Granite (Earth Sciences)

A geochemically and mineralogically diverse group of granitoids is present within an area of 900 km 2 in the southern Snake Range of eastern Nevada. The granitoids exposed range in age from Jurassic through Cretaceous to Oligocene and include two calcic intrusions, two different types of two-mica granites, and aplites. The younger intrusions appear to have been emplaced at progressively more shallow depths.

Il est presenté ici un certain nombre de resultats sur l'étude des caracteristiques physico-mecanigues d'un granite fissuré provenant de la region sud-est du Massif Central francais. La premiere phase de l'étude comprend la caractérisation petrographique et physique du granite. On a étudié la composition mineralogique, la fissuration, le poids volumique, la porosité totale, la célérité des ondes longitudinales et la perméabilite a l'azote. Dans la deuxième phase, on a soumis des eprouvettes a des efforts mécaniques  de compression simple et de traction indirecte (brésilienne), ce qui a permis d'avoir une idée du comportement d'un type particulier de roche fissurée. Enfin, on a fait une serie de correlations entre les paramètres physiques et mécaniques pour connaitre les variations des uns par rapport aux autres.

This article deals with some geochemical parameters of some selected chemical data of the younger granite of Egypt. The younger granites have a composition ranging from Alkali feldspar granite to syenogranites. the major oxides (FeO, CaO, MgO, Al2O3, MnO, Na2O) show symmetrical variation which indicated continuous variation and fractional crystallization from the pure magmatic melt. It was concluded that these rocks exhibit alkaline affinity and fractional crystallization from the magmatic melt. This younger granites are classified according to their geological setting and petrography to belong to Phase III which is mainly alkali granites. The younger granite of Egypt seems to be homogeneous chemically and mineralogically, unfoliated, hard resist weathering to a great extent. The relations between Al2O3 and SiO2 indicate that most investigated samples are post-orogenic granite(POG). These results are also confirmed by using the relation between (FeOt/FeOt+MgO) and SiO2 wt%.

This book provides an explanatory account of the landforms and landscapes developed on granitic rocks. Granite is exposed over about 15% of the continents and is thus of an areal significance comparable to the carbonate rocks. But whereas there are many texts concerned with karst landscapes few books bring together the collective wisdom of granitic terrains with granitic forms. Up to the present the normal approach is based on climatic control or is merely descriptive. The book not only provides a detailed consideration of the forms major and minor, well-known and not so familiar, developed over large areas of the continents, but also presents interpretations which are the wider or general significance in the analysis and understanding of landscapes. General theories are discussed in the context of granite landforms. The importance of structure, including crustal stresses, is emphasised as are the importance of etching or subsurface initiation, multi stages or two stages development, neotectonic forms, solution forms as well the antiquitiy of some forms and surfaces (inherited forms). Morphogenetic forms are placed in perspective and comparison drawn with similar forms in other rock types.

h i g h l i g h t s The workability of the concrete reduces as the EAFS replacement level increases. The use of EAFS reduced the setting time of GGBS-PFA ternary blended concrete. Incorporation of EAFS tends to enhance the mechanical strength of concrete. Incorporation of EAFS reduced the magnitude of drying shrinkage of concrete. EAFS can be partial or fully utilize in the production of concrete. a b s t r a c t The manufacturing of concrete composites have released high volume of carbon dioxide (CO 2) gaseous to the environment in the world. Therefore, finding an alternative materials to replace the raw material used in the production of concrete composites have become a current agenda. The industrial waste materials mainly from local coal-fuelled power plant, granite quarrying process, and iron and steel manufacturing industry were utilized in the high-performance concrete production. The waste materials incorporated included ground granulated blast-furnace slag (GGBS), pulverized fly ash (PFA), granite quarry dust (GQD) and electric arc furnace slag (EAFS) were used to partially or completely replace the usage of a synthetic and natural constituent materials in the concrete production which included ordinary Portland cement (OPC), natural river sand (NRS), and natural granite rock (NGR). The study was aimed to establish the feasibility of using EAFS as partial or complete replacement of NGR as the coarse aggregate of concrete with other industrial waste materials in the binder and fine aggregate phase. In addition, the method of optimization on the OPC-GGBS-PFA as a ternary blended binder system was also established. Meanwhile, the optimum combination of chemical admixture dosage was also determined in this study. The concrete composition with the established optimum ternary blended binder system, chemical admixture combination and NRS-GQD composition as a fine aggregate were examined with various NGR replacement level with EAFS ranging from 0% to 100% at the increment of 20%. The properties of the concrete mixes were examined by setting time test on the fresh concrete, mechanical strength tests and drying shrinkage assessment on the hardened concrete. The results showed that the inclusion of the aforementioned waste tends to improve the mechanical strength properties of the concrete, while, reducing the magnitude of length change in terms of drying shrinkage. With such, a concrete with compressive strength of 80 MPa able to be produced with the used of waste material from the industry up to 80% of the total volume.

