Lacustrine record of high magnitude flood events and climate variability during mid to late Holocene in the semiarid alluvial plains, western India

Alluvial-lacustrine record of Mid- to Late-Holocene moisture variations trend verified by multiple proxies in the middle and lower reaches of the Hutubi River, northwest China

“…This variation could be attributed to the transportation of a substantial influx of exogenous sediments during periods of enhanced hydraulic energy (such as flash floods) and intensified riverbank erosion occurring in relatively warm and humid periods. This influx leads to alterations in the concentration of magnetic minerals within the existing fluvial sediments (Basavaiah et al, 2004; Bøe et al, 2006; Sridhar et al, 2020). In conjunction with the arid environment in the study area characterized by high evaporation, limited effective precipitation, and weak soil formation processes, it is suggested that the response of coarse-grained magnetic minerals to climate and environmental signals is more sensitive than that of fine-grained magnetic minerals (Pizarro et al, 2019).…”

Fate of Palynofacies (sedimentary organic matter) in suburban and urban flood plains of Gomati River, Lucknow, India

“…and Alternaria sp.) points towards clear and standing water with a low velocity of the channel and local erosion (Quamar, 2015;Sridhar et al, 2020). The variation in the AOM shows a certain degree of organic matter degradation by natural processes during transport by mechanical breakdown and further by post-deposition burial (Tyson, 1995).…”

“…After thoroughly washing and sieving the samples using a 20-micron sieve, polyvinyl alcohol was used to produce strewn slides, which were subsequently mounted with Canada balsam (Combaz, 1964;Traverse, 1994;Tyson, 1995;Batten, 1996) and scanned under an Olympus BH-2 microscope and photographs captured with a DP-25 camera on 200X/400X/1000X. The palynofacies recovered were grouped into three broad categories: opaque phytoclasts (degraded and charcoal organic matter (OM), degraded brown OM, Structured OM), palynomorphs (viz., pollen/spore, algal/fungal remains, grass remains, Zoomorphs) and amorphous OM using the published literature (Traverse, 1994;Tyson, 1995;Sebag et al, 2006;Prasad et al, 2013;Sridhar et al, 2020). Along with the palynofacies, ratio of various palynofacies such as degraded charcoal (Dc), burnt charcoal (Bc), cuticle (C), and tracheid (T) have been carried on the frequency data to provide better insight into the transport and degradation of organic matter.…”

“…Later, Tyson (1995) introduced the idea of modern palynofacies and its applied elements to identify a particular group of environmental importance and their relationship to hydrocarbon potential. Palynofacies is a significant unsoluble portion of the biotic component in any sedimentary environment, providing crucial information for interpreting process-driven changes both naturally and anthropogenically (Traverse, 1994;Sebag et al, 2006;Mendonça Filho et al, 2011a;Sridhar et al, 2020;Xenopoulos et al, 2021) enabling us to recognize, measure, and evaluate the state of preservation (Traverse, 1994;Tyson, 1995;Sebag et al, 2006;Mendonça Filho et al, 2011a). For multi-dimensional investigations such as climate change, hydrodynamic conditions, oxic-anoxic habitats, run-off-related processes, proximal-distal trends, palaeoenvironments, and archaeology study, both in continental and marine records, it is currently acknowledged as a reliable proxy (Tyson and Follows, 2000;Hoaen, 2000;Closas et al, 2005;Carvalho et al, 2013;Mueller et al, 2014;Sridhar et al, 2020) along with addressing the taphonomical biases (Tyson, 1995;Batten, 1996;Prasad et al, 2007;Prasad et al, 2013).…”

“…Palynofacies is a significant unsoluble portion of the biotic component in any sedimentary environment, providing crucial information for interpreting process-driven changes both naturally and anthropogenically (Traverse, 1994;Sebag et al, 2006;Mendonça Filho et al, 2011a;Sridhar et al, 2020;Xenopoulos et al, 2021) enabling us to recognize, measure, and evaluate the state of preservation (Traverse, 1994;Tyson, 1995;Sebag et al, 2006;Mendonça Filho et al, 2011a). For multi-dimensional investigations such as climate change, hydrodynamic conditions, oxic-anoxic habitats, run-off-related processes, proximal-distal trends, palaeoenvironments, and archaeology study, both in continental and marine records, it is currently acknowledged as a reliable proxy (Tyson and Follows, 2000;Hoaen, 2000;Closas et al, 2005;Carvalho et al, 2013;Mueller et al, 2014;Sridhar et al, 2020) along with addressing the taphonomical biases (Tyson, 1995;Batten, 1996;Prasad et al, 2007;Prasad et al, 2013). The epicontinental samples and deposits of marine origin have been extensively studied using palynofacies and organic geochemistry techniques from Paleozoic (Mendonça-Filho, 1999; Mendonça Filho et al, 2011a), Mesozoic (Carvalho et al, 2006a;Iemini et al, 2007), and Cenozoic rocks (Del Papa et al, 2002;Menezes and Mendonça, 2011a).…”