Results 131 to 140 of about 31,485 (279)

Pyrite and Pyrrhotite [PDF]

open access: yes, 1979
Pyrite and pyrrhotite are the only minerals other than native sulphur used in the manufacture of sulphuric acid. Pyrite is known to occur separately in Amjhore area of Bihar and as associated mineral in the complex base metal sulphides of ...
Altekar, V A   +3 more
core  

Reaffirming the Consistency of the Original Stock of NBS 19 Limestone and Its Byproduct With Finer Grain Size for δ13C and δ18O Calibrations—Both Distributed Internationally

open access: yesRapid Communications in Mass Spectrometry, Volume 40, Issue 18, 30 September 2026.
ABSTRACT Rationale Approximately 3–4 kg of NBS 19 limestone, prepared in 1982 by the U.S. Geological Survey (USGS), serves as a primary reference for the carbon isotope scales VPDB and VPDB‐LSVEC and the oxygen isotope scale VPDB. Its consensus values are +1.95‰ for δ13C and −2.2‰ for δ18O measurements.
Haiping Qi   +3 more
wiley   +1 more source

Beach Gold and Heavy Mineral Concentrates on Tiwai Spit Gravel Strand Plain, Southland, New Zealand

open access: yesNew Zealand Journal of Geology and Geophysics, Volume 69, Issue 3, September 2026.
The Holocene Tiwai Spit on Foveaux Strait is a 12 km by 2 km gravel‐dominated strand plain, ∼10 m above present sea level. Gravel clasts are dominated by well‐rounded quartz cobbles, pebbles and granules derived from Otago Schist 200 km to the north in evolving river drainage systems during late Cenozoic.
Marshall Palmer, Dave Craw
wiley   +1 more source

Authigenic pyrite-magnetic susceptibility relationships influenced by methane seepage (Site U1445, Bay of Bengal)

open access: yesFrontiers in Marine Science
The sulfate-methane transition zone (SMTZ) is a pivotal biogeochemical site within marine sediment columns where anaerobic oxidation of methane (AOM) facilitates the reductive dissolution of Fe-(oxyhydr)oxides and forms iron sulfide minerals (ultimately ...
Qiang Song   +10 more
doaj   +1 more source

Massive Rocky Planets May Suppress Deep Melting

open access: yesAGU Advances, Volume 7, Issue 4, August 2026.
Abstract Melting properties of silicates are critical to understanding the thermal evolution of rocky planetary interiors. In the deep mantles of massive rocky planets, post‐post‐spinel Mg2SiO4 ${\text{Mg}}_{2}{\text{SiO}}_{4}$ is potentially one of the most abundant mineral phases, yet its melting behavior remains unconstrained. Here, we determine the
Donghao Zheng, Yihang Peng, Jie Deng
wiley   +1 more source

Ceramic Production and Geodiversity in Iron Age Iberia: An Archaeometric Study of Pottery from Castrejón de Capote (SW Spain)

open access: yesArchaeometry, Volume 68, Issue 4, Page 659-673, August 2026.
ABSTRACT The hillfort of Castrejón de Capote is one of the best investigated settlements of Late Iron Age southwest Iberia. Located in the territory that the classical sources attributed to the Celtici, it was occupied between the early 4th and the 1st centuries bce.
Beatrijs de Groot   +2 more
wiley   +1 more source

Palladium‐Doping‐Enabled Interface Synergy for Superb Ampere Level Ammonia Electrosynthesis From Nitrate

open access: yesAngewandte Chemie, Volume 138, Issue 28, 6 July 2026.
Isolated Pd sites in a metallic Co matrix boost nitrate‐to‐ammonia conversion. Pd doping optimizes intermediate adsorption and reconstructs the interfacial microenvironment, promoting cation enrichment and a hydrogen‐down‐oriented water network. This dual modulation facilitates proton transfer and intermediate stabilization, enabling high ammonia ...
Qun He   +6 more
wiley   +2 more sources

Climate conditions on the South‐Iberian Palaeomargin during the latest Pliensbachian to early Toarcian: A mineralogical and geochemical study from hemipelagic deposits

open access: yesSedimentology, Volume 73, Issue 5, Page 1631-1663, August 2026.
ABSTRACT The integrated analysis of lithofacies, mineralogy and geochemistry of the hemipelagic marine succession exposed in La Cerradura section (South‐Iberian Palaeomargin) provides new information to characterise the palaeoenvironmental conditions during the latest Pliensbachian to early Toarcian, including the Jenkyns Event.
Chaima Ayadi   +4 more
wiley   +1 more source

Utilização de compósito carvão/Fe2O3 e pirita como catalisadores de peroxidação de efluentes têxteis [PDF]

open access: yes, 2007
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia QuímicaÓxidos de ferro são catalisadores efetivos na oxidação catalítica do peróxido de hidrogênio e este processo tem sido ...
Machado, Luciano Luiz
core  

Sedimentology of silica granules and haematite in the 3.47 Ga Antarctic Creek Member, Mount Ada Basalt, Western Australia

open access: yesSedimentology, Volume 73, Issue 5, Page 1842-1866, August 2026.
ABSTRACT The Paleoarchean Antarctic Creek Member of the Mount Ada Basalt, Eastern Pilbara Terrane, Western Australia, includes beds of jasper and white chert composed of sand‐sized silica granules that often contain or are mixed with silt‐sized particles of haematite.
Donald R. Lowe, Gary R. Byerly
wiley   +1 more source

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