EARTH SCIENCE AND HYDROCARBON EXPLORATION FIELD WORK

EARTH SCIENCE AND HYDROCARBON EXPLORATION FIELD WORK [PE227]

- Fieldwork at and around Mata-no-Madh,Kutch District,Gujarat.

Date: 6 th – 14 th of February, 2015

Submitted To:

Submitted By:

Group No. : 12th

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List of Respective Group Students

Sr. No Roll No. Name of the Student

1. 14BPE47 Chirag katariya

2. 14BPE60 Areb Madani

3. 14BPE65 Nishannt Mehta

4. 14BPE69 Vishvajith Mohri

5. 14BPE76 Jai Patadia

6. 14BPE96 Nilesh Patel

7. 14BPE104 Santosh Chaitanya (Co-Leader)

8. 14BPE115 Yash Sunesara

9. 14BPE127 Hardik Vyas ( Group Leader)

10. 14BPE153D HardeepSingh Zala

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ACKNOWLEDGEMENT

It is a genuine pleasure to express our deep sense of thanks and gratitude to Dr. Anirbid Sircar, Director, School of Petroleum Technology, PDPU and Dr. D. J. Pandian, Director General, PDPU for supporting us all the time. We are eminently thankful for our respective faculties Dr. Ashish Sarkar, Dr. Uttam Kumar bhui, Dr. Bhawani Singh Desai Dr. Natarajan Madhavan. We are also thankful to Mr. Suvik Patel, Ms. Suruchi Patel, and Mr. Bhavesh Patel and other respective coordinators for supporting, helping in all the ways from supplying food to taking care of us. We would also like to thank Mr. Purushottambhai for providing us excellent food. We are highly indebted to Patidar Dharamshala, Mata no Madh, Kutch for providing us shelter for all the 9 days. We also thank the transport service for making us reach the destinations.

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EXECUTIVE SUMMARY

As a part of the curriculum EARTH SCIENCE AND HYDROCARBON EXPLORATION FIELD WORK [PE227], we have undergone this 10 days field trip to understand the various aspects of petroleum system, and how it can contribute for the production of petroleum. The report includes details on activities conducted in field at different location in terms of age (Old to young succession) of formation.

This report includes important information on regional geology and climatic conditions of Kutch, details on Geomorphology and drainage pattern of Kutch. Geologically, Kutch is constituted by the rocks of Mesozoic and Cainozoic age. Present report includes collection of rock samples from various formations of having age ranging from upper-middle Jurassic Miocene. The report also present orientation and attitude of investigated geologic feature of different locations.

It includes measurement of Strike, Dip and Dip amount. It also features collection of data on sedimentary structures, Paleo-current direction/Trend, and Fault, joints and fractures characteristics and accordingly sedimentary litholog was prepared. At last all data are plotted on graph paper and Steronet and Rose diagram are constructed.

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INDEX

1. INTRODUCTION

1.1 Location …………………………………. 7

1.2 Tectonic & Stratigraphic framework…………………………………. 8

1.3 Climate …………………………………. 10

1.4 Accessibility …………………………………. 11

1.5 Geomorphology …………………………………. 12

1.6 Drainage ………………………………….. 13

2. FIELD WORK ……………………………... 14

3. APPENDIX …………………………....... 63

4. CONCLUSION ……………………………… 66

5. INTERPRETATION ……………………………… 67

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INTRODUCTION

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1.1 Location:

Kutch is a district of Gujarat state in western India. Covering an area of 45,652 km², it is the largest district of India. Kutch region has a population of 2,092,371 according to 2011 census in Gujarat state of West India, bounded on the North by Pakistan. It is largely barren except for a fertile band along the Gulf of Kutch in the Arabian Sea. Mandvi, Bhuj, and Kandla, a new port, are the chief towns.

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1.2 Tectonic & Stratigraphic framework:

The structure, basin architecture and evolution of Kutch region has been discussed in a series of publications by Biswas (1980, 1981, 1982 and 1987). The major faults like Kutch mainland fault (KMF), Katrol hill fault (KHF), Island belt fault (IBF), Allahband fault, etc. have always been discussed by many while describing the tectonic framework of Kutch basin . The regional slope of the basin is towards WSW and the depositional axis passes close to the Saurashtra uplift to the south. The basin is featured by residual basement ridge along primordial faults parallel to the major Precambrian trends (Biswas, 1982).The culmination along the marginal flexures formed domal structures which expose older Mesozoic strata.

