Three of the samples nl 32 nl 66 nl 74 all appear to be altered sedimentary rocks as.
Petrographic description of granite.
A recent paper by prof.
The thin sections were made by janwill petrograhics and the descriptions were completed by alana murphy.
National museum washington upon an occurrence of free gold in granite describes an interesting instance of the dissemination of this noble metal in the substance of granite of normal composition believed to be from sonora mexico.
5 4 petrographic examination of aggregate considered for use in hydraulic cement concrete is one aspect of the evaluation of aggregate but petrographic examination is also used for many other purposes.
4 2 1 barotiya group of rocks the barotiya group of rocks of mesoproterozoic age include an assemblage of metasediments dominantly mica schist along with conglometrate meta arkose and.
Some common rock types as seen under the microscope.
These are photomicrographs very thin slices of rock seen in plane polarised light or between crossed polarisers when the colours seen are produced by interference of light.
These descriptions with photographs are included in appendix i.
Merrill curator of the department of geology of the u.
In this chapter petrographic characteristics of these rocks are explained in detail.
He found the gold in small scales rarely exceeding a.
Petrographic description and petrochemical character of granitoid rocks in mudu area northern part of maungmagan dawei district myanmar myo zaw set1 and htay win1 search and discovery article 51267 2016 posted june 20 2016.
Rocks under the microscope.
2014 079 1 this sample is a plutonic rock dominated by anhedral feldspar 60 percent and a lesser amount of quartz 40 percent.
Granite and govindgarh granite.
The general process for writing rock descriptions is to start off with a general description general colour grain size texture followed by identification of the minerals within the rock the mineral assemblage the name of the rock deduced from the assemblage and then finally your best guess on how and where it was formed.
Included in this section is a list of applicable standards and test methods for granite descriptions and standards for related construction components fabrication tolerances standard finish descriptions geological and petrographic descriptions of granite physical and mechanical property requirements as well as descriptions of common repairs and reinforcements.
Petrography is a branch of petrology that focuses on detailed descriptions of rocks someone who studies petrography is called a petrographer the mineral content and the textural relationships within the rock are described in detail.
