• A-1, Tanohata Granite
• A I, Tappi Volcanic Rocks
• A-2, Tanohata Granite
• A II, Tappi Volcanic Rocks
• A-3, Tanohata Granite
• A III, Tappi Volcanic Rocks
• A-4, Tanohata Granite
• A IV, Tappi Volcanic Rocks
• A-5, Sr-poor, Tanohata Granite
• A-5, Sr-rich, Tanohata Granite
• A-6, Tanohata Granite
• A-7, Tanohata Granite

• Abashiri Formation
• Abetsu Formation
• Abire Granodiorite
• Abire intrusion
• Abodani Lava
• Abotoge Lava
• Abugawa Sandstone-Mudstone Member
• Abu Group
• Abukasanbe Mélange
• Abukuma Granitic Rocks
• Aburato Formation
• Aburatsubo Pyroclastic Rock Member
• Abuzuru Formation

• Adachi-Medeshima Pumice Bed
• Adachi-Medeshima Tephra
• Adatara volcano

• AFA

• Age Group
• Agekura Formation
• Agi Formation

• Aida Formation
• Ai-domari Lavas
• Aikawa Andesite and Pyroclastic Rock Member
• Aikawa Andesite Member
• Aikawa and Kotokawa Terrace Deposit
• Aikawa Group
• Aikawa Volcanic Rock Member
• Aikodake Granite
• Ainaizawa Formation
• Ainomine pyroclastic cone
• Ainosawa Formation
• Ainoyama Formation
• Aioi Group
• Aira Formation
• Aira-Tn Tephra
• Aishiro Formation
• A-Ito
• Aizawa Formation
• Aizen Basalt
• Aizu-kaneyama Volcanic Rocks

• Ajarayama Andesite
• Ajarayama Andesite Member
• Ajigasawa Formation, Lower part
• Ajigasawa Formation, Upper part
• Ajima Formation
• Ajiri Formation

• Ak1, Akan volcano
• AK-1, Akita-Komagatake volcano
• Ak2
• Ak3
• Ak3pfa
• Ak3pfl
• Ak4
• Ak5
• Ak6
• Ak6-a
• Ak6-apfa
• Ak6-apfl
• Ak6-b
• Ak6-c
• Ak6-d
• Ak7
• Ak7-a
• Ak7-b
• Ak7-c
• Ak7-cpfa
• Ak7-cpfl
• Ak7-d
• Ak7-e
• Ak8
• Ak9
• Ak9-a
• Ak9-b
• Ak9-c
• Ak10
• Ak11
• Ak12
• Ak12-a
• Ak12-b
• Ak12-c
• Ak13
• Ak13-a
• Ak13-b
• Ak14
• Ak14-a
• Ak14-b
• Ak14-c
• Ak14-d
• Ak14-e
• Ak14-f
• Ak14-g
• Ak15
• Ak15-a
• Ak15-b
• Ak15-c
• Ak15-d
• Ak15-e
• Ak15-f
• Ak16
• Ak17
• Akabira Formation
• Akada Formation
• Akagami Formation
• Akagami Shale Formation
• Akagawa Lavas
• Akagi Volcano
• Akahage Lava
• Akahageyama Formation
• Akahani volcano
• Akahira Group
• Akai Pyroclastic Flow Deposit
• Akaishidake Formation
• Akaishi Formaiton
• Akaishigawa Diorite Porphyrite
• Akaishi Group
• Akaishi Lava
• Akaiwa Formation, Otaru
• Akaiwa Formation, Tetori Group
• Akaiwa Subgroup
• Akakura Caldera Fill Deposit
• Akakuradake 1st-stage Lava
• Akakuradake 2nd-stage Lava
• Akakuradake 3rd-stage Lava
• Akakuradake 3rd-stage Pyroclastic Rocks
• Akakuradake 4th-stage Lavas
• Akakuradake Lava
• Akakuradake Pyroclastic Rocks
• Akakura Tuff Member
• Akakurazawa Mudflow Deposit
• Akakurazawa Pyroclastic Flow Deposit
• Akakuzuregawa Lava
• Akakuzureyama Andesite
• Akakuzureyama Lava
• Akakuzurezawamigimata Lava
• Akamori Formation
• Akamori Tuff Breccia Member
• Akana Granodiorite
• Akandana Dome Lava
• Akandana volcano
• Akandana Pyroclastic Rocks
• Akan Pyroclastic Fall Deposit
• Akanuma Formation
• Akan volcano
• Akan Welded Tuff
• Akasaka Limestone
• Akasaki Formation
• Akasawa Mud Member
• Akashima Formation
• Akashima Lavas
• Akataki Complex
• Akataki Formation
• Akazawa Formation
• Akazawa Lava
• Akedo Terrace Deposits
• Aketo Formation
• Aketo Sandstone
• Akeyo Formation
• AK-g
• AK-h
• Akibasaki Porphyritic Granite
• Aki Group
• Akita Coastal Dune
• Akita-Komagadake volcano
• Akita-Oshiromori Volcanic Products
• Akiu Group
• Akiyamago Formation
• Akiyoshi Belt
• Akiyoshi Limestone
• Akiyoshi Limestone Group
• Akiyoshi terrane
• Ak-K
• Akka Belt
• Akka Formation
• Akkagawa Formation
• Akka Limestone
• Akka - Tanohata Sub-belt
• Akka Unit
• Akka Volcanic Ash
• Akusa Formation

