• U1, Chiba pref.
• U-1, Toyama pref.
• U2A
• U2A'
• U2B
• U3A
• U3B
• U4
• U4.5
• U5
• U6A
• U6B
• U6C
• U6D
• U7
• U7.5
• U7.6B
• U8
• U9
• U9.2
• U10A
• U10B
• U11
• U12
• U-I Formation, Himenoura Group
• U-II Formation, Himenoura Group
• U-IIa Member, Himenoura Group
• U-IIb Member, Himenoura Group
• U-IIb1 Member, Himenoura Group
• U-IIb2 Member, Himenoura Group
• U-IIb3 Member, Himenoura Group
• U-III Formation, Himenoura Group
• U-IIIa Member, Himenoura Group
• U-IIIb Member, Himenoura Group
• U-IIIc Member, Himenoura Group
• U-IV Formation, Himenoura Group
• U-IVa Member, Himenoura Group
• U-IVb Member, Himenoura Group
• U-IVc Member, Himenoura Group

• Ua, Haborogawa Formation
• Ua, Kashima Formation
• Ua, Lower, Ontake volcano
• Ua, Upper, Ontake volcano

• Ub
• Ubagadake volcano
• Ubagatake Formation
• Ubaguchi Dacite Member
• Ubaishi Formation
• Ubakura Lava
• Ub-c, Haborogawa Formation
• Ube Coal-bearing Formation
• Ube Group
• Ube-Kibe Granite
• Ub, Kashima Formation

• Uc
• Uchigatani Formation
• Uchigo Group
• Uchiidani Granophyre
• Uchikawa Formation
• Uchikawame Formation
• Uchimanbe Formation
• Uchimura Formation
• Uchinada Sand Dune Deposit
• Uchinamigawa Formation
• Uchino Body
• Uchinohae Formation
• Uchinohara Formation
• Uchinomi Formation
• Uchinosawa type, Tanohata Granite
• Uchiono Formation
• Uchiura Andesites
• Uchiura Group
• Uchiura Volcanic Breccia
• Uchiyama Formation
• Uchiyama Member
• Uc, Kashima Formation
• Uchu Formation, lower
• Uchu Formation, upper

• Ud
• Udagawa Granodiorite
• Udatsuyama Formation
• Udeyama Sandstone-dominated sandstone-mudstone Member
• Ud-f, Haborogawa Formation
• Ud, Kashima Formation
• Udogasawa Lava
• Udoneshima volcano

• Ue, Lower
• Ue, Upper
• Uechigane Pyroclastic Flow Deposit
• Ueda Mudflow Deposit
• Uejigane Formation
• Ue, Kashima Formation
• Uemachi Formation
• Uemura Formation
• Ueno Basaltic Rocks
• Ueno Colluvial Deposit
• Uenodai Lava
• Ueno Formation, Aichi pref.
• Ueno Formation, Mie pref.
• Ueno Formation, Kyoto pref.
• Uenohara Formation
• Uenohara Welded Tuff
• Uenohata Formation
• Uenotaira Interbeds of Volcaniclastic Rocks, Conglomerate and Sandstone Member
• Uenotaira Lava
• Uenotaira Tuff Breccia
• Ueno Tephra
• Uenoyama Terrace
• Uenshiri Formation
• Uenzaru-Pankenuushi Body, eastern
• Uenzaru-Pankenuushi Body, western

• Uf, Kashima Formation
• Uf, Ontake volcano

• Ug, Haborogawa Formation
• Ug, Kashima Formation
• Ug, Ontake volcano
• UG
• Uguigawa Welded Tuff
• Uguisugawa Basalt
• Uguisu Unit

• Uh, Haborogawa Formation
• Uh, Kashima Formation
• Uh, Ontake volcano

• Ui-j, Haborogawa Formation
• Ui Sandstone-mudstone Member
• Uishi Formation

• Uji Member
• Uji Sand Dune Deposit
• Uji Shell Bed
• Ujitawara Unit
• Uji Tephra

• Ukan Formation
• Uk, Haborogawa Formation
• Ukeji Formation
• Ukekoi Formation
• Ukibuta Basalt Member
• Ukibuta Basalts

• Ul, Upper Yezo Group
• Ultramafic rocks, Hidaka Plutonic Rocks
• Ultramafic Unit
• Ultra-Tamba Belt

• Um
• Umaiwa Body
• Umamichi Terrace Deposits
• Umanokamiyama Formation
• Umanose Agglutinate
• Umeda Formation
• Umedaira Member
• Umegasawa Pumice Tuff
• Umegasawa Tuff
• Umegase Formation
• Umegashima Sheet
• Umekami Formation
• Umetani III Tephra
• Umetani Formation
• Umetsubo Formation
• Umetsu Formation
• Umeura Volcanic Rocks
• Umezako Formation
• Umikawa Formation
• Umikawa Volcanic Rocks
• Uminodaira Lavas
• Uminodaira volcano
• Uminokuchibokujo Lava
• Uminokuchi Pyroclastic Rocks
• Uminonakamichi Sand Member
• Uminoura Formation

