The fossil floras of Kachchh- IV. Tertiary palynostratigraphy

Abstract

The palynological work so far done on the various Tertiary sediments of Kachchh has been reassessed and new information added. Many genera have been redefined and new genera, viz., Intrareticulites, Retitribrevicolporites, Dermatobrevicolporites, Triangulorites, Arengapollenites, Minutitricolporites, Acanthotricolpites, Angulocolporites, Pseudonyssapollenites, Pilatricolporites, Tribrevicolporites, Triangulotricolporites, Retitetrabrevicoporites, Tripilaorites, Ligulifloraedites, Spinulotetradites, Verrudandotiaspora, Tricolporopilites, Tricolporocolumellites, Ratariacolporites, Plicatiaperturites, Palaeomalvaceaepollis, Pilapanporites, Verrupolyporites, Khariasporites, Magnamonocolpites and Hibisceaepollenites have been proposed. On the basis of relative frequency of all taxa the Matanomadh Formation (Palaeocene) has been divided into (i) Barren Zone, (ii) Dandotiaspora dilata Cenozone, (iii) Tricolpites minutus Cenozone, (iv) Couperipollis kutchensis Cenozone, and (v) Sponge spicules Zone; Naredi Formation (Lower Eocene) has been divided into (i) Lakiapollis ovatus Cenozone, and (ii) Lygodiumsporites lakiensis Cenozone. The Middle Eocene palynological assemblage has been divided into Proxapertites microreticulatus Cenozone for Harudi Formation and Cheilanthoidspora enigmata Cenozone for the Rataria bore-core. Maniyara Fort Formation (Oligocene) has been divided into (i) Operculodinium centrocarpum Cenozone, (ii) Trisyncolpites ramanujamii Cenozone, and (iii) Aplanosporites robustus Cenozone and Khari Nadi Formation (Miocene) has been classified into (i) Cordosphaeridium cantharellum Cenozone, (ii) Striatriletes susannae Cenozone, and (iii) Operculodinium israelianum Cenozone. Thus in total, there are approximately 179 spore-pollen species in Palaeocene, Lower and Middle Eocene, Oligocene and Miocene. Of them, 42 species are confined to Palaeocene, 39 species to Eocene, 25 species to Oligocene and 21 species to Miocene. The Lower Eocene has maximum number (113) of spore-pollen species. The population gradually decreases and in Miocene only three species of angiosperms are recorded. On the basis of morphological characters of spores and pollen grains the families Parkeriaceae, Amaranthaceae-Chenopodiaceae, Clusiaceae, Bombacaceae, Malvaceae, Acacieae, Caesalpiniaceae, Rhizophoraceae, Lecythidaceae, Meliaceae, Ctenolophonaceae, Polygalaceae, Alangiaceae, Apiaceae, Asteraceae, Poaceae and Arecaceae could be recognized. The palynological cenozones proposed in this paper have also been compared with other known assemblages from India.