Abstract Volume

Landslide Hazard Zonation: A case study from Garhwal Himalaya

T. Siddique1,2, Ali P. Yunus1, S.P. Pradhan2, M.E.A. Mondal1

1Department of Geology, Aligarh Muslim University, Aligarh, 202002, India
2Indian Institute of Technology Roorkee, Roorkee, 247667, India

Email: [email protected]

Landslide is a common natural hazard that usually occurs in tectonically active mountain belts like
Himalayas. In addition to natural factors like geology and climate, anthropogenic factors also
aggravated slope instability to great extend and continuously disrupting the equilibrium among
resistive and driving forces causing slope failures in the region. Due to swift growth in population
and demand of rapid pace in urbanization intervene existing natural slopes consequently led to
inevitable slope failures. Large and small scale mass movement activities in the region cause lots of
injuries, fatalities and inconvenience in traffic that ultimately hamper tourism, socio-economic and
other developmental activities. For sustainable development of the region, schematic monitoring of
slope stability should be performed on routine basis to mark vulnerable zones in terms of stability.
Accordingly remedial measures should be suggested and implemented to attain much safer and
economic design. In this light the present study has been undermined by Macro Landslide Hazard
Zonation (LHZ) along national highway-58, near Kaudiyala of Garhwal Himalaya. LHZ map has
been prepared using Landslide Hazard Evaluation Factor (LHEF) rating scheme as per Bureau of
Indian Standards IS 14496(Part-2) 1998 which includes ratings for different causative factors viz.
lithology, structure, slope morphometry, relative relief, landuse/landcover and hydrological
conditions. Total Estimated Hazard (TEHD) values have been calculated for each slope facet by
adding ratings of each causative factor. LHZ map of the area would help in proper planning and
design of cut slopes along the road.

Page189

Assessment of Land Use/ Land covers change in North West Delhi: Using
Remote Sensing and GIS Techniques

Tanseer Alam Khan

Syed Colony, New Sir Syed Nagar, Civil Lines, Aligarh-202002, India

Email: [email protected]

This study reveals that urban land use transformation is in and out-growth of urban areas caused by
uncontrolled, uncoordinated and unplanned growth. A city mainly expanded due to the population
growth and leads to changes in its spatial dimensions. Urban population growth and urban expansion
induced land use changes and land transformation. The main changes took place along the periphery
of cities such as the railways, highways and main connecting roads. In developing countries like India
where urbanization rate is high, population growth is a significant contributor of the land use change.
Land use transformation is an inevitable process which can only be managed by the proper planning.
Most of the geographical changes at urban periphery are concerned with the rural to urban land use
transformations. There is an urgent need to estimate land use change where land transformations are
taking place very rapidly, Like Delhi-NCT, national capital of India and this estimation can easily be
done by high-resolution remote sensing data. Land use/land cover of North West Delhi has been
analyzed for the time period of 1977–2016. The required data for the study have been taken from
Landsat images of 1977 and 2016 with a spatial resolution of 30 m and other relevant data from the
toposheets of Survey of India (SOI) at the scale of 1:50,000. For the estimation of land use/ land cover
change supervised classification is applied on both the satellite imageries and change detection model
has also been applied in ERDAS Imagine to find out the land use/land cover change during 1977 to
2016. Many land use classes were identified but main dominated classes were built up area and
agricultural land.

