulas and well-documented examples of mineral chemistry reported in RRUFF and associated databases, typically including a ~5-10% tolerance in stoichiometric ratios based on measurement errors, vacancies, and substitutions. The MIST model can therefore efficiently filter the GEOROC mineral compilation files to recognize compositions whose normalized oxides match the labeled mineral stoichiometry. Furthermore, the MIST output includes results of intermediate data manipulation steps, a detailed stoichiometric formula for each input composition, and consistently calculated mineral endmembers such as Fo, En, Ws, and Fs. MIST is agnostic to the instrument used to collect oxide data. Because MIST uses normalized oxides, it cannot distinguish between some mineral species, where applicable, they are reported as a group (e.g., gypsum/bassanite/anhydrite). MIST can only recognize minerals encoded in the algorithm, so other real but less common minerals will not be recognized. The full list of minerals MIST can recognize, along with more details of the algorithm and results pages, are published in Siebach et al. (https://doi.org/10.1016/j.cageo.2025.106021). This dataset includes fifteen of the Compiled Mineral files published by GEOROC in 12-2024 including the MIST results (whether or not a species was confirmed by MIST). Prior to running the data through MIST, all files were filtered to only include mineral compositions that included major oxides (e.g., silicate mineral compositions where SiO2 > 0 wt%). Furthermore, all variations of reported Fe were collapsed into a single column representing FeOT. Metadata is preserved from the original compiled GEOROC files, so users may add additional filters as appropriate for different purposes. Results have not been filtered for reported sum of total oxides, but doing so can help identify particular mineral species (e.g., separate gypsum from bassanite). An additional file preserves the full reference information for each mineral compilation. We suggest using the compositions that MIST identifies as stoichiometrically consistent with a mineral species as a standardized filter on the GEOROC datasets prior to utilizing the data in machine learning models or similar applications. These may also be helpful any time a user would like standardized formulas or mineral endmember information for these mineral compilations.
The USGS has suspended the distribution of the widely used whole rock reference materials BHVO, BCR and BIR. The goal of this work is to identify a material as similar as possible to the original BIR Islandic basalt. This material can then undergo an ISO-compliant certification of the whole rock powder major and trace element contents. The sampling quarry east of Reykjavik has multiple basalt flows and it is not known which one was originally sampled in 1980 for production of above mentioned reference materials. In this study, three samples were tested to see which is most similar to what was published by Flanigan (1984). Here, the results of this exploratory sample collection are presented, but note that these data are not part of the certification process or represent certified results.
Full element (major elements, minor elements, platinum-group elements and gold) analysis of high- and low-Mg lavas from several eruptions of Tolbachik volcano, Kamchatka, Russia. Eruptions include 2012-13, 1975-76, 1941 and several recent prehistoric (<1400 years old) eruptions. Major elements were measured by XRF, minor elements by ICP-MS and platinum-group elements and gold were measured using Ni-sulfide fire assay and ICP-MS. All analyses were undertaken at Geoscience Laboratories (Geo Labs) Ontario Geological Survey in 2019. These data were originally published as a supplement to Kutyrev et al. (2021), Noble Metals in Arc Basaltic Magmas Worldwide: A Case Study of Modern and Pre-Historic Lavas of the Tolbachik Volcano, Kamchatka, In Frontiers in Earth Science (9), https://doi.org/10.3389/feart.2021.791465. This work was funded by the Ministry of Science and High Education of the Russian Federation (Grant No 075-15-2019-1883), The National Research Foundation (NRF) of the Korean government (No. 2019R1A2C1009809A) and the Russian Science Foundation (Grant #21-17-00122).
This data set is the source of my doctoral thesis and of three resulting publications. Through whole rock geochemistry of selected samples and microprobe and geochronological analyses of key minerals, formerly selected by extensive microscopical studies, standard geothermobarometry and modelling was applied. It has been shown that metamorphic rocks, in particular, the eclogites of the northern Kaghan Valley, Pakistan, were buried to depths of 140-100 km (36-30 kbar) at 790-640°C. Subsequently, cooling during decompression (exhumation) towards 40-35 km (17-10 kbar) and 630-580°C has been superseded by a phase of reheating to about 720-650°C at roughly the same depth before final exhumation has taken place. In the southern-most part of the Kaghan Valley, amphibolite facies assemblages with formation conditions similar to the deduced reheating phase indicate a juxtaposition of both areas after the eclogite facies stage and thus a stacking of Indian Plate units. Radiometric dating of zircon, titanite and rutile by U-Pb and amphibole and micas by Ar-Ar reveal peak pressure conditions at 47-48 Ma. With a maximum exhumation rate of 14 cm/a these rocks reached the crust-mantle boundary at 40-35 km within 1 Ma. Subsequent exhumation (46-41 Ma, 40-35 km) decelerated to ca. 1 mm/a at the base of the continental crust but rose again to about 2 mm/a in the period of 41-31 Ma, equivalent to 35-20 km. Apatite fission track (AFT) and (U-Th)/He ages from eclogites, amphibolites, micaschists and gneisses yielded moderate Oligocene to Miocene cooling rates of about 10°C/Ma in the high altitude northern parts