The effect of aqueous alteration and metamorphism in the survival of presolar silicate grains in chondrites [PDF]
, 2008 Relatively small amounts (typically between 2-200 parts per million) of presolar grains have been preserved in the matrices of chondritic meteorites.
Bischoff +31 more
core +2 more sources
U-Pb SHRIMP zircon dating of Grenvillian metamorphism in Western Sierras Pampeanas (Argentina) : correlation with the Arequipa-Antofalla craton and constraints on the extent of the Precordillera Terrane [PDF]
, 2006 The Sierras Pampeanas of Argentina, the largest outcrop of pre-Andean crystalline basement in southern South America, resulted from plate interactions along the proto-Andean margin of Gondwana, from as early as Mesoproterozoic to Late Paleozoic times (e ...
C. Mark Fanning +31 more
core +4 more sources
ORE GEOLOGY PROBLEMS AND THE HUMAN FACTOR. PART 4. METAMORPHISM AND MESOTHERMAL OREFORMATION
Известия Томского политехнического университета: Инжиниринг георесурсов, 2019 The relevance of the research. The conditions of the known large mesothermal gold deposits formation into black shales states of different age form the subject of animated discussion which often acquires the signs of substitute and probably therefore the
Igor V. Kucherenko
doaj +1 more source
Pressure, temperature and time constraints on tectonic models for southwestern Sweden [PDF]
, 2010 In this work, a number of key localities have been investigated in detail in order to provide precise constraints on models for the tectonic evolution of southern Sweden.
Austin Hegardt, Eric
core +1 more source
Lethaia, EarlyView., 2021 Biomineralization is a generic term used to indicate biological‐mediated mineral formation. In carbonate mineralization, nucleation of crystals can be: (1) controlled directly by the organisms, like in the skeletal formation of most metazoans; (2) induced by microbial communities, by indirect precipitation mediated by their metabolic activities; or (3)
Adriano Guido +4 more
wiley +1 more source
Late Precambrian U-Pb titanite age for peak regional metamorphism and deformation (Knoydartian orogeny) in the western Moine, Scotland [PDF]
, 2003 There has been controversy over the number and timing of orogenies in the Precambrian Moine block in the Scottish Caledonides since the earliest radiometric dating in the 1960s. This work challenges a recent hypothesis, that this sector of the Laurentian
Evans, J.A., Tanner, P.W.G.
core +1 more source
Литосфера, 2017 The ophiolites of the northern slope of the Kuznetsk-Alatau Ridge are the most representative fragments of the sub-oceanic crust in the region. In this article, we present the results of a study of the metabasites from ophiolite paragenesis of the ...
N. A. Dugarova +3 more
doaj +1 more source
Palaeoproterozoic prograde metasomatic-metamorphic overprint zones in Archean tonalitic gneisses, eastern Finland [PDF]
Bulletin of the Geological Society of Finland, 1999 Several occurrences of coarse-grained kyanite rocks are exposed in the Archaean area of eastern Finland in zones trending predominantly northwest-southeast that crosscut all the Archaean structures and, locally, the Palaeoproterozoic metadiabase dykes ...
M. Pajunen, M. Poutiainen
doaj +1 more source
A black shale protolith for gold-tellurium mineralisation in the Dalradian Supergroup (Neoproterozoic) of Britain and Ireland [PDF]
, 2017 The Dalradian Supergroup of Britain and Ireland is mineralised by gold-tellurium vein deposits. The host succession includes carbonaceous, pyritic shales (pelites) which were a source of trace elements, including gold and tellurium.
Armstrong, J. +5 more
core +1 more source
Jewelry Morocco septaria. Gemological characteristics and mineral composition
Известия высших учебных заведений: Геология и разведка, 2023 Background. Septaria, comprising calcareous-clay nodules with calcite veins, are widely used as jewelry and ornamental materials. Septaria from Morocco represented on the world and Russian markets of jewelry and ornamental stones remain gemologically and
D. A. Petrochenkov
doaj +1 more source