Figure: Tectonic map of Kutch (After Biswas and Khatri 2002)

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The Middle Jurassic to Lower Cretaceous rocks are exposed in the highlands, while the Upper Cretaceous sediments have been encountered only in the offshore wells in Kutch continental shelf, about 35km from the coast. The early Middle Jurassic strata are exposed in the northern island chain, whereas a complete and thicker succession ranging from Middle Jurassic to Lower Cretaceous is exposed in the Kutch Mainland which is the depocentral region. Strata of intermediate age are seen in Wagad highland. Excepting in the south where the Mesozoic rocks are covered by 1000 m thick Deccan Trap lava flows, these rocks are overlain by the Tertiary and Quaternary deposits.

Stratigraphic classification scheme for Kutch in shown below:

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1.3 Climate:

The Kutch region generally falls within the arid to hyper arid belt of western India. Average rainfall in the district is between 300 to 400 mm/year. On an average there are very less, approximately 15 rainy days during the entire year that has increased to 25 days in recent years. The day temperatures particularly in summers are generally low in the coastal region than the interior. In summers the day temperatures go above 460C. January is the coldest month of the year when the mean daily maximum temperature is 260C and the mean daily minimum temperature is 11oC. However, during the cold wave conditions, temperature goes down below the minimum level. Humidity remains high throughout the year along the coast, generally exceeding 60% on an average.

Figure: Map of the study area showing various locations referred to in the text and its general climate.

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1.4 Accessibility:

The Kutch can be accessed by road, railway, air and water through different routes.

Kutch has a reasonably good network of all-weather roads. The Ahmedabad-Kandla national highway is the only national highway in the entire Kutch district which connects it with other parts of the country. Amongst the state highways the important one are the Bhuj-Anjar-Gandhidham road, Bhuj-Mandvi road, and Bhuj-Desalpar-Roha-Naliya-Jakhau road. Mandvi situated in almost center of study area between Jakhau and Kandla, is well connected with all other taluka headquarters of the Kutch.

In Kutch district, almost half of the villages are connected directly or indirectly with state highway. Local transport can be done through jeeps and by foot.

Figure: Communication map of the Kutch district showing major road and rail network with main location.

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1.5 Geomorphology:

The mainland Kutch has a rocky terrain with two sub parallel E-W trending hill ranges separated by an intervening rocky plain. The Southern faces Katrol hill Range and the Northern Hill Range, mark the Katrol Hill Fault (KHF) and Kutch Mainland Fault (KMF). The Northern Hill Range, boundary of Kutch mainland is bordered by the Banni Plain and the Great Rann of Kutch in the north and by the high upland areas in the south. Geomorphologically Kutch is categorized into four major E-W trending zones:

1. Coastal Zone - demarcating the southern fringe. 2. Kutch Mainland- divided into the central portion comprising rocky upland, northern hill range and coastal plains. 3. Banni Plains (less than 5m MSL)-marked by raised fluvial-marine sediments, mud flats and salt pans. 4. The two Ranns: Great Rann ( ~2m MSL) in the north and little Rann in the east comprising vast saline wasteland. The boundaries of these main geomorphic zones are bounded by the major E-W trending faults.

Figure: Map showing major geomorphic division of Kutch.

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1.6 Drainage: The drainage of Kutch provides an interesting example of a combination of lithologic and tectonic controls along with the influence of sea level fluctuations during Quaternary Period. The central Highland forms the main watershed with numerous consequent streams draining the slopes with a radial pattern and pouring their water and sediment load into the Arabian Sea, the Gulf of Kutch and the plains of Banni and the Rann in west, south and north respectively (Figure ). In general, the streams are ephemeral (seasonal) and carry water only during good monsoon. Many streams like Kankawati, Kaswali, Kharod, Rukmawati and Bhukhi etc. show very broad channels and vertical cliffy banks in their lower reaches.

