Deccan Education Society's Fergusson College, Pune

Deccan Education Society’s Fergusson College, Pune Department of Geology CONTENT

FEATURE STORY

15 Lonar lake of Heritage Explore one of the few meteor craters in India

51 The Telltale Fossil Wood of Sattanur Story of the plants from Cretaceous.

55 D for Diamonds Journey into the world of most beautiful and attractive gem

60 Causative Factors of Malin Landslide Insight into the disaster of the year

2 CONGLOMERATE OTHER Piezoelectricity 11 Mentors Dr. R.G.Pardeshi Geology Science Principal Fergusson College, Pune of Earth 18 Dr.R.N. Mache Crystal Caves Head, Department of Geology at Naica 21 Fergusson College, Pune

Geological Timescale 23 Dr. Tanuuja Marathe Dr. P.K.Sarkar Geology around Sangamner and Aane ghat area 26 Prof. S.D.Raut Dr. S.N.Mude Introducing and Classifying Prof. Devdutt Upasani Dinosuars 29 Prof. Madhuri Ukey Prof. Aneesh Soman Batu caves Malaysia 35 Mr. Chinmay Thite Mr. Amey Dashputre Rare Polymorphs of Miss Aditi Bharadwaj Olivine and Quartz 38 Editorial Committee Fluorescence of minerals 44 Prof. Devdutt Upasani Mr. Chinmay Thite The Gabbro Intrusions 47 Mr. Amey Dashputre T.Y.B.Sc. Geology Students 2014-15 The most expensive coconut of my life 49 Cover Page and Back Cover : Columns of basalts Rolling Stones 64 from Isle of Staffa,(Fingal’s Cave) Scotland, United Kingdom Where giants walked 66 Photography : Chinmay Thite Magazine cover and Design : Chinmayi Dumbre Rocky Times 70

Flash Stones 73 Published by : Department of Geology Fergusson College, Pune REGULARS Contact : [email protected] Preface 4 For academic and educational purposes only Foreword 5 Our Department 7

3 CONGLOMERATE PREFACE Student and Staff Department of Geology Fergusson College

Geology is an earth science comprising E-Geo Magazine aims at taking the subject to the study of solid Earth, the rocks of which it the masses, especially the school students, so is composed, and the processes by which they that the subject can be nurtured in their minds change. Geology gives insight into the history since the beginning. of the Earth by providing the primary evidence We, the students and staff of Department for plate tectonics, the evolutionary history of Geology, Fergusson College, take great of life, and past climates. In modern times, pride in presenting to you this inaugural issue geology is commercially important for mineral of our magazine. Sincere efforts have been and hydrocarbon exploration / exploitation taken by all, to present articles and data of as well as for evaluating water resources. It is utmost importance and interest and that too also important for the prediction and under- in a lucid manner so that even non-geologist standing of natural hazards, the remediation reader friends can benefit from it. of environmental problems and for providing Care has been taken so that no copyright insights into past climate changes. Geology laws are broken in the magazine. References of also plays a role in geotechnical engineering the original writers and researchers have been and is a major academic discipline. Geology included wherever required. In spite of this if is a subject that is considered by many Indian any copyright has been flouted we would offer students. The career opportunities available our sincere apologies for the same. for students who finish their studies in this We would also like to urge all the readers field are also high. to recommend the magazine to all their friends In spite of the subject being so important, and family, so that our subject gets the much in India the common-man is aloof of the sub- deserved attention and importance. ject and also the advances happening in it. The

4 CONGLOMERATE The Deccan Education Society, Pune was established in 1884 and registered on 13th August 1885 by patriotic visionaries like Vishnu Shastri Chiplunkar, Bal Gangadhar Tilak, Gopal Ganesh Agarkar, Mahadeo Ballal Namjoshi and Vaman Shivram Apte-who were already recognized as the pioneers of new education in India with the Launch of New English School in Pune in the year 1880. Dec- can Education Society’s, Fergusson College, was established in the year 1885 and since its inception has been imparting quality education of the highest level, such that today, it is recognised as one of India’s premier institutes. Fergusson College has been re-accredited by the National Assessment & Accreditation FOREWORD Dr. Ravindrasinh G. Pardeshi Principal, Council, Bangalore and awarded an “A” Grade Fergusson College with CGPA of 3.26. The Geology department is one of the well established departments of Fergusson College. The subject of geology was introduced in Fergusson College in 1908 as one of the optional subjects at the inter science examination. In 1951, the University of Pune introduced the B.Sc. (General) course at the college. Teaching of M.Sc. degree by research to the students was offered by the authorities

5 CONGLOMERATE of the Fergusson College till the year 1955 after which M.Sc. course was also started at the department. The centenary year of the Geology Department was celebrated on grand scale in December 2008 and centennial seminar was organized during this celebration. Today, the Geology department offers undergraduate and postgraduate courses and it also has a Research Centre for Ph.D. programmes. The Department has produced many famous geologists - in the field, industry and in academics. As part of our outreach to the general public, our goal is to inform the interested public of the nature and scope of geology and geologic research. The launch of E-Geo Maga- zine of Fergusson College is a celebration of the work our Geology Department and Geosci- entists, who have struggled to understand and reconstruct our rich geological past. As a part of that celebration, we are dedicating this very first issue of the Magazine to a retrospective display of articles published in the recent and not so recent past, field trip evaluations, and work submissions by our students and faculty. We endeavour to incorporate various papers on the subject, review articles and discuss all aspects of geology covering mineralogy, petrology, palaeontology, stratigraphy, structural geology, geophysics, geochemistry and geomorphology. Let’s work towards making this E-Geo Magazine a success, with a mine of information, for generations to come.

6 CONGLOMERATE Geology is that branch of Science, with which everybody is not familiar. Yet it helps in finding practical solutions to the everyday problems as well as those that have long term consequences. It is a challenge for government and industry to develop infrastructure without disturbing the natural harmony, for which geological data obtained by geologists is very useful. Yet, there are still very few undergraduate colleges where Geology is taught even today. This situation speaks of the sagacity of Fergusson College, when it decided to launch the Geology teaching department for their undergraduate classes, way back in 1908. Having been established then, the Geology Our Department One of the Oldest Department of Geology Dr. Ram Mache Head, Department of Fergusson College is one of the Department of Geology, oldest departments in India. Fergusson College Initially, Prof. T.G. Yeolekar, who was Head of Zoology Department, looked after the duties of the Head of Geology Department also. Those days Prof G.G. Narke used to teach Geology in the Engineering College of Pune. Having developed an interest for Geology, he accepted with enthusiasm to teach Geology in Fergusson College as an honorary teacher.

7 CONGLOMERATE Prof. K.V. Kelkar joined this college in 1924 as a Junior Lecturer, to assist Prof. Yeolekar. A milestone was set in 1926, when students were allowed to offer Geology as the principal Subject for graduation level. Eventu- ally, Prof. Kelkar was appointed as Head of the Geology Department in 1932. Over the years that followed, some past students viz. R.D. Godbole, Y.T. Apte, R.V. Sathe, L.V.Agashe, R.B. Gupte and S.Y. Date had short stints here as lecturers and had their contributions in the development of this department. For a short period, after the Pune University was established in 1949, there were certain practical difficulties for the University to start postgraduate teaching in Geology. During those years (1949-1955), the College was conducting classes for M. Sc. in Geology by research. In 1946, the Government of India appointed the Geology Education Commit- tee, its members being stalwarts like Dr. W.D. West, Dr. D.N. Wadia and Dr. S.P. Parija. The Committee was highly impressed by the prog- ress made by the department. As a result, it recommended a handsome grant for a separate building for the department. Due to various reasons, the construction work could not be completed till 1959. The new building was inaugurated in September 1959 at the hands of Prof. D.G. Karve, the then Vice-chancellor of the Pune University.

