emulsion in coolant reservoir

any one have any idea as to why i would have thich white emulsion sitting at the bottom of my coolant reservoir and blocking the pipe that goes to the radiator fill cap ??
It was about 2 - 3 inches deep in the reservoir,, I washed it all out earlier and took it for a run about 30 miles and all seems ok now ,, temperature sits bang on the centre where it has always,
it reminds me of an old ohv ford when they used to get choked up with white emulsion.

my first thought was head gasket ??
but if it was oil surely it would float in the water not sit at the bottom ?? and probably overheat

my next thought was too many short journeys,, it does 2 miles to work and 2 miles home ,, Thats it,, nothing above 50 mph.
would this cause emulsion ??

my next thought was ?????????

anyone have an opinion on my symptoms

It is an 02 mini one 1.6 if that helps

From what you say the short journeys are the problem.

But, check your oil, see if it's low or shows the same emulsion problem

oil is within min and max ,,
oil has only done 1,500 miles and shows no signs of contamination,
oil is clear and oil cap is clean as well

can you post some pics?? I will ask the techs at work tomorrow see what they say

sorry never took any pics ,, just unbolted the reservoir straight away and washed it
and the pipe out.
surely if it was the head gasket it would be showing emulsion again after taking it a run of 30 miles
down the motorway at 70 + mph ??
what i do not understand is why my oil is not contaminated as well if it is the gasket..
surely short journeys would cause condensation in the oil making emulsion
but i have emulsion in the coolant, how else could i get thick yogurt like substance (not frothy ) into the coolant ??

Then I suspect that's it's condensation build up due to the short journeys

took car to mini centre for mot today (it passed) and while there got mechanic to check the white gunge,
he does not think it is the gasket but said to get a radiator flush and refill and keep an eye on it,
does not believe short journeys would make any difference to the coolant.
so will flush it through tomorrow and see what happens
fingers crossed as they said will be about £8oo to get new gasket depending whether head needs skimmed