Figure: Regional drainage map of Kutch

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FIELD WORK

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Middle Jurassic

Location: Kalo-Dungar (Lat. 23°56’13”N ; Long. 68°48’51”E)

Kalo Dungar is the highest point in Kutch, Gujarat, India, at 462 m. It is located at 97 km from District headquarters of Bhuj and 25 km from

nearest town Khavda. It is located in Pachham Island in Island Belt. The hill occurs along the northern faulted border of the island marking the

boundary between rugged hilly terrain and vast plain of Great Rann of Kutch.

Depositional Environment: Infra-littoral. 

Age : Middle Jurassic (Bathonian)

Stratigraphy:

Upper part of Kalo Dungar Formation has massive sandstone with calcareous bands; lower part is around 178 million years old and consists of alternate bands of sandstone, siltstone and conglomerate. The formation is exposed in the Kalo Dungar range and is conformably overlain by Goradongar Formation, showing change in facies from sandstone to flaggy limestone.

Features Observed:

Figure. Schematic Diagram of Kalo Dungar

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As seen in the schematic diagram, the lowermost bed is of siliciclastic sandstone which are overlaid by alteration of sand and shale. Over sand & shale alteration lies thick sandstone bed which is overlaid by Limestone along with pebbly Conglomerate.

Entire lithology represents syn-rift deposition and rapid sedimentation.

Ammonites were formed 2-10 million years ago were found in the uppermost calcareous limestone layer which depicts Fully Marine Condition while the below thick sandstone bed depicts presence of fluvial system.

Herringbone Structure and Ripple Marks can also be seen at topmost layer of Kalo Dungar. Presence of Zoophycos is an indicator of continental shelf.

Figure. Ripple Laminations on the rock beds.

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Figure. Herringbone Structure

Figure. Pebbly Conglomerate

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Middle to Upper Jurassic

Location: Jumara Dome(Lat. 23°41’42”N ; Long. 69°04’04”E)

Age: Middle to Upper Jurassic

Depositional Environment: Sub-littoral

Stratigraphy: This formation consists of grey gypseous shales, thin bands of fossiliferous oolitic marl. It is present in Kutch Mainland and Banni Graben. It is overlain by Jhuran Formation.

Figure. Jumara Dome

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Features Observed:

Location 1:

The entire dome can be differentiated in upper and lower unit. The upper unit comprises of lime dominated sandstone while the lower unit comprises of sand dominated limestone.

The attitude of different bedding planes were taken and beds were plotted on stereonet which depicted the structure as a dome.

Figure. Stereographic Projection of Bedding Planes

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A huge fault was also observed as seen in below figure:

Figure. Shows a huge fault. There were also presence of fossiliferous Carbonate.

Figure. Shows presence of Bivalves on the Carbonate rock Location 2:

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Location: ( Lat. 23°41’42”N ; Long.  69°04’04”E)

This is the other side of the dome. The attitude of the beds is: Strike: N 1000

Dip: N 1900

Dip Amount: 180

There were presence of secondary fractures on the beds. The attitudes were:

Strike Dip Dip AmountN 2850 N 1950 200

N 2800 N 1900 220

N 2650 N 1750 240

There was presence of Zoophycos and Ammonite on the beds.

Figure. 1) Shows ammonite ; 2) Shows Zoophycos of diameter of 4 inch.

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Upper Jurrasic

Location: Rudramata Shale (Lat. N23°38’17.2’’ ; Longitude: E69°3’50.6’’)

Altitude: 70m above mean sea level.

Environment: Infra-littoral.

Features Observed:

This section belongs to Rudramata member of Jhuran formation. It consists of mainly grey shales with thin sandstones and silt bands. This formation is famously known as “Rudramata Shale” which is of

Jurassic age deposition. This shale is very rich in organic matter as directed by its black color. The grains are very well sorted and have decent porosity in sand layers. In between the shale layers the mature organic matter was converted into

bitumen. This soft sedimentation deformation structures are confined to lower and

middle part of the section and upper part of section comprises of sandstone layers.

Load cast structures precisely ball and pillow structure are observed in the section.

At the waterfall side layers of salt over sand were observed. The thickness of central part is 40 ft. The sandstone present is well sorted and has good porosity. The entire formation is dipping in N 2900 with a dip of 80.

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Figures. Shows the Shale and silt alterations.

