### Clue: Soup or crude sandwiches by volunteers (6)
### Answer: OXTAIL 
 ### Explanation: OIL(*crude* oil, what comes from underground before being refined into useful products, primary route of taking carbon from under the ground and putting it into the atmosphere) around(*sandwiches*) X(times,multiplied *by*, an arithmetical operator) + TA(Territorial Army, in UK, made up of *volunteers*.  Even though it's now replaced by TAVR, TA is too useful to be discarded in Crosswordland).  Defn:  Soup made with that part of cattle.