Geologic units in San Jacinto county, Texas

Willis Formation (Pliocene) at surface, covers 39 % of this area

Willis Formation

Fleming Formation (Miocene) at surface, covers 28 % of this area

Fleming Formation

Lissie Formation (Quaternary; Middle Pleistocene) at surface, covers 14 % of this area

Lissie Formation

Deweyville Formation (Quaternary; Pleistocene and Holocene?) at surface, covers 6 % of this area

Deweyville Formation

Alluvium (Holocene) at surface, covers 6 % of this area

Alluvium

Deweyville Formation with higher level? (Quaternary; Pleistocene and Holocene?) at surface, covers 4 % of this area

Deweyville Formation with higher level?

Beaumont Formation, areas predominantly sand (Quaternary; Late Pleistocene) at surface, covers 4 % of this area

Beaumont Formation, areas predominantly sand

Terrace deposits (Pleistocene and Holocene) at surface, covers 1 % of this area

Terrace deposits