Results 1 to 10 of about 313 (146)
Petrological and geochemical characterisation of the sarsen stones at Stonehenge [PDF]
PLoS ONE, 2021 Little is known of the properties of the sarsen stones (or silcretes) that comprise the main architecture of Stonehenge. The only studies of rock struck from the monument date from the 19th century, while 20th century investigations have focussed on ...
David J. Nash +14 more
doaj +9 more sources
Titania in Australian massive silcretes
Australian Journal of Earth Sciences, 2017 Selected silcretes formed by cementation of stream sediments and having >90 wt% SiO2, have been examined optically and by scanning electron microscopy. Such silcretes have quartz framework grains cemented by a plasma of quartz and anatase.
R A Eggleton
exaly +5 more sources
Knapping force as a function of stone heat treatment [PDF]
PLoS ONE, 2022 We propose a quantitative framework for understanding the knapping force requirements imposed by different raw materials in their unheated and heat-treated states.
Klaus G. Nickel, Patrick Schmidt
doaj +3 more sources
Journal of the Geological Society of Australia, 1972 Detailed petrographic and chemical studies of silcretes collected from Beda Valley near the southern extremity of Lake Torrens, South Australia, have shown that there are at least two distinct types.
C R Twidale, A R Milnes
exaly +4 more sources
Reassessing southern African silcrete geochemistry: implications for silcrete origin and sourcing of silcrete artefacts [PDF]
Earth Surface Processes and Landforms, 2020 A synthesis of the geochemistry of silcretes and their host sediments in the Kalahari Desert and Cape coastal zone, using isocon comparisons, shows that silcretes in the two regions are very different.
Nash, David; id_orcid +3 more
core +4 more sources
The composition, geography, biology and assembly of the coastal flora of the Cape Floristic Region [PDF]
PeerJ, 2021 The Cape Floristic Region (CFR) is globally recognized as a hotspot of plant diversity and endemism. Much of this diversity stems from radiations associated with infertile acid sands derived from sandstones of the geologically ancient Cape Fold Belt ...
B. Adriaan Grobler, Richard M. Cowling
doaj +3 more sources
Late Neogene terrestrial climate reconstruction of the central Namib Desert derived by the combination of U–Pb silcrete and terrestrial cosmogenic nuclide exposure dating [PDF]
Geochronology, 2023 The chronology of the Cenozoic “Namib Group” of the Namib Desert is rather poorly understood and lacks direct radiometric dating. Thus, the paleoclimate and landscape evolution of the central Namib Desert remains imprecise, complicating the detailed ...
B. Ritter +8 more
doaj +2 more sources
Silcrete: an Australian perspective
Australian Journal of Earth Sciences, 2020 We know how most rocks are formed. Silcrete is something of an enigma, for although there are many interpretations of the origins of individual silcrete bodies, such as those in the Paris Basin, England, Botswana and central Australia, an overarching ...
Taylor, G, Eggleton, Richard
core +4 more sources
Calcretes, silcretes and intergrade duricrusts [PDF]
, 2022 Calcretes and silcretes are the most widely encountered ‘rocks’ in the Kalahari sandveld that covers much of Botswana. This chapter presents the first holistic overview of current knowledge about these duricrusts at a national scale.
Nash, David; id_orcid
core +2 more sources