Academic literature on the topic 'Extrusive rocks, basalts, magma-type'

The present contribution reports on the field, petrographical and geochemical observations of the volcano-plutonic rocks of the Nakora Ring Complex (NRC) from the Neoproterozoic, Malani Igneous Suite (MIS) (Northwestern Peninsular India) and confers about their magmatic evolution and tectonic implications. Three magmatic phases are notable in the NRC which is Extrusive, Intrusive and Dyke phase where with small quantities of basaltic flows was initiated and accompanied by extensive/voluminous acidic flows. Petrographically, rhyolite shows flow bands, porphyritic, spherulitic, aphyritic and perlitic textures whereas basalt flows are distinguished by the presence of labradorite in lath-shaped crystals (plagioclase feldspar) and clinopyroxene (augite). The presence of high silica and total alkalis in NRC rocks, as well as high field strength elements (HFSE), enrichment of trace elements and negative anomalies of Sr., Eu, P, and Ti indicates that the emplacement of the lava flows was controlled by complex magmatic processes such as fractional crystallization, crustal contamination and partial melting. The association of basalt-trachyte-rhyolite means that the magma chamber was supplied a significant amount of heat to the crust before the eruption. Moreover, a volcanic vent was also reported at NRC where rhyolite was associated with agglomerate, volcanic breccia, perlite and tuff. The current research proposed that the Neoproterozoic magmatism at NRC was controlled by rift-related mechanism and produced from crustal source where the heat was supplied by mantle plume.

It seems anorthosites are by far interested by geologists because they give us great information about Earth history and how it was evolved in planetary geology. Planetary geology is subject the geology of the celestial bodies such as the planets and their moons, asteroids, comets, and meteorites. It is nearly abundant in the moon. So, it seems studying of these rocks give us good information about planetary evolution and the own early time conditions. Anorthosites can be divided into few types on earth such as: Archean-age (between 4,000 to 2,500 million years ago) anorthosites, Proterozoic (2.5 billion years ago) anorthosite (also known as massif or massif-type anorthosite) – the most abundant type of anorthosite on Earth, Anorthosite xenoliths in other rocks (often granites, kimberlites, or basalts). Furthermore, Lunar anorthosites constitute the light-colored areas of the Moon’s surface and have been the subject of much research. According to the Giant-impact hypothesis the moon and earth were both originated from ejecta of a collision between the proto-Earth and a Mars-sized planetesimal, approximately 4.5 billion years ago. The geology of the Moon (lunar science) is different from Earth. The Moon has a lower gravity and it got cooled faster due to its small size. Also, it has no plate tectonics and due to lack of a true atmosphere it has no erosion and weathering alike the earth. However, Eric A.K. Middlemost believed the astrogeology will help petrologist to make better petrogenic models to understand the magma changing process despite some terms geological differences among the Earth and other extraterrestrial bodies like the Moon. So, it seems that these future studies will clarify new facts about planet formation in planetary and earth, too.