- Iida Diatomaceous Mudstone Formation
- Iida Formation, Ishikawa pref.
- Iida Formation, Chichibu city, Saitama pref.
- Iida Formation, Ogawa city, Saitama pref.
- Iidesan Granodiorite
- Iigamori Lava
- Iijichuo Lava Dome
- Iijima Tuff
- Iiji volcano
- Iikura Conglomerate Member
- Iimori Conglomerate Member
- Iimori Formation
- Iimori Conglomerate Member
- Iimori Unit
- Iimoriyama Lava
- Iimoriyama parasitic cone
- Iimuro Formation
- Iinoya Formation, upper
- Iinoya Formation, middle
- Iinoya Formation, lower
- Iinoyama Member
- Iitomi Formation
- Iizawa Formation
- Iizuka Diatomaceous Mudstone Formation
- Iizuka Formation
- Iizume Formation, upper
- Iizume Formation, lower
- Iizuna Basalts
- Iizuna Formation
- Iizuna Lava
- Iizuna proper strato-volcanic products
- Iizuna Pyroclastic Flow Deposit
- Iizuna Tuff
- Iizuna Volcanic Ash
- Iizuna Volcanic-Fan Deposit
- Iizuna volcano
- Iizuna volcano caldera Lacustrine Deposit
- Iizunayama Lava, Iizuna city
- Iizunayama Lava, Takayama city
- IW1
- IW2
- Iwabuchi Basalt Lava
- Iwabuchi Formation, Lower
- Iwabuchi Formation, Upper
- Iwade Formation, Tochigi pref.
- Iwade Formation, Wakayama pref.
- Iwadeyama Pumice
- Iwadono Formation
- Iwadonozawa Formation
- Iwagamiyama Formation
- Iwagoyama Granite
- Iwahashiyama Granite
- Iwahata Limestone Member
- Iwahatayama Lava
- Iwaibukuro Formation
- Iwaidani Lava
- Iwaidani Mylonite
- Iwai Formation
- Iwaine Formation
- Iwaine Group
- Iwai Pyroclastic Member
- Iwaisawa Lava
- Iwaizaki Formation
- Iwaizaki Limestone
- Iwaizumi Belt
- Iwaizumi Belt
- Iwaizumi Formation
- Iwaizumi Group
- Iwajuku Terrace Deposit
- Iwaki Formation, Shiramizu Group
- Iwaki Formation, Chichibu Belt
- Iwakisan Volcaniclastic Rocks
- Iwakisan volcano
- Iwaki Terrace Deposits
- Iwakokekotani Lavas
- Iwakoyama Formation
- Iwakuni Granite
- Iwakura Formation, Fukushima pref.
- Iwakura Formation, Mie pref.
- Iwakura Lava
- Iwakura Pyroclastic Flow Deposit
- Iwakurayama Body
- Iwakurayama Complex
- Iwakurayama Rhyolite
- Iwamatsu Formation
- Iwami Formation
- Iwami Granite
- Iwami Group
- Iwami Rhyolites and Dacites
- Iwamizawa Formation
- Iwamori Tephra
- Iwamura Group
- Iwamuro I Tephra
- Iwamuro II Tephra
- Iwamuro Clays Member
- Iwamuro Formation
- Iwamuro Sands Member
- Iwamurotoho Ultramafic Rocks
- Iwanamesawa Mudstone Member
- Iwane Rhyolite
- Iwano Formation
- Iwanosawa Formation
- Iwaobashi Sandstone Member
- Iwaodaki Tuffaceous Sandstone Member
- Iwao Formation
- Iwaoji Formation
- Iwappara Lava
- Iwasaka Formation
- Iwase Formation
- Iwase Granodiorite Porphyry
- Iwase Tuff
- Iwashimizu Complex
- Iwashimizu Conglomerate Formation
- Iwashimizu Formation
- Iwashimizu Lava
- Iwashita Andesites
- Iwatahara Gravel Bed
- Iwatake Glaciolacustrine Deposits
- Iwatake stage
- Iwatakeyama Welded Tuff
- Iwataki Welded Tuff
- Iwata Loam
- Iwatate Basalt
- Iwate-Fudotai Tephra
- Iwate-Kariya Scoria
- Iwate-Oide Scoria
- Iwate-Okawakaitaku Scoria
- Iwate-Shirishida Scoria
- Iwate-Suko Scoria
- Iwate volcanic group
- Iwate volcano
- Iwatoyama Formation
- Iwatsubodani Formation
- Iwatsubodani Lava
- Iwatsubodani Pyroclastic Rocks
- Iwatsubodanigentou Lava
- Iwatsuboyama Lava
- Iwatsuboyama volcano
- Iwatsuboyama Welded Tuff
- Iwaya Formation, Akita pref.
- Iwaya Formation, Aichi pref.
- Iwaya Formation, Hyogo pref.
- Iwaya Granite
- Iwayakan'non stratovolcano
- Iwayakannon Lava
- Iwayama Lavas
- Iwayama Tephra
- Iwayatani Member
- Iw-Fd Tephra
- Iw-KS Tephra
- Iw-OdS Tephra
- Iw-OkS Tephra
- Iw-ph1 Tephra
- Iw-ph2 Tephra
- Iw-ph3 Tephra
- Iw-ph4 Tephra
- Iw-ph5 Tephra
- Iw-ph6 Tephra
- Iw-ph7 Tephra
- Iw-ph8 Tephra
- Iw-ph9 Tephra
- Iw-ph10 Tephra
- Iw-ph11 Tephra
- Iw-ph12 Tephra
- Iw-SS Tephra
- Iw-SuS Tephra
- Iw-W6a Tephra
- Iw-W6b Tephra
- Iw-W6c Tephra
- Iw-W6d Tephra
- Iw-W7a Tephra
- Iw-W8a Tephra
- Iw-W8b Tephra
- Iw-W9 Tephra