Page190

Geomorphology of Pawalgarh conservation Reserve, Terai- Arc
landscape, Uttarakhand

Tanveer Ahmed1,2*, Harendra Singh Bargali2, Neha Verma3, Afifullah Khan1

1Department of wildlife sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
2The Corbett Foundation, Dhikuli, Ramnagar, Nainital, Uttarakhand-244715, India
3Ramnagar Forest Division, Ramnagar, Nainital, Uttarakhand244715, India

Email: [email protected]

Pawalgarh Conservation Reserve (henceforth PCR) formed recently is the third conservation reserve
of Uttarakhand and first of Kumaon zone. Owing to the location of PCR at the junction where
Shivaliks meets the Tarai plains, most of the part of the PCR is occupied by the Tertiary foot hill
rocks of Shivalik group and alluvium of the plains. We assessed the relief, elevation, slope, aspect,
flow direction and flow accumulation of PCR using Aster DEM image acquired on 17 October 2011.
PCR was found to have hilly terrain with elevation ranged between 373 and 760 meters. A large
portion of the PCR (<70%) fall under very gentle (0° - 8°) and gentle slope (9° - 16°). Most of the
area of PCR is south facing (17%) converging most of the streams to south.

Page191

Assessing the status of wildlife habitats in Ramnagar Forest Division,
Terai-Arc landscape, Uttarakhand

Tanveer Ahmed1,2*, Harendra Singh Bargali2, Neha Verma3, Afifullah Khan1

1Department of wildlife sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
2The Corbett Foundation, Dhikuli, Ramnagar, Nainital, Uttarakhand-244715, India
3Ramnagar Forest Division, Ramnagar, Nainital, Uttarakhand244715, India

Email:* [email protected]

The Terai-Arc landscape in the foothills of Himalaya supports a mosaic of wildlife habitats that
sustains an amazing biodiversity. The high human pressure coupled with developmental activities,
not only degrading wildlife habitats but hurdles the dispersal of wild animals particularly in multiple
use forest (Forest Division). We determine the status of wildlife habitats in and around Ramnagar
Forest Division classifying Landsat 8 OLI/TIRS image acquired on April 2015. Landsat Aster DEM
acquired on 17 October 2011 image was used to assess the slope, aspect and elevation of the study
area. Mixed forest was the dominant class followed by sal forest, human habitation and barrenland.
The elevation ranges between 307 and 1892m with most area having gentle slope (50 to 100). Most of
the region was found to be south facing. The current information is expected to serve as baseline to
determine any change in wildlife habitats in future.

Page192

Study on landuse/ cover change in Shahzad river basin based on remotely Page193
sensed data

Tanzeel Khatoon

Department of Geology, Aligarh Muslim University, Aligarh-202002, India

Email: [email protected]

Landuse/cover is an important component that reflects the interaction between environment and
human activities. Landuse/cover pattern is an outcome of natural and socio-economic factors and
their utilization by man in space and time. The present study makes an attempt to monitor landcover
dynamics in Shahzad river basin, a rainfed basin in Lalitpur district of U.P using remote sensing and
GIS technique. Multi-temporal satellite data of IRS-1D LISS III and IRS-P6 LISS III of 2005 and
2015 has been analyzed based on visual interpretation technique. DEM was prepared using ASTER
data and landuse/cover changes have been correlated with DEM elevation, which suggest that in
Shahzad river basin major landuse/cover changes have been observed in southwest part where
elevation range 330 to 415 m and represent gentle slope. The basin is mainly drained by Shahzad
river and its tributaries. The drainage pattern is dendritic to sub-dendritic, the elevation ranges from
286 m to 502 m above MSL. The higher elevations are encountered in southern most parts of the
basin whereas lower elevations are in the north. The slope is from south to north, as defined by the
course of the Shahzad river. Two dams namely Govindsagar and Shahzad are built on Shahzad river,
used for irrigation and drinking water supply. The major crops are wheat, barley, gram, maize,
mustard etc. Mapping of IRS FCC data led to the identification of various landuse/cover categories
viz. agricultural land, dense forest, open forest, open scrub, wasteland, stone quarry, water bodies,
dry waterbody, exposed rock, settlement and industrial land. Landuse/cover maps of 2005 and 2015
derived from satellite data were digitized in Arc GIS environment. Editing and topology building was
carried out using Arc GIS 10 and area under each category of landuse/cover was computed in sq. km
as well as in percentage. A comparison of 2005 and 2015 data analysis of the river basin suggests that
the area under water body has increased from 19.53 Km2 in 2005 to 34.85 Km2 in 2015, i.e. 15.32
Km2 (1.39%), area under uncultivated land has decreased from 352.81 Km2 (32.61%) in 2005 to
337.80 Km2 (30.7%) in 2015, showing 15.01 Km2 (1.91%) decrease. Area under cultivated land has
increased from 464.78 Km2 (42.76%) to 473.06 Km2 (43%), marking 8.28 Km2 (0.24%) increase.
Area under open forest and dense forest has reduced by 11.37 Km2 (1.04%) and 13.27 Km2 (1.21%)
respectively during 2005-2015. Open scrub, stone quarry, built-up land, exposed rock and wasteland
have also reported change in their respective areas. Open scrub has increased from 73.63 Km2 (6.69%)
to 76.23 Km2 (6.93%), whereas stone quarry has increased from 1.78 km2 (0.16%) to 3.53 Km2
(0.32%), which suggests that quarrying activity has increased.