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Figure. Ball and Pillow structures observed.

Figure. Shows the alterations of shale and silt.

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Lower Cretaceous

Location: Jhara-Mara (Lat . 23°42’24”N ; Long. 69°0’13”E)

Depositional Environment: Prodelta

Age : Lower Cretaceous

Paleo-Current Direction : Towards WEST (N270o)

Features Observed:

Figure. Alternate sequence of shale, sandstone and siltstone

As seen in above figure, the whole section has alternating sandstone, shale and siltstone layers. The section is divided in different layers with varying thickness. Deltaic depositions are irregular and hence the repetition of different beds is irregular.

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In this section, the top beds and bottom beds have nearly similar strike but the top beds are having dip amount ranging from 7o-10o whereas for lower beds it is 5o-7o

The litholog of this section is given below:

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The height of the section is 32 meter.

There are massive sandstone bodies without any sedimentary structures and having irregular base. This depicts that they were deposited in high energy condition.

The grains of the sandstone are angular in shape and have less porosity. The section has coarsening up sequence.

Ripple Laminations of cm scale on Siltstone beds were observed that depicts low energy condition and also gives the Paleo-current Direction as N270o

along with trace fossils such as Conichus Conichnus.

At some regions the sand body pinches out, thickens and disappears. The later deposited sand will push the stiffer sand deposited earlier and it will give rise to lots of small faults. This generally happens when sediments are fresh.

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Soft sedimentary structures such as Flame structures can be seen and they generally occur on slope where delta front slope is very harp or overburden pushing from back.

Figure. Flame Structure observed in the sandstone beds.

On other site, there was massive deposition of sandstone which depicted presence of distributor channels or lobes. Base of that section comprises of tubular which is overlaid by layers of sandstone.

The height of the massive sandstone beds is 8m. Grain size ranges from fine to medium. The grains are very well sorted and thus having good reservoir properties.

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Upper Jurassic to Lower CretaceousPart of Katesar Formation

Location: North-south vertical exposed road section near Siyot village. (Lat. 230 73ʹ N ; Long. 680 90’E).

Features Observed:

The whole section has an alteration of sandstone and shale beds. The road cutting lithology displays a dominance of sandstone. The lithology of the road cutting can be basically divided into four beds . The base layer accounts for a 1.3m thick sandstone bed , above which

lies a shale bed of 23 cm thick . The topmost layer being the thickest of all is 1.9m and sandstone rich.

Beneath this layer lies another sandstone layer which is yellowish in colour and 60 cm thick. Cross bedding can be observed in this particular bed .

Apart from this a normal fault can clearly be observed . The fault zone corresponds to a tensile stress regime.

Figure. Shows Normal Fault on one side of the road section.

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Figure. Shows the various beds of different thickness.

The fault observed has a strike of 2040N and a dip direction of 1140N. The dip amount corresponding to fault is 750 and throw is 55 cm.

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The Litholog of the following section was made and is as follows:

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The fault continuation on the other side of the road can be well observed.

Figure. The continuation of the fault on the other side of road

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Upper Jurassic to Lower Cretaceous

Location: Katesar (Lat. 230 46' 14.88'' N ; Long. 680 54' 53.28” E)

Age: Upper Jurassic to Lower Cretaceous

Regional Setup:

Jhuran formation comprises a thick sequence of alternating beds of sandstone and shale.

The Jhuran Formation is defined by Dhosa Oolite Member below and non-marine sandstone of Bhuj Formation above.

The upper limit of this formation is defined by the contact between marine and non-marine rocks.

The environment of deposition shifted from sub-littoral to supra-littoral environment and finally into continental.

The Formation is divided into four informal members out of which only the Katesar member was part of our field work.

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Features Observed:

Location 1:

Lithology : Sandstone Beds

Structures Observed: Angular Cross-stratifications, Trough Cross Stratifications.

Observations:

The first location consisted of many exposed sections of Sandstone beds throughout the location dipping in a particular direction.

The attitudes of some of the sandstone beds and their dip amount were measured to co-relate the entire Katesar area.

There was trace of Angular Cross-Stratifications on these sandstone beds.Also some Trough Cross-Stratifications were observed on the little exposed sandstone beds and measured the Paleo-current direction by the tangent method.