Zircon grains extracted from S-type granites of the Mêda-Escalhão-Penedono Massif (Central Iberian Zone, Variscan Orogen) constrain the timing of emplacement and provide information about potential magma sources. Simple and composite zircon grains from three samples of S-type granite were analyzed by LA-ICP-MS. New U–Pb data indicate that granites crystallized in the Bashkirian (318.7 ± 4.8 Ma) overlapping the proposed age range of ca. 321–317 Ma of the nearby S-type granitic rocks of the Carrazeda de Anciães, Lamego and Ucanha-Vilar massifs. The timing of emplacement of such S-type granites seems to coincide with the waning stages of activity of a D2 extensional shear zone (i.e. Pinhel shear zone) developed in metamorphic conditions that reached partial melting and anatexis (ca. 321–317 Ma). Dykes of two-mica granites (resembling diatexite migmatite) are concordant and discordant to the compositional layering and S2 (main) foliation of the high-grade metamorphic rocks of the Pinhel shear zone. Much of the planar fabric in these dykes was formed during magmatic crystallization and subsequent solid-state deformation. Field relationships suggest contemporaneity between the ca. 319–317 Ma old magmatism of the study area and the switch from late D2 extensional deformation to early D3 contractional deformation. Inherited zircon cores are well preserved in these late D2-early D3 S-type granite plutons. U–Pb ages of inherited zircon cores range from ca. 2576 to ca. 421 Ma. The spectra of inherited cores overlap closely the range of detrital and magmatic zircon grains displayed by the Ediacaran to Silurian metasedimentary and metaigneous rocks of the Iberian autochthonous and parautochthonous domains. This is evidence of a genetic relationship between S-type granites and the host metamorphic rocks. There is no substantial evidence for the addition of mantle-derived material in the genesis of these late D2–early D3 S-type granitic rocks. The εNd arrays of heterogeneous crustal anatectic melts may be just inherited from the source, probably reflecting mixing of a range of crustal materials with different ages and primary isotopic signatures. The generation of the Bashkirian S-type granites has been dominated by continental crust recycling, rather than the addition of new material from mantle sources.

This contribution provides a case example on the generation of large-scale recumbent folds in syn-orogenic gran-itoids. We analyze the progressive reworking of extension-related structures into later ones after a period of crustal thickening. The Padrón migmatitic dome formed after the climax of the Gondwana-Laurussia collision in the late Paleozoic. Petrostructural analysis carried out in the eastern flank of this dome reveals that extensional flow resulted in progressive exhumation of mainland Gondwana, which rested under peri-gondwanan alloch-thonous terranes and a suture zone during maximum crustal thickening. Exhumation proceeded up to upper crust levels (andalusite stability field) along with partial melting of the middle-lower crust and with the generation of granitoid laccoliths during an early extensional stage. Newly-formed lithological and mechanical anisot-ropies, such as the presence of variably-sized sheet-shaped bodies of syn-orogenic granitoids, provided a favorable rheological setting for fold nucleation during the intermediate stages of extension. In extending oro-genic crust, whether recumbent folds occur after significant melt production depends on the lateral/vertical flow ratio, and on the orientation of deforming bodies with regard to kinematic/strain axes. We suggest that subhorizontal extensional flow dominated over vertical flow during the early and intermediate stages of the evolution of the Padrón dome. A component of vertical (diapiric) flow caused progressive tilting of the sheet-like bodies and obliquity respect to strain axes. This resulted in the development of regional-scale folds at the expense of syn-orogenic granitoids, such as in the case of the Portomouro recumbent synform. Extensional ductile flow was oblique to the trend of the orogen during the whole process, and directed to the NNW during the formation of recumbent folds. Non-coaxial shearing favored an (NNW-SSE) elongate shape for the syn-kinematic granitic massifs as well as the subsequent nucleation of recumbent folds. Deformation concentrated along discrete detachments during the late stages of extension.

Rapakivi granites and the associated suite (anorthosite, mangerite and charnockite) that developed during the Mid-Proterozoic escape the global rules that control usual granitic magma formation. About 40 points that characterise the Proterozoic magmatism confirm the originality of the magmatism. Rapakivi granites developed without a global orogenic context within the supercontinent Columbia. The intrusions extend from the East European shield to the western US, through Fennoscandia, Greenland and Labrador. Other occurrences in the Amazonian shield, Australia or South China are less well documented. They show no definite trend in age or chemistry that would explain large-scale (mantle plume) effects. A mantle upwelling of material is contradictory with the re-assembly of a supercontinent because it occurred before this magmatic episode (1.9–1.8 Ga). At ∼1.7 Ga, the supercontinent Columbia amalgamated with the collision of the Yapavai and Mazatzal Provinces. A model is suggested that
takes into account the supercontinent re-assembly, defining a downwelling flow in the mantle that anchors the continent above it. In contrast to a material flow, heat is still delivered to the base of the continental lithosphere, and is focused toward the juvenile suture zone. The base of the crust must reach  200–1300 ◦C before producing anorthosite magmas. Under such a high temperature gradient lasting over a long time, magmas are transferred toward the upper crust, giving the thin (5 km) and square-shape (100 km) that the intrusions presently have. Heat delivery is essentially conductive, leading to long time-spans for intrusions. The presence of the supercontinent, immobile over a descending cell (poloidal mode of convection) developed a tangential force (toroidal mode of convection) that partly split the continent through strike–slip deformation due to plate rotation. It developed progressively between 1.57 and 1.3 Ga, starting from Fennoscandia, and then passing to Amazonia, western US and Labrador in a clockwise sense. The associated rotation induced sinistral shear manifested by small-scale shear zones and the orientation of late magmatic facies (topaz-bearing granites) in each province. The  Proterozoic magmatism appears to be unique because it requires a supercontinent with a zone of juvenile crust surrounded by older cratons. The present Moho still show remnants of this process, having bumpy undulations that may reach 22 km in amplitude over a distance of 200 km.