8 CONGLOMERATE Meanwhile, the Pune University had The Department celebrated its centenary established their postgraduate Geology on 19th and 20th December, 2008. The main Department. However it was located in the function of the event was the Centennial Semi- Fergusson College premises. Therefore, in nar, when past students working on key posts 1959, both the undergraduate geology depart- of certain organizations spoke on the status of ment of Fergusson College and postgraduate the art pertaining to their own fields. geology department of the Pune University A gala get together of past were shifted to the new building. In the year students was arranged, which was attended by 1971, the University shifted their postgraduate over 250 alumni of the department, of batches teaching department to the University campus. ranging from 1944 to 2008. The past students But this Department started postgraduate collected a fund of Rs. 75,000/- on the occa- teaching on non-grant basis, leading to the M. sion, for the development of the Department. Sc. degree of University of Pune, from July The response received was overwhelming. 2007. Large crowds thronged the Museum. Notable The Geology Department of Fergusson among them were the school children accom- College has an excellent and unique Museum panied by their parents. The event received a known as Prof. K.V.Kelkar Museum. This wide coverage by print and electronic media. Museum was set up in 1962 when Prof. K.V. During the Academic year 2012-13, the Kelkar retired as the Head of the Geology Department was recognized as a ‘Research Department. The museum was established by Centre in Geology’. Simultaneously, five teach- the students in honour of their teacher, who ers have been granted recognition as research was a pioneer in graduate and post-graduate guides for M. Phil. and Ph. D. degrees of the studies in Geology in the western part of Savitribai Phule Pune University. Presently Maharashtra. The Museum is a vest treasure the Department has three research laboratories of specimens of rocks, minerals and fossils, viz. Remote Sensing-GIS, Petrology and Pal- donated by the students of the department aeontology-Sedimentology. The laboratories as well as those collected by the teachers and are equipped with high resolution Petrological students during their field trips. Some typical microscopes, Gemological microscope and Ore specimens have also been purchased from microscopes; and also various software for GIS dealers within the country and outside. Nota- studies ble contributors have been Mr. R.V. Mandhare, The department is always keen to orga- who has donated a wide range of specimens nize seminars, workshops and lecture series in the form of minerals and gemstones. Some for the benefit of the postgraduate and under- of the specimens donated by him are priceless, graduate students. It must be specially men- especially the giant quartz crystals collected tioned here that the Department had organised from the Himalaya. Prof. A.V.Phadake, Geol- ‘The International Conference on Recent ogy Department, University of Pune, has Developments in Stratigraphy’ (ICRDS-2013) also donated excellent specimens of zeolites during 14th December 2013 to 16th December collected from around Pune and many other 2013, which was inaugurated by Padmashree fine mineral specimens from different parts of Prof. K. S. Valdiya, former Vice Chancellor, the world. The Museum is a great asset to the Kumaon University, Nainital. ‘National Con- department and is a landmark of Fergusson ference on Emerging Trends in Stratigraphy’ College, Pune. was also organized prior to this International Another specialty of the department is Conference. The geology association activ- the Library facility. The departmental library ity called as ‘FLINTS’ is being organized has more than 1000 books on various topics every year for about three days. This activity such as Palaeontology, Mineralogy, Crystal- includes Prof. K. V. Kelkar Memorial Lecture lography, Petrology, Applied Geology, Stratig- and exhibition of geological specimens raphy, Structural Geology, General Geology, All the class-rooms and laboratories in Geomorphology and general books on Earth the department have DLP Projector facility. Science. The internet facilities are extended to the

9 CONGLOMERATE rooms of the staff members, computer and programmes. The Department has produced research laboratories. The students also have many famous geologists - in the field, industry access to the internet in the computer labora- and in academics. tory. As part of our outreach to the general Presently the department is having elev- public, our goal is to inform the interested en highly qualified teaching faculty for under- public of the nature and scope of geology and graduate and post graduate classes assisted geologic research. The launch of E-Geo Maga- by one Lab assistant and six Lab attendants. zine of Fergusson College is a celebration of There are more than 500 students admitted to the work our Geology Department and Geosci- UG and PG classes who have opted for Geol- entists, who have struggled to understand and ogy subject. The department is also extending reconstruct our rich geological past. As a part all kind of help for placements and is always of that celebration, we are dedicating this very keen in arranging field study tours for all UG first issue of the Magazine to a retrospective and PG classes. display of articles published in the recent and to the students was offered by the author- not so recent past, field trip evaluations, and ities of the Fergusson College till the year 1955 work submissions by our students and faculty. after which M.Sc. course was also started at We endeavour to incorporate various the department. The centenary year of the papers on the subject, review articles and Geology Department was celebrated on grand discuss all aspects of geology covering miner- scale in December 2008 and centennial seminar alogy, petrology, palaeontology, stratigraphy, was organized during this celebration. structural geology, geophysics, geochemistry Today, the Geology department offers and geomorphology. Let’s work towards mak- undergraduate and postgraduate courses ing this E-Geo Magazine a success, with a mine and it also has a Research Centre for Ph.D. of information, for generations to come.

10 CONGLOMERATE Piezoelectricity Nikita Zankar T.Y. B.Sc

For the annual function of the Geo Association i.e. ‘Flints’ in the year 2013-14, we had to make a project based on our geological knowledge. After a lot of study and search, we struck upon this very interesting topic of Piezoelectricity. As we read more about it, we found it more and more interesting and we decided to make a model showing this phenomenon. As it was a new concept for us, we had to think a lot about what would the project exactly be, or which model would best describe our concept. Upon loads of discussions and meetings we came up with the idea of showing piezoelectric roads that help in lighting the street lamps. A glimpse of what Piezoelectricity is and what our project was about is presented in this article.

WHAT IS PIEZOELECTRICITY?

It is the ability of certain minerals to capacitor or a battery, which can store the generate an AC voltage when subjected to energy for later use. mechanical pressure. This is also called as the The concept of Piezoelectricity has been Piezoelectric effect. around since the 1880s’ and was discovered Piezoelectric materials are used to obtain by Jacques and Pierre Currie. The theories energy from exerted forces or vibrations. The behind piezoelectricity, or the conversion of deformation of the material produces an movements and vibrations into electricity, internal dipole moment, which in turn, pro- have existed for many years. However, very duces an electrical charge across its surfaces. few applications of piezoelectricity exist in this This process is reversible—when an electric modern age. current is run through the material, its shape Even if the planet with doubled the also changes. The polarity of charge results in amount of solar and wind power available, alternating current (AC) which is then there would still be a shortage of clean elec- converted into direct current (DC). The tricity in the coming years. We need to grab converted current is then used to charge a energy from wherever we can find it, which is

11 CONGLOMERATE why piezoelectricity—the charge that is genrally thought to act as a biological force gathers in solid materials like crystal and sensor) ceramic in response to strain—has recently begun to pique the interest of entrepreneurs and scientists alike. A number of materials are piezoelectric, including topaz, quartz, cane sugar, and HOW CAN IT BE USED? tourmaline. Other minerals used are Rochelle salts and various solids. That means a charge Man made piezoelectric material includes begins accumulating inside these materials barium titanate and lead zirconate titanate. when pressure is applied. Piezoelectrics are Piezoelectric plates are placed under the already commonly used in a number of cross-walk so that vibrations and pressure applications. Quartz clocks, for example, rely fluctuations caused by cars and pedestrians on piezoelectricity for power, as do many can be converted into electricity. sensors, lighters, and actuators. But these are The electricity can be piped to power the old uses for piezoelectricity. Scientists street lamps, traffic signals, cameras and other today have much more interesting piezoelec- electronic devices located in the vicinity. tric plans in mind. So, the concept is to use mechanical energy or external force to create electricity by the use of specific crystals. It can be used at various public places like, 1. Railway stations, Bus stations PIEZOELECTRIC MATERIALS 2. Roads, Highways 3. Walking tracks, Footpaths Piezoelectric materials are materials that 4. Discos, Pubs etc. produce an electric current nwhen they are Imagine, walking down the street and placed under mechanical stress. There are charging your phone as you walk, or charging several materials that we have known for some your laptop by typing, or powering a night- time that posses piezoelectric property, includ- club by dancing on a piezoelectric floor!!! This ing bones, proteins, crystals (e.g. Quartz) and is possible if piezoelectricity is used. ceramics (e.g. Lead Zirconate Titanate) In May 2012, some scientists from University of California Berkeley lab have found a mechanism of harnessing piezoelec- APPLICATION OF tricity from viruses also. This is the first time PIEZOELECTRICTY IN a biological material has been used to make DAILY LIFE piezoelectricity. The piezoelectric effect is exhibited 1. The first and the most recent use of by 20 out of 32 crystal classes and is always piezoelectricity was seen in 2008 at Club associated with non centrosymmetric crystals. Watt, a dance spot in the Netherlands, dubbed Naturally occurring materials, such as Quartz, the world’s first sustainable dance club. The exhibit this effect as a result of their crystalline club installed piezoelectric materials in its structure. Engineered materials like PZT for dance floor to turn patrons’ moves into elec- instance, are subjected to a process called pol- tricity that is used to change the color of the ing to impart the piezoelectric behavior. floor’s surface. Some naturally occurring piezoelectric 2. Tokyo railway station installed a materials include Berlinite (structurally identi- piezoelectric floor that uses kinetic energy to cal to quartz), cane sugar, quartz, Rochelle generate 1,400 kW of energy per day—enough salt, topaz, tourmaline and bone (dry bone to power ticket gates and displays. exhibits some piezoelectric properties due to 3. Toulouse, France, recently became the the apatite crystals, and the piezoelectric effect first city to put pressure-sensitive piezoelectric

12 CONGLOMERATE modules on the sidewalk, generating enough put under the road and were connected to the energy to power streetlamps. battery where the electricity was stored. 4. The United Kingdom plans to install This model was well thought and we power-generating tiles on London streets to made it as simple as possible, where the small light up bus stops and pedestrian crossings. LED’s were attached by wires which stood as 5. In 2009, a British supermarket streetlights in the middle of our road made by installed kinetic road plates that collect energy using the base as thermacol. These un-insu- from customers driving over road bumps lated copper wires were connected in parallel in the store parking lot. The road plates are and a resistor was used to control the flow of pushed down by vehicle weight, which creates current. This was further given a connection a rocking motion that turns generators. with the 6V battery and attached to a button to 6. In Israel, a company called ‘Innowat- switch on and off the lights. tech’ is installing strips of asphalt embedded There was also another small model with piezoelectric materials. According to to show the use of quartz as a piezoelectric the company, the generators could produce 1 crystal. A Cigarette lighter was used and the MWh of electricity from a four lane highway, enough to power 2,500 homes. Piezoelectric sidewalks, roads, and cloth- Actual Model ing items haven’t taken off in a big way quite yet, but they probably will soon.

