¹⁴C Dates (yr BP)

Location, Local (L) Biozone,

Depth from MSL (cm)

Biostratigraphic Zones

Environment of Deposition

Geomorphic Changes

and Evolution of

Bengal Delta

5000-3000

to present

Calcutta (L) CVBZ V

Depth +600 to 00

DumDum (L) D1BZIII

Depth +500 to 00

Barrackpore (L) B1BZ1a

Depth +600 to+65

Barrackpore (L) B1BZ1b

Depth +65 to −50

BBH. BZ. V: Heritiera-Potamogeton- Typha-Fern-Concentricystes rubinus (Type-II) Gloetrichia- Gavialis-Chitra-Bellamya- Pila Thiara-Lymnaea

Freshwater

with Brackish Water Influence to Fresh

Water

Delta Top to Inland

6175 - 5000

Calcutta

(L)CVBZIV

Depth 00 to −200

DumDum (L) D1BZII

Depth 00 to −150

BBH. BZ. IV: Heritiera-Bruguiera-Pandanus- Cheno-Amaranthus-Poaceae-Typha- Fern-Concentricystes rubinus (Type I)

Brackish Water Mixed Fresh Water

Delta Top

6400 - 6175

Calcutta

(L) CV BZIII

Depth −200 to −500

DumDum (L) D1BZI

Depth −150 to −300

BBH. BZ. III: Ceriops-Bruguiera-Excoecaria- Avicennia-Sonneratia Rhizophora-Heritiera-Typha- palaeocirrenalia-Callimothallus- Concentricystes rubinus (TypeI)-Bankia

Estuarine

Mangrove with

High Precipitation

Tidal mudflat

6500 - 6400

Calcutta

(L) CV BZII

Depth −500 to −610

Kolaghat (L)K1 BZII

Depth +100 to −50

BBH. BZ. II: Avicennia-Sonneratia-Rhizophora- Ceriops-Bruguiera-Excoecaria-Heritiera- Fern-Ammonia-Neritina-Telescopium- Geloina-Bankia-Martesia

Shallow Marine

to Swampy Mangrove

Shallow marine

to Delta Front

7000 - 6500

Calcutta (L) CV BZI

Depth −610 to −625

Kolaghat (L)K1 BZI

Depth −50 to −100 to −500

BBH. BZ. I: Heritiera-Bruguiera-Acrostichum- Fern-Ammonia

Marine Inundation

(Flandrian Transgression)

in Freshwater

Condition

Estuarine to

Shallow Marine

>7000

Calcutta CV (L) Barren Zone Depth −625 to −700 Kolaghat K1(L) Barren Zone Depth −500 to −550

BBH.BZ Barren zone of Kankar nodules

Arid

Dry, Upland