There is presence of Ferruginous minerals and other minerals like Quartz, Mica etc. on these sandstone beds.

After some distance there was a change in the dip direction of the beds.

From the Trough Cross-stratification, with the measured paleo-current direction a rose diagram was plotted and it is as follows.

Fig. Trough Cross-stratification

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Readings:

For the Sandstone Beds:

Sr. No STRIKE DIP DIP AMOUNT

1. N 3400 N 2500 320

2. N 3240 N 2340 100

3. N 3050 N 2150 150

4. N 3050 N 2150 250

5. N 2780 N 1880 130

6. N 2860 N 1960 190

7. N 2950 N 2050 250

Fig. Sandstone Bed of Strike : N 3400 and Dip amount : 320

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Figures. Indicates Sandstone beds of different attitudes.

Rose Diagram determining the Paleo-current direction:

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Location 2.

Lithology : Igneous Intrusion ( Basaltic)

Location : Lat. 23.77º N ; Long. 68.8921º

Observations :

There was igneous intrusion of fine to medium grain black coloured basalt.

It is significant because of the fact that after that location there are all deposition in north direction are of quaternary age.

There was presence of black and some red coloured basalt which is indication of presence of oxic and anoxic condition.

There was presence of some heavy minerals viz. quartz, mica in basalt. It have trend of N95º measured using of brunton compass. To trace its location on the topo sheet the back bearing from known

location had been taken which are N 275º of katesar temple, and another is N 2800 of Kalimatha Temple.

It is exposure and part of Kutch mainland fault(KMF) of lower cretaceous age There were also presence of fossils of Ammonite and Belemnite

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Figure. Igneous (Basalt) rock obtained at the center of the dome.

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CretaceousLocation: Atda to Delta127

Features Observed:

Location 1:

Location: 20°N Katesar Temple and 155°N Atda Village.

Observations:

Moving little ahead on the West side there was a normal fault. Attitude of fault:

Strike: N65°Dip: N155°Dip Amount: 70°

Lithology: Sand stone, silt stone, Thin shale layer, Volcanic intrusion.

The lower part of the section was red in color which indicated the iron deposition at early stage.

Then looking at middle part of the section there is alteration of yellow and grey sand and silt.

Then again at upper stage we find red colored iron rich sand deposition.

The fault itself is significantly big with Throw 3.5m and Heave 5cm.

In between the fault zone, volcanic intrusion has occurred which indicates that it goes very deeper in the surface.

The paleo-current direction is NNW-SSE.

Figure. Shows the Fault zone.

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Location 2:

Observations:

Further walking towards West we find a joint in river valley. The area around the joint is weathered and full of fractures. The attitude of this joint is as follows

Strike: N260°Dip: N350°Dip amount: 64°

The lithology of this section was mainly sandstone. This sandstone layers shows alteration of red and yellow sand in which

the red sand indicates the presence of Iron as seen in previous fault.

Figure. Image showing the joint with attitude 2600N

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Location 3:

Location: N140° from village Atda, N 450 from Katesar Temple N 2280

from

delta 127.

Observations:

Moving towards South-East direction we encountered “Rifted Zone”. Attitude of this Rift zone

Strike: N35°Dip: N305°Dip amount: 12°

As we can make out form the attitude the West side of the rift zone has come up.

Location 4:

Magma intrusion in sand body. Further moving approximately 250m West- South direction we saw

magma intrusion in sand layers. The sandstone rock was converted in volcanic environment and thus have

interlocking structure as shown in below figure: This effect was very localized and and we didn’t see this type of intrusion

around here. The sand stone was very compacted and hard.

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The stereonet of the beds, fault, joint were plotted in a stereonet as follows:

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Cretaceous

Location: Reservoir Rock (Lat. N 1230 38’ 05’’ ; Long. N 680 57’ 53.6’’ )

Altitude: 132m ( Above MSL)

Age:

Description:

Location 1:

The location mainly consists of sandstones and siltstones with presence of ferruginous material.

The beds of sandstone were horizontal while the beds of siltstone were inclined.

The inclined siltstone beds between two horizontal beds depicts that the deposition had occurred in deltaic environment.