Granitic gruses are usually considered as a product of deep weathering, but the influence of hydrothermal fluids was also noticed. In this work, a wide range of mineralogical and chemical methods performed on 43 samples from three representative outcrops and a reference site is used to determine the influence of hydrothermal and weathering fluids on the development of granitic gruses from the coarse grained Karkonosze granite. Four types of altered granites have been distinguished, including compact and friable granite, typical grus, and localized heavy altered zones. Mineralogical observations such as complete albitization of plagioclase and crystalliza-tion of secondary quartz revealed an important role of hydrothermal alteration at the early stage of grusification. The origin of smectite and alteration of biotite into muscovite are likely to be connected with circulation of hydro-thermal fluids too. Grusification sensu stricto was primarily caused by vermiculitization of biotite which resulted in volumetric expansion and the development of transmineral microcracks with non-accordant pore surfaces. Thus, it requires hydrothermal alteration to be relatively minor, confined to postmagmatic changes, since more advanced alteration of biotite into muscovite rather than vermiculite arrests further development of microcracks and leads to the development of friable granite.

Topics

Sessions

    Applications to Specific Archaeological Questions – Use of Marble
   
    Provenance Identification I: Marble
   
    Provenance Identification II: Other Stones
    .
    Advances in Provenance Techniques, Methodologies and Databases
   
    Quarries and Geology (Quarrying Techniques, Organization, Transport of Stones, New Quarries, Stone Carving and Dressing, Hazards to and Preservation of Quarries)
   
    Stone Properties, Weathering Effects and Restoration, as related to diagnosis problems, matching of stone fragments and authenticity
   
    Pigments and Paintings on Marble
   
    Special Theme Session: 
    »Production and trade of marble and other stones in the Alpine and Danube provinces – regional resources and Mediterranean imports«
   
    Poster Session I:
    Applications to Specific Archaeological Questions, Provenance Identification I and II, Advances in Provenance Techniques, Methodologies and Databases
   
    Poster Session II:
    Quarries and Geology, Stone Properties, Weathering Effects and Restoration, Pigments and Paintings on Marble, Special Theme Session

The Ossa-Morena zone in SW Iberia represents a section of the northern margin of West Gondwana that formed part of a Cordilleran-type orogenic system during the Neoproterozoic (Cadomian orogeny). The crustal section in this zone preserves the record of rifting that led to the opening of the Rheic Ocean in the early Paleozoic and the collision of Gondwana and Laurussia in the late Paleozoic (Variscan orogeny). We present U-Pb zircon data from three alkaline to peralkaline syenites that intruded Neoproterozoic and Cambrian strata and give crystallization ages ranging between ca. 490 Ma and 470 Ma. Lu/Hf isotopic data from these zircons give positive initial εHf values (0 ≤ εHf(t) ≤ +11.5) that approach the model values for the depleted mantle at the time of crystallization. This suggests that a significant proportion of the magma was derived from the mantle, with limited mixing/assimilation with crustal-derived melts. Alkaline/peralkaline magmatic suites of similar age and chemical composition intruded other sections of the northern margin of West Gondwana and along the boundaries of the continental blocks that today make up Iberia. These blocks are further characterized by the presence of high-pressure metamorphic belts that formed during accretion and subsequent collision of peri-Gondwanan domains against Laurussia during the Devonian and Carboniferous (Variscan orogeny). Our U-Pb and Lu-Hf data set indicates that during the Cambrian−Ordovician transition, lithosphere extension reached a stage of narrow intracontinental rifting, where deeply sourced magmas, probably coming from the lower crust and/or the upper mantle, intruded continental upper crust across various sections of previously stretched crust. We propose that necking of the Gondwana lithosphere into several continental microblocks with fertile mantle beneath them compartmentalized extension (multiblock model), which favored the onset of early Paleozoic peralkaline and alkaline magmas. The boundaries of microblocks represent zones of inherited crustal weakness that were later reactivated during the late Paleozoic as major accretionary faults related to the amalgamation of Pangea during the Variscan orogeny. Our dynamic model provides an explanation for the unusual spatial relationship between peralkaline and alkaline igneous provinces (usually shallow in the crust) and the occurrence of high-pressure rocks. Our observations suggest that Cordilleran-type orogens subjected to extension after long-lived subduction can develop wide continental platforms that feature multiple continental blocks. In addition, the formation of sequenced high-pressure belts in collisional orogens can be explained as the ultimate consequence of multiple necking events within continental lithosphere during previous collapse of a Cordilleran-type orogen.

