[en] The Ollo de Sapo Formation comprises variably metamorphosed felsic peraluminous volcanic rocks and highlevel granites that crop out over some 600km from the Cantabrian coast to central Spain in the northern part of the Central Iberian Zone. The Ollo de Sapo magmatism is not obviously connected with any major tectonic or metamorphic event so its origin is controversial. Some authors, based on trace-elements, have proposed that the Ollo de Sapo magmas originated in a supra-subduction setting but others, based on abnormally high zircon inheritance and field and structural data, favored a rifting environment. Here we present new oxygen and hafnium isotope data from the very characteristic Ollo the Sapo zircons, which in most cases, consist of ca. 485Ma rims and ca. 590-615Ma cores. We found that the Cambrian-Ordovician rims yielded unimodal distributions that cluster around ∂18O = 10, typical of S-type magmas formed from melting of altered crust. The Ediacaran cores, in contrast, cluster around ∂18O = 6.5, consistent with being arc-magmas. Rims and cores have the same average Hf isotope composition, but the rims are considerably more uniform. These data, coupled with existing wholerock element and Sr and Nd isotopic data, indicate that the Ollo de Sapo were S-type magmas that resulted from anatexis of younger-than-600Ma immature sediments mostly derived from different Ediacaran igneous rocks with a wide range of Hf isotope composition.

[en] The activity concentration of plutonium in an environmental sample does not usually constitute sufficient information to determine if it is due only to fallout. Alpha and gamma spectrometry are used here conjointly in the study of environmental soil samples to distinguish between samples showing plutonium contamination due to fallout exclusively, and samples contaminated with plutonium from another source. The method was applied to soil samples collected in Palomares (Spain), where an accidental release of aerosols contaminated with plutonium occurred. The two contributions (fallout and accidentally released plutonium) were separated by means of the activity ratios between various radionuclides present in the samples analyzed. The fallout level was estimated from the ^239+240Pu/¹³⁷Cs activity ratio. For samples showing contamination due to the accident, the ²³⁸Pu/^239+240Pu and ²³⁹Pu/²⁴⁰Pu activity ratios were also calculated to determine the grade of plutonium of this contamination

[en] The Variscan orogen of NW Iberia contains abundant syn- and post-tectonic granitoids. The post-tectonic granitoids are metaluminous to slightly peraluminous, I-type granites, monzogranites ± granodiorites ± tonalites. The Porriño pluton studied here is a representative example. It consists of two units: i) a pink-red, peraluminous, biotite granite and ii) a gray, metaluminous to peraluminous, biotite (± amphibole ± titanite) monzogranite, including maficintermediate enclaves. SHRIMP U-Pb dating yielded 290-295Ma ages for all the units. The mineralogy and geochemistry show that the pink-red granite has features of I- and A-type granites, whereas the gray monzogranite and enclaves are I-types. Sr isotopes show scattered values for the pink-red granite (87Sr/86Sr295Ma ≈ 0.702-0.710) and uniform values for the gray monzogranite and enclaves (87Sr/86Sr295Ma≈ 0.705-0.706). Geochemical results indicate a peritectic entrainment of clinopyroxene + orthopyroxene ± Ca-plagioclase ± ilmenite ± garnet, and minor accessory phases (± zircon ± titanite ± apatite) into a melt similar to the leucocratic gray monzogranite. A mafic-intermediate source is proposed for the gray monzogranite and its enclaves. Restitic protoliths generated granitic melts with A-type features such as the pink-red granite. The I-type nature of many post-tectonic granitoids could be explained by the previous extraction of S-type syn-tectonic granites that left restites and less fertile rocks. Late orogenic new melting affected the previously unmelted and more mafic lithologies of the lower-middle crust, and gave rise to I-type granitoids. Repeated melting events affecting such lithologies and previous restites could have generated granitic melts with A-type features.

[en] Using the classical U-Pb method and laser ablation method the isotopic age of zircons from gneisses of Kozhubaevskii Metamorphic Complex located in the eastern slope of the South Urals was estimated. The results obtained by the two methods suggest Proterozoic (no less than 1800-2000 mln. years) age of the complex. Morphological features of the zircons permit identifying the dating with granulitic metamorphism stage

[en] Using the LA-ICP-MS method based on a combination of laser ablation (LA) and inductively coupled plasma mass spectrometry (ICP-MS), the U-Pb dating of some grains of polygenic zircons isolated from granites and adamellites of the Adui Batholith, was conducted. For most of zircons studied the model age value was 291±8 mln. years. However, for certain zircons the age proved no less than 1451 mln. years, i.e. the solitary crystals were able to retain relic memory of early stages of their existence

No abstract available

[en] We describe an application of dynamic holography in rubidium vapour for laser ultrasound detection. This medium combines good signal to noise ratio with high cut-off frequency of approximately 1 MHz.

[en] For refining the data on the age of metamorphic rocks of the Murzinka metamorphic complex and the earliest stage of their formation the age of zircons within plagiogneisses of the rocks was identified. The age was identified by two methods, i.e. laser ablation (LA-ICP-MS) and classical U-Pb method. It is shown that the oldest dating of the gneisses by the method of laser ablation, which is 1600-1800 mln. years, agrees well with the data provided by U-Pb method (1639 ± 42 mln. years)

[en] Detailed isotopic-geochemical study of pseudoleucite tilaites in the Kytlym massif located in the Northern Urals was performed. By the method of Rb-Sr dating it was ascertained that formation of dunite-clino-pyroxenite-tilaite series of the above-mentioned massif embraced the time range from 360 to 330 ml. years, which is at least 80-60 ml. years younger than the main magmatism phase manifested in this sector of the Urals

[en] Granitoids of the Verkhisetsk massif in the Middle Urals are studied through the Rb-Sr dating method and by measuring the ¹⁴³Nd/¹⁴⁴Nd isotope ratios. Each association of the studied rocks was specified by a separate Rb-Sr-isochrone. Two out of three isochrones showed close age values 316 and 320 mln years, whereas another one indicated essentially younger age - 284 mln years. Causes of observed variations are discussed