Application of Ground Penetrating Radar (GPR) Studies in Some
Landslides of Manipur, Northeast India

Thounaojam Joyraj Singh, Heisnam Sanatomba Singh, Soibam Ibotombi,
Maisnam Pradipchandra Singh

Department of Earth Sciences, Manipur University, Imphal-795003

Emails: [email protected], [email protected]

Ground Penetrating Radar (GPR) is a pulse-echo or pulse-electromagnetic technique to determine the
structure of buried features. It works like ultrasound, but uses radio waves rather than sound waves
to penetrate the ground materials. GPR is a non-destructive and environment friendly method to detect,
locate and map subsurface features. As the GPR can provide a detailed image of the ground materials
up to some depth, revealing the subsurface configuration and thickness of the ground materials, in
this paper, an attempt is made to study the relationship between the structural configuration and
overburden thickness, and the landslide susceptibility of a slope mass.

GPR surveys have been carried out, using MALA Low Frequency System comprising of a Control
Unit (CUII including Data Storage Device, GPS), unshielded ground-coupled antenna (100 MHz
central frequency, MALA RTA) over some slide areas in order to generate radar grams of the slides
i.e. soils and rocks forming the slope masses. The surveys were conducted over half a dozen landslide
sites viz. Leinganglok, Laijang, Awangkhul, Vizang, Tupul and Thangjalok along NH-37(53). The
GPR data of the slides reveal wide information on the subsurface structural features of the ground
materials and thickness of the soil columns as well as about the different reflection patterns of the
various structural elements, and variation in the physical properties of the ground materials (soils and
rocks) of the slide areas. Normally, in majority of the slides, thickness of soil column ranges from 1.3
to 2.8m as evident from the GPR data radar gram diagrams. Combination of GPR profile data and
field outcrop studies indicate that any slope mass that has a thickness of 1.8m (2.0m) or more are
susceptible to slide provided the slope angle is moderate or steeper. The study reveals that thickness
of overburden soil column plays an important role in causing landslide or destabilising the slopes.

Page194

Relative active tectonic assessment and classification based on
geomorphic indices in the Sukhnag catchment, Kashmir Basin

Umair Ali1, Syed Ahmad Ali2, Mannan Bashir2, Javed Ikbal2

1Department of Earth Sciences, University of Kashmir, Srinagar, India
2Department of Geology, Aligarh Muslim University, Aligarh, India

Email: [email protected]

