- lithofacies
- lithologic trap
- lithophile element
- lithophysa structure
- lithosphere
- lithostratigraphic unit
- lithostratigraphy
- littoral facies
- Liujiagou Formation
- Lizigou Formation
- Llandeilian Age
- Llandeilian Stage
- Llandoverian Epoch
- Llandoverian Series
- Llanvirnian Age
- Llanvirnian Stage
- load
- load cast, load structure
- load metamorphism
- local background
- local equilibrium
- local metamorphism
- maturity of organic matter
- maximum hydroscopic moisture, maximum molecular moisture cap
- mazzite
- meagre coal
- meandering river
- medium-pressure facies series
- megacycle
- meionite
- Meishucun Formation
- Meishucunian Age
- Meishucunian Stage
- Meitan Formation
- melange
- melanocrate
- melilite
- meliphanite
- melting curve
- member
- Menevian Age
- Menevian Stage
- Menkadun Formation
- meridional structural system
- meridional tectonic belt
- mesocratic rock
- mesodesmic structure
- Mesoproterozoic Era
- Mesoproterozoic Erathem
- mesosiderite, pyroxene-plagioclase stony-iron