INTRODUCTION
Floodplains are regions of land adjacent to a river that stretches from
the channel’s banks to the foot of the valley’s surrounding walls and is
subjected to flooding during times of heavy flow with soil composition
made up of clays, silts, sands, and gravels that have been left behind
by floods. Due to their high soil fertility, they deposit nutrients and
water in the form of organic matter and helped to provide some
significant agricultural regions, such as the Mississippi river basin
and the Nile (Aslan, 2003; Kovács, János, 2013). Fluvial
geomorphological and biological processes both pioneer in shaping river
landscapes (Aslan, 2003; Gurnell et al., 2012; van Oorschot et al.,
2016; Kleinhans et al., 2018; Kleinhans et al., 2019). Due to the
fertile nature of the soil and freshwater availability, both
agricultural and urban sectors grow close to or on floodplains, the
large rivers such as the Ganga, the Mississippi, and the Nile are
typical examples (Aslan, 2003; Singh 1996; Tandon and Sinha, 2007; Jain
and Tandon, 2010; Kovács, János, 2013;). The Ganga Basin along with its
different tributaries is a magnificent example of a floodplain region
with numerous geomorphic features in a foreland basin (Singh 1996;
Tandon and Sinha, 2007; Jain and Tandon, 2010). Due to the high
agriculture, urbanisation, with surface and ground water systems, the
basin is well known on a global scale for its potential at variable
scales. When paired with geomorphological information, the palynofacies
(particulate organic matter) is an effective analytical tool that is
used to evaluate the depositional environment and the potential for
producing hydrocarbons (older successions) in both contemporary and
historical samples (Traverse, 1994; Tyson, 1995; Batten 1996; Sebag et
al., 2006; Mendonça Filho et al., 2011a; Carvalho et al., 2013; Mueller
et al., 2014; Thakur et al., 2019). The analysis of palynological
organic matter (palynofacies), entails a comprehensive examination of
all aspects of the sediment, including the identification of the various
particulate constituents and evaluation of their absolute and relative
proportions, particle sizes, and preservation statuses (Sebag et al.,
2006; Mendonça Filho et al., 2011a).
The term ’palynofacies’ was coined by Combaz (1964) and describes the
total assemblage of particulate organic matter contained in sediments
and sedimentary rocks after removing the carbonates and silica. 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). 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). Principally it aids in inferring depositional
environments from sedimentary/ lithofacies which may be unfossiliferous.
When interpreting the mechanisms governing deposition, they also aid in
understanding sedimentary sequences and developing sequence
stratigraphic framework (Prasad et al., 2013).
Sebag et al. (2006) provide a detailed review of the major approaches
for palynofacies characterization in recent terrestrial environments and
is based on applied examples in surface deposits, soil profiles,
wetlands, lacustrine ecosystems, and within catchments.
The present study takes into account the palynofacies constituents and
sediment texture analyses on the surface sediments from the flood plain
of the Gomati River to analyse the fate of biotic components. The modern
analogue will serve as a representation of the sediment texture,
distribution, and conservation of palynofacies. It looks for subtle
variations in palynofacies and sediment texture variability in an
environment with fluvial system (mostly the meandering stage). The goal
is to comprehend the recent to sub-recent sediments from flood plain
zones of Gomati River that are influenced by anthropogenic and natural
factors. Their variation and correlation are related to environmental
conditions and aims to gauge changes in the depositional system in the
flood plains of the Gomati River in the Lucknow district, Uttar Pradesh,
India. The study aims to ratify the modest changes of palynofacies that
have not yet been explored in fluvial system studies elsewhere in the
terrestrial domain. The Ganga plain, where the Gomati River runs, has
very fertile soil since antiquity. With examples like Hulas Khera,
Hariharpur, Zoharganj, Gopalpur, Saraiya, Brahamanpur, Krishnapur, and
many more, it has also benefited archaeology (Upadhyay, 2019).
Establishing human activities in the Middle Ganga Plain requires a major
effort with integrated study of proxies such as palynofacies and
sediment texture and others. The study also looks into the utilisation
of ratios of burned and degraded charcoal, as well as cuticle and
tracheids, to define the degradation and deterioration of organic matter
in urban to suburban reaches. The processes governing the transport,
deposition, and degradation of palynofacies in the terrestrial system
and their fate by natural and anthropogenic agents, needs to be
established (Tyson, 1995; Medeanic and Silva, 2010; Mendonça Filho et
al., 2011a; Hoaen, 2000).