• Unami Tephra
• Unazawa Formation
• Unazawa Unit
• Unazuki Granite
• Unazuki Metamorphic Rocks
• Unazuki zone
• Unit 1, Aso-4 Pyroclastic Flow Deposits
• Unit 1, Daito Formation
• Unit 1, Kashima Formation
• Unit 1, Kourijima Formation
• Unit 1, Kuzu Complex
• Unit 1, Mugi Mélange
• Unit 1, Naha Formation
• Unit 1, Sannomatazawa Pumice Flow Deposit
• Unit 2, Aso-4 Pyroclastic Flow Deposits
• Unit 2, Daito Formation
• Unit 2, Kashima Formation
• Unit 2, Kourijima Formation
• Unit 2, Kuzu Complex
• Unit 2, Mugi Mélange
• Unit 2, Naha Formation
• Unit 2, Sannomatazawa Pumice Flow Deposit
• Unit 2a, Daito Formation
• Unit 2b, Daito Formation
• Unit 3, Aso-4 Pyroclastic Flow Deposits
• Unit 3, Daito Formation
• Unit 3, Kashima Formation
• Unit 3, Kourijima Formation
• Unit 3, Kuzu Complex
• Unit 3, Mugi Mélange
• Unit 3, Naha Formation
• Unit 4, Aso-4 Pyroclastic Flow Deposits
• Unit 4, Kourijima Formation
• Unit 4, Mugi Mélange
• Unit 4, Naha Formation
• Unit 5, Mugi Mélange
• Unit 6, Mugi Mélange
• Unit I, Kuga Group
• Unit I, Northern Chichibu Belt
• Unit I, Numazawa volcano
• Unit I, Southern Chichibu Belt
• Unit II, Kuga Group
• Unit II, Northern Chichibu Belt
• Unit II, Numazawa volcano
• Unit II, Southern Chichibu Belt
• Unit III, Kuga Group
• Unit III, Northern Chichibu Belt
• Unit III, Numazawa volcano
• Unit III, Southern Chichibu Belt
• Unit IV, Numazawa volcano
• Unit IV, Southern Chichibu Belt
• Unit V, Southern Chichibu Belt
• Unit A-1, northern Chichibu Belt
• Unit A, Tokachidake volcano
• Unit B-1, northern Chichibu Belt
• Unit B-2, northern Chichibu Belt
• Unit B-3, northern Chichibu Belt
• Unit B, Tokachidake volcano
• Unit C, Tokachidake volcano
• UNK-9
• UN-MD2
• Unohana Alternation of Sandstone and Shale
• Unokawa Complex
• Unokawa Formation
• Unoke Terrace Deposits
• Unoki Metamorphic Rock
• Unoki Terrace Deposit
• Unzen 1993 Lahar Deposit

• U-Oki
• Uomisaki volcano
• Uonogawa Loam
• Uonoko Lava
• Uonuma Formation
• Uonuma Group
• Uonum-Pink Tephra
• Uosakatoge Sandstone Conglomerate Member
• Uosakatoge Sandstone Member
• Uozu buried forest

• UP, Saitama pref.
• UP, Kanagawa pref.
• Upper Akakuzurezawa Lava
• Upper Akan Pumice Flow Deposit
• Upper Akazawagawa Lava
• Upper Basalt Lava Member
• Upper Eboshidake Lava
• Upper Fluvial Terrace Deposits, Minauchi
• Upper Formation, Maizuru Group
• Upper Formation, Mifune Group
• Upper Formation, Sasayama Group
• Upper Formation, Suzuka Group
• Upper granitoids, Hidaka Plutonic Rocks
• Upper Haborogawa Formation
• Upper Hijochi Formation
• Upper Himenoura Subgroup
• Upper Hiuchidake Lava
• Upper Igarashi Lava
• Upper, Ikeda Group
• Upper Kanamuro Conglomerate
• Upper Kanegasaki Terrace Deposit
• Upper Kanomatagawa Lava
• Upper Karitasan Lava
• Upper Lignite-bearing Member
• Upper Mashu-b Tephra Formaiton
• Upper Mashu Tephra Formation
• Upper Member, Bangamoriyama Formation
• Upper Member, Hashikadani Formation
• Upper Member, Hayaguchigawa Formation
• Upper Member, Kameyama Formation
• Upper Member, Kaneyama Formation
• Upper Member, Kodomari Formation
• Upper Member, Mitsuya Formation
• Upper metamorphics, Hidaka Metamorphic Rocks
• Upper Mitsumineyama Lava
• Upper Mizusawa Lava
• Upper Morita Pumice Tuff Member
• Uppermost, Ikeda Group
• Uppermost Fluvial Terrace Deposits, Minauchi
• Upper Most part, Osaka Group
• Uppermost part, Sekibutsu Tuff Member
• Upper Mudstone Member, Kawaruppu Formation
• Upper Myojin Lava
• Upper Nakashumbetsu Tephra Formation
• Upper Nanakura Tuff Member
• Upper Nasodani Lava
• Upper Nihonmatsu Tuff
• Upper Nojiriko Member
• Upper Odaino Lava
• Upper Ogahana Lava
• Upper Ogane Shell Bed
• Upper Otofuke Formation
• Upper Oya Formation
• Upper part, Akima Formation
• Upper part, Osaka Group
• Upper Pumice Tuff Member
• Upper pyroclastic flow deposit
• Upper part, Sekibutsu Tuff Member
• Upper Sandstone Unit
• Upper section, Mugi Mélange
• Upper Senjogahara Lava
• Upper sequence, Hidaka Metamorphic Rocks
• Upper sheet, Yakuno Ophiolite
• Upper Shibakura Lava
• Upper Shimotamatagawa Lava
• Upper Shingu Sandstone and Conglomerate Member
• Upper Taya Formation
• Upper Tephra
• Upper Teradomari Formation
• Upper Unit, Shiobara-Otawara Pyroclastic Flow Deposit
• Upper unit, Hata Formation
• Upper Wakamiya Formation
• Upper Washidake Lava
• Upper Yabitsugawa Lava
• Upper Yakeyama Lava
• Upper Yezo Group
• Upper Yuzawa Lava

