Results 41 to 50 of about 26,858 (250)

Ultralight large grain porous material - expanded obsidian [PDF]

E3S Web of Conferences, 2019
In the production of crushed stone, lithoidal pumice and perlite sand, it is advisable to separate and segregate the obsidian. Wherein, the separated obsidian is converted into production waste.
Safaryan Artsruni, Sargsyan Tamara, Kalantaryan Marine, Melyan Hripsime   +3 more
doaj   +1 more source

Spatially heterogeneous argon-isotope systematics and apparent ⁴⁰Ar/³⁹Ar ages in perlitised obsidian [PDF]

, 2018
In situ laser ablation Ar-isotope analyses of variably hydrated and devitrified obsidian from the ~ 27 Ma Cochetopa Dome, San Juan, USA, reveal complex interplay between degassing of initial Ar and absorption of atmospheric Ar.
Amalberti, Ballentine, Befus, Behrens, Behrens, Bindeman, Brown, Carroll, Carroll, Carroll, Castro, Castro, Castro, Castro, Cerling, Clausen, Denton, Denton, Fink, Flude, Flude, Flude, Friedman, Friedman, Gao, Gardner, Gilfillan, Goel, Gottsmann, Gottsmann, Guillou, Helgason, Hugh Tuffen, Huybers, Jezek, Jónasson, Kaneoka, Kaneoka, Kelley, Kuiper, Lachowycz, Lee, Lipman, Lofgren, Manley, Mark, McDougall, McGarvie, McGarvie, McGarvie, McGarvie, Mee, Mee, Morgan, Newman, Owen, Ozima, Paonita, Rampino, Renne, Richter, Richter, Richter, Ross, Ryan, Sarah C. Sherlock, Saubin, Seaman, Sherlock, Sigl, Smellie, Smellie, Smellie, Spell, Stasiuk, Steiger, Stephanie Flude, Stevenson, Stevenson, Storey, Tuffen, Tuffen, van Zuilen, Vogel, von Aulock, von Aulock, Watkins, Wilding   +87 more
core   +2 more sources

Strategies for obtaining obsidian in pre-European contact era New Zealand. [PDF]

PLoS ONE, 2014
Archaeological evidence of people's choices regarding how they supply themselves with obsidian through direct access and different types of exchanges gives us insight in to mobility, social networks, and property rights in the distant past.
Mark D McCoy, Jonathan Carpenter
doaj   +1 more source

The unknown Oldowan. ~1.7-million-year-old standardized obsidian small tools from Garba IV, Melka Kunture, Ethiopia [PDF]

, 2015
The Oldowan Industrial Complex has long been thought to have been static, with limited internal variability, embracing techno-complexes essentially focused on small-to-medium flake production. The flakes were rarely modified by retouch to produce small
GALLOTTI, ROSALIA, MUSSI, Margherita
core   +2 more sources

Energy Landscapes in Chemical Reactions and Transport

ChemPhysChem, Volume 26, Issue 6, March 15, 2025.
Kinetics/dynamics of chemical reactivity and transport of chemical species in a solid are both determined by the energy landscape in which they take place. Discussing common grounds but also distinct differences may help in advancing the understanding in both fields.
Karl‐Michael Weitzel
wiley   +1 more source

Book review: Twenty-Five Years on the Cutting Edge of Obsidian Studies: Selected Readings from the IAOS Bulletin

Journal of Lithic Studies, 2017
Edited by Carolyn D. Dillian (Coastal Carolina University), Twenty-Five Years on the Cutting Edge of Obsidian Studies: Selected Readings from the IAOS Bulletin consists of 19 previously published articles from the International Association for Obsidian ...
Sean Dolan
doaj   +1 more source

TECHNOLOGICAL EXPLORATION AND RITUAL USE OF OBSIDIAN IN ANCIENT CULTURES OF THE PACIFIC

Теория и практика археологических исследований, 2022
The article examines a range of directions and current stage of obsidian studies within the Pacifi c basin such as (1) geochemistry, identifi cation of volcanic glass sources used in ancient cultures; (2) technology, obsidian exploration methods, their ...
А.В. Табарев, А.Н. Попов, Е.А. Еремеева   +2 more
doaj   +1 more source

Chemical diffusion of fluorine in melts in the system Na2OAl2O3SiO2 [PDF]

, 1985
The volatilization of fluorine from three melts in the system Na2OAl2O3SiO2 has been investigated at 1 atm pressure and 1200–1400°C. The melts chosen have base compositions corresponding to albite, jadeite and a peraluminous melt with 75 mole % SiO2 ...
Al-Dulaimy, Angell, Arzi, Bailey, Barlow, Bond, Christiansen, Christopher M. Scarfe, Crank, Delaney, Dingwell, Donald B. Dingwell, Dunn, Eadington, Harris, Hofmann, Hunnold, Jambon, Karsten, Kogarko, Kovalenko, Kumar, Lanford, Magaritz, Manning, Navrotsky, Riebling, Seifert, Shaw, Shimizu, Smith, Taylor, Watson, Wayne Burnham, Winchell   +34 more
core   +1 more source

Challenges in dating blanket peat and implications for understanding its initiation in Ireland

Journal of Quaternary Science, EarlyView.
ABSTRACT Blanket peat is widespread in maritime extra‐tropical environments. Prehistoric land‐use activity was traditionally invoked as the stimulus of blanket peat initiation in the British Isles, but recently, climate has been viewed as the driver of peat formation.
Helen Essell, Gill Plunkett, Maarten Blaauw   +2 more
wiley   +1 more source

Chemical diffusion of fluorine in jadeite melt at high pressure [PDF]

, 1984
The chemical diffusion of fluorine in jadeite melt has been investigated from 10 to 15 kbars and 1200 to 1400°C using diffusion couples of Jadeite melt and fluorine-bearing jadeite melt (6.3 wt.% F). The diffusion profile data indicate that the diffusion
Dingwell, Donald B., Scarfe, Christopher M.   +1 more
core   +1 more source