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    ABSTRACT: This paper deals with the review of pollen based palaeoclimatic records available from the South-west monsoon dominated northeast part of India. Here, a complete overview of available Late Pleistocene eHolocene records of the past vegetation vis-à-vis climate is structured based on a latitudinal subdi-vision of the region. The broad spectrum of the past climate in terms of humid/dry, warm/cold inferred by variations of some key pollen or group of pollen taxa is depicted diagrammatically, thereby providing a glimpse of spatio-temporal vegetation vis-à-vis climatic changes. Here, we attempt to create a standard diagrammatic scale with more reliability than using relative terminology to infer past climate records, based on pollen data from sub-surface sediments.
    Quaternary International 03/2014; 325:41-54.
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    ABSTRACT: Pollen analysis of a 2 m deep sediment core from Khedla Quila Lake, Betul District (southwestern Madhya Pradesh), India has demonstrated the vegetation succession and climate change since the Late-Holocene. The pollen sequences have revealed that between 1416 and 506 cal BP (AD 534–1444), open mixed tropical deciduous forest comprising Madhuca indica, Sapotaceae, Holoptelea, Acacia, and Schleichera occupied the region under a warm and moderately humid climate, corresponding, to a certain extent, with the Medieval Warm Period (MWP) that is known between AD 740 and 1150 worldwide. Between 506 and 120 cal BP (AD 1444–1830), the open mixed tropical deciduous forest was succeeded by dense mixed tropical deciduous forest due to the prevalence of a warm and humid climate, coinciding with the Little Ice Age (LIA) which falls within the temporal range of AD 1450 and 1850 at global level. Since 120 cal BP to Present (AD 1830 onwards), the open mixed tropical deciduous forest again came into existence owing to a warm and less humid climate. The cereal-based agriculture practice continued at almost the same pace, but the lake widened during the second phase, which could be attributed to increased monsoon precipitation.
    Quaternary International 01/2014; 325:74–82.
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    ABSTRACT: The present study deals with the palynological dating, correlation and depositional setting of the sediments from bore cores MGP-11 and MGP-4 from Gauridevipet area of Chintalapudi sub-basin of Godavari master basin, south India. On the basis of palynological studies, three palynoassemblages have been identified, one in bore core MGP-11 a Faunipollenites (=Protohaploxypinus) and Striasulcites assemblage and two in bore core MGP-4; one is characterized by the dominance of striate bisaccates and Densipollenites and the other by Striatopodocarpites and Cresentipollenites palynoassemblages. The other stratigraphically significant taxa include Guttulapollenites hannonicus, Lunatisporites noviaulensis, Lunatisporites pellucidus, Densoisporites contactus, Chordasporites australiensis, Goubinispora spp., Lundbladispora microconata, Lundbladispora raniganjensis and Klausipollenites schaubergeri. The recovered taxa suggest a Late Permian, Lopingian age for these rocks. This interpretation is based on the correlation of the assemblages with similar assemblages from previous Gondwana studies chiefly Densipollenites magnicorpus Zone of Damodar Basin, India and Late Permian palynoassemblages from Africa, Antarctica, Australia and South America. On the basis of palaeobotanical affinity of the identified microflora it has been inferred that the peat forming plant community was composed mainly of gymnosperm pollen attributable to glossopterids, that includes striate and non-striate bisaccates and paucity of cordaites which includes monosaccates. Spores are subordinate and are derived from lycopsids (Lundbladispora, Densoisporites), sphenopsids (Latosporites) and filicopsids (Horriditriletes, Lophotriletes, Verrucosisporites, Osmundacidites, Leiotriletes, Callumispora, Brevitriletes and Microbaculispora) occurring in variable proportions. The dominance of subarborescent/arborescent vegetation suggests a development in a forest swamp probably in a small distant marginal part of the mire or periods of standing water. This flooding environment favoured the growth of herbaceous lycopsids, filicopsids and sphenopsids in the palaeomire. More or less similar environments of deposition have been deduced for both the sedimentary sequences on the basis of palynofacies analysis. Anaerobic, reducing, water logged peat-forming conditions have been inferred based on the abundance of phytoclasts. The relative abundance of structured organic matter implies the existence of a fairly dense vegetation cover in the hinterland. The charcoal fragments recovered from the present study area reflects a possible wildfire in the accumulated swamps or a wildfire in the hinterland after which the sediments were flushed by fluvial systems into the swamps.
    Journal of Asian Earth Sciences 01/2014; 79:382–399.

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