To promote a wider interest in the science of geology through organised lectures, field excursions and social activities.
To provide a link between the amateur, the student, the teacher and the professional geologist.
To foster interest in geological sites within the area with a view to their study and wise conservation.
To establish and maintain good relations with organisations that have common interests.

 

 

 

 
 
 

 

 
 

Where plates collide, temperature and pressure in the rocks is elevated over a very large area causing them to become metamorphosed – hence regional metamorphism. Different physical factors and different original rocks produce different minerals. It has been found that where the rocks were sedimentary and argillaceous being composed originally of clays, shales, mudstones and siltstones new minerals appear in the rock, in zones over large areas – the Barrovian metamorphic zones. The start of each new zone is where a new mineral appears, which is not to say that the other ones disappear.

 

Temperature is the driving force and depends mainly on depth of burial although if there is a high thermal gradient that is not always the case. Depth of burial implies higher pressures and these two – temperature and pressure – together with the stresses involved, bring about the changes.

 

With increasing temperature and pressure the metamorphic ‘grade’ goes up, and different minerals appear, by and large, in a certain order. What is this order and how can we remember them? Stay with it because that’s what this is all about and here 'tis!

 

Can Betty Grable Still Kiss Silkily

 

Chlorite, Biotite, Garnet (almandine), Staurolite, Kyanite, Sillimanite

Betty Grable, for the benefit of our younger readers was the blonde, long-legged, All-American bombshell from next door and yes, I think temperatures would rise!

Jim Jones, a one time member of WEGA, gave me this one many years ago. Come back Jim, all is forgiven.