How to collaborate:

-Go on your journey, excursion or just a trip around your zone with a few zip bags (the ones with hermetic closure) and a few adhesive tags. Both things are on sale in any local stationery, weight nothing and fit anywhere in your luggage and besides they are permitted by any air line (up to date).

-Introduce a sample of sand in the bag (100gr is more than enough, although if it´s auriferous you can send a few pounds). Attach a tag indicating as precisely as possible the place the sample was taken at. Correct tagging procedures are "Beach X,Region, Country" or "River Y at its pass through Z" or "Mount zz, Region,Country". Incorrect tagging procedures are " 'Round the corner of my house", "Uncle Joe´s farm"

When you get home, secure the closure of the bag with some tape, put it in an envelope and mail it to:

Colegio Marista Cristo Rey
Departamento de Ciencias
Elviña 149
A Coruña 15009
Spain
To the attention of prof. Enrique Santillán

We will be thankful for your cooperation.