Timing belt or not?

Hi All. An easy one for you guys. I have just got a auto 2001 disco with a TD5 engine. It's just clocked up 100k with a full service history (mostly landrover) 2 questions really, on the history I cant find anything that says it has had the timing belt changed. So is it a rubber belt or a timing chain? 2nd question is if I carry on with the reg maintenance, how many more miles can I approx expect to get out of it? oh, and what oil should I use in it before trawling through the manual. Thanks for any help guys.
Steve.

chain not belt

Great! thanks

a well maintained(and carefully used) Td5 engine would last at least 250K miles IMO without major obverhaul

as about oil, i recommend Castrol Edge 5w40 but you can use any 5w30 or 5w40 oil which is suitable for engines with electronic unit injectors(PD-s), or google out STC50527 (1 litre) or STC50528 (4 litre...you better buy 2 of this cos you need 7 l), these are the LR part numbers for engine oil.