ABOUT OUR PROJECT

When we understood the basic concept of Piezoelectricity, we decided on applying it on a very simple level, like it has been happening in many other countries. We designed a road with streetlamps and tried to show the electricity generation to light the lamps by the help of mechanical pressure in form of vibrations applied by cars on the road. Here, we assumed that the piezoelectric crystals were

Rough Sketch of the model

demonstration of how, when the pressure is given on the lighter knob, the quartz crystal present inside it shows piezoelectric effect and with the help of liquid present, ignites the flame There are three issues that we are current- ly faced with when trying to tap piezoelectricity as a viable electricity production method.

13 CONGLOMERATE LIMITATIONS OF CONCLUSIONS OF OUR PIEZOELECTRICITY: PROJECT:

The major issue is that the quantity of The use of piezoelectricity for sensors is electricity produced is so small, so unless vast widely accepted; however, doubt still remains installations are set up, it simply would have concerning its efficiency as a direct source of not enough strength to power our energy. Because of the sheer amount of force it latest gadgets. takes to generate a very small amount of elec- The current is only produced when there tricity, many believe that piezoelectricity will is mechanical stress being applied, so as soon never have large scale applications. However, as you stop compressing the material, there is in examples like the train stations in Japan, the no charge produced. individually insignificant footsteps of people Another issue is that up till now, many add up to significant electricity to power the of the starting products needed to produce the lightning systems and gates. It would seem piezoelectric materials are toxic and difficult to this potential is too great to ignore—and that work with. future research into piezoelectricity as a pro- spective power source is well worth the effort.

REFERENCES Brenda Ou, Dec ‘11, Submitted as a coursework for J. Ryall, “Japan Harnesses Energy from Footsteps” The PH240, Stanford University, Fall 2011 Telegraph, Dec ‘08 Rex garland, April ’13, Submitted as a coursework for Wikipedia PH240, Stanford University, Fall 2012 science.howstuffworks.com J. Fraden, Handbook of Modern Sensors: Physics, Designs www.piezomaterials.com and Applications (Springer, 2004) www.thegreenage.co.uk – piezoelectric materials I. Amato, “Piezo: Tough Plastic With a Sensitive Side,” www.nanomotion.com/ piezoelectric-motor-technology/ Los Angeles Times, Dec ‘89 piezoelectric effect/

14 CONGLOMERATE LONARA lake of heritage Neeraja S. Chinchalkar T.Y.B.Sc.

he Lonar Crater, completely, or to slow down nature. Being located in the located near the and eventually have a free Deccan Traps, one of the TLonar village in fall. A meteor on hitting the largest igneous provinces in Buldhana district of Maharash- surface of the earth is known the world, Lonar crater was tra, is one of the most unique as a ‘meteorite’. If the meteor originally considered to be meteorite impact craters on is sufficiently large enough of a volcanic origin. On the the Earth, formed nearly 5, to withstand the resistance contrary, recent studies have 70,000 years ago(F. Jourdan et from the atmosphere, it may led scientist to attribute the al, 2011). The crater itself with continue to travel with a formation of this crater to a its raised rim is about 1.8 km hypervelocity and collide with meteorite impact. in diameter, while the saline the surface of the earth, giving Geoscientists from lake that it harbors is about 1.2 rise to a depression known across the world have pro- km in diameter. Impact craters as an ‘impact crater’. Some of vided evidences through on the earth are not uncom- the well known examples of their research to corroborate mon; in fact, as many as 170 impact craters are Barringer this theory. The bowl-shaped terrestrial impact craters have Crater (Meteor Crater) in structure of the crater along been identified [2](Grieve et al., Arizona and Chixulub Crater with a raised rim is typcal of 2005). Even though it cannot in Mexico. an impact crater. The impact be asserted with complete cer- has given rise to many fra- tainty, Lonar crater is probably Impact craters may be tures appearing in radial, the largest and most preserved classified as Simple or Com conical as well as concentric impact crater on earth formed plex, depending on their systems in the crater. These entirely in a basaltic terrain. structure. The basic differ- fracture systems form an ence between the two lies in essential component while The Earth, in its orbit that the Simple Crater has a describing the impact. around the Sun, passes flat floor while the Complex The matter excavated through a lot of debris left Crater has an uplifted centre by the impactor surrounds behind by comets and within the flat floor. Lonar the Lonar crater up to about asteroids. This debris, in Crater has been classified as 1350m and is known as ‘ejecta the form of meteors, enters a Simple Crater as it shows matter’ or ‘ejecta blanket’ the earth’s atmosphere no central uplift, among other (P. Senthil Kumar, 2005). at velocities greater than factors. Basalts from the ejecta have 10km/sec. The friction with The theories about the undergone shock metamor- the atmosphere causes the formation of the Lonar crater phism due to the tremendous meteors to either burn away have been of a controversial heat and high pressure

15 CONGLOMERATE generated during the impact. inside and outside the crater. The most important effect of These are known as ‘Impact shock metamorphism in these Glass’ and cannot be clearly basalts is the conversion of distinguished from volcanic Plagioclase to Maskelynite. glass without sophisticated Maskelynite is a diaplectic laboratory techniques. No glass which is formed only fragments of the impactor by the processes involving have been recovered from temperatures and pressures as the crater. The large diameter high as those generated dur- of the crater suggests that ing impact processes. Occur- the impactor was probably rence of completely vaporized, thus Planar Deformation Features making it difficult to find any (Image courtesy www.2astro.psu.edu) or PDFs in the Feldspars of fragments. these basalts has served as A comprehensive study Formation of an Impact Crater. an unambiguous evidence of the crater would allow for for recognizing Lonar as an a wider understanding of the impact crater. PDFs are a effects of meteorite impact on impact structures, are almost result of shock metamorphism basalts. Such studies will also completely made up of and cannot be formed due help better understand the basaltic strata. to volcanic activities. Dark impact structures on moon Lonar is not only coloured glassy rocks show- and terrestrial planets, as the important from a geological ing vitreous lustre have been surfaces of these bodies which perspective but it also has a found at various locations are riddled with numerous lot more to offer. Lonar Crater

A view of Lonar Lake in November 2013

16 CONGLOMERATE Daitya Sudan Temple at Lonar

is home to many biological of humans, created the lake References: species ranging from nitrogen to bury and protect her trea- F. Jourdan, F. Moynier, C. Koeber3, fixing micro organisms to sures which the villagers of and S. Eroglu, 40Ar/39Ar Age of migratory birdslike flamingos, Lonar still believe to be hid- the Lonar crater and consequence and countless other species of den under the lake. Religious for the geochronology of planetary plants and animals. Temples festivals, deforestation and impacts of historical and archaeologi- construction around the crater Grieve, R.A.F.; Cintala, M.J.; Tagle, R. cal significance built thou- are responsible for the pollu- (2007). Planetary Impacts in Encyclo- sands of years back are still tion and exploitation of the pedia of the Solar System, 2nd ed., preserved and prided by the lake. If such activities are not L-A. McFadden et al. Eds, p. 826 villagers. The ‘Daitya Sudan checked, the crater will lose its P. Senthil Kumar, Structural effects Temple’ of Lord Vishnu at beauty in no time. of meteorite impact on Basalt: Lonar is a classic example of Even though the Lonar evidence from Lonar Crater, India the ‘Hemadpanthi’ style and Crater has been a subject of (2005). features exquisite carvings research and speculations for Wikipedia: Lonar Crater Lake throughout. ‘Kamalja Devi a long time, many of its mys- Lonar Crater, India: Analog for Mars Temple’ and’ Gomukh teries are yet to be explored. in the field and laboratory – S.P. Temple’ are also very well We must not forget that Wright, Auburn (Eight International known among pilgrims. nature has created this enig- Conference on Mars – 2014) matic wonder and it is in our No evidence of impact induced vola- However, a lot of hands to preserve and cherish tile loss from Maskelynite of Lonar ignorance still exists about it before it disappears forever. Crater, India – S. Misra et al (2007). the Lonar Crater. The stories Geology of Lonar Crater – of how the crater came into Maloof et al (2010). being revolve around myths and beliefs of the local people of Lonar village. One such myth states that a Goddess, offended by treacherous acts

