2. OUTLINE
INTRODUCTION
ANALYTICAL TECHNIQUES
PALEOENVIRONMENTAL PROXIES
CASE STUDY
CLAY MINERALOGY IN OIL AND GAS
CLAY MINERALS AND THEIR
PALEOENVIRONMENTAL SIGNIFICANCE
3. INTRODUCTION
The clay mineralogical composition of
sediments can reflect several
Paleoenvironmental conditions such as
Paleoclimatic conditions, Burial history,
Paleotectonic regimes, sea level
fluctuations, as well as continental and
basin morphology, evolutionary history
and the timing of various geologic events.
4. INTRODUCTION
Clay mineralogy is considered a powerful
tool for the interpretation of weathering
conditions and Paleoclimate in a source
area (Ahlberg et al., 2003; Chamley,
1989; Deconinck et al., 2005; Dera et al.,
2009; Ruffell et al., 2002).
5. ANALYTICAL TECHNIQUES
X-Ray Diffraction Analysis
Scanning Electron Microscopy
Transmission Electron Microscopy
Infrared Spectroscopy
Differential Thermal Analysis
Thermo-Gravimetric Analysis
Chemical Analysis
6. ANALYTICAL TECHNIQUES
Neutron Scattering
Electron Spin Resonance,
Neutron Magnetic Resonance,
Mossbauer Spectroscopy and
Ultraviolet and Visible Light Spectroscopy
10. CASE STUDY- PINJOR FORMATION
Figure 3. Geological map of the Pinjor Formation in the type area Pinjor and surrounding
regions (After Chaudri and Singh, 2012).
11. CASE STUDY- PINJOR FORMATION
Pinjor Formation is Late Pliocene-Early
Pleistocene in age.
The three lithostratigraphic units of the
Formation are the Kona Clay Member, the
Tanda Bhagwanpur Wacke Member and the
Chauki Nadah Pebbly Bed Member which are
well exposed along the Berwala-Mandhna
section, the Kona-Karaundanwala section and
the Ghagar River-Chauki Nadah section on,
northwestern Himalaya, India.
12. PINJOR FORMATION
X-ray diffraction techniques have been
utilized for analyzing the clays of the Pinjor
Formation mainly because of availability of
instrument and reliability of the technique
(Rostasi et al., 2009).
Forty seven representative samples from
each of the measured section and random
samples of the Pinjor Formation were
analyzed for clay mineral studies. The area of
investigation spreads over 504 sq. km. in the
frontal Himalayan terrain.
13. PINJOR FORMATION
Schoonmaker et al. (1986) found that the
depth distribution of Illite/Smectite (I/S)
compositions showed an irregular, zig-zag
trend with depth. This trend indicates
multi-stage reverse faultings which
resulted from the compressional tectonic
movement.
I/S data were also used to infer several
kilometers of uplift and subsequent
erosion of the section.
14. CLAY MINERALOGY IN OIL AND GAS
Figure 4. Generalized relationship between temperature, hydrocarbon generation, diagenesis, source
rock maturity (vitrinite reflectance), changes in mixed-layer illite/smectite. Figure and data summarized
from Foscolos et al (1976), Hoffman and Hower (1979), Waples (1980), Tissot and Welte (1984).
15. CLAY MINERALS AND THEIR
PALEOENVIRONMENTAL SIGNIFICANCE
Paleoclimate is inferred from the presence
of certain clay mineral species in a
sediment.
Knowledge of the Physicochemical
condition that surrounds the formation of
these mineral species are used to infer
the Paleoclimatic condition of the
environment as at time of their formation
16. CLAY MINERALS AND THEIR
PALEOENVIRONMENTAL SIGNIFICANCE
Formation of illite and chlorite is typical during the
initial stages of chemical weathering by the
transformation of micas and ferro-magnesian
minerals, respectively (Fürsich et al., 2005; Weaver,
1989).
They are common products in low-hydrolysis
weathering regimes, typical of cool and temperate or
dry climates because they are insensitive to chemical
weathering relative to mafic rock forming minerals
and feldspars.
Additionally, they are typical clay minerals of the
present-day high latitudes indicating the
predominance of physical weathering over continental
hydrolysis (Weaver, 1989).
17. CLAY MINERALS AND THEIR
PALEOENVIRONMENTAL SIGNIFICANCE
Presence of illite and kaolinite suggests
their derivation from crystalline rocks
containing feldspar and mica as also from
pre-existing soils and sedimentary rocks
During the advanced stages of chemical
weathering, formation of smectite and
kaolinite are typical (Chamley, 1989;
Fürsich et al., 2005; Weaver, 1989).
18. CLAY MINERALS AND THEIR
PALEOENVIRONMENTAL SIGNIFICANCE
The abundance of kaolinite is a particularly good
marker for the weathering of landmasses with steep
slopes and good drainage under a hot and humid
(subtropical to tropical) climate (Chamley, 1989;
Fürsich et al., 2005; Ruffell et al., 2002).
Smectite forms under seasonally wet and dry
climates and indicates landmasses with low and
poorly drained relief (Fürsich et al., 2005; Ruffell et
al., 2002). Accordingly, kaolinite/illite, smectite/illite
and smectite/(illite+chlorite) ratios are used by many
authors for palaeoclimatic reconstructions (e.g.
Deconinck et al., 2003, 2005; Liu et al., 2005;
Raucsik and Varga, 2008 ).
