Planet - habitable, tidally locked planet orbitting red dwarf.
Aim: a realistic answer (neither involving handwavium nor aliens that used it all) why a virgin planet that already experienced a while ago its great oxygenation event, has practically no easily accessible (by standards of early XXIst century technology) fossil fuels sources. I mean especially oil and natural gas, however lack of coal would also be beneficial.
Thus the questions:
1) How to explain that?
2) What fossil fuel sources would still be accessible anyway?
1a) Maybe continental drift that moved continent with fossil fuels sources in the coldest regions under a few km of ice, and moved those that were covered with ice to the light side of the planet)
1b) Really deep ocean - makes any drilling extra hard
2) Presumably some bog would be unavoidable. I have no idea about gas and oil. To be safe I thought about putting them in tiny quantities that do not justify drilling.