Geologic units in Harris county, Texas

Lissie Formation (Quaternary; Middle Pleistocene) at surface, covers 36 % of this area

Lissie Formation

Beaumont Formation, areas predominantly clay (Quaternary; Late Pleistocene) at surface, covers 36 % of this area

Beaumont Formation, areas predominantly clay

Beaumont Formation, areas predominantly sand (Quaternary; Late Pleistocene) at surface, covers 17 % of this area

Beaumont Formation, areas predominantly sand

Willis Formation (Pliocene) at surface, covers 7 % of this area

Willis Formation

Alluvium (Holocene) at surface, covers 2 % of this area

Alluvium

Deweyville Formation (Quaternary; Pleistocene and Holocene?) at surface, covers 1 % of this area

Deweyville Formation

Fill and spoil (Holocene) at surface, covers 0.5 % of this area

Fill and spoil

Terrace deposits (Pleistocene and Holocene) at surface, covers 0.1 % of this area

Terrace deposits