• Urado Formation
• Uragawara Formation
• Urago Formation
• Urahoro Group
• Urakawa Formation
• Urakawa Lamprophyre
• Urakura Lavas
• Urakurayama volcanic edifice
• Uranona Pyroxene Andesites
• Uranosawa Formation
• Urata Lava
• Urato Formation, Miyagi pref.
• Urato Formation, Mie pref.
• Urawa Formation
• Urayama Formation, upper
• Urayama Group
• Urayama Terrace Deposits
• Uryuzutoge Alternation Member
• Uriuzutoge Sands and Gravels Member
• Urizura Formation
• Urushidani Coal-bearing Member
• Urushihata Terrace Deposits
• Urushikubo Formation
• Uryu Formation
• Uryuno Formation
• Uryuno Member
• Uryuzaka Formation
• Uryuzutoge Alternation Member

• Usami-Taga volcanoes
• Usami volcano
• Us-b
• Usg
• Ushibuse Formation
• Ushibuseyama Lava
• Ushidaki facies
• Ushifuseyama Lava
• Ushigakubi Formation
• Ushigasawa Body
• Ushikawa Formation
• Ushikiri Formation
• Ushikiri-yama Granodiorite
• Ushikubi Formation
• Ushikubitoge Formation
• Ushine Rhyolite
• Ushioi Conglomerate
• Ushioi Sandstone and Shale
• Ushiro-Asahidake Lavas
• Ushiro-Asahidake volcanic edifice
• Ushirodani Granite
• Ushirokawa Tuff Breccia Member
• Ushiroshirahigeyama Lower Lavas
• Ushiroshirahigeyama Upper Lavas
• Ushiroyama Andesite Member, Yamaguchi pref.
• Ushiroyama Member, Nagano pref.
• Ushiwatarigawa Lava
• Ushiwatari Lava
• Ushiya Formation
• Usonokuchi Gravel Bed
• Usp
• Usu-b Pumice Bed
• Usu-b Tephra
• Usuginu Conglomerate
• Usuginu Formation
• Usuizawa Formation
• Usuki Lava
• Usunaka Rhyolite
• Usunami Granite
• Usunami Granodiorite
• Usutaniyama Rhyolitic Lava
• Usu volcano
• Usuzawa Member

• UT-1 Sub-belt
• UT-2 Sub-belt
• UT-3 Sub-belt
• Utafue Formation
• Utahime Clay Bed
• Utano Formation
• Utaosa Rhyolite
• Utarube Volcanic Ash Unit
• Uto Formation
• Utogi Unit
• Utono Formation
• Utsubo Granite
• Utsubuna Member
• Utsugino Formation
• Utsukushigahara Volcanics
• Utsukushinohara volcaniclastic rock series
• Utsumi Formation
• Utsumi Member
• Utsuno Formation
• Utsunoya Sheet
• Utsushigatake Gabbroic Mass
• Utsutoge Formation
• Utto Formation
• Uttonai Lava

• Uw-1
• Uw-2
• Uw-3
• Uw-13
• Uw-14
• Uw-15
• Uw-19
• Uw-20
• Uw-21
• Uw-22
• Uw-23
• Uw-24
• Uw-25
• Uw-26
• Uwadana Mudstone Member
• Uwada Tuff
• Uwa Formation
• Uwagaya Formation
• Uwaichi Terrace Gravels
• Uwaigusa caldera
• Uwaigusa Formation
• Uwaigusa Tuff Breccia
• Uwajima Formation
• Uwajimako Sandy Muds Member
• Uwakai Formation
• Uwamukai Tuff Breccia Member
• Uwano Formation, Fukushima pref.
• Uwano Formation, Niigata pref.
• Uwano Mudflow Deposit

• Uyamaen Lava
• Uyamasegi Lava
• Uyashinai Formation, Aniai
• Uyashinai Formation, Kakunodate
• Uyashinai Mudstone Member, Aniai
• Uyashinai Mudstone Member, Kakunodate
• Uykp

• UUzuhiki Unit