Igneous
71Carbonatite — Carbonatites (pronEng|kɑrˈbɒnətaɪt) are intrusive or extrusive igneous rocks defined by mineralogy that comprises more than 50 volume % carbonate minerals. Carbonatites may be confused with marble, and may require geochemical… …
72Nephelinite — lava (grey) containing a xenolith of peridotite (yellow), Kaiserstuhl, Germany. Nephelinite is a fine grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite). If olivine is present, the rock may… …
73Rock microstructure — includes the texture of a rock and the small scale rock structures. The words texture and microstructure are interchangeable, with the latter preferred in modern geological literature. However, texture is still acceptable because it is a useful… …
74Normative mineralogy — is a geochemical calculation of the whole rock geochemistry of a rock sample that estimates the idealised mineralogy of a rock according to the principles of geochemistry. Normative mineral calculations can be achieved via either the CIPW Norm or …
75List of Spider Rider episodes — This is a list of episodes from the animated series Spider Riders . The series originally started in May of 2006, and end in April 2007.Episodes{|class= wikitable width= 98% ! # !! Title !! Original airdate colspan= 4 bgcolor= #CCCCFF Episode… …
76Glossary of geology terms — Here is a glossary of Geological terms.A*Abyssal plain Flat or very gently sloping areas of the deep ocean basin floor. *Absolute dating the process of determining a specific date (in years or some other unit of time) for an archaeological,… …
77Jurassic Period — Interval of geologic time, 206–144 million years ago, that is one of the three major divisions of the Mesozoic Era, preceded by the Triassic Period and followed by the Cretaceous. During the Jurassic, Pangea began to break up into the present day …
78Precambrian time — Interval of geologic time from с 3. 8 billion years ago, the age of the oldest known rocks, to 544 million years ago, the beginning of the Cambrian Period. This interval represents more than 80% of the geologic record and thus provides important… …
79Petrology — A volcanic sand grain seen under the microscope, with plane polarized light in the upper picture, and cross polarized light in the lower picture. Scale box is 0.25 mm. Petrology (from Greek: πέτρα, petra, rock; and λόγος, logos, knowledge) is the …
80Nepheline syenite — of the Intrusive Complex of Tanguá, State of Rio de Janeiro, Brasil (Motoki et al., 2011a) Nephelene syenite is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or… …
