Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Passage: Ya bazu kusan arewa zuwa kudu a gabar gabashin Kogin Hooghly, Kolkata yana zaune a cikin Ganges Delta na gabashin Indiya kimanin kilomita 75 (47 mi) yamma da iyakar kasa da kasa da Bangladesh; tsawan garin ya kai mita 1.5. Yawancin birni a asali wuri ne mai ruwa wanda aka sake shi tsawon shekaru don saukar da yawan jama'a. Sauran wuraren da ba a ci gaba ba, waɗanda aka sani da Gabashin Kolkata Wetlands, an sanya su a matsayin "wuraren da ke da mahimmancin duniya" ta Yarjejeniyar Ramsar (1975). Kamar yadda yake tare da yawancin filayen Indo-Gangetic, ƙasa da ruwa galibi suna da asali. Kolkata yana kan "Bengal basin", wani yanki na uku. Bengal kwari ya ƙunshi raka'a uku na tsari: shiryayye ko dandamali a yamma; tsaka-tsaki na tsakiya ko shiryayye / gangara; da zurfin ɓangaren kwari a gabas da kudu maso gabas. Kolkata yana saman ɓangaren yammacin yankin hinge wanda ke da nisan kilomita 25 (16 mi) a zurfin kusan mita 45,000 (148,000 ft) a ƙarƙashin ƙasa. Shelf da yankunan hinge suna da kurakurai da yawa, daga cikinsu wasu suna aiki. Jimlar kaurin dutsen da ke ƙasa da Kolkata kusan 7,500 m (24,600 ft) sama da ginshikin crystalline; daga cikin waɗannan saman 350<unk>450 m (1,150<unk>1,480 ft) shine Quaternary, sannan kuma 4,500<unk>5,500 m (14,760<unk>18,040 ft) na Tertiary sediments, 500<unk>700 m (1,640<unk>2,300 ft) tarkon tarkon Cretaceous da 600<unk>800 m (1,970<unk>2,620 ft) Permian-Carboniferous Gondwana duwatsu. Ƙungiyoyin quaternary sun ƙunshi yumbu, silt, da kuma nau'o'in yashi da dutse. Wadannan sediments suna sandwiched tsakanin gado biyu na yumbu: ƙananan a zurfin 250<unk>650 m (820<unk>2,130 ft); babba 10<unk>40 m (30<unk>130 ft) a kauri. Dangane da Ofishin Ka'idojin Indiya, a kan sikelin da ya fara daga I zuwa V don haɓaka haɗarin girgizar ƙasa, garin yana cikin yankin girgizar ƙasa III.  Tambaya: A wane yanki ne garin yake?
yankin girgizar ƙasa III