Geologic Structures
Anticline - Answer an upward fold in rock formed by compression of Earth's crust
Syncline - Answer A downward fold in rock formed by compression in Earth's crust
Recumbent Fold - Answer A fold overturned to such an extent that the limbs are
essentially horizontal.
Overturned Fold - Answer a structural feature in which the fold limb is tilted beyond
vertical, which results in both limbs inclined in the same direction, but not at the same
angle
Isoclinal fold - Answer Compressional stress so intense that limbs become parallel
Open fold - Answer A fold with gently dipping limbs.
Normal fault - Answer A type of fault where the hanging wall slides downward; caused
by tension in the crust
Reverse fault - Answer A type of fault where the hanging wall slides upward
strike-slip fault - Answer A type of fault in which rocks on either side move past each
other sideways with little up or down motion.
Thrust fault - Answer Low angle reverse fault
Dome - Answer A large or elliptical structure formed by the fractureless upwarping of
rock strata.
Horst - Answer an elongated, uplifted block of crust bounded by faults
Graben - Answer an elongated block of the earth's crust lying between two faults and
displaced downward relative to the blocks on either side, as in a rift valley.
Stratovolcano/Composite Volcano - Answer A conical volcano built up by many layers
(strata) of hardened lava, tephra, pumice, and volcanic ash.
Shield Volcano - Answer a wide, gently sloping mountain made of layers of lava and
formed by quiet eruptions
cinder cone - Answer A steep, cone-shaped hill or small mountain made of volcanic
ash, cinders, and bombs piled up around a volcano's opening
Plateau - Answer A large area of flat land elevated high above sea level
Mesa - Answer An isolated, flat-topped elevation, ridge or hill, which is bounded from all
sides by steep escarpments and stands distinctly above a surrounding plain.
Anticline - Answer an upward fold in rock formed by compression of Earth's crust
Syncline - Answer A downward fold in rock formed by compression in Earth's crust
Recumbent Fold - Answer A fold overturned to such an extent that the limbs are
essentially horizontal.
Overturned Fold - Answer a structural feature in which the fold limb is tilted beyond
vertical, which results in both limbs inclined in the same direction, but not at the same
angle
Isoclinal fold - Answer Compressional stress so intense that limbs become parallel
Open fold - Answer A fold with gently dipping limbs.
Normal fault - Answer A type of fault where the hanging wall slides downward; caused
by tension in the crust
Reverse fault - Answer A type of fault where the hanging wall slides upward
strike-slip fault - Answer A type of fault in which rocks on either side move past each
other sideways with little up or down motion.
Thrust fault - Answer Low angle reverse fault
Dome - Answer A large or elliptical structure formed by the fractureless upwarping of
rock strata.
Horst - Answer an elongated, uplifted block of crust bounded by faults
Graben - Answer an elongated block of the earth's crust lying between two faults and
displaced downward relative to the blocks on either side, as in a rift valley.
Stratovolcano/Composite Volcano - Answer A conical volcano built up by many layers
(strata) of hardened lava, tephra, pumice, and volcanic ash.
Shield Volcano - Answer a wide, gently sloping mountain made of layers of lava and
formed by quiet eruptions
cinder cone - Answer A steep, cone-shaped hill or small mountain made of volcanic
ash, cinders, and bombs piled up around a volcano's opening
Plateau - Answer A large area of flat land elevated high above sea level
Mesa - Answer An isolated, flat-topped elevation, ridge or hill, which is bounded from all
sides by steep escarpments and stands distinctly above a surrounding plain.
