Samples/Methods/Results part:
Samples/Methods:
The samples were given randomly. I got one of low silica bainites samples which is sample” U1439C 35R”. In order to reach results on what minerals we have in our samples, we used a polarizing microscope as first step. Polarizing microscope was our first method to figure out what does our samples looks like. I used some optic properties to know what minerals I had like pleochroism, relief, cleavage, extinction angel and twinning. Second, we discussed in group what samples are the best to send them to Miami where our second method (ESEM) located. We had several SEM sessions in the lab, and I used the Electron microscope (JEOL 8700 Superprobe with five Wavelength Dispersive spectrometers) using running conditions (a 2 x amp beam current, and a 15KV potential gradient) to choose a spot and get a graph of elements and their portions in each spot. Based on the elements we narrow down the list of the possible minerals. The elements gave us general information on what mineral is that, but their portions made us able to decide which mineral is that.
Results:
Petrography results using polarizing microscope:
Primary minerals
Secondary minerals
Textures
Zoning/overgrowth
U1439C 35R
-Pigeonite
-Plagioclase
-Calcite
– Felty flakes of pigeonite
-None
U1439C 46G1
– Magnetite
– Enstatite
– Plagioclase
– Iron oxide replacement of Enstatite
Intersertal texturing with variolitic clots of plagioclase
Iron oxide has overgrowth
U1439C 28R
Round Olivine grains
Enstatite
Plagioclase
Clinopyroxenese
-Calcite
-Zeolite
-Serpentine
– Intergranular Olivine
– Intersertal plagioclase
– Zoning in Zeolite
U1442A 55R2
Clinopyroxene (augite)
Plagioclase
Enstatite
-Zeolite
-Vesicular Zeolite
-Intersertal texture
-Zoning in plagioclase
U1442A 57R1
Biotite
Olivine
Clinopyroxene
-Serpentine around the Olivine
-Seriate with Variolitic crystals of plagioclase
-None
U1442A 36R2
Pyroxenes
Olivine
Enstatite
-Serpentine
-Glomerocrysts of pyroxene
-Zoning in pyroxene
U1442A 53R1
Plagioclase
Olivine
Enstatite
Pigeonite
-Calcite
-Zeolite
-Felty plagioclase
– Glomerocrysts Olivine and Enstatite
– Alteration infilling fracture of calcite
SEM microprobe results:
Sample “U1442A 57R1” was the only sample run on the electron microprobe from the “Low Silica Boninites” core. The following picture represent spot#1:
Spectrum#
Mineral
Notes
Image of elements chart
Spectrum#1
Augite.
The shape reflects that this is earthier plagioclase or pyroxene, but plagioclase doesn’t contain Mg element so it’s probably pyroxene (Augite).
Spectrum#2
Spectrum#3
Spectrum#4
Spectrum#5
The post Samples/Methods/Results part: Samples/Methods: The samples were given randomly. I got one of appeared first on PapersSpot.
