white cream gunge on oil cap 2002 1.0 corsa?

Had my car for6 months and never caused me any trouble serviced when I got the car.

I have an apprentice so i do 6 weeks at work where I travel around 50 mile a day, but past 2 weeks I have been at college Which is short journeys, and all this week my car has been parked up as been getting lifts, but yesturday I did 30 mile came to check oil on my car today and noticed the oil cap is full of white gunge, the car isn't losing coolant, heaters still working, not over heating and no water in oil, could this be with the cold weather and doing short journeys for the past 3 weeks, ?