Results 51 to 60 of about 23,609 (212)

Lithic analysis in African archaeology: Advances and key themes

Archaeometry, EarlyView.
Abstract Stone artifacts (lithics) preserve for extended periods; thus they are key evidence for probing the evolution of human technological behaviors. Africa boasts the oldest record of stone artifacts, spanning 3.3 Ma, rare instances of ethnographic stone tool‐making, and stone tool archives from diverse ecological settings, making it an anchor for ...
Deborah I. Olszewski, Amanuel Beyin, Justin Pargeter   +2 more
wiley   +1 more source

Fluidal pyroclasts reveal the intensity of peralkaline rhyolite pumice cone eruptions

Nature Communications, 2019
Dynamics of peralkaline rhyolite eruptions remain elusive due to the lack of direct observations. Here the authors provide X-ray Computed Tomography, thermal modelling and field data of fluidal shaped pyroclasts and show that peralkaline rhyolite pumice ...
Ben Clarke, Eliza S. Calder, Firawalin Dessalegn, Karen Fontijn, Joaquín A. Cortés, Mark Naylor, Ian Butler, William Hutchison, Gezahegn Yirgu   +8 more
doaj   +1 more source

Implications of Multiple Disequilibrium Textures in Quartz-Hosted Embayments

Frontiers in Earth Science, 2021
The faces of volcanic phenocrysts may be marked by imperfections occurring as holes that penetrate the crystal interior. When filled with glass these features, called embayments or reentrants, have been used to petrologically constrain magmatic ascent ...
Anna C. Ruefer, Anna C. Ruefer, Kenneth S. Befus, James O. Thompson, Benjamin J. Andrews   +4 more
doaj   +1 more source

The Rhyolite Factory: Insights from Rhyolite-MELTS Geobarometry of Plutonic Rocks and Associated Volcanics

Journal of Petrology, 2023
Abstract Magmatic systems feed eruptions to the surface; lead to the formation of ore deposits; provide energy for geothermal systems; and are key to Earth’s differentiation. While it is commonly accepted that silicic magmatic systems span much of the crust, little direct evidence is available for their vertical continuity (or lack ...
Guilherme Gualda, Calvin Miller, Blake Wallrich   +2 more
openaire   +1 more source

Thermodynamic and rheological properties of rhyolite and andesite melts [PDF]

, 1993
The heat capacities of a rhyolite and an andesite glass and liquid have been investigated from relative-enthalpy measurements made between 400 and 1800 K.
Courtial, Philippe, Dingwell, Donald B., Neuville, Daniel R., Richet, Pascal   +3 more
core   +1 more source

What can lithics tell us about hominin technology's ‘primordial soup’? An origin of stone knapping via the emulation of Mother Nature

Archaeometry, EarlyView.
Abstract The use of stone hammers to produce sharp stone flakes—knapping—is thought to represent a significant stage in hominin technological evolution because it facilitated the exploitation of novel resources, including meat obtained from medium‐to‐large‐sized vertebrates. The invention of knapping may have occurred via an additive (i.e., cumulative)
Metin I. Eren, Stephen J. Lycett, Michelle R. Bebber, Alastair Key, Briggs Buchanan, Emma Finestone, Joseph Benson, Rebecca Biermann Gürbüz, Adela Cebeiro, Roman Garba, Anne Grunow, C. Owen Lovejoy, Danielle MacDonald, Erica Maletic, G. Logan Miller, Joseph D. Ortiz, Jonathan Paige, Justin Pargeter, Tomos Proffitt, Mary Ann Raghanti, Teal Riley, Jeffrey I. Rose, David M. Singer, Robert S. Walker   +23 more
wiley   +1 more source

Bottom sediments of Lake Rotoma [PDF]

, 1983
Lake Rotoma is a deep (70-80 m), oligotrophic, warm monomictic lake of volcanic origin with insignificant stream inflow and no clearly defined outflow. For at least 60 years up to 1972 the lake level fluctuated markedly about an overall rising trend of ...
_____, _____, _____, _____, _____, _____, Anonymous, Brown J. M. A., Cassie Vivienne, Chapman V. J., Clayton J. S., Cole J. W., Davis R. B., Emery K. O., Ewart A., Fish G. R., Flint E. A., Folk R. L., Folk R. L., Gee F., Glasby G. P., Grange L. T., Healy J., Healy J., Howard R. K., Howorth R., Irwin J., Jolly V. H., Jolly V. H., Jordan C. F., Kamp P. J. J., Kirkman J. H., Kohn B. P., Lawless J. V., Lister G. S., Main W. de L., McColl R. H. S., McManus D. A., Mitsui K., Passega R., Phillips C. J., Pickrill R. A., Stumm W., Swift D. J. P., Visher G. S., Vucetich C. G., White E.   +46 more
core   +2 more sources

Sourcing carnelian beads from the ancient Mesopotamian site of Kish, Iraq, 2450–2200 BCE: Stylistic, technological and geochemical approaches

Archaeometry, EarlyView.
Abstract Trade between Mesopotamia and the Indus Civilization is studied through the analysis of Early Dynastic III Period (2600–2350 BCE) carnelian beads from the site of Kish, Iraq. Morphological and technological features of the beads are compared with beads from the Indus region.
J. Mark Kenoyer, Randall W. Law, Laure Dussubieux   +2 more
wiley   +1 more source

Greek Commodities in Phoenicia: An Interdisciplinary Study of Imported Amphorae From Tell el‐Burak (Lebanon)

Archaeometry, EarlyView.
ABSTRACT This paper examines transport amphorae of Greek/Aegean types from the 7th–4th c. BCE imported to the Phoenician coastal settlement of Tell el‐Burak, Lebanon. We present a selection of 58 pieces analyzed by typological, chemical (NAA), and petrographic approaches.
Maximilian Rönnberg, Marcel Frenken, Johannes H. Sterba, Silvia Amicone   +3 more
wiley   +1 more source

Evidence for Miocene subduction beneath the Alboran Sea (Western Mediterranean) from 40Ar/39Ar age dating and the geochemistry of volcanic rocks from holes 977A and 978A [PDF]

, 1999
Volcanic pebbles in gravels from Sites 977 and 978 in the Alboran Sea (western Mediterranean) were dated (using the 40Ar/ 39Ar single-crystal laser technique) and analyzed for their major- and trace-element compositions (determined by X-ray ...
Duggen, Svend, Garbe-Schönberg, Dieter, Hoernle, Kaj, Mocek, Beate, van den Bogaard, Paul   +4 more
core