Diglur–Biloli–Dharmabad sector exposes Palaeoproterozoic Nanded granitoids (NG) belonging to the northern extensions of Peninsular Gneissic Complex (PGC) within Deccan Trap country.  They are predominantly represented by coarse grained to porphyritic pink and grey granites with patches and enclaves of mafic rocks and are profusely traversed by pegmatitic/quartzofeldspathic/quartz veins and ENE–WSW, NE–SW and WNW–ESE trending mafic dykes.  Geochemically, they are similar to medium- to high-K, calc-alkaline granitoids with higher total alkali content (5.96–11.52%) and show an overall predominance of K over Na. Higher abundance of LILE and incompatible HFSE indicate important role played by the fractionation and progressive differentiation in the formation of these highly evolved granites. These elements are mostly associated with resistate minerals such as zircon, monazite, thorite, allanite and sphene. The compositional diversity of NG ranging from granite(s.s.) to granodiorite–adamellite suite with predominantly metaluminous to mild peraluminous nature and presence of biotite± hornblende as the dominant ferromagnesian minerals point towards derivation of magma from upper mantle or lower crustal source with I-type signatures in active continental margin setting. Negative correlation of SiO2 with MgO, FeOt, CaO, Al2O3 and positive correlation with K2O and Na2O substantiates highly fractionated nature of these granitoids, whereas high differentiation index (71.36–97.10), enrichment of K at the expense of Ca and ubiquitous presence of pegmatoids point towards derivation from sub-crustal source by partial melting in a volatile rich system with S-type features. Hence, it appears that crustal contamination has caused distortion in major and trace element representation and show gradation between mantle-dominated and crust-dominated patterns.
Anomalous radioelemental concentration (upto 1403 ppm U and 1600 ppm Th; n=69) has been recorded in NG and distribution pattern of heat producing elements (U, Th and K) have indicated high heat production values (1.25–480.4 μWm-3), which might have played important role in uranium remobilisation and concentration by supporting hydrothermal gradient along the dilatant structures. Considering highly labile nature of uranium in this reactivated terrain, the Nanded granitoids form a potential fertile provenance for uranium mineralisation.

Potassic granitoids (2.6-2.5Ga) emplaced in the Eastern Dharwar Craton (EDC)
provide the potential basement for Meso-Neoproterozoic Bhima group of sediments. In the north-eastern parts of Bhima basin in EDC, the basement granitoids from different localities around Nawalga-Miryan area indicate an overall similarity in their major, trace and REE geochemistry together with field and petrographic observations. They are ‘granite-granodiorite’ in composition, occasionally consist of intrusive basic dykes and invariably traversed by quartzofeldspathic veins. Average major chemical constituents like SiO2 (74%), Al2O3 (13%), FeOt (1.6%) are nearly parallel to the upper continental crustal granites. These granitoids are distinctly potassic (av. K2O 5.7% and K2O/Na2O ratio 3.1), belong to high-K calc-alkaline series, weakly peraluminous exhibiting an average A/CNK value of 1.05. Trace element distribution displays anomalous average abundance of U (16ppm), Th (58ppm), As (16ppm), Ba (1008ppm), Sr (248ppm) and Pb (50ppm). Granitoids indicate high U/Th (0.3) and K/Rb (479) ratios and show marginal to marked depletion of Nb, Zr, Y and Sc. They show an exclusive LREE enrichment over HREE, with (LREE)cn/ (HREE)cn ratio ranging from 1.4 to 4.9 (av. 2.7) and a marginally negative Eu anomaly (Eu/Eu* 0.7); however, the overall REE content is low. These granitoids are analogous to S-type granite, with HFSE (High Field Strength Element) depleted and LILE (Large Ion Lithophile Element) enriched feature, indicate syn-collisional to volcanic arc tectonic environment. Comprehensive critical observations of field setting, geochemistry and petrography point out the possibility of their anatectic origin by the reworking of supracrustal metasedimentary protoliths, in the mid-upper crustal levels. The rocks posses an average DI of 88 and Mg# 42, suggesting limited opportunity for differentiation. Potassic fertile granitoids of similar age range and strtigraphic status in the regional vicinity acted as source and host rocks for uranium deposits at Gogi in Bhima basin and Lambapur-Chitrial in Srisailam sub-basin. Similar to these cases, the process of release and remobilization of uranium from the basement granitoids at Nawalga-Miryan area, followed by transportation and re-precipitation in structural loci beneath the cover rocks possibly lead into interesting mineralisation.

This book provides an explanatory account of the landforms and landscapes developed on granitic rocks. Granite is exposed over about 15% of the continents and is thus of an areal significance comparable to the carbonate rocks. But whereas there are many texts concerned with karst landscapes few books bring together the collective wisdom of granitic terrains with granitic forms. Up to the present the normal approach is based on climatic control or is merely descriptive. The book not only provides a detailed consideration of the forms major and minor, well-known and not so familiar, developed over large areas of the continents, but also presents interpretations which are the wider or general significance in the analysis and understanding of landscapes. General theories are discussed in the context of granite landforms. The importance of structure, including crustal stresses, is emphasised as are the importance of etching or subsurface initiation, multi stages or two stages development, neotectonic forms, solution forms as well the antiquitiy of some forms and surfaces (inherited forms). Morphogenetic forms are placed in perspective and comparison drawn with similar forms in other rock types.