Sedimentary structures such as Trough Cross-stratification and Angular Cross-stratification were observed.

The Paleo-current direction can be identified from the cross-stratifications and it was measured as N 3300.

The attitude of the Sandstone bed is as follows:

Strike Dip Dip-Amount

N 170 0 N 260 0 6 0

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The lithology of the formation is as follows:

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Location 2:

Whole sections have alternation of sand and silt layers having different thickness.

Base layer is having lithology of sandstone with red or orange colour with trace fossils which is overlying by silt layer .

Over which there is another layer of sandstone of maroon colour with cross bedding which is overlain by sand layer.

And also shows that all layers are fining upward sequence. Layer thickness Upper Sand layer: 0.95 m Silt layer: 1.10 m Maroon sand layer: 0.3 m Lower sand layer : 1.3 m There is a one fault plane having strike of N175º and dip amount of 55º

with dip direction of N265º measured with brunton compass and making throw of 175 cm and heave 8 cm.

It was a Normal fault (sealing fault) as some gauge material could be clearly seen along the fault plane most probably containing calcite with cement.

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Paleocene

Location: Mata No Madh Formation(23°32’52”N ; 68°56’13”E)

Age: Paleocene

Depositional Environment: Different Terrestrial during warming up phase of volcanicity.

Stratigraphy: This formation is exposed bordering tertiary outcrops in the western part of Kutch on land and consists of lateritic conglomerates, laterite, bauxite and ferruginous clay with volcanic ash. It is overlain by Naredi formation and contact is marked by lignite band. It directly overlies the Deccan trap.

Features Observed:

Location 1 :

The entire section is of sandstone lithology. Sedimentary Structures such as cross-straifications can be observed. There are two sandstone bodies. Both the sandstone bed have fining upward

sequence the entire unit is cross-stratified. Lower unit doesn’t have any trace fossils(Conichnus Conicus) while the

upper unit contains trace fossils. Lower unit contains thick small coarser units and has angular grains. They

were formed during spring tide. It was deposited in high energy condition. Upper unit consists of planar beds and thin smaller units and were formed

during neap tide. Burrows were maintained by sea animals during incoming sedimentation.

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Figure. Conichnus Conichus (Trace Fossil)

Location 2:

Figure. Chemically weathered igneous rock

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Observations:

Leaching is a process involving loss of soluble substances and colloids from the top layer of soil by percolating precipitation. This process leads to porous and open top layer and a dense bottom part. Due to this the nutrients are generally lost leaving quartz, hydroxides of iron, magnesium and aluminum. This forms distinctive type of soil called laterite.

In this section, clay with high amount of Fe3+ and Fe2+ ions is observed which gives yellowish and reddish color respectively.

No quartz traces are found hence it can be concluded that the initial rock before weathering is not sandstone.

So the initial rock could probably be an igneous rock like Basalt since it contains Feldspar but quartz is absent.

Rocks upon weathering are converted into clays and these cay are of two types phyllosilicates and tectosilicates.

Except quartz all other minerals have cleavages. More the no. of cleavage more is tendency of weathering. Weathering increases which in turn leads to formation of weaker and extremely weathered surface.

The sudden presence of Basalt rock here is due to the Deccan trap region nearby.

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Location 3:

The Mata No Madh formation represents a heterolithic volcanoclastic association consisting of mainly conglomerate bearing trap pebbles, tuffaceous shales, sandstone and bentonite mudstone,etc

It is deposited on Deccan trap basement. The lithology consists of gray-coarse grained sand, greenish gray silty clay, laterite and tuffs.

This is overlain by dominantly argillaceous unit. It consists of grayish yellow and gray thinly laminated gypceous shale and dark brown to reddish clay.

A reefal limestone build up can also be seen. Moreover, it is very hard, compact and contains a rich variety of coral-mollascan association that possibly represents patch reef.

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In the middle part several bands of muddy limestone studded with larger forums alternate with shale. Lignite beds also occur in the middle part and their thickness varies laterally extensively.

Different types of corals were found and collected. Presence of coral depicts the water depth up to 50 meters.

Depositional Environment was shallow marine to fluvial.

Presence of Gypsum was found in the mudstone layers.

Figure. Shows the lithology of the location.

