CHEM 112/6.0 (see first year Chemistry)
GEOL 104/3.0 and GEOL 107/3.0 (Geology: see What GEOL course should I take?)
MATH 121/6.0 or MATH 120/6.0 (calculus: see What MATH course should I take?)
PHYS 106/6.0 or PHYS 104/6.0 (Physics: see What PHYS course should I take?)
And optionally one of:
MATH 110/6.0 or MATH 111/6.0 (linear algebra: see What MATH course should I take?)
or
BIOL 102/3.0 and BIOL 103/3.0 (Biology: see What BIOL course should I take?)
Note that the linear algebra/biology option is not required by all Geology Plans, and may be deferred to second year.
For a list of electives see here