Journal of the Palaeontological Society of India,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 19, 2024
The
Cretaceous-Palaeogene
intertrappean
deposits
of
the
Deccan
Volcanic
Province
India
comprise
vertebrate,
invertebrate
and
plant
fossils
dominantly
continental
realm.
A
3–4
m
thick
shaly-sandstone
lacustrine
sequence
Early
Palaeogene
(Palaeocene-Early
Eocene)
Bamanbor
Formation,
Chotila
Basin
(Saurashtra
province,
Gujarat
State,
western
India)
has
yielded
a
collection
molluscans
(bivalve
few
gastropods)
fauna.
High-resolution
digital
photography
radiography
recovered
bivalves
allowed
us
to
gain
detailed
inferences
on
shell
morphology.
In
taxonomical
context,
we
herein
propose
new
unionid
molluscan
superfamily
Deccanoidea
nov.
represented
by
single
family
Deccanoidae
that
includes
two
subfamilies,
is,
Deccanoinae
(represented
genera
Deccanoida
gen.
[including
four
species:
D.
conrugis
sp.
nov.,
aleta
costaria
nov.]
Bamanboria
one
species
oblongis
et
Chotiloinae
[represented
genus
Chotilia
three
trappeansis
C.
tuberculata
deccanensis
nov.]).
Inorganic
geochemistry
host
(unionid-yielding)
lithologies
reveals
oxic-freshwater
conditions,
humid-climate
moderate
rainfall.
data
historical
biogeography
Indian
subcontinent
hosted
unionids
during
late
Cretaceous;
however,
presence
(at
family/generic
level)
fauna
in
indicates
changes
geographic
position
ecologic
condition
linked
northward
drift
lava
outpouring,
respectively.
disjunct
distribution
erstwhile
Gondwanan
continents
insular
interval
can
be
explained
terms
both
vicariance
dispersal.
Acta Geologica Sinica - English Edition,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 19, 2025
Abstract
The
relationship
between
marine
transgression
and
the
distribution
of
lacustrine
organic
matter
has
restricted
shale
oil
gas
exploration
for
decades.
In
this
study,
research
objective
is
to
analyze
sedimentary
environment
evaluate
its
influence
on
in
transgressive
shale.
study
uses
various
analyses
including
total
carbon
(TOC),
Rock‐Eval
pyrolysis,
chromatography‐mass
spectrometry
(GC‐MS),
trace
element
isotope
analysis.
Finally,
proposes
an
enrichment
model
matter.
second
member
Funing
Formation
(E
1
f
2
)
divided
into
three
sequences.
results
indicate
that
depositional
during
period
was
arid
humid,
reduced,
closed,
rift
lake
basin.
first
sequence,
high
salinity
resulted
from
increased
evaporation,
leading
low
primary
biological
productivity.
At
time,
basin
belonged
a
salinized
closed
Intermittent
transgressions
began
with
deep
area
still
being
dominated
by
reducing
environment.
third
sequence
saw
evolve
characterized
warm
humid
freshwater
Marine
introduce
substantial
amount
plankton,
nutrient
elements,
as
well
more
CO
3
2–
lake,
source
rocks
proposed
here
serves
example
similar
basins.
Heliyon,
Год журнала:
2023,
Номер
9(6), С. e17142 - e17142
Опубликована: Июнь 1, 2023
Black
shales
are
highly
enriched
in
essential
elements
containing
critical
information
on
metallic
richness
and
paleoclimatic
imprints
during
deposition.
The
Cretaceous
period
marks
the
age
of
Basin
formation
from
which
Mamfe
was
formed
Albian
to
Cenomanian.
purpose
this
study
is
investigate
geochemical
behaviour
their
metallogenic
significance.
Twenty-five
representative
shale
samples
were
collected
seven
sites
outcrops
Basin.
major
trace
composition
analysed
using
Inductively
Coupled
Plasma-Atomic
Emission
Spectrometry
(ICP-AES)
Plasma
Mass
(ICP-MS).
In
comparison
with
standard
values
for
metalliferous
shales,
Boron
(B),
only
few
Li,
Rb,
Cu,
Pb
Zn.
Aluminium
module
(Alm)
ternary
diagram
plotted
Al-Fe-Mn
shows
that
all
considered
as
terrigenous
sediments
02
(08%)
falling
within
zone
sediments.
characteristics
inferred
C-values
(0.3-3.1),
Sr/Cu
(0.6-8.9),
Sr/Ba
(0.1-2.8),
Rb/Sr
(0.3-0.9),
Fe/Mn
(1.8-180),
Al/Mg
(0.31-31)
Mg/Ca
(0.05-16.4)
data
indicate
climate
existed
source
area
weathering
ranged
a
sub
humid
more
≤5%
displaying
arid
climate.
Scientific African,
Год журнала:
2023,
Номер
20, С. e01611 - e01611
Опубликована: Март 2, 2023
The
aim
of
this
study
was
to
characterise
the
maceral
properties,
depositional
environment
and
petroleum
source
rock
properties
black
shales
deposits
lower
Mundeck
Formation
Douala
Kribi
Campo
sub-basin
from
organic
petrography
trace
element
geochemical
studies.
showed
that
are
typically
dominated
by
liptinite
group
macerals,
followed
vitrinite
inertinite
respectively.
is
primarily
represented
lamalginite,
bituminite
solid
bitumen,
while
consists
collotelinite,
vitrodetrinite,
corpogelinite.
least
abundant
fusinite,
semifusinite,
pyrolytic
carbon,
funginite
inertodetrinite.
constituents
in
point
a
type
II
III
kerogen
which
proficient
generating
oil
gas.
Based
on
reflectance,
may
be
classified
as
being
subbituminous
A/B
A/high
volatile
bituminous
C
rank.
In
terms
production,
these
regarded
thermally
immature
with
an
indicated
Tmax
temperature
(from
programmed
pyrolysis)
421
°C.
Trace
ratios
Sr/Ba
for
studied
shows
values
between
0.18
0.34
indicating
were
deposited
both
fresh
water
estuary
environment.
have
resulted
marine
contamination
seen
only
one
shale
sample.
V/Ni
V/V+Ni
ratio
>1
ranges
0.60–0.94
respectively,
revealing
their
deposition
anoxic
