GLOSSARY 



OF GEOLOGICAL AND OTHER SCIENTIFIC TERMS. 

 FKOM LXELL'S rUINCIPLES OF GEOLOGY. 



diluvium. Earth, sand, grave], stones, and other transported matter 

 which has been washed away and thrown down by rivers, 

 floods, or other causes, upon land not permanently submerged 

 beneath the waters of lakes or seas. Etym., alluo, to wash 

 upon. 



Amorphous. Bodies devoid of regular form. Etym., a, a, without, 

 and fAoptpv], 7110 rp he, form. 



Amygdaloid. One of the forms of the Trap-rocks, in which agates 

 and simple minerals appear to be scattered like almonds in a 

 cake. Etym., apvySaXu, amygdala, an almond. 



Analcime. A simple mineral of the Zeolite family also called Cu- 

 bizite, of frequent occurrence in the trap-rocks. 



Anticlinal Axis. If a range of hills, or a valley, be composed of 

 strata, which on the two sides dip in opposite directions, the 

 imaginary line that lies between them, towards which the 

 strata on each side rise, is called the anticlinal axis. In a 

 row of houses with steep roofs facing the south, the slates 

 represent inclined strata dipping north and south, and the ridge 

 is an east and west anticlinal axis. 



Arenaceous. Sandy. Etym., arena, sand. 



Argillaceous. Clayey, composed of clay. Etym., argilla, clay. 



Arragonite. A simple mineral, a variety of carbonate of lime, so 

 called from having been first found in Arragon, in Spain. 



Augite. A simple mineral of a dark green or black colour, which 

 forms a constituent part of many varieties of volcanic rocks. 



Basalt. One of the most common varieties of the Trap-rocks. It 

 is a dark green or black stone, composed of augite and felspar, 

 very compact in texture, and of considerable hardness, often 

 found in regular pillars of three or more sides, called basaltic 



