Results 81 to 90 of about 51,695 (270)

Thortveitite-type Tm2Si2O7

Acta Crystallographica Section E, 2014
Single crystals of dithulium disilicate, Tm2Si2O7, were obtained in flux synthesis experiments in the system SiO2–Tm2O3–LiF at ambient pressure. The compound belongs to the group of sorosilicates, i.e. it is based on [Si2O7]-units and crystallizes in the
Volker Kahlenberg, Paul Aichholzer
doaj   +1 more source

The development of numerical forecasting systems of primary sources of gold on the results of placer sampling in the example Vagran placer cluster (North Urals)

Georesursy, 2020
Based on the results of field research, as well as data from stock reports, two types of placer gold were identified within the Vagran placer cluster, which are indicators of primary mineralization.
Alexander V. Lalomov, Anna A. Bochneva , Roman M. Chefranov   +2 more
doaj   +1 more source

Petrologic evidence for earliest Miocene tectonic mobility on eastern Taranaki Basin margin [PDF]

, 2006
At Gibsons Beach on the west coast of central North Island, the earliest Miocene (Waitakian) Otorohanga Limestone, the top-most formation in the Te Kuiti Group, is unconformably overlain on an undulating, locally channelised erosion surface by the Early ...
Hood, Steven D., Kamp, Peter J.J., Nelson, Campbell S., Tripathi, Anand Ratnakar Prasad   +3 more
core   +1 more source

Relationship between Degree of Deformation in Quartz and Silica Dissolution for the Development of Alkali-Silica Reaction in Concrete. [PDF]

, 2017
This paper presents research on the influence of quartz deformation in aggregates for the development of the alkali-silica reaction in concrete and its relationship with silica dissolution.
Dal Molin, Denise, Gomes, Marcia, Hasparyk, Nicole, MONTEIRO, Paulo J.m., Tiecher, Francieli   +4 more
core   +1 more source

Confirming the impact origin of the São Miguel do Tapuio structure, northeastern Brazil

Meteoritics &Planetary Science, EarlyView.
Abstract The São Miguel do Tapuio structure (SMT) is a remarkable, nearcircular feature of about 21 km diameter, centered at 5°37.6′ S, 41°23.3′ W in Piauí state, northeastern Brazil. The structure is located within the sedimentary strata of the Paleozoic–Mesozoic Parnaíba Basin and predominantly comprises sandstones of the Devonian Pimenteiras and ...
Alvaro Penteado Crósta, Neivaldo Araújo de Castro, Marcos Alberto Rodrigues Vasconcelos, Airton Natanael Coelho Dias, Ludovic Ferrière, Wolf Uwe Reimold, Ana Maria Góes, Jackson Alves Martins, Liliana Sayuri Osako, Raimundo Mariano Gomes Castelo Branco   +9 more
wiley   +1 more source

K9Y3[Si12O32]F2

Acta Crystallographica Section E, 2014
Single-crystals of the title compound, nonapotassium triyttrium dodecasilicate difluoride, were obtained from flux synthesis experiments in the system SiO2—Y2O3—KF.
Volker Kahlenberg, Tanja Manninger
doaj   +1 more source

The Moss (CO3) meteorite: an integrated isotopic, organic and mineralogical study [PDF]

, 2007
The recent Moss meteorite fall presents a unique opportunity to investigate the processes that operated on the CO3 parent body. The results of an integrated study indicate that alteration on the CO3 asteroid was more complex than previously ...
Bartoschewitz, R., Franchi, I. A., Greenwood, R. C., Johnson, D., Pearson, V. K., Raade, G., Roaldset, E., Verchovsky, A. B.   +7 more
core  

The effect of terrestrial weathering on the mineralogy and petrologic (sub)types of CM chondrites explored by kinetic modeling and laboratory experiments

Meteoritics &Planetary Science, EarlyView.
Abstract Terrestrial weathering alters the chemical and isotopic composition, and mineralogy, of meteorites; its effects on ordinary chondrites are well‐studied, but relatively little is known about the susceptibility of carbonaceous chondrites. We combined laboratory experiments, whereby Chwichiya 002 (C3‐ung find), Murchison (CM2 fall) and Kolang ...
Robin L. Haller, Martin R. Lee, Mark E. Hodson   +2 more
wiley   +1 more source

Peculiarities of formation, isomorphism and geochemistry of trace elements of sphalerite and wurtzite unusual varieties from the Goniatite occurrence (Pai-Khoi Ridge, Nenets Autonomous District)

Записки Горного института
A unique Mn-, Cd-bearing sphalerite from quartz-calcite veins in the coal-bearing series (Visean C1v) marine sediments in a 50 km segment of the middle course of the Silova-Yakha River in the Arctic zone of the European part of Russia (Pai-Khoi Ridge ...
Aleksandr B. Makeyev, Ilya V. Vikentyev, Elena V. Kovalchuk, Vera D. Abramova, Vsevolod Yu. Prokofyev   +4 more
doaj  

Aqueous alteration in C2‐ung Bells through the analysis of carbonates – Does a CR origin ring true?

Meteoritics &Planetary Science, EarlyView.
Abstract Bells is an ungrouped carbonaceous chondrite that has in recent years been proposed as a CR‐an. This link to CR chondrites has previously been identified through the analysis of anhydrous silicates, for example, oxygen isotopic compositions of olivine (Marrocchi et al., 2023).
L. J. Riches, M. D. Suttle, I. A. Franchi, X. Zhao, M. M. Grady   +4 more
wiley   +1 more source