Egypt (Sid Metagabbros, MG, and Younger Gabbro, YG) have been subjected to EPMA.
There are distinct geochemical differences between the amphiboles of these two types. The
amphiboles of the YG show relatively high TiO 2, A1 2 O 3, Na 2 O, K 2 O and low SiO 2 and
Fe 2 O 3 than the MG. The YG have also (Na+ K)> 0.5 and A1 IV> 1.3. The amphiboles of the
MG are mainly magnesio-hornblende with subordinate actinolitic hornblende, whereas, the …