Geochemical dataGeochemical data

All electromagnetic waves travel at the speed of light (3 x 108 ms-1) and are discussed in terms of wavelength and frequency

The electromagnetic spectrum

Spectrometry

Energy Source AbsorptionDetectorSample

EmissionDetector

Output withabsorption trough

Output withemission peak

Absorbedradiation

Emittedradiation

The K emission spectrum of copper

X-ray spectrum of an olivine

Composition of Earth shellsElements wt%

  Crust Mantle Core

  Continental Oceanic Upper Lower Outer Inner

O 41.2 43.7 44.7 43.710--15

 

Si 28 22 21.1 22.5  

Al 14.3 7.5 1.9 1.6    

Fe 4.7 8.5 5.6 9.8 80--85 80

Ca 3.9 7.1 1.4 1.7    

K 2.3 0.33 0.08 0.11    

Na 2.2 1.6 0.15 0.84    

Mg 1.9 7.6 24.7 18.8    

Ti 0.4 1.1 0.12 0.08    

C 0.3          

H 0.2          

Mn 0.07 0.15 0.07 0.33    

Ni         5 20

Cr       0.51    

Nucleosynthesis

« Bethe’s cycle »

Elements stability

Elements abundance

• Lights > Heavies

• Even > Odd

• Abundance peak close to Fe (n=56)

Solar system abundance

Formation of a planetary nebula-

Planetary nebulas

Temperature gradients in the planetary nebula

Differenciation of planets