of the Kaghan Valley using the mineral-pair method. AFT ages are of 24.5±3.8 to 15.6±2.1 Ma whereas apatite (U-Th)/He analyses yielded ages between 21.0±0.6 and 5.3±0.2 Ma. The southern-most part of the Valley is dominated by younger late Miocene to Pliocene apatite fission track ages of 7.6±2.1 and 4.0±0.5 Ma that support earlier tectonically and petrologically findings of a juxtaposition and stack of Indian Plate units. As this nappe is tectonically lowermost, a later distinct exhumation and uplift driven by thrusting along the Main Boundary Thrust is inferred. Out of this geochemical, petrological, isotope-geochemical and low temperature thermochronology investigations it was concluded that the exhumation was buoyancy driven and caused an initial rapid exhumation: exhumation as fast as recent normal plate movements (ca. 10 cm/a). As the exhuming units reached the crust-mantle boundary the process slowed down due to changes in buoyancy. Most likely, this exhumation pause has initiated the reheating event that is petrologically evident (e.g. glaucophane rimmed by hornblende, ilmenite overgrowth of rutile). Late stage processes involved widespread thrusting and folding with accompanied regional greenschist facies metamorphism, whereby contemporaneous thrusting on the Batal Thrust (seen sometimes equivalent to the MCT) and back sliding of the Kohistan Arc along the inverse reactivated Main Mantle Thrust caused final exposure of these rocks. Similar circumstances have been seen at Tso Morari, Ladakh, India, 200 km further east where comparable rock assemblages occur. In conclusion, as exhumation was already done well before the initiation of the monsoonal system, climate dependent effects (erosion) appear negligible in comparison to far-field tectonic effects. Thus, the channel flow model is not applicable for this part of the Himalayas.
This data publication contains mineralogical, geochemical and magnetic susceptibility data of an 87.2 m deep profile of hydrothermally altered plutonic rock in a semi-arid region of the Chilean Coastal Cordillera (Santa Gracia). The profile was recovered during a drilling campaign (March and April 2019) as part of the German Science Foundation (DFG) priority research program SPP-1803 “EarthShape: Earth Surface Shaping by Biota” which aims at understanding weathering of plutonic rock in dependency on different climatic conditions. The goal of the drilling campaign was to recover the entire weathering profile spanning from the surface to the weathering front and to investigate the weathering processes at depth. To this end, we used rock samples obtained by drilling and soil/saprolite samples from a manually dug 2 m deep soil pit next to the borehole. To elucidate the role of iron-bearing minerals for the weathering, we measured the magnetic susceptibility, determined the mineral content and analysed the geochemistry as well as the composition of Fe-bearing minerals (Mössbauer spectroscopy) in selected samples.
During the Egyptian 18th dynasty (c. 1550–1292 BC), cobalt ore was mined, processed and used as a colourant for glass, faience and blue-painted pottery. Co-coloured glass objects have a mid- to dark blue colour and were produced in order to imitate the semi-precious stone lapis lazuli. During this period, the glass objects were manufactured predominantly at two sites: Malqata (25°42'51.2"N 32°35'33.4"E) and Amarna (27°38'40.3"N 30°53'55.0"E).Major, minor and trace element concentration data from 38 blue glass objects from Amarna in the collection of Egyptian Museum and Papyrus Collection in Berlin are reported in this data publication. For comparison, glass objects from the same period and location, but of different colours (one red, two each of colourless, green and turquoise-blue glass) were analysed with the same method. These objects were originally brought to Berlin subsequent to the 1911–1914 excavations at Amarna carried out under the direction of Ludwig Borchardt on behalf of the Deutsche Orient-Gesellschaft. Unfortunately, most of these have by now lost their specific finds location. In addition, two recent samples of cobalt ore from the region of Ain Asil, near the Dakhla oasis (25°30'59.6"N 29°09'59.8"E), were included in the analysis.
The Central Rift in Kenya (CRK) comprises the lakes Naivasha, Elementaita and Nakuru and the Longonot, Eburru and Menengai volcanos. The alkaline magmas, produced by the volcanoes within the CRK, lead to solid rocks likes trachytes, phonolites, and fewer basalts and accompanied soft rocks like ashes, tuffs, pumices and ignimbrites (e.g. Macdonald et al., 1987; Macdonald, 2014). Lacustrine sediments and beds of diatoms are remnants of former lake level variations caused by climate variability and topographic changes (e.g. Stoof-Leichsenring et al., 2011). The samples have been taken within the frame of a VW-Foundation funded project that tries to detect, map and monitor groundwater pollution from anthropogenic and natural sources. For a previous VW-Foundation funded project (grant 85465), also the groundwater fluoride enrichment in the CRK have been studied (Olaka et al., 2016).This data report presents the metadata, inclusive GPS data from 52 solid volcanic rock and sediment samples taken during a field excursion during May 2017. A geological map with all data locations is included in this report. After sample preparation, we performed X-ray diffraction (XRD) analyses to get the mineral content and X-ray fluorescence (XRF) as well as Ion-Chromatographic (IC) analyses to get the elemental concentration of those samples. The results are given together with analytical limitations and few additional information despite a graphic visualization of the XRD-data.The data are presented in tab-delimited text format and described in the dataset description.
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