Results 51 to 60 of about 313 (146)

Pseudo-Karst Silicification Related to Late Ni Reworking in New Caledonia

, 2023
International audienceSilicification in New Caledonian pseudo-karsts developed on peridotite was assessed using δ18O and δ30Si pairs on quartz cements. The objective was to document the chronology of pseudo-karst development and cementation relative to ...
Jean-Louis Grimaud, Boiron, Marie-Christine, Sylvain Favier, Grimaud, Jean-Louis, Fabrice Golfier, Teitler, Yoram, Marie-Christine Boiron, Favier, Sylvain, Cathelineau, Michel, Golfier, Fabrice, Yoram Teitler, Michel Cathelineau   +11 more
core   +1 more source

Root calcretes and uranium-bearing silcretes at sedimentary discontinuities in the Miocene of the Madrid Basin (Toledo, Spain)

, 2013
This paper reports a detailed study of the calcrete and silcrete profiles in the Miocene detrital deposits in the western area of Madrid, at the boundary of two main sedimentary units.
Alonso-Zarza, Ana María, Bustillo, Mª Ángeles, Bustillo, M., Plet, Chloé, Bustillo Revuelta, María Ángeles, Alonso Zarza, Ana María, Alonso-Zarza, A.   +6 more
core   +1 more source

What causes differences in fracture rates of silcrete during heat treatment? A near-infrared study of water-related transformations in South African silcretes

, 2021
Discussions of heat treatment in the southern African Middle Stone Age often focus on the importance of this innovation to the development of complex technologies and the evolution of modern human cognition. Debates regarding the context of silcrete heat
Patrick Schmidt (849967), Mark N Grote (20273652), Shezani Nasoordeen (20273649), Alex Mackay (763088), Sara Watson (5347919)   +4 more
core  

Archean (3.3 Ga) paleosols and paleoenvironments of Western Australia. [PDF]

PLoS One, 2023
Retallack GJ, Schmitz MD.
europepmc   +1 more source

Phénoménes karstiques dans les roches siliceuses au Niger oriental

, 1994
Dans le Niger oriental, des phénomenes karstiques sont fréquents dans les roches siliceuses: gres, silcretes, croûtes ferrugineuses, roches cristallines. A partir des études géomorphologiques et micromorphologiques, on peut conclure a une kartsification,
Sponholtz, Barbara, Sponholz, Barbara, Barbara Sponholtz   +2 more
core   +1 more source

Eocene animal trace fossils in 1.7-billion-year-old metaquartzites. [PDF]

Proc Natl Acad Sci U S A, 2021
Bengtson S, Rasmussen B, Zi JW, Fletcher IR, Gehling JG, Runnegar B.   +5 more
europepmc   +1 more source

Silcretes in the Cobar area, New South Wales

Journal and proceedings of the Royal Society of New South Wales, 1983
(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.
Glen, R A, Hutton, J T
openaire   +2 more sources

Moganite in the Chalcedony Varieties of Continental Cherts (Miocene, Madrid Basin, Spain)

, 2012
Varieties of chalcedony (calcedonite, quartzine, and lutecite) and other optical micro- and cryptocrystalline textures of quartz and opal from Miocene silcretes of the Madrid Basin were studied using a Thermo Fisher DXR Raman microscope.
Furió Vega, Marta, Pérez Jiménez, José Luis, Bustillo Revuelta, María Ángeles, Alonso Zarza, Ana María   +3 more
core   +1 more source

Portable, non-destructive colorimetry and visible reflectance spectroscopy paired with machine learning can classify experimentally heat-treated silcrete from three South African sources. [PDF]

PLoS One, 2022
Murray JK, Oestmo S, Zipkin AM.
europepmc   +1 more source

Micromorphology and geochemistry of groundwater silcrete boulders in the eastern South Downs, UK

, 2006
Groundwater silcretes have been recognised recently as major terrestrial silicon sinks and yet their origins are poorly understood. This paper aims to further understanding of the micro-fabric, geochemistry and formation of groundwater silcretes, through
Nash, David; id_orcid, Ullyott, John
core   +1 more source