There are total 6 layers of shale in the above section

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Lower Eocene Age

Location: Panandhro Coal Mine (Lat. 22°42’13’’ to 23°39’56’’ N ;Long.64°45’00’’ to 68°44’55’’.

Age: Lower Eocene Age(~50 Ma before present)

Depositional Environment : The formations formed during these periods vary from marine, estuarine to lacustrine.

Features Observed:

Location 1:

Era: Tertiary

Period: Lower Eocene

Location: Coal Mine

Coal type: Lignite

Observations:

The lignite belongs to the Lower Eocene age. The lignite produced is transported in trucks due to its soft nature. Blasting and drilling processes are not practiced in the mine. There is presence of the hard limestone (pointed load) and it is produced by

the use of bucket with two teeth’s. Dumping (both Virgin and backfilling) is being practiced in mine. The total void space in the mine is 100 acres. The TDS of the ground water is 8000 ppm. The sulfur present in the lignite or carp shale makes the water acidic. Some traps of white colour strata were also present. The coal mine is dipping in S-W direction from one end and S-E direction

from another end to the center. The coal mine contains limestone (yellowish and whitish) of 2-3 m

thickness and a thin strata of shale.

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DATA ABOUT THE COAL MINE:

Lease Area 1151 Hectare

Lease Coordinates Latitude : 22°42'13" to 23°39'56"Longitude 64°45'00" to 68°44'55"

Commencement period 1973-1974

Mineral mined Lignite and Limestone

Total Exploration area 11.33 sq.km

No. of Exploration Boreholes 362 within lease area

Void 100 Acres

Ground water TDS of 8000 ppm

Figure: Stacking of different layers & stepwise mining.

LOCAL GEOLOGICAL FORMATION:

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Period Series Formation

Recent - Top Soil

Lower Oligocene Lower Nari Hard and Compact Siliceous Limestone

Upper Eocene Kirthar Nummulitic Limestone

Lower Eocene

Middle Eocene

Laki Shales , Clays , Lignite

Unconformity

Paleocene Supratrappeans Clays, Sands Altered Formations

Unconformity

Upper Cretaceous Basic Volcanic Rocks/ Traps

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Figure. Shows shale interface in the coal beds

Figure. Shows different layers of the coal mine.

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BABIA HILL:

Era: Tertiary

Period: Upper Eocene

Age: 40-60 Ma

Rock type: Nummilitic limestone calcareous

Height: 85m from MSL, 35m from Ground level

Observations:

The Babia hill is of Upper Eocene section, and due to the presence of some valuable fossils, this hill was not removed by the mining authorities.

This hill section consists of large amounts of Nummulitic Limestone and fossils. Fossils like Nummulites, Foraminifera and Corals.

Figure. Fossils of Nummulites on the Limestone of Babia Hill.

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Middle Eocene

Location: Lakhpat (23°49’52.57”N ; 68°46’38.43”E)

Lakhpat is located northwest of Bhuj at a distance of 170 km. Lakhpat is the last town situated at the western end of India at the junction of

Kori Creek and the Rann of Kutch.

Depositional Environment: Marine

Age : Middle Eocene

Stratigraphy:

Lakhpat is a large area of well exposed Middle Eocene Fulra Limestone Formation. This limestone belt extends from Lakhpat at the western band to Vinjhan at the south-central region of mainland.

Features Observed:

The limestone beds are packed with variety of Nummulites species. They are the most important micro-fauna in the marine early tertiary seas across the globe.

The Nummulites are very unique fossils and can easily be recognized by its coin shaped structure.

Nummulites

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Figure: Button type foraminifera

Figure: Discocyclina foraminifera and Nummulite

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Holocene Location 1:

Location: Jhakau (Lat. 230 13’7” N ; Long. 68043’01” E)

Tidal flats, are coastal wetlands that form when mud is deposited by tides or rivers.

Tidal flats may be viewed geologically as exposed layers of bay mud, resulting from deposition of estuarine silts, clays.

Most of the sediment within a mudflat is within the intertidal zone, and thus the flat is submerged and exposed approximately twice daily.

Tidal flats have generally gentle slope. Even 0.5 cm of rise will flood the sediments upto large distance.

When water goes down, water is drained out in channles, in most of the cases the channels are filled with mud. Sand can also be present in the channels.

