Results 51 to 60 of about 4,305 (211)

Tourmaline ⁴⁰Ar/³⁹Ar chronology of tourmaline-rich rocks from Central Iberia dates the main Variscan deformation phases

Geologica Acta, 2009
During crustal thickening, metapelites taken to depth release boron-bearing hydrothermal fluids because of progressive heating and dehydration. These fluids swiftly percolate upwards, especially if the crust is being actively deformed, to form tourmaline
F. BEA, A. PESQUERA PÉREZ, P. GONZÁLEZ MONTERO, J. TORRES RUIZ, P.P. GIL CRESPO   +4 more
doaj  

Petrography and Geochemistry of tourmaline nodules from Aderba leucogranite (northeast of Golpaygan) [PDF]

پترولوژی, 2016
The Aderba leucogranite in the Golpayegan metamorphic core complex (GMC), a part of Sanandaj-Sirjan zone, host lentiform small (2*4 cm)(Type 1) and large (7*14 cm)(Type 2)tourmaline nodules. In terms of mineralogical features, the core of these two types
Akramosadat Mirlohi, Mahmoud Khalili
doaj  

Determination of Twelve Major and Minor Elements in Tourmaline by X-ray Fluorescence Spectrometry with Fusion Sample Preparation

Yankuang ceshi, 2018
Tourmaline is a class of boron-bearing aluminosilicate minerals. It has a complex chemical component and stable chemical property, and is difficult to decompose by wet methods. The high content of B2O3 makes it difficult to simultaneously determine major
XIA Chuan-bo, CHENG Xue-hai, ZHANG Hui-tang, ZHAO Wei, WANG Qing   +4 more
doaj   +1 more source

Synergism of uncoupler dicoumarin and nonmetallic mineral tourmaline for the sewage sludge treatment process: Reducing sludge generation

Cleaner Engineering and Technology, 2020
Environmental concerns linked to the recycling of sewage sludge on land involve the hazard of nutrient leaching, impacts on soil biodiversity and greenhouse gas emissions.
Jun Li, Salma Tabassum
doaj   +1 more source

Spectroscopic Characteristics and Color Origin of Red Tourmaline from Brazil

Journal of Spectroscopy, 2022
In the present paper, I report on the spectroscopic study for tourmaline color origin, performed red samples from Minas Geras State, Brazil, by gemological routine testing, X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible ...
Ming Li
doaj   +1 more source

Two Cycles of Devonian–Triassic Extension and Compression in the Altai Accretionary Wedge: Insights From Tsogt Core Complex

Tectonics, Volume 44, Issue 12, December 2025.
Abstract The Altai Accretionary Wedge in the Mongolian Altai records a polyphase geodynamic evolution involving two extensional–compressional tectonic cycles, constrained by petrostructural analysis and zircon, monazite U–Pb, and Ar–Ar geochronology. The studied section includes a southwestern high‐grade and a northeastern low‐grade domain, previously ...
O. Lexa, P. Jeřábek, K. Schulmann, M. Racek, Y. Jiang, A. R. C. Kylander‐Clark, J. Míková, R. Spikings   +7 more
wiley   +1 more source

Insights from the compositional evolution of a multi-coloured, zoned tourmaline from the Cruzeiro pegmatite, Minas Gerais, Brazil [PDF]

European Journal of Mineralogy
This study compares the compositional evolution of a multi-coloured, zoned tourmaline crystal from the Cruzeiro pegmatite, Brazil, with the compositions of homogeneous tourmaline crystals systematically collected from the outer to the inner zones of the ...
G. B. Andreozzi, G. B. Andreozzi, C. Gori, H. Skogby, U. Hålenius, A. Altieri, F. Bosi, F. Bosi   +7 more
doaj   +1 more source

The Piedmont Zone From the Western Alps (Italy): New Insights From High‐Pressure Ophiolitic Metasediments in the Soana Valley

Journal of Metamorphic Geology, Volume 43, Issue 9, Page 909-937, December 2025.
ABSTRACT Metaophiolites and metasediments of the Piedmont Zone are exposed in the Soana Valley, a poorly studied area of the Western Alps, located between the Europe‐related Gran Paradiso massif and the Adria‐related Sesia–Lanzo zone. Previous investigations reported the occurrence of only greenschist‐facies metamorphic assemblages in the metasediments.
Alessia Modesti, Francesco Gosio, Paolo Nimis, Paola Tartarotti, Omar Bartoli, Silvana Martin   +5 more
wiley   +1 more source

Geoarchaeological Perspectives on Stelae Production Throughout the Bronze Age: Provenance, Material Properties and Rock Selection at Zebros (Idanha‐a‐Nova, Portugal)

Geoarchaeology, Volume 40, Issue 6, November/December 2025.
ABSTRACT At Monte dos Zebros (Idanha‐a‐Nova, Central Portugal), the discovery of three stelae—two Iberian Late Bronze Age stelae and one fragment of an Early/Middle Bronze Age anthropomorphic stela—represents a rare case of rock art monuments from different chronologies coexisting in the same place within a broader archaeological landscape, which ...
Rafael Ferreiro Mählmann, Ralph Araque Gonzalez, Dirk Scheuvens, Pedro Baptista, Francisco Henriques   +4 more
wiley   +1 more source

Surface Modification and Structural Characterization of Tourmaline Powder by KH-171

Kuangchan zonghe liyong
This is an article in the field of mineral materials. The tourmaline powder was modified with silane coupling agent KH-171, and the process conditions were optimized with the parameters of contact angle and turbidity of the modified product in liquid ...
Kui CUI, Yingmo HU, Baobao PANG, Shasha WU, Zhen ZHANG, Sufang GUO   +5 more
doaj   +1 more source