The document analyzes two meteorite samples using EPMA (electron probe microanalysis). For both samples: - Major minerals like olivine and pyroxene were identified. - Elements like Si, Mg, and Fe were mainly found within grains, while others like Ti, K, Ca, Na were in the matrix. - Quantitative analysis identified mineral compositions like Mg-rich olivine and enstatite. - Elemental maps showed varying distributions and helped determine mineral associations.

1. Elemental mapping and Quantative
Analysis of Meteorite Sample by
using EPMA
By
Sanjay Dubey
Doctoral Researcher
IPM

2. Image of the object in the sample
A B C
D E
A. Mosaic Image(100x) of sample ALL01-c1-3-1
B. Zoom image of the Object No.1
C. BSE image (250x) of the region in the Object 1
and this region is used for the EPMA analyzer to
calculate the distribution of element.
D. Zoom Region of object no.2
E. BSE image (100x) of the region in the object
no.2 and Quantative analysis was perform on
this region

3. SEI images of the region within object no.1
SEI Image 250X
SEI Images is Secondary Electron Image
Observation:
• Holes can be visualize
• Grain shape, surface and boundaries can be visualize
• Grain boundaries resemble the chondrule like
structure (which are formed at high temperatures as
dispersed molten droplets, which subsequently
solidified and aggregated into chondritic masses.)
• Cracks can be observed in the images
• The formation of irregular crack on the surface of
grain can explain about the shock metamorphism.
(Impacts on the parent body of a meteoroid can
produce very large pressures. These pressures heat,
melt and deform the rocks.)
• Matrix can be observed around the grains

4. BSE image of the region within the object no.1
BSE Image at 250X
COMPO Images is Backscattered Electron Image
Observation:
•
BSE images show complex internal morphology
• Chondrule looks in big gray color
• Small white spots indicate metallic oxide
• It also show inclusion material.
• Cracks and Holes can be visualize in black colors and better
than SEI image
• Grain surface and boundaries can be visualize with the
COMPO Images
• BSE images of chondrule and matrix showing various
minerals present in this multicomponent meteorite piece
• Matrix can be observed around the grains and Matrix is
brighter than chondrule explain metal rich composition.
• Grey and dark areas are mostly olivine's and pyroxenes,
the major minerals of chondrite

5. X-ray Image of the Sample with High concentration elements
Observation:
• Si seem to be distributed uniformly mostly around the grain boundary and
inside the grain compare to Mg and Fe
• High concentration of Si can be observe at the matrix compare to the inside of
the grain.
• Concentration of Mg is high around the center of the grain compare. Mg
concentration seem to be very less around the grain boundary and matrix.
• Fe concentration is very less inside the matrix and around the center of the
grain. Fe is non-uniformly distributed across grain, grain boundary and the
matrix.

6. X-ray image of the sample with low concentration elements
Observation:
• Calcium is rarely seen in the grain.
There is high concentration of Ca
present in the few region of the
matrix.
• K distribution seems mostly around
the grain boundary and inside the
matrix. Few region in the matrix has
high concentration of K more than
Ca
• Al concentration seems mostly
distributed to the matrix and around
the grain boundary. Concentration
of Al inside matrix is more compare
to Ca and K

7. X-ray Images of the sample with low concentration element
Observation:
• Distribution of Na and Cl is more densely located
nearby the grain boundary and in the matrix compare
to inside the grain.
• Na and Cl are absent in the grain. High concentration
of Cl and Na is observed around inside of the matrix
BSE Image at 250X

8. X-ray image of the sample with very-low concentration elements
Observation:
• Very less concentration of Cr, P, F, Ni and Ti is
observe in the X-ray image of the region in
the object 1.
• Some red spot indicate high concentration of
Cr, Ti, Ni, P and F present in the region of the
object no 1.

9. Quantative analysis of the region in Object no.1

10. Color Superposition of Elemental X-ray Maps of the region in Object no.1
Figure A: Mg-Si-Fe (Red-Green-Blue) Image Figure B: Ca-Na-K (Red-Green-Blue) Image
• Figure A explain about the distribution of Mg-Si-Fe(Red-Green-Blue) in the region of Object no1. It also explain about end member of
Olivine that is Frosterite and Fayalite. Mix color of red and green around the center of the grain explain more about the Frosterite presence
whereas mix color of green and blue which can also seen as dark green indicate there can be presence of more Fayalite.
• Figure B explain more about the distribution of Ca-Na-K in the region of object no.2 It also explain about the end member of ternary
feldspar that is Anorthite, Albite and Orthoclase. Grain boundary and matrix resembles the phase more of ternary feldspar phase

