Results 71 to 80 of about 763 (175)

Evolution Model for the Paleoproterozoic Talvivaara Mudstone‐Hosted Ni‐Zn‐Cu‐Co Deposit in Fennoscandia

Terra Nova, EarlyView.
ABSTRACT The Paleoproterozoic Talvivaara mudstone is a very large sulfidic Ni‐Co deposit that records enhanced organic matter accumulation during the global Shunga Event. Here, rock geochemistry and microscale S and Fe isotope composition of in situ pyrrhotites and pyrites are studied in well‐characterised, well‐preserved drill core samples.
Raimo Lahtinen, Jaakko J. Laitala, Joonas J. Virtasalo, Martin J. Whitehouse   +3 more
wiley   +1 more source

Is Endmember Extraction a Critical Step in the Analysis of Hyperspectral Images in Mining Environments?

Remote Sensing
Hyperspectral imaging systems (HSIs) are becoming widespread in the mining industry for mineral classification. The spectral features detectable from near infrared to long-wave infrared make HSIs a potentially efficient tool for exploration, clay mapping,
Jingping He, Dean N. Riley, Isabel Barton   +2 more
doaj   +1 more source

Automatic Extraction of Optimal Endmembers from Airborne Hyperspectral Imagery Using Iterative Error Analysis (IEA) and Spectral Discrimination Measurements

Sensors, 2015
Pure surface materials denoted by endmembers play an important role in hyperspectral processing in various fields. Many endmember extraction algorithms (EEAs) have been proposed to find appropriate endmember sets.
Ahram Song, Anjin Chang, Jaewan Choi, Seokkeun Choi, Yongil Kim   +4 more
doaj   +1 more source

Extraordinary methane levels in a small bar‐built tropical estuary

Limnology and Oceanography Letters, Volume 11, Issue 4, July 2026.
Abstract Small estuaries link uplands and nearshore marine environments but are understudied in many regions. We quantified spatial and temporal variability in CH4, CO2, nutrients, and organic matter in a small, deep, bar‐built tropical estuary in Fajardo, Puerto Rico.
William H. McDowell, Tatiana Barreto‐Vélez, Ricardo Colón‐Rivera, Jody D. Potter   +3 more
wiley   +1 more source

Global Glacial Rock Weathering Signature Depends on Competing Contributions From Ice Sheets and Alpine Glaciers

Geophysical Research Letters, Volume 53, Issue 11, 16 June 2026.
Abstract Rock weathering influences Earth's atmosphere and climate. The dissolution of silicate minerals draws down atmospheric CO2 while sulfide oxidation coupled with carbonate dissolution releases CO2. Alpine glacier rock weathering causes high sulfide oxidation and carbonate dissolution.
S. Muñoz, L. C. Smith, G. Piccione, S. E. Esenther, E. J. Ramos, J. Jenckes, L. A. Munk, D. E. Ibarra   +7 more
wiley   +1 more source

A Physically Constrained and Library-Guided Convolutional Autoencoder for Mineral Hyperspectral Unmixing

Remote Sensing
Hyperspectral unmixing is an important technique for mineral mapping because natural geological scenes commonly contain mixed pixels composed of multiple spectrally overlapping materials.
Yuxi Hao, Kai Qin, Yingjun Zhao, Guofang Yang, Xin Cui, Ling Zhu, Jun Yang   +6 more
doaj   +1 more source

Elucidating the Reactivity and Fate of Dissolved Organic Matter in Groundwater Entering the Alaska Beaufort Sea Coast Using 14C Ramped Oxidation

Geophysical Research Letters, Volume 53, Issue 11, 16 June 2026.
Abstract Supra‐permafrost groundwater (SPGW) is a significant but understudied source of dissolved organic matter (DOM) to Arctic coastal systems. We applied ramped pyrolysis/oxidation (RPO) with Δ14C and δ13C isotopic analysis to assess DOM reactivity and origin in SPGW, river, and lagoon waters along the Alaska Beaufort Sea coast.
C. T. Connolly, R. G. M. Spencer, J. W. McClelland   +2 more
wiley   +1 more source

Sodium Tetraazidoaurate(III)—From Na[AuCl4]·2H2O to Na[Au(N3)4] and Beyond One Step at a Time

Chemistry – A European Journal, Volume 32, Issue 22, 9 June 2026.
Novel sodium chlorido‐/azidoaurate(III) dihydrates Na[AuCl4–x(N3)x]·2H2O (x = 0, 1, 2, 3, 4) provide the first example of a complete series of gradual substitution on tetramer complex anions to be described. Controlled dehydration of Na[Au(N3)4]·2H2O leads to Na[Au(N3)4]·H2O and Na[Au(N3)4], the latter being a highly explosive material.
Mehmet Somer, Joannis Psilitelis, Raul Cardoso‐Gil, Thomas Doert, Franziska Jach, Ayberk Yılmaz, Alexander Ovchinnikov, Yurii Prots, Helge Rosner, Marcus P. Schmidt, Peter Höhn   +10 more
wiley   +1 more source

Vertical and Spatial Geochemical Variations of Nishinoshima Volcaniclastic Deposits, Japan, During Episode 4

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
Nishinoshima is a volcanic island in the Ogasawara Arc that has exhibited intermittent activity since 2013, including four major eruptive episodes: 2013–2015 (Episode 1), 2017 (Episode 2), 2018 (Episode 3), and 2019–2020 (Episode 4). Previous studies reported a change in eruption style—from a Strombolian eruption with lava flows (Episode 1 to the early
Erika Tanaka, Kenta Yoshida, Tomoki Sato, Yoshiro Nishio, Yoshihiko Tamura   +4 more
wiley   +1 more source

Bioanalytical TERS and Advanced Data Processing Methods

Journal of Raman Spectroscopy, Volume 57, Issue 6, Page 977-994, June 2026.
Tip‐enhanced Raman spectroscopy delivers label‐free, subnanometer vibrational imaging of biological systems. Recent advances in instrumentation, data analysis, and ambient/liquid operation enable surface‐selective mapping of molecular heterogeneity in proteins, nucleic acids, membranes, and viruses, positioning TERS as a powerful platform for nanoscale
Sarika Joshi, Ankit Dodla, Sarthak Saxena, Twinkle Soni, Sumit Saxena, Shobha Shukla, Bayden R. Wood   +6 more
wiley   +1 more source