17 CONGLOMERATE Science of the Earth Navnath Ghodake, T.Y.B.Sc

Geology is the science of the earth, which deals with its physical and chemical characters, as also its structure, origin, age and history. It also deals with the materials (rocks, minerals, ores, coal and petroleum deposits etc.) that constitute it and the processes, both external and internal that operate on and within it. The name geology is coined from the Greek word ‘gea’ or ‘gaia’, meaning the earth and ‘logy’ meaning science. Richard de Bury was the first to use the word geology. In the year 1473, he applied it to the ‘law’ or earthly science as opposed to ‘theology’ or heavenly science. There are 3 unique features in the subject of geology: Firstly, it covers an immense period of time, about 4.6 billion years i.e. from the origin of the earth, its differentiation and evolution, till the present day. Secondly, geology is basically a field science. The field work and field observations are most essential in answering most of the questions, regarding natural events. Thirdly, geology is an interdisciplinary science i.e. it requires direct or indirect assistance from other sciences. For e.g.: To know the chemical composition of a rock, knowledge of chemistry is essential. It would not be an exaggeration if one said ‘geology serves and prospers the nation’. Natural resources and their proper exploitation plays a vital role in nation building. Knowledge of geology is essential for effective generation of power and energy. All natural resources except solar energy are directly linked with the earth. The earth

18 CONGLOMERATE holds metallic, non-metallic and atomic min- study of earthquake, volcanoes, mountains, eral deposits. It has generated and movement of continents, oceans, rivers, wind, preserved huge hydrocarbon (petroleum) glaciers etc. It can be summarised that, reserves and coal deposits. Its mineral whatever is happening today, on and within constituents from diamonds to kaolin (a type the earth has happened in the geological past. of clay) are useful to mankind in everyday life. Thus, a geologist thinks in a reverse manner as The basic need of humans i.e. food and compared to a normal person. shelter, are directly linked with geology. In A bright future awaits the geologist the agricultural sector, groundwater, soil and in the years to come. Nevertheless, a vastly use of fertiliser, are the prime factors and can diversified and developing country like India, be tackled with the help of geology. Shelter offers many opportunities to the geologist in in the form of single or multi-storeyed build- both private and public sectors. Those who do ings, cannot be built without bricks, rocks and not wish to pursue higher studies and want cement. Therefore, knowledge of geology is to do something on their own, can start their essential for their search and analysis, both own consultancy in the field of ground water, quantitative and qualitative. engineering geology, soil analysis, Planning of huge hydroelectric projects, gemmology, cutting and polishing of big water reservoirs, railways, tunnels requires semiprecious stones, trading of building proper geological information and advice. material, small scale mining, procurement of The search of economically important miner- mining lease etc. Private and government als, ore, coal, petroleum and atomic minerals, enterprises always require geologists. For the becomes much easier with the help of geologi- past decade, many multinational oil cal studies. companies are recruiting qualified petroleum Geology is further extended, to include geologists.

Some important organisations where geological services are required are:

1. G.S.I : Geological Survey of India 16. M.T.Co. : Mica Trading Company 2. S.A.I.L : Steel Authority of India Ltd. 17. M.O.I.L. : Manganese Ore India Ltd 3. A.M.D : Atomic Mineral Division 18. N.L.C. : Neyveli Lignite Corporation 4. B.G.M.L. : Bharat Gold Miners Ltd. 19. U.C.I.L : Uranium Corporation India Ltd 5. C.G.W.B : Central Ground Water Board 20. N.M.D.C. : National Mining Development 6. C.I.L : Coal India Ltd. Corporation 7. H.C.L. : Hindustan Copper Ltd. 21. N.M.L. : National Metallurgical Laboratory 8. H.Z.L. : Hindustan Zinc Ltd. 22. S.C.C.L. : Singareni Colliories Company Ltd 9. I.B.M : Indian Bureau of Mines 23. T.I.S.C.O. : Tata Iron and Steel Company 10. I.S.R.O : Indian Space Research Organisation 24. K.I.O.C.L : Kundermukh Iron Ore Company Ltd 11. I.I.G : Indian Institute of Geomagnetism 25. A.C.C. : Associated Cement Company 12. N.G.R.I : National Geophysical Research Institute 26. M.M.L : Mysore Mineral Ltd 13. N.I.O : National Institute of Oceanography 27. G.M.D.C. : Gujarat Mine Development 14. I.R.E.L : Indian Rare Earth Ltd. Corporation 15. M.G.M.I. : Mining Geological and Metallurgical 28. I.B.M. : Indian of Bureau of Mines Institute of India

19 CONGLOMERATE 29. G.S.D.A. : Ground Water Survey and Development Agency 30. N.R.S.C. : National Remote Sensing Centre

Oil Companies:

1. O.N.G.C. : Oil and Natural Gas Corporation 2. I.O.C. : Indian Oil Corporation 3. C.P.C. : Chennai Petroleum Corporation 4. G.A.I.L. : Gas Authority of India Ltd 5. G.S.P.C. : Gujarat State Petroleum Corporation 6. Reliance Petroleum

Multinational Oil Companies: 1. ExxonMobiL 2. Armaco 3. Shell Oil 4. Petronas 5. British Petroleum 6. Chevron Corporation

20 CONGLOMERATE CRYSTAL CAVES AT NAICA Sakshi Maheshwari, F.Y.B.Sc

Before we study about crystal caves we need to know what are caves actually. Cave: A natural underground chamber in a hillside or clif Crystal in Naica cave (image courtesy- news.na- Naica Caves tionalgeographic.com) Cave of the Crystals also called as the Giant Crystal Cave is a cave connected to the Naica mine 300 metres below the surface in Naica, Mihuahua, Mexico. The main chamber contains giant selenite crystals (gypsum,CaSO4·2 H2O), some of the largest natural crystals ever found. The cave’s largest crystal found to date is 12 m (39 ft) in length, 4 m (13 ft) in diameter and 55 tons in weight. The cave is extremely hot with air temperatures reaching up to 58 °C with 90 to 99 percent humidity. The cave is relatively unexplored due to these factors. Without proper protection people can only endure approximately ten minutes of exposure at a time. A group of scientists on the Naica Project have been heavily involved in researching these(image courtetsy- www. caverns. picture-newsletter.com) The History Of Crystal Caves The discovery of crystal caves is credited to a local sixteen year old farm boy, William R. Vanasse. In 1881, William was chasing a squirrel and when the squirrel disappeared down a sink hole, William went home and told his brother George about his discovery (Green, 2004). The next day, armed with rope and a lantern, the two boys explored the hole and found themselves in the main room on the second floor. Over the years, explorers visited the Sander’s Corner Cave, and it went largely under-explored until

21 CONGLOMERATE 1941 (Green 2004).

Formation of the crystals Naica lies on an ancient fault and there is an underground magma chamber below the cave. The magma heated the ground water and it became saturated with minerals, including large quantities of gypsum. The hollow space of the cave was filled with this mineral- rich hot water and remained filled for about 500,000 years. During this time, the temperature of the water remained very stable at over Diagram showing formations of crystals 50 °C (122 °F). This allowed crystals to form and grow to immense sizes. known cave;located in Wisconsins’s Peirce country, less than a mile west of spring valley on State Highway 29. Discovered by accident Explorer in 1881 by William Vanasse, Crystal Cave is a exploring inside multi-level solutional cave formed in dolomite the Naica cave bedrock located in the Prairie du Chien group- ( image courtesy- ing. The Dolomite was formed approximately http://crys- 485 million years ago in the lower Ordovician talcavepa.com) period when a warm shallow ocean covered much of Wisconsin and Minnesota.