The area is located in seismically active belt NW Himalaya resultant of collision between
Indo-Eurasian plates. Due to presence of faults and active tectonics of Himalayan region;
mountain front designs, behavior of fluvial system, and landform development has been
extensively shaped and sculptured by tectonic activity. Therefore, assessment of tectonic
activity is carried out using six geomorphic indices: the stream length-gradient index (SL),
basin asymmetry (Af), hypsometric integral (Hi), valley floor width-valley height ratio (Vf),
basin shape (Bs), and mountain-front sinuosity (Smf). These indices are jointly used to
compute relative tectonic activity (Iat) with an aim to highlight the more influenced
subwatersheds in Sukhnag catchement of seismogenic compressional Kashmir basin. Thus,
the catchments have been categorized into four classes based on Iat values: Class 1 (very
high relative tectonic activity, nill); Class 2 (high, SF 1, 2, 5, 6, 9 & 11); Class 3 (moderate,
SF 3, 4, 7, 8 & 13); and Class 4 (low, SF10, 12 & 14). High tectonic activity sub-watersheds
lie in southwest where various tectonic imprints like stream deflections, straightness of
streams, deep valleys, steep slopes and lineaments showed their presence; these lineaments
have linear trend with distribution of earthquake epicenters around the region. Thus, the study
area showed higher tectonic activity towards the Pir-Panjal side (SW) having rugged terrain
deciphered by various geomorphic indices and supported by presence of various geomorphic,
tectonic and field evidences.

Page195

Geospatial approach for solving space constraint problem in power
distribution system

Varun Prakash, Aiman Khan

GIS Department, BSES Rajdhani Power Limited, New Delhi, India

Emails: [email protected]; [email protected]

This paper presents a methodology of using geospatial technology and tools to solve the problem of
identification locations to install distribution transformers in high congested areas of Delhi and to
come up with best possible options for the government of Delhi. It is a joint effort of BSES Rajdhani
Power Limited and government of Delhi to solve some most critical cases of overloaded distribution
transformers in Delhi. The identification of over loaded distribution transformers and extraction of
identified govt school, park and buildings within 500km radius of overloaded distribution
transformers has been executed to help the government to solve the problem. With the approval of
the government of the proposed location there will be very low outage in the area.

Page196

Remote Sensing: A remedial tool in Natural Disasters

Vibhuti Rai1 and Anamika Singh2

1Department of Geology, University of Lucknow, Lucknow, Uttar Pradesh, India 226007
2Central Pollution Control Board, Lucknow
[email protected]

The objective of this paper is to look into the aspect of natural disaster mitigation through the Remote
Sensing tools. Remote Sensing data is either generated through satellites or through aerial surveys in
different types of data sets, spatial resolution, bands, repeat-pass frequency, on board sensors
(multispectral, infrared, thermal and panchromatic) etc. The variety of sensors can have applications
in disaster monitoring and mitigation based on the type of disaster and electromagnetic response of
the earth objects. Microwave sensors have the ability to capture soil moisture, thermal sensors
effectively captures forest fires and volcanic hazards, infrared sensors are quite useful in flood
disasters etc. Few disasters, such as, cyclones and floods, earthquakes, land slides, volcanoes,
tsunamis, forest fires, mining related environmental hazards etc. are discussed for monitoring and for
consideration of disaster mitigation by remotely sensed data . GIS (Geographic Information Systems)
data for the same area can additionally provide significant information in assessing the extent of
affected area and help in calculating the quantum of relief measures for the same. Prior planning of
such affected areas (based on previous history) can help in quick response to relief measures as the
time becomes most crucial in all such disaster events. Marooned and cut-off areas with no
communication links can also be studied for relief measures through Remote Sensing tools. All these
issues have been discussed in the paper with necessary examples.

Page197

Petrological and Geotechnical evaluation of Vindhyan Sandstone from Page198
parts of Son Valley

Videshi Chaudhary1, S.K. Tiwari2, S.B. Dwivedi3, A.Ram4, R.S.Patel5, S.Barman6

Department of Geology, CAS, Institute of Science, Banaras Hindu University, Varanasi- 221005,
India

Email: [email protected]

