• Z3 Formation

• Zaimokugawa Formation
• Zaimokuzaka Lava
• Zaimokuzawa Formation
• Zakogawa Formation
• Zakuro Member
• Zakuro Tephra
• Zama Formation
• Zama Hills Formation
• Zama Hills Terrace Deposit
• Zao volcano
• Zaratoge Welded Pyroclastic Rocks
• Zarumoriyama Volcanic Products
• Zasshoku Pumice and Lapilli
• Zasunbo Conglomerate, Sandstone and Mudtone Member

• Zempoji Formation
• Zengo Graval
• Zenisu Volcanic Rocks
• Zenjinike Lava
• Zenjino Terrace Deposits
• Zenjoji Formation
• Zenjoji-yama body
• Zenjoji-yama Formation
• Zenkojionsen Formation
• Zenkoshidaira Porphyrite
• Zenpukuji I Tephra
• Zenpukuji II Tephra
• Zensanji Tephra
• Zentoku Quartz Diorites
• Zentoku Tuff Member
• Zeze I Tephra
• Zeze II Tephra
• Zeze Alternation Member
• Zeze Formation

• Zike Formation

• Zn
• Znp
• Znp-Ohta Tephra

• Zoshiki Loam

• ZP1
• ZP2

• Zr

• Zuiko Limestone
• Zukawa Formation
• Zukawakosen Sandstone Member
• Zukawa Sandstone Member
• Zushi 2 Tephra
• Zushi Formation
• Zushi Mudstone Formation

• Zyumonzi Formation
• Zyumonzi Sandstone Member