Palynofacies - Grain size
The palynofacies data of the Gomati River flood plain in the Lucknow
district is shown in Table 1. The ratio of degraded charcoal (Dc), burnt
charcoal (Bc), cuticle (C), and tracheid (T) has also been shown in
Table 2. Based on the CONISS cluster analysis four zones were identified
for the palynofacies and grain size data (Figure 3):
Zone – I (GR-12 – GR-13):- In this zone, the palynofacies are
represented chiefly by an abundance of phytoclasts mainly, opaque
phytoclast (degraded and burnt charcoal) ranging 37% to 40%, and
degraded brown organic matter (OM) (18% to 21%). The other
palynofacies components i.e. palynomorphs comprise fungal spores (12%
to 15%) while filamentous algae vary from 9% to 10%. The structured
OM and animal remains are represented below 5%. Amorphous OM varies by
~15% (Table 1, Figure 3). The ratio of degraded
charcoal (Dc), burnt charcoal (Bc), cuticle (C), and tracheid (T) has
also been carried on the raw counts to ascertain the transport and
degradation of organic matter. A representative variety of non-pollen
palynomorphs such as Brachydesmiella , and Glomus along
with fungal mycelium, and stellate trichome are recorded in the present
zone. The Dc/Bc in this zone varies from 1.05 to 0.71 while the C/T
varies from 0.41 to 0.31 (Table 2, Figure 4).
The grain size data shows high silt content ranging from 71% to 74%,
however, the greater fraction of the silt is mainly comprised of fine
silt. The sand percent ranges from 20% to 21%. The sand fraction is
composed of very fine sand with low percent of fine to medium sand. The
clay content in this zone varies from 4% to 8% (Table 1). The mean
grain size in phi unit is 3.8, sorting 1.0 - 1.3, skewness (-0.253 to
-0.418), and kurtosis (0.9 - 1.48).
Zone – II (GR-8 – GR-11):- The characteristic palynofacies
comprise a high percentage of opaque phytoclast (degraded and burnt
charcoal) varying 22% to 41% with degraded brown OM (28% to 48%).
Fungal spores varies from 4% to 14%, and filamentous algae 5% - 7%.
Structured OM, animal remains, and Cyanobacteria vary by less than 5%.
Amorphous OM varies 10% to 20% (Table 1, Figure 3). The ratio of Dc/Bc
varies from 5 to 3 whereas the C/T ranges from 0.9 to 2 (Table 2, Figure
4). Fungal mycelium, oxidized Tilletia spore, Spirogyra ,Helicoon , Glomus are among the few fungal remains
recorded in this zone.
The clay varies from 2.7% to 4.5% while the silt varies from 51% to
67% with high percent of fine to medium silt (Table 1, Figure 3). The
total sand varies from 30% to 46% in this zone with high contribution
of very fine sand followed by fine and medium sand. The mean grain size
ranges 3.12 to 3.61 phi units, the sorting varies 1.20 to 1.45. The
skewness varies -0.08 to -0.34 while the kurtosis ranges 0.84 to 1.04
phi units (Figure 5 a-d). The grain size shows unimodal to bimodal
texture, poorly sorted with symmetrical to very coarse skewed, and
platykurtic to mesokurtic (Folk and Ward 1957; Blott and Pye 2001).
Zone – III (G4 – G7):- The zone is characterized by a high
percentage of degraded brown OM, filamentous algae, and opaque
phytoclast (degraded and burnt charcoal). The degraded brown OM varies
from 27% to 44% while the filamentous algae (12% to 30%) and opaque
phytoclast (2% to 19%). Fungal spores vary from 6% to 15% in this
zone. Structured OM, thecamoebians, pollen/ spore, cyanobacteria, and
animal remains account for less than 5%. Amorphous OM ranges from 15%
to 20% (Table 1, Figure 3). The ratio of Dc/Bc varies higher from
earlier zones and ranges 3 to 65 while the C/T ranges from 0.59 to 1.22
(Table 2, Figure 4). Among the fungal remains the zone comprises colony
of Smut fungi, mycelium remains, etc.
This zone characterizes high silt percent (55% to 69%). The silt
proportion comprises a high percentage of fine to medium silt than
coarse silt. The sand percent varies from 26% to 40% and it is
recorded that the very fine sand contribute higher than fine to medium
and coarse sand. The clay fraction is restricted with 5 percent in the
present zone (Table 1, Figure 3). The mean varies 3.2 to 3.6 with
sorting 1.0 to 1.4 phi units. The samples are negatively skewed with
-0.21 to -0.4 while the kurtosis vary from 0.78 to 0.87 phi units
(Figure 5 a-d). In this zone, the grains are unimodal to bimodal, poorly
sorted, coarse to very coarse skewed, and platykurtic to mesokurtic
(Folk and Ward 1957; Blott and Pye 2001).
Zone – IV (GR-1 – GR-3):- This zone is characterized by a
high percent of degraded brown, filamentous algae, and opaque
phytoclast. The degraded brown OM varies from 30% to 39%, the
filamentous algae from 16% to 17%, and opaque phytoclast from 9% to
21%. The fungal spores range from 6% to 19%. The structured OM is
less than 5% in this zone. The amorphous OM varies from 10% to 20%.
The oxidized land plant tissue, thecamoebians, pollen/ spore,
cyanobacteria, and animals remain to account for less than 5% (Table 1,
Figure 3). In this zone also the ratio of Dc/Bc varies from 1.5.-6.7
while the C/T has a broader range from 0.31 to 1.36 (Table 2, Figure 4).
This zone records pollen of Croton , charcoal remains,Glomus , Acacia pollen, Periconia macrospinosa ,
Trilete spore, Helminthosporium , and, Zoomorphs.
This zone comprises equivalent sand and silt percentages. The silt
content varies from 48% to 55% while the sand percent ranges from 40%
to 48%. The medium and coarse silt vary in similar proportions in this
zone. The sand content varies from 41% to 48% with high percent of
very fine sand followed by fine sand, medium and coasre sand
respectively. The clay percent is limited to 4% only (Table 1, Figure
3). The mean grain size ranges 3.1 to 3.2 with sorting 1.21 to 1.39 phi
units. The skewness varies -0.15 to 0.036 and kurtosis 0.756 to 0.833
phi units (Figure 5 a-d). The samples show unimodal to bimodal sediment
character, poor sorted, symmetrical to coarse skewness, and platykurtic
as per Gradistat statistical inferences (Folk and Ward 1957; Blott and
Pye 2001).