Search results for "Dolomite"
showing 9 items of 29 documents
Investigation of mass graves in the Churchyard of St. Gertrude’s, Riga, Latvia
2011
Formation of calcium containing minerals in the low temperature dolomite ceramics
2011
In order to elaborate low temperature dolomite ceramics, potentially suitable for the production of building materials, local low carbonate clay and dolomite siftings were used as a raw materials. Relationship between mechanical properties, mineral composition and firing temperature kept in the range of 600-800° C were established. According to the obtained data it was detected that the optimal burning temperature, giving the highest crushing strength (40 MPa) was around 700-750° C, optimal proportion of dolomite and clay expressed as ratio between CaO and Al2O3 - 2.5 wt%. Gradual formation of C3A occurs during firing, yielding C4AHX, i.e. mainly C4AH13 after hydratation of obtained composi…
Sedimentology, petrography and geochemistry of a limestone breccia (Pietra di Billiemi) from NW Sicily, Italy: implications for evolution of the Teth…
2009
In this study, the Pietra di Billiemi, a famous dimension stone, is investigated because it records the tectonic evolution of the south Tethys continental margin and preserves a record of major environmental changes occurring near the Triassic/Jurassic boundary. The Pietra di Billiemi is a grey, coarse-grained and clast-supported limestone breccia cropping out in an area of the Palermo Mountains representing a segment of the Apennine–Maghrebian chain in western Sicily. The rock consists of metre-sized to centimetre-sized angular clasts, derived from Upper Triassic sponge boundstones and rudstones, with a differently coloured, silt-grained matrix. Fitted fragments are observed commonly which…
Roman quarries of the Iberian Peninsula: "Anasol" and "Anasol-type".
2007
The Iberian peninsula is rich in marble, both white and coloured, of excellent quality, used in the past (Pliny NH, XXXVI, II) and also at the present time as material for building and decoration. Many types of these marbles are similar to some, better known, Greek, Italian, Egyptian and Asian marbles. During the Roman Empire “ marmor carystium ” was extensively used. Taking into account the great similarity of this marble with the “ anasol ” and “ anasol ”-types mined in Spain and Portugal, this work presents a minero-petrographic, chemical and geochemical characterisation of these lithotypes, aiming at finding parameters to distinguish them from the better-known Greek and Italian “ cipoll…
Lead isotopes of the carbonate-hosted Kabwe, Tsumeb, and Kipushi Pb-Zn-CU sulphide deposits in relation to Pan African orogenesis in the Damaran-Lufi…
1999
Lead isotope ratios of galena from the carbonate-hosted massive sulphide deposits of Kabwe (Pb-Zn) and Tsumeb (Pb-Zn-Cu) in Zambia and Namibia, respectively, have been measured and found to be homogeneous and characteristic of upper crustal source rocks. Kabwe galena has average isotope ratios of 206/204Pb = 17.997 ± 0.007, 207/204Pb = 15.713 ± 0.010 and 208/204Pb = 38.410 ± 0.033. Tsumeb galena has slightly higher 206/204Pb (18.112 ± 0.035) and slightly lower 207/204Pb (15.674 ± 0.016) and 208/204Pb (38.276 ± 0.073) ratios than Kabwe galena. The isotopic differences are attributed to local differences in the age and composition of the respective source rocks for Kabwe and Tsumeb. The homog…
Ladinia dolomitica
2020
Scopo di questo contributo è offrire una panoramica sull’area che viene usualmente definita “Ladinia dolomitica” e sulla varietà linguistica che vi viene tradizionalmente parlata, il ladino. L'articolo descrive brevemente la storia dell'area e dello sviluppo del ladino, e in seguito descrive le caratteristiche fonologiche, morfologiche, sintattiche e lessicali principali del ladino, che lo distinguono dalle vicine varietà italoromanze. In seguito si illustrano le peculiarità linguistiche dei singoli dialetti ladini, che sono parlati ognuno in una valle diversa delle Dolomiti. L'articolo è fortemente innovativo e originale, perché permette di ascoltare i file audio che esemplificano i tratti…
Pēdu fosiliju kompleksi galvenā devona lauka Franas stāva nogulumos
2013
ANOTĀCIJA Promocijas darbā analizēts pēdu fosiliju komplekss Franas stāva nogulumos Galvenajā devona laukā. Balsttes uz ievākt un notikt ihnofosiliju matriālu, tka izveidota sistmātskā ihnoloģija, pēc kuras analīzes nodalītas ihnokompleksu grupas un ihnofācijas. Iegūte dat ļāva papildināt iepriekš pastāvošos priekšstatus par Galvenā devona lauka Franas stāva nogulumos pārstāvēt organismu grupu daudzveidību, intrpretēt faciālo apstākļu mainību un paleoekoloģiskos apstākļus Baltjas devona baseinā Franas laikmetā. Galvenā devona lauka Franas stāva nogulumos dominējošās ihnofācijas norāda uz seklas jūras sedimentācijas vidi un mainīgiem faciālajiem apstākļiem. Pētījumā tka konstatēta ihnofosili…
Zemes dzīļu bagātības Latvijā: DOLOMĪTS
2021
Buklets "Zemes dzīļu bagātības Latvijā: DOLOMĪTS" iepazīstina ar vienu no Latvijas vērtīgākajiem dabas resursiem, tā daudzveidību un tajā atklātajiem interesantajiem minerāliem. Iekļauta informācija par dolomītu pētniecību, nozīmīgākajām mūsdienās izmantojamām dolomīta atradnēm un atšķirīgajiem pielietojuma veidiem. Bukletu ilustrē Latvijas Universitātes Muzeja Ģeoloģijas kolekciju dolomīta paraugu fotogrāfijas.
The carbonates of the Permian Lakes of North Massif central, France
1992
During the Permian, large fluvio-lacustrine basins occurred within the West European Hercynian chain. The deposits were mainly detrital (conglomerates, sandstones and pelites). The two studied sites, Couy borehole and Aumance basin contain several dolomitic beds alternating with pelites containing Ostracods. The carbonate layers constitute various dolomitized facies with dolosparite, laminated and bituminous dolomites, oolites, oncolites and stromatolites, and pedological nodules. Microfacies are varied. The dolomite crystals can be either isolated rhombs scattered in pelites or rhombs and xenomorphic crystals cementing sandstones; in dolomicrites, dolomicrosparites and dolosparites, crysta…