• ALP
• Alternation facies

• Amadanai Formation
• Ama Formation
• Amagase Formation
• Amagiri Sandstone and Mudstone Member
• Amago Intrusive Rocks
• Amaike-toho Lava
• Amami Quartz-diorite
• Amanokawara Formation
• Amatsu Formation
• Amatsu Mudstone Formation
• A Member, Gumizaki Formation
• A Member, Nambayama Formation
• a Member, U-II Formation, Himenoura Group
• a Member, U-III Formation, Himenoura Group
• a Member, U-IV Formation, Himenoura Group
• Amidagawa Pyroclastic Flow Deposit
• Amino Formation
• Amura Formation

• Anami Formation
• Anamizuzawa Basalt Member
• Anamizuzawa Lithic Tuff Member
• Anausi Conglomerate Member
• Anausi Sands
• Anazawa Formation
• Anbo Sandstone Member
• Ancient Sand Dune, Tottori Sand Dunes
• Anden Formation
• Anden Sand Member
• Andesite-basalt Lava and Pyroclastic Rocks Member, Niitsuki Formation
• Andesitic Pyroclastic Rock Member, Niitsuki Formation
• Anegahama Sandstone Member
• Anesaki Formation
• Aniai Coal-bearing Member
• Aniai Formation
• Aniai Group
• Anigawa Formation
• Animatsukurasawa Lavas
• Annaka Group
• Anne Formation
• Anno Formation
• Anto Andesite
• Anto Volcanic Rock Member
• Anyobo Sandstone and Mudstone Alternation Member
• Anzenji Tuff

• Aobayama Formation
• Aobunayama Pyroclastic Rocks and Lava
• Ao Granite
• Aoiwa Conglomerate Formation
• Aoiwa Conglomerate Member
• Aojiki Basalt
• Aoki Formation
• Aoki Granite
• Aokiite
• Aokiyama Formation
• Aoni Basalt Member
• Aoni Formation
• Aonigawa Lavas
• Aoni Tuff
• Aonomine Group
• Aosawa Basaltic Tuff Breccia Member
• Aosawa Formation
• Aoshima Facies
• Aoshima Formation
• Aoso Formation
• Aoyama Basalt

• AP
• Appidakechienosawa Lava
• Appidake Lava

• Arai Mud Member
• Araizawagawa Lava
• Araizawa Lava
• Arakawa Dolerite
• Arakawa Formation
• Arakawa Group
• Arakawa Pyroclastic Rocks
• Arakida Formation
• Arakigawa Formation
• Arakuragawa Lava
• Arakurayama Pyroclastic Member
• Arakurayama Tuff Breccia Member
• Aramachi Formation
• Arasawa Formation
• Arato Formation
• Aratozaki Formation
• Araya Formation
• Ariake Clay Formation
• Ariake Granite
• Arida Formation
• Ariga Formation
• Ariga Lignite Member
• Arima Group
• Arimine Acidic Volcanic Rocks
• Arimine Formation
• Arimine Group
• Ariminehigashitani Formation
• Ariminenishitani Formation
• Arimine Shale
• Arimine Tunnel Lava
• Arinesawa Lava
• Arinotowatari Lava
• Arisu Formation