11. Quantative analysis of the region in Object no.1
Points Minerals Derived Formula
point A Mg-rich olivine SiFe.47Mg1.53O4.005
point B Mg-rich olivine SiFe.395Mg1.563O3.958
point C
62-An and 38-Ab
Plagioclase
Si3.415Al1Fe.764Ca.90Na.50O10.72
point D melilite Si3.762Al2Fe.2108Mg.59Ca1.68Na2.216O10.93
point E Mg-rich olivine SiFe.646Mg1.95O3.58
point F Mg-rich olivine SiFe1.16Mg1.394O4.54
point G
60-An and 40-Ab
Plagioclase
SiAl.279Fe.197Mg0.142Ca0.295Na0.1928O3.1482
point H Mg-rich olivine SiMg1.48Fe.533O4.013
point I Clinopyroxene SiTi0.05Al0.01Fe0.245Mg0.318Ca0.524Na0.06O3
point J Mg-rich olivine SiFe.617Mg1.36O3.97
point K Mg-rich olivine SiFe.66Mg1.36O3.519
point L Fe-rich Olivine Si1.36FeMg1.36Na.43Ti0.0834O5.50
point M Mg-rich olivine SiFe.702Mg1.3O4.003

12. SEI and BSE images of the object no.2
SEI image 55X of Object No.2 BSE Image at 100X of Object No.2

13. X-ray Image of the object No.2
Observation:
• Object no 2. It is Chondrule which
consist of many grains within it.
• Concentration of Si seem to be
distributed mostly uniformly within the
chondrule. Si concentration drop
outside the chondrule.
• Mg distribution is mostly within the
matrix of chondrule.
• Concentration of Fe within the
chondrule is very less compare to the
outside matrix
• Mg-Si-Fe(Red-Green-Blue) indicate the
superposition of three element. Light
green represent mostly low Fe
concentration and Dark green
represent high Fe. Which can also
explain more about the olivine and
pyroxene distribution with in the
chondrule and outside of it

14. X-ray Image of the Object No.2
Observation:
• K is mostly distributed with in the
matrix of chondrule compare to the
grains in the chondrule. Concentration
of K drops outside the chondrule.
• Concentration Ca seems to be very less
within the chondrule compare to K and
Na.
• Na concentration is mostly distributed
within the matrix of the chondrule
similar to K.
• Ca-Na-K(Red-Green-Blue) is not
present in the grain of the chondrule.
Dark pink indicate the high
concentration of Ca and K and light
indicate low K. Yellow color in the
matrix within chondrule represent high
concentration Ca and Na.

15. X-ray Image of the Object No.2
Observation:
• Concentration of Mn is very less around
the edge of chondrule and in the matrix of
chondrule
• Concentration Ti is very less with in the
matrix of the chondrule. Ti is least compare
to the Mn and Cr.
• Cr is mainly distributed around the
boundary of the chondrule and very small
quantity with in the matrix
• Ti-Cr-Mn (Red-Green-Blue) show there
non-uniform distribution of this element
within and boundary of the chondrule.
Pink represent high value Mn-and Ti . Light
Green indicate High Ti and Cr.Mn is widely
distributed outside the chondrule and with
in the matrix but very less within the grain
of the chondrule

16. Quantative analysis of the region in Object no.2

17. Quantative analysis of the region in Object no.2
Points Mineral Formulae
A
Mg -rich
Olivine
SiFe0.168Mg1.796O3.975
B
Mg -rich
Olivine SiFe0.123Mg1.860O4.00
C
Mg -rich
Olivine
SiFe.105Mg1.870O3.98
D Enstatite SiFe0.008Mg0.940Ca0.033O3.086
E Enstatite Si1.00Fe0.010Mg0.952Ca0.010O3.
031
F
Mg -rich
Olivine
SiFe0.135Mg1.818O3.973
H
Mg -rich
Olivine
SiFe0.141Mg1.845O3.998

18. • Superimposing three elemental maps that have been assigned primary colors red, green, blue! provides a simple
method for determining elemental associations. This color mapping assist to extract quantitative information of the
elements
• Its apparent that after Si and O, the elements Fe>Mg>S>Al>Na>Mn is order of abundance in Meteorites[1]. In this case-
study quantity of Mg was mostly higher than the Fe, S, Al and Mn in both the object 1 and 2.
• Among the above 6 elements, Fe and Mg show the maximum abundance as they form the bulk meteoritic minerals
Olivine and Pyroxene. Main phase present in both objects were Olivine, Pyroxene and Plagioclase. In object 2 contain
very little iron oxide (FeO), resulting in olivine and pyroxene that are close to Frosterite(Mg2SiO4) and Enstatite(MgSiO3)
in composition. Such chondrule formed in the region of object no 2 are formed under less oxidizing condition and
called as type 1 chondrule[2].
• In this study, elements like Ti, Ni, Cr, K, Ca, Na, P and Mn are mainly found at the grain boundary or within the matrix
and elements like Si, Mg and Fe are mainly present within the grain of the both objects.
1.Patwardhan, A. M. (2012). The dynamic earth system. PHI Learning Pvt. Ltd.
2. Jones, R., & Scott, E. (1996). Chondrules and the protoplanetary disk. Cambridge University Press.
Inference