This paper deals with the petrogenesis of two-mica granites within the amphibolite-facies metamorphic rocks in the Uludağ Massif (NW Turkey). The two-mica granites are represented by three different types (i) a ~17 km long and ~ 1.5 km-wide strongly foliated and lineated metagranite, (ii) a relatively younger circular granite, ~ 11 km by ~ 6.5 km, free of any penetrative fabric, and (iii) up to 5 m thick dikes of unfoliated granite-porphyries. Mineral constituents include quartz, plagioclase, microcline, biotite, muscovite and minor apatite, zircon, ilmenite and monazite. U–Pb zircon dating indicates that the metagranite was emplaced at 35 ± 1 Ma (2σ, latest Eocene) and the unfoliated granite at 28 ± 1 Ma (2σ) (Early-Late Oligocene boundary). Overall, the two-mica granites are characterized by (i) a restricted bulk composition (SiO 2 ~70–76 wt.%), (ii) near-linear to linear inter-element variations, (iii) high concentrations of Al 2 O 3 , Sr, Ba, LREEs, and low abundances of Rb, Y, Sc and HREEs, comparable with adakitic rocks, (iv) variably pronounced concave-upward shape of HREEs and absent to feeble Eu anomaly, (v) relatively high Na 2 O, CaO and Sr, and lower K 2 O and Rb contents at identical silica contents relative to the classical S-type granites. 87 Sr/ 86 Sr (i) and εNd (i) values range from 0.7052 to 0.7080, and 0.7 to − 3.6, respectively. The 206 Pb/ 204 Pb (i) values range from 18.23 to 18.69, 207 Pb/ 204 Pb (i) from 15.63 to 15.70 and 208 Pb/ 204 Pb (i) from 38.48 to 38.77. 87 Sr/ 86 Sr (i) and εNd (i) , and εNd (i) and 207 Pb/ 204 Pb (i) values are negatively correlated. Isotopic variation and negative correlations can best be explained by a heterogeneous source, including an older crustal component and a more juvenile basic component. Magma temperatures are estimated as 754–790 °C based on zircon and monazite saturation. All these features such as (i) relatively Na-, Ca-and Sr-rich compositions, (ii) isotopically heterogeneous source with inferred residual phases such as garnet and horn-blende, (iii) occurrence in a ductile strike-slip zone, and (iv) relatively low magma temperatures can be accounted for by water-fluxed melting of a metagreywacke source with substantial mafic component at middle to lower crustal depths.

ÖZET: Doğal taşlar insanlar var olduğu günden beri bir şekliyle hayatında var olmuştur. Artan bilgi birikimi ve gelişen teknolojiye rağmen doğal taşlar insan hayatındaki varlığını korumaya devam etmiştir ve de etmektedir. Türkiye'de doğal taş varlığı açısından şanslı ülkelerden biri olup gerek rezerv gerekse çeşitlilik açısından büyük bir potansiyele sahiptir. Ülkemizde özellikle son yıllarda üretim ve ihracatta kendini bu pazarda kanıtlamıştır. Aynı zamanda Türkiye'nin kendine has taşları ve coğrafi konumuyla da sektörde özel bir yeri bulunmaktadır. Tüm bu olumlu yönlerin yanında maalesef hala çok sayıda eksiklik de söz konusudur. Bu çalışmada Türkiye'nin doğal taş varlığının değerlendirilip, iktisadi coğrafya odağında analizi yapılmış, sektörün sorunları ele alınarak, bu alanda yapılması gerekenler üzerinde durulmuştur. ZUSAMMENFASSUNG: Seit anbeginn der menschheit gibt es die natursteine im leben des menschen in irgendeiner form. Trotz hohem wissenstand und weit entwickelter technik, bleibt die wichtigkeit der natursteinkunde weiterhin im leben des menschheit bestehen. Die Türkei ist ein land mit seinen sehr üppigen natursteinen. Sei es die menge oder aber auch die vielfalt hat dieses land genug potential. Die Türkei hat sich in den letzten jahren in produktion und export der welt beweisen können. Bedingt durch die geographische lage und den typisch Türkischen Steinen, hat es einen besonderen stellenwert. Trotz den vielen dafür sprechenden aspekten, fehlt es an einigen Ecken. Im Mittelpunkt dieser arbeit und der witschaftsgeographie, werden die probleme dieses sektors behandelt.

Palaeoproterozoic granitoids exposed around Thadisaoli area, Nanded district, Maharashtra are northeastern extensions of Peninsular Gneissic Complex (PGC) in Dharwar Craton and belong to its younger phase.  These granitoids are predominantly represented by pink granite and pegmatitic/quarzofeldspathic rock (± maghemite clusters), which are subsequently traversed by younger phosphatic cherty cataclasites close to the Deccan Trap capping.  Anomalous radioelemental concentrations have been recorded in these granitoids (33ppm–1% U3O8, 0.007–0.20% ThO2; n=9) and phosphatic cherty cataclasite (0.023–0.11% U3O8, <0.005% ThO2; n=14). The granitoids are also rich in rare metal and rare earth elements (Nb– 77ppm; Y–111ppm; Zr–432ppm; n=9, and total REE–1167ppm; n=3) whereas phosphatic cherty cataclasites are poor in RM&REE content. Predominance of LREE over HREE (LREE/HREE = 4.37) and fractionation among LREE are characteristic feature of Thadisaoli granitoids. The higher concentrations of radioelements and REE in granitoids have been reflected in the form of presence of discrete uranium (primary– uraninite; secondary– -uranophane) and thorium (thorite) minerals vis-à-vis high content of resistates viz., apatite, zircon, allanite, sphene, cerianite, monazite, ilmenite etc. while radioactivity is mainly associated with phosphatic material in cherty cataclasites. In thorium–uranium diagram, a pronounced and progressive enrichment of uranium has been indicated in both, granitoids and cherty cataclasites, which might have lead to uranium mineralisation. However, granitoids do contain comparatively high thorium which can be explained by the coexistence of uraninite, thorite and a few rare earth bearing minerals.