The alterations of sandstone and mudstone can be found in the tidal flats.

The mud present in the channles is usually covered by algae. Due to deposition of sand on mud will build anoxic environment and

the mudstone will give rise to excellent souce rock. In some of the extreme cases tidal flats are also site for evaporate this

will give rise to alterations of mud and salt and this environment is known as SABKHA.

There was presence of burrows and the only vegetation found in these region are mangroves.

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Figure. Shows the presence of burrows.

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Location 2:

Location: Pingleshwar Beach (Lat. 230 3’62” N ; Long. 68048’06” E)

Low tide and high tide can be seen very nicely from there with the interval of time.

In the ocean a small line was there from which all the waves break from that line that is called the ‘Breaker zone’.

Figure. Shows the Breaker zone.

The breaker zone is the one where sandbars are generated but at that place level of sandbars are low compare to other zones because of the low gradient.

There were continuous formation of ripple marks on the sand. The below picture shows the texture of the ripple marks of that place

which are very well. Ripple marks indicates the agitation by water or air.

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Figure. Shows the formation of Ripple Marks

On dipping the surface there parallel bed lamination can be showed. The beds have yellowish and blackish in colour. The black layer indicates that it contains of high organic matter

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The cross-section of the dunes was also observed.

Figure. Shows the Cross-section of Dunes

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Appendix

1. Jhumara (Middle Jurassic)

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STRIKE DIP DIRECTION

DIPAMOUNT

930 N 30 N 240

860 N 3560 N 260

960 N 60 N 210

840 N 3540 N 240

870 N 30 N 210

2750 N 50 N 240

970 N 70 N 230

1080 N 180 N 260

1070 N 170 N 200

650 N 3350 N 270

860 N 3560 N 270

750 N 3450 N 270

660 N 3360 N 180

560 N 3260 N 130

1750 N 2650 N 120

200 N 2900 N 100

150 N 2850 N 190

3000 N 2100 N 60

3200 N 2300 N 150

2900 N 2000 N 220

2700 N 1800 N 160

2600 N 1700 N 260

2. Katesar (Lower Cretaceous)

Strike Dip Dip Amount

N 3400 N 2500 320

N 3240 N 2340 100

N 3050 N 2150 150

N 2510 N 1610 120

N 3050 N 2150 250

N 2780 N 1880 130

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N 2860 N 1960 190

N 2950 N 2050 250

Paleo-current Direction from Trough Cross-stratification

Plot 1 Plot 2

2080 2250

2000 2050

2150 2250

2550 2300

2200 2200

2250 2150

2050 2080

2100 2050

2050 2150

3. Atda-Guneri (Creatceous)Strike Dip Dip Amount Type

N 3200 N 2300 350 Sandstone, shaleN 650 N 1550 700 Fault zoneN 00 N 2700 20 Outcrop

N 2600 N 3500 640 JointN 350 N 3050 120 RiftN 2300 N 3200 200 OutcropN 3500 N 800 70 Sandstone

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Paleo-current Direction Type

N 2060 Trough Cross-stratification

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Conclusion

Hydrocarbon exploration field trip included application of theoretical knowledge of petroleum and sedimentary geology in the field. The study involved the investigation of entire exposed Mesozoic and Cainozoic sequence. A detailed interpretation was drawn on the basis of data collected and observations made. Moreover dating of formation, Geological band mapping , preparation of Rose diagram and litholog was carried out. Also Stereo net of various location was constructed.

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INTERPREATATION

During the field trip, different samples were collected from number of locations and subsequently observation was made. Investigating all samples in sequence gives detailed idea about the evolution of basin.

Trace fossil of Zoophycos at Jhumara dome indicated maximum incursion of sea towards land.

At Kutch Mainland Fault, cretaceous sandstone and Miocene limestone is present which shows unconformity.

Eastern side of the Kachchh rift basin consist of thin feldspathic sandstone whereas western side of basin is having thick quartz rich sandstone. Kutch rift basin shows an extensional regime which gave rise to normal faults.

The study of igneous rocks indicates a presence of large ultramafic body in lower

All this observation indicated that basin was full of Mesozoic, Tertiary and Quaternary sediments.

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