Vindhyan basin of central India is one of the largest and best preserved Mesozoic-proterozoic
sedimentary basins of world. This ENE trending sickle-shaped Vindhyan basin spreads over
Rajasthan, MP, UP and Bihar with an area of about 1,04,000 km2, extending from Sasaram (24°58’:
74°04’) in Bihar to Chhoti Sadri, south of Chittaurgarh (24°54’: 74°42’) in Rajasthan. Vindhyan basin
rest over Bundelkhand Craton and also wraps around this block with an exposed area of 60,000 km2
and concealed area of 1,62,000 km2 under Cretaceous – Palaeogene, Deccan Volcanic in south- west.
The Vindhyan Supergroup consist of four Groups namely Semri(Lower Vindhyan), Kaimur , Rewa
and Bhander(Upper Vindhyan). Upper Vindhyan is three times thicker than Lower Vindhyan.
Vindhyan basin has been divided into 3 sub-basins: Bundelkhand, Rajasthan, Son valley. The study
comprises Vindhyan Sandstone, Kaimur district in Bihar; Sonbhadra and Mirzapur districts, U.P. in
the Son valley. The samples encompass sandstones from Bhagwanpur, Umapur, Saraiya and around
the Mundeshwri tempel in Kaimur district, Bihar; Markundi, Salkhan, Ghurma in Sonbhadra district
and Chunar, Ahraura in Mirzapur district in Uttar Pradesh. A detailed petrographic study of thin
section of sandstone was carried out under a high resolution Leica DMRX microscope. The studies
indicate that the rocks of Kaimur Group are dominantly quartz arenites. Most quartz arenite appears
to be multicyclic in origin i.e., they have been derived from pre- existing source. The study of thin-
sections shows that the Sandstones are predominantly made up of framework quartz grains with a
small amount of other mineral grains and lithic fragments embedded in ferruginous cement (hematite
and goethite). The shape of quartz grains varies from subangular to subrounded or rounded, and
ranges in size from 0.03 to 2.15 mm with an average of 0.2 mm. The shape indicates sandstones are
of fluvial origin. The lithic grains mostly show rounded shape, and are 0.07 to 0.4 mm in size with an
average size of 0.16 mm. The sandstone of Markundi Sandstone and Mangesar Formation is sub-
litharenite to quartz arenite while Dhandraul sandstone is sub-arkose to quartz arenite. Geotechnical
Parameter of sandstone viz. Density, porosity, compressibility and indirect tensile strengths, hardness,
modulus of deformation, Poisson's ratio and slake durability index and physico-mechanical properties
are being studied in detail to find out their applicative and various Geotechnical Engineering
properties.

Importance of Remote Sensing and GIS to identify the Forest Cover
Changes in the Himalayan town Area of Nainital

Vivekananda Biswas1, Deepak Kumar Tyagi2, Vandana Tyagi3

1Department Urban Planning, School of Planning and Architecture, New Delhi, India
2Department of Geography, Jamia Millia Islamia University, Delhi, India
3Department of Geography, SD PG College, Muzaffarnagar, India

Email: [email protected]

The present study illustrates an integrated approach of remote sensing and GIS, i.e.,
Geospatial techniques for assessment of landuse/cover dynamics of a tourist town located in
the middle Himalayan range of the Uttarakhand State (India) viz., the Nainital. Landsat
satellite imageries of two different time periods, i.e., Landsat TM of 1990 and Landsat TM
2010 were acquired by USGS Earth Explorer and quantified the land use/cover changes in
the Nainital town from 1990 to 2010 and Google Earth Satellite Image 2017. Supervised
Classification methodology has been employed using Maximum Likelihood Technique in
ERDAS 10.2 and ArcGIS 10.3. The images of the study area were categorized into five
different classes, viz., built-up area, forest land, agricultural land, water bodies and open
space. The results indicate that during the last two decades, built-up area and open space of
the Nainital town area has been increased about 15.96% (i.e., 1.95 km2) and 0.15% (i.e., 0.02
km2), respectively, while area under other land categories such as vegetation, agricultural
land have decreased about 15.36% (i.e., 1.86 km2), 0.75% (i.e., 0.09 km2) respectively. No
traceable change is found in the water bodies of the town area. The study reveals because of
increasing settlement like house and hotels forest has degraded as a result they are facing
different natural calamities like land sliding, flooding, soil erosion etc.