Bulk rock chemistry of granitoids have shown wide spread in SiO2 (57–81.31%), Al2O3 (8.52–15.97%), K2O (2.84–5.22%), Na2O (2.47–4.49%), CaO (0.85–4.68%), MgO (0.04–2.70%) and FeO(total) (1.26–9.13%) where low silica content is shown by maghemite clusters bearing QFR which is commensurate  with high content of alumina, iron (Fe2O3:FeO– 1:0.27), magnesium and calcium. In contrast, phosphatic cherty cataclasites chemistry is mainly controlled by silica, calcium and phosphate with average values (n=14) of 60.81%, 21.54% and 15.16%, respectively. The compositional diversity of calc-alkaline granitoids of study area belonging to granodiorite–adamellite suite with predominant metaluminous nature (A/CNK– 0.87-1.01) points towards derivation of magma from upper mantle or lower crustal source with I-type signature. However, high differentiation index (85.29–93.31), pronounced negative Eu anomaly (0.64) and ubiquitous presence of pegmatitic/quartzofeldspathic rocks (QFR) points towards their derivation from sub-crustal source by partial melting in a volatile rich system. Hence, possibility of magma mixing can not be ruled out during their evolution.  Moderate to strong negative correlation of SiO2 with MgO, FeO(total), CaO, Al2O3 and positive correlation with K2O and Na2O indicates strongly fractionated nature, which is further substantiated by antipathetic relationship of CaO, MgO and FeO with differentiation index, and low initial ratio of 87Sr/86Sr (0.7009±0.0005).  In Rb–Nb+Y and Nb–Y tectonic discrimination diagrams, these granitoids indicate a within plate (WP) tectonic regime at the time of magmatic evolution.

Enhanced radioelemental concentration in Thadisaoli granitoids is due to their highly differentiated and fractionated nature, where progressive differentiation and evolution of granitic magma led to the enrichment of these incompatible HFS elements.  Post-magmatic events such as hydrothermal activity and alteration phenomenon (saussuritisation, sericitisation and chloritisation) have further enhanced mobilisation and concentrated radioelements along suitable structural aureoles leading to uranium mineralisation, which is further supported by the presence of anomalous uranium content in phosphatic cherty cataclasites.

In this study we present preliminary results of potassium X-Ray Fluorescence (XRF) analysis in granite samples that may give a first estimation of the samples radioactivity. Results of the radioactivity measurements in granites samples using gamma ray spectrometry with a NaI detector are given and they are correlated with the total potassium concentration (yield) in the same samples that measured using XRF analysis. The relative concentrations of other elements in the same samples were also measured and evaluated.

In the eastern part of Ladakh, the right-lateral Karakoram Fault Zone (KFZ) bifurcates into two strands
called the Pangong Strand and the Tangtse Strand. These two strands bound a region called the Pangong
Transpression Zone (PTZ), which consists of migmatitic dioritic gneiss, calc-silicates and the Durbuk
Pluton; a pluton of two-mica leucogranite. Outcrop scale observations suggest pervasive migration of
leucogranitic melt through the existing tectonic structures of the gneiss. Magnetic fabric from both the
tectonized and undeformed parts of the Durbuk Pluton show parallelism with the tectonic fabric of the
host gneiss, which, along with pervasive melt migration, indicates syn-kinematic relationship between
deformation along the KFZ, leucogranite magmatism and emplacement of the Durbuk Pluton. UePb
geochronology of zircons from the dioritic gneiss yields a crystallization age of 63.6
1.5 Ma and also
shows younger zircon growth down to w13 Ma, which suggest arc magmatism at w65 Ma followed by
partial melting and leucogranite magmatism in the KFZ till w13 Ma. One two-mica leucogranite sample
from the Durbuk Pluton gives a crystallization age of 22.7
0.5 Ma. As the Durbuk Pluton is syn-tectonic
with deformation along KFZ, it is inferred that the KFZ initiated at least w23 Ma ago.

River sand is nowadays a scarce
commodity and exploring alternatives. So an attempt
is made on replacing the granite sludge powder as a
partial replacement for fine aggregate in concrete.
The study is carried out with 20, 40, 60 and 80
percentage replacement of fine aggregate by the
granite sludge powder in M20 grade concrete. The
workability of fresh concrete, compressive strength
and split tensile strength of hardened concrete mix
at 7th,14th and 28th days of curing period is
determined and results are analysed and compared
with the conventional mix.

The Late Mesoproterozoic Sveconorwegian Province is commonly correlated with the continent-collision related Grenville Province in eastern Canada. Recently, however, the evolution of the Sveconorwegian Province in SW Norway has been strongly debated, casting doubt on a direct correlation between these provinces.

Metamorphism in SW Norway has traditionally been interpreted as representing a main collisional event between ca. 1030 and 970 Ma, followed by a contact metamorphic event at 930 Ma. Magmatism has been grouped into a ‘syn-collisional’ suite at 1050–1035 Ma, a ‘post-collisional’ suite at 980–930 Ma, and an anorthosite–mangerite–charnockite–granite (AMCG) suite at 930 Ma. New detailed mapping and geochronology in the area reveal a very different and much more complex evolution, and require re-evaluation of previously presented models. In this paper, we focus on the introduction and description of a newly discovered, ca. 200 km × 50 km magmatic belt, the Sirdal Magmatic Belt (SMB). Previously mapped as granitic gneisses in many areas, the existence of this large, commonly undeformed and unmetamorphosed granitoid batholith was only recognized a few years ago (Slagstad et al., 2013a). Magmatism in this belt between 1060 and 1020 Ma precedes and overlaps the main Sveconorwegian metamorphic event(s) that affected the region.

