In this book the author attempts to provide up-to-date information about the geochemistry, exotic mineralogy, petrology, and experimental studies on ultrapotassic feldspathoid-bearing mafic and ultramafic rocks, which are quite distinct from the rocks of basalt family. The parental liquids for this intriguing group of rocks bear definite signature of their deep mantle source.

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 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 .

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). <...>