Crystal Cave (Wisconsin) Inside the crystal cave in Wisconsin (image courtesy-www.whereisbermuda.com)

Giant Crystal Cave’s Mystery Solved A geologist announced that he and a team of researchers had unlocked the mystery of just how the minerals in Mexico Cueva de los Cristales (Cave of Crystals) achieved their monumental forms. Buried a thousand feet (300 meters) below Naica mountain in the Chihuahuan Desert, the cave was discovered by two miners excavating a new tunnel for the Industrias Peñoles company in 2000. The cave contains some of the largest natural crystals ever found: translucent gypsum beams Refrences measuring up to 36 feet (11 meters) long and www.wikipedia.com weighing up to 55 tons. www.sequoiahistory.org “It’s a natural marvel,” said García-Ruiz, www.nationalgeographic.com of the University of Granada in Spain. www.wisconsincaves.org Crystal Cave in Wisconsin is longest www.crystallinks.com

22 CONGLOMERATE The Geological Time Mesozoic (time of middle life) Scale is a unique classification and Cenozoic (time of recent of the past 4.6 billion years life or modern life). These of Earth’s history preserved divisions are based on the in the rocks. The Time Scale evidences of life or its absence. is classified into various sub- The beginning of the Eras divisions based on age of the and the Periods are not well minerals in the rocks, the for- marked but they fall in the mation of the rock itself and range of some (+/-) 2, 5 or 10 the identifiable fossil record million years. These boundar- preserved in the sediments. ies are identified by observing The stratigraphers and some sudden change in the palaeontologists made an lithological character or the account of developing a Time change in the fossil content Scale for approximately last or by a period of non-deposition/erosion. THE The Hadean Era is placed at the bottom of the Time Scale and starts from 4600 mil- GEOLOGICAL lion years up to 4000 million years. It includes the formation of the Earth in the Solar TIME SCALE System and the formation of Rucha Kulkarni the Moon. It is the time when M.Sc 1 half a billion years about a the Earth was in a molten century ago. In the recent state and was slowly getting years there have been a lot condensed forming a thin of drilling activities for the crust. This process continued exploration of the ocean floor. for about 1000 million years. Geology of the remote areas, Unfortunately, there is scanty exploration of petroleum record of the Hadean Era reservoirs etc. also gave new preserved for us. The oldest ideas and information to rocks on the earth’s crust are refine the aspect of the Time of about 3700 to 4000 million Scale established before. years in age which form the A Danish scientist first ever geological record Nicholas Steno made the first available. The atmosphere was approach to modern stratig- still developing along with the raphy in the year 1686. The formation of primordial crust sequence was arranged on the of the Earth and therefore, it basis of order of superposi- was of a highly mixed compo- tion and faunal succession sition. along with the interpreting of The next is the Archaean physical evidences as well as Era which began at about 4000 volcanic activities. The Time million years and ended at Scale is divided into 6 major about 2500 million years. The Eras namely Hadean (forma- atmosphere during the Early tion of the Earth), Archaeozoic Archaean time was similar (time of the initial life), Pro- to the Hadean time, though terozoic (time of earliest life), there was gradual increase Palaeozoic (time of old life), in the oxygen levels along

23 CONGLOMERATE with the minor evolution of forms in the water. were abundant marine inver- initial life forms. As the time The Phanerozoic Eon is tebrates in the Cambrian and passed through the Archean, full of life forms which sud- the Period is characterized by the atmosphere started chang- denly appeared at the begin- the index fossil Trilobite. The ing by the end of the era. The ning of the Eon. This Eon Ordovician Period had the deposition of the sedimentary begins with the Palaeozoic Era first appearance of the verte- – volcanic sequence is sup- which began at approximately brates. The European orogeny posed to be the first geological 570 million years and lasted and the first ever terrestrial record which is approximately up to 245 million years. The plants were reported in the of the age of the Hadean – Era is sub-divided into 6 Peri- Silurian Period. The Devonian Archaean Boundary. The ods: Cambrian, Ordovician, is also known as the age of hydrosphere present was Silurian, Devonian, Carbonif- fishes and there was the first extremely acidic and there erous and Permian. There was appearance of insects and was extensive volcanism. a sudden diversification and amphibians, also the growth During the Late Archaean, the abundance in the life forms, of the forests began in this first anaerobic bacteria called both simple and complex in period. In the Carboniferous as phytolites were formed. A the marine waters. The life the forest growth of the Era very pronounced unconfor- started evolving in the waters reached its peak. The Carbon- mity, that is, the Eparchaean of the Cambrian to Devonian iferous Period also has the Unconformity, separates the time. Meanwhile, there was first appearance of reptiles, Archean Era from the overly- an ice age at the end of the the amphibian-like reptile ing Proterozoic Era. Ordovician Period. Until the forms and the abundance The Proterozoic Era Carboniferous Period all the of amphibians. During the was first established from life was present in the water, Permian period there was the Canadian Craton. The era but in the Early Carbonifer- a glaciation in the Southern began at about 2500 million ous time, slowly some of Hemisphere and the reptiles years and lasted till about the aquatic animals started spread all over the globe and 570 million years. During migrating to the land. This diversified. Even though there the Early Proterozoic time, was in response to the orogen- was such a great development there was a shallow marine ic activities during these times of life on Earth, it was sud- environment prevailing on the which increased the land area, denly destroyed by the Perm- Earth. There was an improve- providing abundant space for ian – Triassic Mass Extinction ment in the atmosphere the animals to flourish. The which took place at the end and the hydrosphere by the atmosphere had abundant of the Permian and became removal of toxic substances, oxygen content and compara- the boundary between the which supported the growth tively less carbon-di-oxide lev- Palaeozoic and Mesozoic Eras. of life in water. Thus, small els which supported the life to The extinction is also known simple life forms such as algae settle on land. There was also as ‘Great Dying’ as more than started growing in the marine a huge growth in the marine 90% of the species and life waters. These life forms were fauna as well as in the ter- forms went extinct. The ones so simple that they were restrial fauna during the late who survived the destruction devoid of hard parts and Palaeozoic Era. There were continued to diversify and hence are not preserved in dense forest covers near the evolve in the later time. the sediments. Some of these equator and gradually became The Mesozoic Era began algae have been observed to scarce towards the poles. Dur- at about 230 million years and leave their traces in the form ing the Palaeozoic Era there ended with yet another mass of stromatolites on the lime- was only one supercontinent extinction at about 65 million stones and dolomites. By the i.e. a single land mass on the years. The Era is sub-divided Late Proterozoic, the changes Earth named as Pangaea and into3 Periods: Triassic, Juras- in the hydrosphere permitted the rest was the water body sic and Cretaceous. The the birth of some complex life known as Panthyalssa. There Mesozoic is also known as the

24 CONGLOMERATE Geological Timescale 2014

‘Golden age of Reptiles’. The very high. The end of the Triassic Period is character- Era was by the abrupt disap- had the hominids and Plio- ized in the geological history pearance of the dinosaurs cene had the first human-like by the first appearance of the and other plants. Though the animals on Earth. Animals fossil dinosaurs. The Juras- dinosaurs got extinct from like mammoths, saber tooth, sic Period had the first ever Earth, the destruction caused etc. belonged to the Tertiary appearance of mammals on was less as compared to the Period and few of the spe- Earth and also the tremendous previous Permian – Triassic cies even continued in the evolution and diversification Mass Extinction. This event Quaternary. The Quaternary of dinosaurs. Also there was is known as the Cretaceous – Period consists of Pleistocene a great orogeny in the North Tertiary Mass Extinction. and Holocene. The Pleistocene American area of the super- The Coenozoic Era Start- Epoch had the modern ice age continent. The breaking of ed at approximately 65 million and the evolution of humans Pangaea started around this years and is the ongoing Era. had a successful beginning. time and the plates started The Coenozoic is divided The Holocene began with the drifting towards the direc- into two Periods: Tertiary most recent glaciation and the tions in which the present and Quaternary and further existence of the present day continents are situated with divided into Epochs. Each Earth. respect to the supercontinent. Epoch is characterized by The Geological Time There were also some birds some adaptations in life forms Scale is refined continuously which started appearing in and distributed in the Tertiary by the Geological Society of the Jurassic time. During the and Quaternary Periods. The America with a time interval Cretaceous the dinosaurs Tertiary Period consists of of few years. There is a huge and other reptiles were well Paleocene, Eocene, Oligocene, increase in the availability of adapted to the environ- Miocene and Pliocene. Dur- the data due to the modern ment and were grown to ing the Paleocene there were technology. The present Time the maximum size they can orogenies that were occurring Scale is refined in the year attain. There was sudden in Europe and Asia. In the 2013. The Geological Society appearance of the flowering Eocene there was the first of America has been provid- plants and they also diversi- appearance in fossil records of ing the time scales since last fied themselves rapidly. The monkeys, horses and whales, 30 years since 1983. The first climate during the Cretaceous whereas, the Oligocene has time scale was published in was warmer than the present the first fossil record of apes the year 1913, in the book by and the sea levels were also and elephants. The Miocene Aurther Holmes.

