Most of the rocks that compose the crystalline-rock and undifferentiated sedimentary-rock aquifers are crystalline metamorphic and igneous rocks of many types.
(the rocks; compose; the crystalline-rock) (Most of the rocks that compose the crystalline-rock and undifferentiated sedimentary-rock aquifers; are; crystalline metamorphic and igneous rocks of many types)
the rocks Most of the rocks that compose the crystalline-rock and undifferentiated sedimentary-rock aquifers
compose are
the crystalline-rock
crystalline metamorphic and igneous rocks of many types