Igneous Africa

Magma Composition and Igneous Rocks

Introduction In the following chapters we will find that nearly all of the varied aspects of volcanism are either directly or indirectly controlled by the chemical composition of magma and the rate at which it cools and solidifies. If you are to understand and appreciate subsequent discussions of volcanoes and related volcanic phenomena, it is essential that you have a good grasp of the basic c...

Igneous Petrogenesis of Yamato Nakhlites

Introduction: We have carried out detailed petrographical-mineralogical description of three Yamato nakhlites (Y000593, Y000749 and Y000802). These three are paired. We clarified chemical compositional differences between the Yamato nakhlites and other nakhlites, and subclassified the Yamato nakhlites as an intermediate type between NWA817 and others (Nakhla, Governador Valadares and Lafayette)...

Occurrence, Texture, and Classification of Igneous Rocks

U–Pb geochronology documents out-of-sequence emplacement of ultramafic layers in the Bushveld Igneous Complex of South Africa

Layered intrusions represent part of the plumbing systems that deliver vast quantities of magma through the Earth's crust during the formation of large igneous provinces, which disrupt global ecosystems and host most of the Earth's endowment of Pt, Ni and Cr deposits. The Rustenburg Layered Suite of the enormous Bushveld Igneous Complex of South Africa has been presumed to have formed by deposi...

An Igneous Origin for Martian Magnetic Anomalies?

Introduction: The presence of alternately magnetized sources on Mars indicates that at one time Mars had a magnetic field, presumably generated by an internal dynamo, and that its polarity reversed at least once before shutting off. Mars does not currently possess a magnetic field, so the anomalies are attributed to remanent magnetization (RM) of minerals in the crust. The initiation and cessat...