tMax is the temperature at which maximum hydrocarbons are
emitted during the S2 phase of pyrolysis. During the S2 phase, only
kerogen is emitted as all other hydrocarbons should have been
released during the S1 phase.
A higher tMax indicates that the kerogen required higher
pyrolysis temperatures to crack. A lower tMax indicates that the
kerogen requires lower pyrolysis temperatures to crack.
Kerogen cracked at lower temperatures (lower tMax) is more
immature since it did not encounter equal temperatures/pressures in
situ. Kerogen cracked at higher temperatures is said to be more
mature, since all easily accessible kerogen was already cracked in
situ (indicating a prolonged exposure to heat and pressure).