• Asabu Sandstone Member
• Asadokoro Formation
• Asagai Formation
• Asagaridani Granodiorite
• Asago body
• Asahi Body
• Asahidaira Lava and Pyroclastic Rock
• Asahidake South Lavas
• Asahidake Subgroup
• Asahidake Summit Pyroclastic Rock
• Asahidake Upper Pyroclastic Rock and Lava
• Asahidake volcanic edifice
• Asahidake West Lower Lavas
• Asahidake West Upper Lava and Pyroclastic Rock
• Asahi Formation
• Asahigawa Formation
• Asahimori Rhyolite
• Asahi Mountains Younger Granites
• Asahinadake Lava
• Asahinadake volcano
• Asahiyama Agglomerate Beds
• Asahiyama Andesite Member
• Asaji Metamorphic Rocks
• Asakawa Formation
• Asakawa Mudstone Member
• Asakura Granodiorite
• Asakusazawa Pyroclastic Flow Deposit
• Asama-Eboshi volcanoes
• Asamigawa Member
• Asanai Terrace Deposit
• Asari Group
• As-BP
• Aseishigawa Basalt
• Asemigawa Unit
• Ashigara Group
• Ashiharahira type, Miyako Granite
• Ashi-jima Mass
• Ashikajima Formation
• Ashikawa Formation
• Ashikita Group
• Ashino Pyroclastic Flow Deposit
• Ashio Belt
• Ashiu Sandstone Member
• Ashizawa Formation, Yamagata pref.
• Ashizawa Formation, Futaba Group
• Aso-1 Pyroclastic Flow Deposits
• Aso-2 Pyroclastic Flow Deposits
• Aso-3 Pyroclastic Flow Deposits
• Aso-4
• Aso-4A
• Aso-4B
• Aso-4 Pyroclastic Flow Deposits
• Aso-4T
• Asogawa Shale and Tuff Member
• Aso Limestone
• Asou Formation
• Aso volcano
• Asso Formation

• AT
• At-1
• At-2
• At-3
• At-3low
• At-3up
• At-4
• At-5
• Atagoyama Formation
• Atagoyama Group
• Atagoyama Unit
• Ata
• Ata-Th
• Ato Formation
• Atokura Conglomerate Member
• Atokura Formation
• Atoroku Formation
• Atosanupuri I Lava Dome
• Atosanupuri II Lava Dome
• Atosanupuri Pyroclastic Flow Deposit
• Atosanupuri Somma Lava
• Atosanupuri volcano
• Atosugiyama Formation
• Atotsugawa Formation
• Atotsugawa Group
• Atsuchi Mudstone Member
• Atsu Group
• Atsumidake Formation
• Atsumi Dolerite
• Atsumi Group, Yamagata pref.
• Atsumi Group, Aichi pref.
• Atsuta Formation
• Attari Formation

• AUP

• Awa Group
• Awagura Formation
• Awagura Tuff Formation
• Awano Conglomerate and Sandstone Member
• Awano Formation
• Awanotaki Tuff Breccia Member
• Awashima Dolerites
• Awashima Formation
• Awashima Shale Member
• Awashimaura Dolerites
• Awazu Formation
• AWP

• Aya Formation
• Ayagawa Formation
• Ayakita Formation
• Ayama Formation
• Aya Member
• Ayaminamigawa Formation
• Ayukawa Formation, Miyagi pref.
• Ayukawa Formation, Ibaraki pref.
• Ayukawa Formation, Hitachi Metamorphic Rocks
• Ayukawa Group
• Ayukawa Slate Formation

• Azamizawa Formation
• Azechi Sandstone and Conglomerate Member
• Azegamaru Body
• Azenotani Mudstone Member
• Azuma Formation
• Azumagawa Rhyolite Member
• Azuma volcano
• Azumaya Lavas
• Azumaya volcano