Our observations of cross-cutting relationships between previously metamorphosed gneisses and SMB rocks indicate that at least one episode of amphibolite- to granulite-facies metamorphism occurred in the region during or prior to emplacement. A lack of widespread metamorphic overprinting and common preservation of igneous textures in most of the SMB indicate that high-grade Sveconorwegian metamorphism after ca. 1020 Ma was local rather than regional in SW Norway.

The orogenic evolution of SW Norway is characterized by emplacement of large volumes of granitic magma and more localized UHT metamorphism, which is quite different from the widespread, long-lasting metamorphic evolution observed in the Grenville Province, and may point to different tectonic regimes for the two provinces.

The timing of the onset of an orogeny is commonly constrained indirectly, because early orogenic structures are rarely exposed, or are overprinted. Establishing the onset of an Archean orogeny is considerably more challenging, because of the more fragmented geological record and the general lack of consensus about Archean geodynamics.
We combine existing tectono-stratigraphic data with new structural and geophysical datasets to establish the onset of the Neoarchean Yilgarn Orogeny (Yilgarn Craton, Western Australia). We show that the surface of the c. 2960–2750 Ma deep-marine Yilgarn greenstone sequence was uplifted, eroded and unconformably overlain by a c. 2730 Ma, syntectonic clastic sequence, deposited in shallow marine to subaerial conditions, and derived from the erosion of the underlying greenstones. This c. 2730 Ma regional unconformity predates the oldest-known Yilgarn structures, therefore its tectonic significance is so far unknown.
At around the same time, at deeper crustal levels, the c. 2728 Ma Yarraquin pluton was being emplaced along an active, large-scale shear zone network. Our meso- and microstructural analysis shows that the bulk of the fabric in the granite and its country rocks developed during pluton emplacement, and was largely assisted by magma-present shearing. Overall, these structures reflect an important event of syn-emplacement crustal shortening. The regional unconformity and the syndeformational emplacement of the Yarraquin pluton are both expressions of a c. 2730 Ma regional deformation event associated with significant crustal thickening, marking the onset of the Neoarchean Yilgarn Orogeny.

We report for the first time ultrapotassic granites from Sudasna area, Mehsana district, Gujarat.  These granites occur as isolated small linear bodies within Idar granitic suite, which are intrusive to Delhi metasediments. Bulk rock compositions show very high total alkalis (mainly K2O upto 14.46%) with dominance of K over Na and significant enrichment of U, Th, REE, HFSE (Zr, Y, Nb) and some transition elements (Ga, Zn, Sn) relative to normal granites. These are typical characteristics of ultrapotassic, silica saturated, alkaline rocks of anorogenic, post-collisional settings and classified as A-type granites. The highly evolved ultrapotassic Sudasna granites were generated by fractional crystallisation and progressive differentiation of crustal/underplated alkali-metasomatised mafic magma at shallow crustal levels.
Keywords: Ultrapotassic A-type granite, Geochemistry, Geodynamic, Petrogenesis, Sudasna, Gujarat

The virtual obliteration of primary architecture and tectonostratigraphic relationships in most Precambrian orogens hinders the reconstruction of tectonic events, even at the first-order level. The Capricorn Orogen in Western Australia is a prime example of these difficulties. Although widely regarded as recording the collision of the Archean Yilgarn and Pilbara Cratons during the Capricorn Orogeny at 1820–1770 Ma, a recent program of regional mapping, ion microprobe (SHRIMP) U–Pb zircon dating, and whole-rock geochemistry in the Gascoyne Province, at the western end of the orogen, has identified no evidence of subduction-related magmatism, or of a suture that could be related to the Capricorn Orogeny. Instead, the spatial and temporal patterns of sedimentation and magmatism, along with the chemical and isotopic compositions of the granites in the province, are best explained by intracontinental reworking during the Capricorn Orogeny. The Capricorn Orogen formed by accretion of the ...

Alkaline (A-type and highly fractionated felsic I-type) granites that may have formed in post-collisional plate tectonic environments are present in the Alaskan Cordillera, the New England and Lachlan Fold Belts of Australia, and the Arabian-Nubian Shield. Their emplacement is associated with diffuse extension and/or strike-slip shear movements that follow the proposed collisional events by-25 to 75 Ma. The post-collisional alkaline granites are compositionally most similar to within-plate (anorogenic) alkaline granites, but also show affinities with volcanic arc and syn-collisional granites. They may easily be mistaken for anorogenic granites in complexly deformed or poorly exposed terranes. Most of the alkaline granites probably originate by middle or lower crustal anatexis, but the origin of the necessarily high melting temperatures remains unresolved. Their source rocks are just as likely to be previously unmelted mafic meta-tonalites as they are to be restite from which I-type granitic melt had been extracted earlier.