Page199

Application of Google Earth images for Glacio-Geomorphic Studies in
Pārbati River basin, Himachal Pradesh, India

Zabiullah Ansari, Khatib Khan

Department of Geology, Aligarh Muslim University, Aligarh -202002, India

Email: [email protected], [email protected]

The glacio-geomorphic units were identified in Pārbati valley using Google earth images along with
field campaign. Numerous glacio-geomorphic features were identified i.e., snout, proglacial Lake, a
different type of the moraines, outwash plain, cirque glaciers. It is found that images taken in early
winter snow cover period are best for proglacial water bodies’ identifications in the glaciated basin.
In a proglacial environment of the glacier, a well preserved terminal moraine occurs at elevation of
4180 a.m.s.l. formed during last stable glacier-climate period. After crossing the well preserved
terminal moraine the occurrences of disoriented moraine material resulted in hummocky terminal up
to snout of the glacier. This indicates a rapid retreat of glacier in recent time.

The glacier history of the valley has been attempt based on the cross section at various locations along
the valley. It is revealed that U-shape valley profile changes to V-shape profile at 2100 a.m.s.l.
indicating that glacier descends up to this elevation in Pārbati valley.

Page200

Morphometric analysis of Khulgad watershed Almora, Uttarakhand

Zainab Fatima
Interdisciplinary Department of Remote Sensing and GIS Application, Aligarh Muslim University,

Aligarh-202 002, India

Rivers are the dynamic and increasingly important part of the physical environment Rivers usually
has well-defined spatial boundaries and these are the medium of energy exchange from one place to
another place in external environment. Morphometry is the measurement and mathematical analysis
of earth’s surface, features, forms and the dimension of the landforms. Morphometric analysis
requires measurement of linear features, aerial aspects and gradient of channel network of the
drainage basin. Morphometric parameters are relevant and useful to identify various hydraulic
characteristics of drainage basin i.e. patterns, shape, stage of stream, permeability of bed rock, health
of streams, as well as help to correlate with lithological characteristics. The study area, is the Khulgad
Watershed (29°34′30.20″– 29°38′48.03″N lat. and 79°32′20.71″–79°37′11.19″E long.) lies 15 km
north-west of Almora township in the Khulgad watershed of Kosi River. The GIS based
Morphometric analysis of this drainage basin revealed that the Khulgad watershed is 6th order
drainage basin and drainage pattern mainly is dendritic type thereby indicates homogeneity in texture
and lack of structural control and The dendritic pattern of drainage indicates that the soil is semi
pervious in nature. Total number of streams is 929, in which 711 are first order, 173 are second order,
33 are third order and 9 are fourth order streams 2 are fifth order streams and 1 is sixth order stream.
The length of stream segment is maximum for first order stream and decreases as the stream order
increases. The drainage density (Dd) of study area is 0.80 and mean bifurcation ratio is 19.52 .This
study would help the local people to utilize the resources for sustainable development of the basin
area.

Page201

Ground water Potential Zonation and Watershed prioritization of Wular
Catchment, Jammu and Kashmir, India using Geographical Information

System

Zahoorul Hassan, T.A Kanth, Aadil Manzoor Nanda and Mohammad Imran Malik

Department of Geography & Regional Development
University of Kashmir, Srinagar J&K, India
[email protected]