25 CONGLOMERATE GEOLOGY AROUND SANGAMNER AND AANE GHAT AREA Ankita Katkar T.Y.Bsc

The following is a brief structures are useful in deci- not observed the present day write up of a one day field phering the palaeocurrent Pravara River which flows work conducted by the Geo- direction of the deposits. through the area. association of Department of How such thick deposits Geology, Fergusson College SEDIMENTARY DEPOSITS - can form with well preserved on 9th of September 2014. The route is admirable and is very Laminations observed in comforting; even non geolo- the clay-rich sediments (Left) gists are likely to find it enter- and Rhizoliths(Right) taining for its scenic beauty A little further of spot and lush green appearance A, at spot B trough cross- during the monsoons. bedding and laminated bedding are seen. Deposits of Location 1: Village- Gab- calcretes (calcium carbonate) hanwadi ,Panchayat-Chan- are seen across the bedding planes as cylindrical, bifurcat- danapuri (near Sangamner) ing tube-like objects. These when broken show remnants At this location a sec- of plant roots. These cylinders tion a seven metre thick can thus also be referred to as quaternary sedimentary ‘rhizoliths’. These rhizoliths deposits is observed. The are formed due to capillary section shows different layers action which occurs usually of coarse, medium and fine during the drier part of the grained rock. Along the sec- year. tion, sedimentary structures These thick deposits like cross bedding, lensoid found around ‘Chandanapuri deposits, laminations, pinch- Ghat’ are a wonder to study ing and swelling of sediments as the energy required for Primary Sedimentary Deposits – etc. is also observed. These such thick deposits to form is Pravara Gravel Formation

26 CONGLOMERATE Outcrop of GPB Sedimentary Deposits With Cross Bedding(Left) and with pinching and swelling structure(Right) in the field. flow lobe starts with chilled margin, followed by pipe B: GPB (Giant amygdales. The pipe amyg- Plagioclase basalts) dales at places are bent in a particular direction indicating At this location mega the flow direction of the lava. porphyritic basalt/Giant Above the pipe amygdales a Plagioclase Basalt (GPB) compact basaltic part is seen with large plagioclase laths followed by vesicular and is observed. The plagioclase amygdaloidal basalts at the laths in the GPB show hori- top. Features like squeeze-ups zontal arrangement at a few are also seen at places. The places. downstream of Mandhol dam This GPB horizon is shows a structurally con- intruded by a mafic discor- trolled stream. dant body. This body is a ver- Natural Bridge at Ane Ghat tical dyke which cuts through the horizontal basalts in the region. The dyke shows well sedimentary structures is still developed horizontal jointing. a mystery! The GPB is a marker flow in the region and is known as M3 LOCATION 2: GULANCH- horizon in the lithostratigra- WADI, ANE GHAT phy of the region. A. Natural arch/Natural LOCATION 3:- MANDHOL bridge DAM At this location a huge natural arch/natural bridge is At this location seen. There are many theories compound lava flows are for the formation of this fea- observed. This type of flow ture. Researchers have attrib- externally shows many sub- uted its formation to weather- ordinate flow units called as ing and erosion, neotectonism flow units/flow lobes. A Red and uplift, jointing in the bole horizon demarcating the basalts etc. Nevertheless it is a different flows in the area is fascinating feature to observe also seen. The base of a typical

27 CONGLOMERATE A dyke inruded into GPB (Left) and contact between dyke and host rock (Right)

Units of compound flow Flow Squeeze-up feature seen at the location.

28 CONGLOMERATE INTRODUCING AND CLASSIFYING DINOSAURS Vikram Vakil T.Y.B.Sc.

What were they? There are four features that de- Nearly everyone knows what dinosaurs termine what counts as a dino- looked like, such as Tyrannosaurus, Tricer- saur atops and Stegosaurus. But they may be much Dinosaurs lived only in the Mesozoic vaguer about the lesser known ones, and may Era:Dinosaur remains have been discovered have difficulty in distinguishing between dino- in rocks which range from the latest part of saurs and other types of prehistoric creatures. the Triassic It’s not at all unusual to overhear an Period (about adult, taking a group of children around a 220 mya) museum display, being reprimanded sharply throughout by the youngsters for failing to realize that a Jurassic woolly mammoth wasn’t a dinosaur, or- more Period and forgivably- that a giant flying reptile such as up to the Pteranodon, wasn’t a dinosaur either, but sim- end of the ply a reptile that lived at the same time as the Cretaceous dinosaurs, having descended from the same, Period(65 common ancestor too- the archosaurs. mya)- span- So what exactly is a dinosaur? And how ning approxi- do palaeontologists decide on the groups they mately 155 belong to? million years

29 CONGLOMERATE of Earth’s history.

Image courtesy- dinosaur world.com

Among these are the giant seagoing reptiles of the Mesozoic Era, the plesiosaurs, Image courtesy- google images There- ichthyosaurs and mosasaurus; as well as the fore, any varied flying reptiles, the pterosaurs, which prehistoric ranged in size from the size of sparrows, like creature which comes from rocks which can be Pterodactylus, to that of small aircrafts like dated at older than 220 million years or young- Quetzalcoatlus. er than 66 million years is highly unlikely to be a dinosaur. All dinosaurs walked on upright, This immediately excludes an enormous pillar-like legs number of types of fossils, and of course rules out the woolly mammoth, whose remains That’s the final and most distinctive maybe a mere 100,000 years old. characteristic of all. Among the reptiles, only 2) Dinosaurs were reptiles: Living reptiles dinosaurs have managed to arrange their are very easy to identify because of their pecu- legs in such a way that they are held directly liar scaly skin, and the fact that they lay eggs beneath their body. with shells. These are rather difficult character- All other reptiles have their legs istics to identify in sprawled outward at an angle from the sides practice, because only a few dinosaurs have been preserved with skin impressions or with fossilised egg shells. Nevertheless, it does help us to eliminate fishes, amphibians (which lay eggs without shells), birds(with feathers), and mammals(with hairs and live-born young). All dinosaurs lived only on land

This is a particularly useful characteristic because it helps us to eliminate a wide range of giant and other bizarre fossils, which are very Image courtesy- google images frequently confused with dinosaurs.

30 CONGLOMERATE of the body, so that their feet remain wide apart. This particular feature was first noticed by Richard Owen in 1842. For the dinosaurs, it was doubly advantageous: it allowed them to swing their legs most effi- ciently beneath their body, so that they could have long- striding legs and could run fast: and it also meant that the legs were able to support the great body weight of the largest dinosaurs, because they could act literally like supporting pillars. backbone by a row of strong ribs, and its lower Classifying Dinosaurs edge forms the upper part of the hip socket. Since 1842, when Richard Owen took the Beneath it is a large bone that points down- vital step of recognising dinosaurs as a distinct ward and forward- the pubis- and behind group, several hundred species have been it there’s a bone extending backwards- the recognised, varying greatly in size and shape. ischium. All three bones meet at the hip socket, However, a great step in understanding which forms a deep, round opening in the side dinosaur relationships came in 1887. By this of the pelvis. time, a number of reasonable skeletons of The dinosaurs which have this type of dinosaurs had been described, and Professor hip structure fall into two distinct types Harry Govier Seely of King’s College, London, Theropods : These include all noticed that they could be separated into two carnivores(meat-eating) types; the name itself distinct groups on the basis of differences in means “beast-foot” on account of the very the structure of their hip bones. sharply clawed three-toed feet of these dino- Seely called these two groups the Sau- saurs. rischia (meaning “lizard/reptile-hipped”) and This group includes notable dinosaurs Ornithischia (meaning “bird –hipped”). such as the giant Tyrannosaurus, the small and very agile The Saurischians Deinonychus, the very early form Coelophysis and so on. As the name suggests, the hip bones are Sauropodomorphs : These were all herbi- arranged in much the same way as they are vores – that is, plant-eaters. They range in size in other reptiles. The large, blade-like upper from the early prosauropods, which appear in bone, called the ilium, is connected to the the Late Triassic and Early Jurassic, up to the gigantic sauropods of the Jurassic and

Image courtesy-forbes paleo club.weebly.com Image courtesy-users.tamuk.edu

31 CONGLOMERATE Image courtesy- tmac1kobe8vc15

Cretaceous Periods.The common sauropods are Diplodocus, Apatosaurus( formerly known as Brontosaurus or “thunder lizard”) etc. The Ornithischians

The arrangement of bones in the hips of these dinosaurs is, as the name suggests, very similar to that seen in living birds- though, confusingly, there’s no family link with birds as far as this group is concerned. The pubis, here, is a narrow, rod-shaped bone lying alongside the ischium. Also, all ornithischians seem to possess a small, horn- covered beak perched on the tip of the lower jaw (a very distinctive feature of dinosaur illustrations). their hind legs for most of the time. Examples There are five major divisions of this group include Lesothosaurus, Heterodontosaurus, Hypsilophodon, Dryosaurus, Iguanodon, Ornithopods:These include many small Tenontosaurus, Camptosaurus, and also the to medium sized dinosaurs which ran on hadrosaurs(meaning “duck-billed dinosaur. Ceratopsians:These were the distinctively horned and frilled dinosaurs, with curiously narrow, parrot-like beaks and appeared very late in dinosaur history, only during the second half of the Cretaceous Period. Examples include Psittacosaurus, Protoceratops-whose egges were first found in Mongolia in the 1920s, Leptoceratops, Triceratops, Anchicer- atops, Torosaurus, Styracosaurus, Pachyrhino- saurus, Chasmosaurus etc. Pachycephalosaurs : They had a very distinctive, curiously domed and massively reinforced heads. These forms appear to have arisen during the middle part of the Creta- ceous and persisted to the close of that period, but they were never particularly abundant as a

32 CONGLOMERATE group. Examples include Pachycephalosaurus, Homalocephale, Dracorex, Stegoceras etc. Stegosaurs : These were the plated dinosaurs of which Stegosaurus is the most common example which seems to have lived from the early part of Jurassic right till the early Cretaceous. The structure of the spines and plates of these dinosaurs has proved to be extremely important and interesting, and provides evidence in the debate as to whether dinosaurs were “warm-blooded” or “cold- blooded”. Ankylosaurs : They were the armoured tanks of the dinosaur world. These dinosaurs were fully covered in thick bony plates in order to ward off the attentions of the larger theropods. They appeared in the early Jurassic but became abundant only in the Late Creta- ceous of Asia and North America. Examples include Ankylosaurus, Edmontonia, Gastonia, Euplocephalus etc. This brings us to the end of my topic strictly pertaining to the introduction and classification of dinosaurs. The subject Dinosaurs is vast and probably beyond one’s imagination when it comes to talking about their evolution from Archosaurs and the continuation of their lineage into modern day birds. Also, their extinction, which took place 65 million years ago, is a mystery in itself as there are no solid evidences till date to entirely support one definite theory.