The Monte Capanne pluton (Tuscan Magmatic Province, Elba Island, Italy) displays a great variety of magmatic products. Mafic microgranular enclaves (MME) are widespread and display variable size, texture and composition. Petrographic and mineralogical features highlight the importance of magma mixing in their genesis. In particular, patchy-zoned phenocrysts and corroded An-rich plagioclase are common in the MME, which, together with their abundance in the monzogranitic host, suggest that mixing between mantle and crustal-derived magmas occurred relatively early in the crystallisation history of the pluton. A gabbroic enclave is characterised by the abundance of An-rich plagioclase and amphibole, the latter possibly replacing former clinopyroxene. Differences in biotite composition between MME reflect the heterogeneous nature of the mafic magmas prior to the enclave formation. The importance of magma mixing is also evident in K-feldspar megacrysts, which commonly exhibit resorption surfaces followed rimward by a high-Ba zone. Hybrid Orano dykes, which are the latest magmas injected into the Monte Capanne pluton, display specific disequilibrium textures (i.e. sieve-textured plagioclase phenocrysts) and mineral content (i.e. abundance of amphibole) compared to the MME.The genesis of most MME, which display a wide spectrum of major and trace element compositions compared to the host monzogranite, involves a complex interplay between mixing and crystallisation following the input of mantle-derived magma into a silicic magma chamber. Possible loss of the liquid phase from the evolving basic magma may have produced MME distinctively depleted in LREE and enriched in MgO. Fingerprinting the chemical and isotopic signature of the basic magma involved in the genesis of the MME is further complicated by subsequent (but limited) exchange between MME and host. The basic magma is inferred to be similar to coeval high-K calc-alkaline volcanic rocks occurring on Capraia Island.Isotopically, the monzogranite and its MME display distinctive trends pointing towards a low-ɛNd end-member, represented by a garnet mica schist xenolith. We propose that these trends, together with the abundance of variably digested metasedimentary xenoliths dispersed throughout the pluton, reflect assimilation of metapelitic crust early in the evolution of the pluton during storage of the magma within the Tuscan basement, i.e. prior to the final emplacement of the pluton at upper crustal levels.The hybrid Orano dykes, which were injected at the end of the Monte Capanne crystallisation history, display distinctive trace element compositions, similar to REE-Sr-Ba-rich andesites on Capraia. The Orano dykes originated from a deeper level of magma storage and interacted with a crystal-rich enclave-bearing monzogranitic mixture.The proposed scenario involving periodic recharge by mantle-derived magmas and crustal assimilation is also in agreement with isotopic variations observed within a zoned K-feldspar megacryst, which exhibits a core with high 87Sr/86Sr and a rimward decrease of 87Sr/86Sr, arguing for a high 87Sr/86Sr silicic system replenished by lower 87Sr/86Sr mantle-derived magmas.

The tourmaline supergroup members are extensively studied in recent years, being the most widespread of cyclosilicate minerals, commonly found in several magmatic rocks, especially in pegmatites and aplites (Bačík 2015; Bosi et. al 2017; Bosi et al. 2018;
Pieczka et al. 2018).
The occurrence of tourmalines in the postmagmatic and metamorphic rocks from Strzegom, Poland, is known from several localities and was reported long ago (Traube 1888 vide Pieczka and Kraczka 1988). Local
granites, pegmatites and aplites are the host rocks for some of well known tourmalines, especially from the schorl group (Janeczek 1985).

More information in the full text.

The Mesoproterozoic Granite-Rhyolite Provinces in North America consist of A-type granitic and rhyolitic rocks, and their formation is commonly ascribed to continental `extension' or `rifting'. The tectonic environment of the extension is, however, poorly understood. New Sm–Nd isotopic data from the Central Gneiss Belt, Grenville Province, Ontario, suggest that rocks compositionally and temporally similar to those in the Granite-Rhyolite Provinces formed in and behind an active continental arc undergoing intra-arc and back-arc extension. Basaltic underplating accompanied extension, providing heat and juvenile material. Source rocks vary from juvenile within the arc, to more mature with increasing distance behind the arc. Recent investigations from SW Baltica show that the Rjukan Group, a proposed Granite-Rhyolite Province correlative, also formed inboard of an active continental arc. A tectonically and temporally similar, and probably recurrent, evolution along the vast Laurentia–Baltica margin points to active continental-margin processes as first-order controls on back-arc granite-rhyolite magmatism.

Abstract An assemblage of NE–SW-trending, imbricate
thrust slices (c. 26 km E–W long × 6.3 km N–S) of granitic
rocks, basic-felsic volcanogenic rocks (Helete volcanics),
ophiolitic rocks (Meydan ophiolite) and melange
(Meydan melange) is exposed near the Tauride thrust front
in SE Anatolia. The volcanogenic rocks were previously
assumed to be Eocene because of associated Nummulitic
limestones. However, ion probe U–Pb dating of zircons
extracted from the intrusive granitic rocks yielded ages of
92.9 ± 2.2–83.1 ± 1.5 Ma (Cenomanian–Campanian). The
Helete volcanic unit and the overlying Meydan ophiolitic
rocks both are intruded by granitic rocks of similar age and
composition. Structurally underlying ophiolite-related melange
includes similar-aged, but fragmented granitic intrusions.
Major, trace element and rare earth element analyses
coupled with electron microprobe analysis of the granitic
rocks show that they are metaluminus to peraluminus and
calc-alkaline in composition. A magmatic arc setting is
inferred from a combination of tectonomagmatic discrimination,
ocean ridge granite-normalized multi-element patterns
and biotite geochemistry. Sr–Nd–Pb isotope data further suggest that the granitoid rocks were derived from
variably mixed mantle and crustal sources. Granitic rocks
cutting the intrusive rocks are inferred to have crystallized
at ~5–16 km depth. The volcanogenic rocks and granitic
rocks originated in a supra-subduction zone setting that was
widely developed throughout SE Anatolia. Initial tectonic
assembly took place during the Late Cretaceous probably
related to northward subduction and accretion beneath the
Tauride continent (Keban and Malatya platforms). Initial
tectonic assembly was followed by exhumation and then
transgression by shelf-depth Nummulitic limestones during
Mid-Eocene, as documented in several key outcrops. Final
emplacement onto the Arabian continental margin took
place during the Early Miocene.