Добрый день, Коллеги. Важное сообщение, просьба принять участие. Музей Ферсмана ищет помощь для реставрационных работ в помещении. Подробности по ссылке
Sometimes interest in the problem of the Moon’s genesis seems exaggerated. Why does this small celestial body, one of many in the solar system, attract so much attention?
First of all, the Moon genesis is part of the Earth genesis problem. Knowledge of our own planet, understanding of how and when its oceans and atmosphere came into existence, how and when the crust and the core of the Earth were formed, and how life originated on the Earth are not just academic issues; these are profound issues of human self-consciousness. Understanding the Earth’s genesis is impossible without solving simultaneously the Moon genesis problem.
In Chapter 4 you looked at plate tectonics and its influence on the climate and habitability of the Earth. In this chapter you will look at a specific aspect of this relationship, namely mountain building. Mountain ranges attract their own microclimates, which tend to be cooler and often wetter than the lowland areas that surround them.
It may strike you as odd that temperatures drop as altitudes increase; after all, the higher the altitude, the closer the Earth’s surface is to the Sun. This is primarily because direct solar radiation causes very little heating of the air; most heating is due to radiation reflected back from the Earth’s surface. Furthermore, air forced to rise by the presence of a mountain will expand and cool in response to the decreasing atmospheric pressure. Eventually, any water vapour in the air will condense. forming clouds and precipitation, which at high altitudes may fall as snow. Even at low latitudes, high mountains may be capped with snow or ice (Figure 5.1). <...>
The term geophysical refers to the workings of the earth. This includes movements on the earth’s surface (crust) as well as beneath the surface. These movements can be hazardous for humans such as when earthquakes and volcanic eruptions occur. Earthquakes and volcanoes occur in the earth’s lithosphere. This is the solid zone of rock on the earth, including the crust and the upper part of the mantle, that extends downwards from the earth’s surface to a depth of about 70 kilometres.
The Cumamona Province (South Australia/New South Wales) and Cloncurry district (NW Queensland) are both extensively metasomatised terrains containing hydrothermal iron oxide copper-gold and related deposits. Structural timing criteria and geochronological data suggest that the deposits formed at 1630-1600 Ma (Cumamona) and 1540-1500 Ma (Cloncurry). The Cloncurry deposits have a close temporal association with I-type granitoids and limited data suggest a similar relationship exists in the Cumamona Province. The majority of deposits are hosted by metamorphosed Palaeoproterozoic supracrustal rocks of varying age, composition and metamorphic grade. Mineralisation was localised by a range of brittle-ductile and brittle structures and produced vein, stockwork, breccia and replacement orebodies. Variations of fluid chemistry, host rocks and physical conditions produced mineralogically-diverse alteration zones, varying Cu:Au ratios, many different minor element associations, and inconsistent spatial relationships between magnetite and ore metals. Regional-scale alteration systems are dominated by Na-(Fe-Ca)-rich assemblages in which the most characteristic mineral is albite. Most of the ore deposits are specifically associated with pre- to synmineralisation alteration assemblages composed of medium to high temperature K-Fe-(Ca-Mg)-rich minerals together with late-stage parageneses containing carbonates. The deposits formed in deep-seated (> 5km) environments by a variety of different geochemical mechanisms from complex H,0-C02±CH4±N2-saIt fluids of magmatic and/or metamorphic derivation .
The exceptional andalusite±kyanite±andalusite sequence occurs in Al-rich graphitic slates in a narrow pelite belt on the hangingwall of a ductile normal fault inNWVariscan Iberia. Early chiastolite is replaced by Ky±Ms±Pg aggregates, which are overgrown by pleochroic andalusite near granites intruded along the fault. Slates plot in AKFM above the chloritoid-chlorite tie-line. Their P±T grids are modelled with Thermocalc v2.7 and the 1998 databases in the NaKFMASH and KFMASH systems. The univariant reaction Ctd+And/Ky=St+Chl+Qtz+H2O ends at progressively lower pressure as F/FM increases and A/AFM decreases, shrinking the assemblage Cld±Ky±Chl, and opening a chlorite-free Cld±Ky trivariant ®eld on the low temperature reaction side. This modelling matches the observed absence of chlorite in high F/FM rocks, which is restricted to low pressure in the andalusite stability field.
The P±T path deduced from modelling shows a ®rst prograde event in the andalusite ®eld followed by retrogression into the kyanite ®eld, most likely coupled with a slight pressure increase. The ®nal prograde evolution into the andalusite field can be explained by two different prograde paths. Granite intrusion caused the ®rst prograde part of the path with andalusite growth. The subsequent thermal relaxation, together with aH2O decrease, generated the retrograde andalusite±kyanite transformation, plus chlorite consumption and chloritoid growth. This transformation could have been related to folding in the beginning, and aided later by downthrowing due to normal faulting. Heat supplied by syntectonic granite intrusion explains the isobaric part of the path in the late stages of evolution, causing the prograde andalusite growth after the assemblage St±Ky±Chl. Near postectonic granites, a prograde path with pressure decrease originated the assemblage St±And±Chl.
Siento la necesidad de celebrar este proyecto con las personas que han transitado por mi universo cotidiano, sentimental y laboral, y que han permitido que desarrolle una formación humana y académica, tanto presente como futura. Este trabajo no hubiera sido posible sin el apoyo incondicional de personas que han dejado su huella ferviente en mi ser: en primer lugar, a mi madre Inés M. M. Peralta y a mi padre Osvaldo Ricardo Sironi, quienes con su amor incondicional apostaron su cotidianeidad para mi devenir humano y profesional. En segundo lugar, a mis hermanos Andrés, Mariano y Sebastián; a mis sobrinos/as Juliana, Juan Justo, Lautaro, Victoria, Juan Cruz y Amalia; a mis cuñadas Carolina, Andrea y Paola, como así también a mis numerosos tíos/as, primos/as y sobrinos/as por filiación materna; quienes han tolerado con mucho amor y paciencia mis altibajos personales, brindándome su apoyo constante en la lucha cotidiana (mas allá de la distancia geográfica que nos separa). <...>
I take pleasure in presenting a further edition (volume 32) of the internationally recognized and acclaimed series ‘Palaeoecology of Africa’ (PoA). Already since 1966 the series has published a large number of interdisciplinary scientific papers on landscape evolution and on former environments of selected areas within the African continent. Since the re-edition and re-launch of ‘Palaeoecology of Africa’ in 2007/2008 it is the fifth volume of the yearbook series that follows the new concept and layout under the restructured editorial board and by support of the publishing houses Routledge and CRC Press. Therefore, the ambitious goal of the editorial board and its editor in chief to have one book a year was almost reached. Many thanks go to all the contributing authors, colleagues and friends who directly and indirectly contributed during the last years to make this re-edition of ‘Palaeoecology of Africa’ a reality and a success. <...>
MORRIS, A. & TARLING, D. H. Palaeomagnetism and tectonics of the Mediterranean region: an introduction
Western Mediterranean
KIRKER, A. & MCCLELLAND, E. Application of net tectonic rotations and inclination analysis to a high-resolution palaeomagnetic study in the Betic Cordillera
VILLALAfN, J. J., OSETE, M. L., VEGAS, R., GARCfA-DUEI~AS, V. & HELLER, F. The Neogene remagnetization in the western Betics: a brief comment on the reliability of palaeomagnetic directions
FEINBERG, H., SADDIQI, O. & MICHARD, A. New constraints on the bending of the Gibraltar Arc from palaeomagnetism of the Ronda peridotites (Betic Cordilleras, Spain)