T-rex skeleton

33 CONGLOMERATE T-rex (Left) and its family member Albertosaurus(Right) T-rex skeletonModel of juvenile T-rex

Pictures and books referred to- Cambridge University press- Dinosaurs – Fastovsky & Weishampel Google images Illustrator Jan Sovak’s masterpieces for Scholastic Dinosaurs A- Z. Dinosaur!- David Norman Dinosaurs – Christopher Maynard

Skulls of Tarbosaurus and Daspletosaurus

34 CONGLOMERATE BATU CAVES MALAYSIA Ankita Katkar T.Y.BSc

This year in June on a tour to Malaysia I shrines. We visited the temple cave for which visited Batu Caves. The following article talks we had to climb 272 steps. As we can see in the about Limestone caves and features found in picture a beautiful 42.7-metre (140 feet) high it. Batu Caves is a limestone hill that has a statue of Lord Murugan is at the foot of the series of caves and cave temples in the Gom- caves. It is the tallest Lord Murugan statue in bak district, 13 kilometres (8 mi) north of Kua- the world. la Lumpur, Malaysia. The Caves are a series of several hundred limestone caverns in a Limestone, a sedimentary rock composed large limestone outcrop overlooking the city of largely of the mineral calcite (calcium car- Kuala Lumpur. Locals say that the caves take bonate: CaCO3) forms these caves. The high their name from the Sungai Batu or Batu River, solubility of Limestone in water and weak acid which flows past the hill. The cave is one of solutions creates caves and cave features. In the most popular Hindu shrines outside India, fact, most natural cave systems are through dedicated to Lord Murugan. It is the focal Limestone bedrocks. point of Hindu festival of Thaipusam in Malaysia. When our guide informed us that these Far off view of the caves are limestone caves. I was the most eager person to climb a steep flight of 272 steps! I was eager to see the Karst topography or at least some part of it like Stalactites /Stalagmites. The limestone forming Batu Caves is said to be around 400 million years old! Rising almost 100 m above the ground, the cave complex consists of three main caves and a few smaller ones. The biggest i.e. the Temple Cave has a very high ceiling and features ornate Hindu

35 CONGLOMERATE In some of sequence will lead to the formation of Sink- the Batu Caves holes, Stalactites, Stalagmites etc. These all are the limestone the components of a ‘Cavern’. has been completely washed away from the top to create natural skylights. These Limestone caves are located so close to the equator that it gives the cave system an unusual tropical environment inside and out Tallest Lord Murugan statue unlike many in the world at the foot of the limestone cave caves. systems in colder climes. Frequent Rainstorms in the area provide plenty of water to carve the caves; this perhaps forms faster and larger caves than in drier Entrance to the caves areas. As we were walking we saw stalactites everywhere on the walls of the caves.

Formation of ‘Caverns’ Rainwater, already slightly acidic mixes with carbon dioxide in the atmosphere and soil layer to form carbonic acid (H2CO3), this acidic water flows through the crevices, cracks and cavities which act to dissolve away limestone. H2O + CO2 = H2CO3 (Water) + (Carbon dioxide) = (Carbonic acid) Most caverns are created at or near the zone of water table. Due to further dissolving of limestone the water table may drop, the area of active cave formation will go lower into the bed rock. The continuation of this process will leave the upper opening in the zone of aeration (i.e. open to air) . Now if this area comes in contact with rain water, the dripping water through these dry passages may deposit Path to the entrance of the caves CaCO3 in various forms collectively known as ‘Speleothems’ The above all processes if act together in

36 CONGLOMERATE Stalactites hanging from the walls of the cave(Left) and some have touched the ground (Bottom left) Natural skylights.( Above)

Features shown by a cavern

REFERENCES- http://www.esi.utexas.edu/outreach/ caves/karst.php http://www.geocaching.com/ geocache/GC1NAJH_batu-caves-kl- earthcache?guid=13cd927c-5ea7-41f0-91ad- df42f9c8aebf

FOR MORE INFO. - http://www.karst.edu.cn/igcp/ igcp448/2002/3-2-7.pdf http://www.iaeg.info/iaeg2006/PAPERS/ IAEG_024.PDF http://www.ejge.com/2009/Ppr09127/ Ppr09127.pdf

37 CONGLOMERATE Rare Polymorphs of Olivine and Quartz Sushant Sudhakar Navarat. T.Y.B.Sc.

Olivine is most abun- are termed as polymorphs of transformations is thought dantly found in ultrabasic olivine. to occur during an extra- & basic igneous rocks. Due On the basis of occur- terrestrial shock event i.e. a to close oxygen packing in rence, they are very rare meteoritic impact on Earth. the atomic structure, olivine minerals. Here are the major exhibites neso-silicate struc- polymorphs of olivine - Wadsleyite ture i.e. it appears in indivi- Wadsleyite & Ringwoodite. sual tetrahedra. Generally, Wadsleyite was named after Wadsleyite is a high- it requires high temperature mineralogist, Arthur David pressure polymorph of oliv- & high pressure conditions Wadsley (1918-1969). And ine, and is an orthorhombic during formation. Although, Ringwoodite was named after mineral found in the Peace the change may occur in the the Australian Earth Scientist, River meteorite in Alberta, crystal structure by the change Ted Ringwood (1930–1993), Canada. It resembles the in surrounding pressure, who studied polymorphic crystal structure of spinel temperature conditions. These phase transitions in the com- and it is based on a distorted minerals which show similar- mon mantle minerals olivine cubic-closest packing of oxy- ity in the chemical composi- and pyroxene at pressures gen atoms. It is polymorphous tion to olivine, But differ in equivalent to depths as great with ringwoodite and is found the crystallisation system as about 600 km. to be stable in the transition zone of the Earth’s upper These minerals are found mantle. These regions are in the upper mantle of the from 400–525 km in depth. earth. Of which wadsleyite Because of oxygens not bound is a polymorph of forster- to silicon in the Si2O7 groups ite Mg2SiO4. In the phase of wadsleyite, it leaves some transformations of forsterite oxygen atoms underbonded, to fayalite, Mg-rich forster- and as a result, these oxy- ite (α-Mg2SiO4)changes to gens are hydrated easily. As wadsleyite (β- Mg2SiO4) a result, there can be high under pressure of 130 to 180 concentrations of hydrogen kbar between depths of 410 atoms in the mineral. Hydrous to 525 km & under 1000 to wadsleyite is considered a 1500 °C temperature, Then potential site for water storage Wadsleyite with increasing pressure, it in the Earth’s mantle due to (image courtesy- www.mindat.org) transforms to ringwoodite the low electrostatic potential (γ-Mg2SiO4). This series of of the underbonded oxygen

38 CONGLOMERATE No. Mineral Silicate Strucure Crystal System Hardness Specific Depth of forma- gravity tion 1 Olivine Neso silicate Orthorhombic 6.5-7 3.27-3.37 250-410 km

