2 4 
glossary. 
Syenite . A mineral composed of Felspar and Hornblende. 
synclinal, see p. 69. 
Trachite. A lava with a low percentage of Silica. 
Trias , see p. 34. 
Urgonian , see p. 40. 
Valangian , see p. 39. 
Verrucano, see p. 33. 
