Triassic igneous rocks in the vicinity of Gettysburg, Pennsylvania
نویسندگان
چکیده
منابع مشابه
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...
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متن کاملAGeochemical 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 ...
متن کاملPetrology of the igneous rocks in the west and southwest of Razan, Hamedan Province
West and southwest of Razan igneous rocks are located in the Hamedan Province in the Sanandaj- Sirjan zone, west Iran. According to petrography and chemical studies, these rock bodies are composed of diorite, gabbrodiorite, monzonite, quartz- monzonite, andesite and andesibasalt. The results of geochemical analysis show that these rocks belong to a cal- alkaline magma series. The geochemical c...
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ژورنال
عنوان ژورنال: Geological Society of America Bulletin
سال: 1916
ISSN: 0016-7606,1943-2674
DOI: 10.1130/gsab-27-623