The present study is an attempt to find out the groundwater potential zones in Wular Catchment by
geo-hydrological characterization of lithology, geomorphology, Lineaments, drainage, NDVI, slope,
soil, and rainfall obtained from remote sensing and ancillary data and establishing their
interrelationship by applying multi criteria decision analysis (MCDA) technique and integrating them
in a GIS environment. The Wular Catchment located in the districts of Bandipora and Baramulla of
Jammu and Kashmir, India is the immediate catchment of Wular Lake, declared as a lake of
international importance by Ramsar convention. The groundwater potential zones have been obtained
by weighted overlay analysis using the spatial analyst tool in ArcGIS 10.1.A pairwise comparison
method based on Saaty’s 9 point scale has been employed and the weights were normalized through
the Eigen vector method of analytic hierarchy process (AHP). The percentage weights obtained by
the various parameters are as lithology (27), geomorphology (18), lineament density (12), drainage
density (5), soil texture (13), NDVI (9), slope (11) and rainfall (5). The Wular Catchment has been
divided into five groundwater potential zones of very high, high, moderate, low, and very low, with
a percentage share of (5.91%), (22.95%), (11.53%), (29.87%), (23.50%). The ground water potential
zone map was finally validated using the location and function of wells in the study area. Finally a
watershed priority map was obtained based on the groundwater potential of each watershed by area
weighted score method. 1EM1a, the watershed with the least groundwater potential was given highest
priority and Wular Periphery with a highest potential for groundwater was given a least priority. Thus
the study has precisely identified the watersheds with poor groundwater availability and amply
highlighted the need to employ measures for improving their groundwater recharge capability

Page202

Diagenesis and Reservoir quality of Ridge Sandstone, Jumara Dome,
Kachchh, Western India

Zuhi Khan, A.H.M. Ahmad

Department of Geology, Aligarh Muslim University, Aligarh (U.P), India

Email: [email protected]

Ridge Sandstone of Jurassic Jumara Dome was studied to quantify the effects of diagenetic processes
on the reservoir quality. Modal analysis reveals that the Ridge Sandstone comprises of 80.33% quartz,
16.54% feldspar and 3.13% lithic fragment and is sub arkose to arkose in composition. The diagenetic
features were analysed using the thin section petrography, Scanning Electron Microscopy (SEM) and
X-ray diffraction (XRD). The diagenetic processes recognized include compaction, cementation,
precipitation of authigenic clays, dissolution of unstable grains and cement, grain replacement and
generation of secondary porosity. Evidence of compaction in Ridge Sandstone is various types of
grain contacts, bending of flexible grain and grain fracture. The strongest process to reduce primary
porosity in the Ridge Sandstone was found to be cementation followed by compaction. The average
porosity loss due to compaction and cementation in the Ridge Sandstone is 19.70% and 27.99%. The
plot of COPL-CEPL and IGV-cement volume suggests that the cementation played a dominating role
than compaction in reduction of primary porosity in Ridge Sandstone. Cementation includes
carbonate, iron and silica cements and authigenic clay such as kaolinite, illite, mixed layer illite-
smectite, smectite, and chlorite. Cements mainly iron and carbonate occurs in intergranular pores of
detrital grains and destroys porosity. Clay mineral occurs as pore filling and pore lining and
deteriorates the porosity and permeability of the Ridge Sandstone. Kaolinite occur as booklet and
vermicular form and results in porosity and permeability loss due to pore occlusion of the reservoir.
Illite, mixed layer illite-smectite, smectite and chlorite occur as pore filling and pore lining and reduce
the porosity and permeability of Ridge Sandstone. Significantly the pore lining chlorite has retained
the porosity by preventing the precipitation of quartz overgrowth. The unstable clastic grains like
feldspar and mica are altered to clay minerals. Secondary porosity generate due to partial or complete
dissolution of feldspar grains and cements. Petrographic analysis along with SEM data is used to
determine the paragenetic sequence of various diagenetic features in Ridge Sandstone. Cementation
like carbonate, iron, silica, clay minerals and little compaction has reduced the primary porosity of
the Ridge Sandstone whereas dissolution of clastic grains and cements has produced secondary
porosity. Thus the Ridge Sandstone has a greater potential to act as a reservoir.

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