Classification of Igneous Rocks: Diorite vs. Syenite – a suggestion to avoid a contradiction

Occurrence, Texture, and Classification of Igneous Rocks

AGeochemical Classification for Feldspathic Igneous Rocks

In this paper we classify the range of feldspathic igneous rocks using five geochemical variables: the FeO/(FeOþMgO) ratio or Fe-index, the modified alkali^lime index, the aluminum-saturation index, the alkalinity index, and the feldspathoid silica-saturation index.The Fe-index distinguishes between melts that have undergone extensive iron enrichment during differentiation from those that have ...

A paleointensity technique for multidomain igneous rocks

[1] We developed a paleointensity technique to account for concave-up Arai diagrams due to multidomain (MD) contributions to determine unbiased paleointensities for 24 trial samples from site GA-X in Pleistocene lavas from Floreana Island, Galapagos Archipelago. The main magnetization carrier is fine-grained low-titanium magnetite of variable grain size. We used a comprehensive back-zero-forth ...

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...

the innovation of a statistical model to estimate dependable rainfall (dr) and develop it for determination and classification of drought and wet years of iran

آب حاصل از بارش منبع تأمین نیازهای بی شمار جانداران به ویژه انسان است و هرگونه کاهش در کم و کیف آن مستقیماً حیات موجودات زنده را تحت تأثیر منفی قرار می دهد. نوسان سال به سال بارش از ویژگی های اساسی و بسیار مهم بارش های سالانه ایران محسوب می شود که آثار زیان بار آن در تمام عرصه های اقتصادی، اجتماعی و حتی سیاسی- امنیتی به نحوی منعکس می شود. چون میزان آب ناشی از بارش یکی از مولفه های اصلی برنامه ...