2 Wadsleyite Soro Silicate Orthorhombic 5.8-6.2 3.82-3.86 410-525 km Sometimes Monoclinic 3 Ringwoodite Neso Silicate Isometric 6.6-6.9 3.56-4.85 525-660 km (Cubic)

atoms. The water solubility ‘Tenham’ meteorite in 1969, An ultra-deep diamond and density of wadsleyite and it is inferred to be present found in Juína, Brazil, con- are ultimately affected by the in large quantity in the Earth’s tained inclusions of ringwood- temperature and pressure mantle. Ringwoodite is one ite, the only known sample inside of the Earth. Wadsleyite of the polymorphs of Olivine, of natural terrestrial origin, was first identified by Ring- and is an isometric mineral thus providing evidence of wood and Major in 1966 and abundantly found in meteor- significant amounts of water as was confirmed to be a stable ites. It occurs in the veinlets of hydroxide in the Earth’s mantle. phase by Akimoto and Sato in quenched shock-melt, cutting 1968. The phase was originally the matrix and replacing oliv- known as “β- Mg2SiO4” or ine produced during shock “Beta-phase”. metamorphism. In the lower Quartz Wadsleyite in Peace Riv- half of the transition zone, er meteorite occurs as micro- it has crucial importance in Quartz is the most abun- crystalline rock fragments, of mantle dynamics and the plas- dant constituent of acidic & size about 0.5 mm in diameter. tic properties of ringwoodite intermediate igneous rocks, The meteor or asteroid that are thought to be critical in which account for 59.12 % in impacted the earth generated determining rheology i.e. flow the form of silica. As well as the mineral phase transforma- of material in this part of the found in sedimentary & meta- tions of olivine to transform mantle. In regions of subduc- morphic rocks as an important into significant amounts of tion zones, the ringwoodite constituent. Due to framework high-density wadsleyite. It stability field hosts high levels structure arrangement of SiO2 also contains sulfide-rich veins of seismicity. tetrahedra, it exhibits com- of olivine. mon tectosilicate structure & belongs to hexagonal system. Ringwoodite But sometimes because of change in pressure & tem- Ringwoodite is an impor- perature conditions, change tant polymorph of olivine in crystal structure may occur that is formed at high tem- without any change in chemi- peratures and pressures of the cal composition. This minerals Earth’s mantle between 525 with the same chemical com- and 660 km depth. Ringwood- position (SiO2), but different ite is notable for being able to crystal structure are known as contain hydroxide ions (-OH) polymorphs of quartz. There within its structure. This min- Ringwoodite(image courtesy- are several polymorphous eral was first identified in the www.wikipedia.com) minerals of quartz namely,

39 CONGLOMERATE Cristobalite, Tridymite, Coesite, Stishovite, Moganite, Seifertite, Keatite. No. Minerals Crystal System Hardness Specific Gravity 1 Cristobalite Tetragonal (Pseudoisometric) 6.0-7.0 2.3 2 Tridymite Monoclinic (Pseudohexagonal) 7-7.2 2.2

3 Coesite Monoclinic (Pseudohexagonal) 7.0-8.0 2.9

4 Stishovite Tetragonal 8 4.3

Cristobalite is a high- or scales, in cavities in felsic within the stability field of temperature polymorph of volcanic rocks. Tridymite was quartz, coesite will eventu- quartz. Cristobalite occurs as first described in 1868 and the ally decay back into quartz white octahedra or spherulites type location is in Hidalgo, with a consequent volume in acidic volcanic rocks such Mexico. The name is from the increase, although the meta- as Obsidian and sometimes Greek tridymos for triplet as morphic reaction is very slow in converted diatomaceous tridymite commonly occurs as at the low temperatures of deposits. Cristobalite is stable twinned crystal trillings. the Earth’s surface. Coesite is only above 1470 °C, but can Tridymite can occur in a polymorph quartz, that is crystallize and persist meta- seven crystalline forms. Two formed when very high pres- stably at lower temperatures. of the most common at stan- sure 20–30 kbar, and moder- The persistence of cristobalite dard pressure are known as α ately high temperature 700 °C outside of its thermodynamic and β. The α-tridymite phase , are applied to quartz. stability range occurs because is favored at elevated temper- In 1960, a natural occur- the transition from cristo- atures more than 870 °C and rence of coesite was reported balite to quartz or tridymite it converts to β-cristobalite at from Barringer Crater, in is “reconstructive”. There is 1470 °C. Arizona, USA which was more than one form of the evidence that the crater must cristobalite framework. At Coesite have been formed by an high temperatures, the struc- impact. After this report, the ture is cubic. But, a tetragonal Coesite is a tectosilicate presence of coesite in unmeta- form of cristobalite occurs on with each silicon atom sur- morphosed rocks was taken cooling below 250 °C at ambi- rounded by four oxygen as evidence of a meteorite ent pressure, and is related atoms in a tetrahedron. It is impact. It was not expected to the cubic form by a static inherently monoclinic and that coesite would survive in tilting of the silica tetrahedra cannot be hexagonal. The high pressure metamorphic in the framework. This transi- crystal structure of coesite rocks. In metamorphic rocks, tion is variously called the low is similar to that of feldspar coesite was initially described or high transition. and consists of four silicon in eclogite xenoliths from dioxi-de-tetrahedra arranged the mantle of the Earth that Tridymite in Si4O8 and Si8O16 rings were carried up by ascending & these rings are further magmas. Kimberlite is the Tridymite is a high-tem- arranged into chains. Coesite most common host of such perature polymorph of quartz was first synthesized by Lor- xenolithic coesite. and usually occurs as minute ing Coes, Jr. , a chemist at the In metamorphic rocks, tabular white or colourless Norton Company, in 1953. coesite is now recognized pseudo-hexagonal crystals, This structure is metastable as one of the best mineral

40 CONGLOMERATE Cristobalite, Tridymite, Coesite, Stishovite, Moganite, Seifertite, Keatite. indicators of metamorphism Cristobalite No. Minerals Crystal System Hardness Specific Gravity at very high pressures (UHP, Ultrahigh-Pressure Metamor- Cristobalite is a high- 1 Cristobalite Tetragonal (Pseudoisometric) 6.0-7.0 2.3 phism). Such UHP metamor- temperature polymorph of phic rocks record subduction quartz. Cristobalite occurs as 2 Tridymite Monoclinic (Pseudohexagonal) 7-7.2 2.2 or continental collisions in white octahedra or spherulites which crustal rocks are carried in acidic volcanic rocks such 3 Coesite Monoclinic (Pseudohexagonal) 7.0-8.0 2.9 to depths of 70 km or more. as Obsidian and sometimes 4 Stishovite Tetragonal 8 4.3 Coesite is formed at pressures in converted diatomaceous Stivshovite(image courtsy-www. above about 25 kbar and deposits. Cristobalite is stable temperature above about 25 only above 1470 °C, but can junpeisato.blogspot.com) kbar and temperature above crystallize and persist meta- 700 °C. This corresponds to a stably at lower temperatures. and usually occurs as minute depth of about 70 km in the The persistence of cristobalite tabular white or colourless Earth. It can be preserved as outside of its thermodynamic pseudo-hexagonal crystals, mineral inclusions in other stability range occurs because or scales, in cavities in felsic phases because as it partially the transition from cristo- volcanic rocks. Tridymite was alters to quartz, the quartz rim balite to quartz or tridymite first described in 1868 and the exerts pressure on the core is “reconstructive”. There is type location is in Hidalgo, of the grain, preserving the more than one form of the Mexico. The name is from the metastable grain as tectonic cristobalite framework. At Greek tridymos for triplet as high temperatures, the struc- tridymite commonly occurs as ture is cubic. But, a tetragonal twinned crystal trillings. form of cristobalite occurs on Tridymite can occur in cooling below 250 °C at ambi- seven crystalline forms. Two ent pressure, and is related of the most common at stan- to the cubic form by a static dard pressure are known as α tilting of the silica tetrahedra and β. The α-tridymite phase in the framework. This transi- is favored at elevated temper- tion is variously called the low atures more than 870 °C and or high transition. it converts to β-cristobalite at 1470 °C. Tridymite Cristobalite (image courtesy- Coesite www.mindat.org) Tridymite is a high-tem- Coesite is a tectosilicate perature polymorph of quartz with each silicon atom surrounded by four oxygen atoms in a tetrahedron. It is inherently monoclinic and cannot be hexagonal. The crystal structure of coesite is sim- Tridymite (image courtesy- ilar to that www.wikimedia.org) Coesite (image courtesy- www.wikimedia.org) of feldspar and consists

41 CONGLOMERATE magmas. Kimberlite is the in the lower mantle. Stishovite most common host of such was named after Sergey M. xenolithic coesite. Stishov , a Russian high-pres- In metamorphic rocks, sure physicist who first coesite is now recognized synthesized the mineral in as one of the best mineral 1961. It was discovered in indicators of metamorphism Meteor Crater in 1962 by at very high pressures (UHP, Edward C. T. Chao. Ultrahigh-Pressure Metamor- Unlike other silica poly- Mogonite (image courtesy- phism). Such UHP metamor- morphs, the crystal structure www.mindat.org) phic rocks record subduction of stishovite resembles that or continental collisions in of rutile (TiO2). The silicon in of four silicon dioxi-de- which crustal rocks are carried stishovite adopts an octahe- tetrahedra arranged in Si4O8 to depths of 70 km or more. dral coordination geometry, and Si8O16 rings & these Coesite is formed at pressures being bound to six oxides. rings are further arranged above about 25 kbar and Similarly, the oxides are into chains. Coesite was first temperature above 700 °C. three-connected, unlike low synthesized by Loring Coes, This corresponds to a depth pressure forms of SiO2. It was Jr. , a chemist at the Norton of about 70 km in the Earth. It long considered the hardest Company, in 1953. This struc- can be preserved as mineral known oxide. However, boron ture is metastable within the inclusions in other phases suboxide has been discovered stability field of quartz, coesite because as it partially alters to in 2002 to be much harder. At will eventually decay back quartz, the quartz rim exerts normal temperature and into quartz with a consequent pressure on the core of the pressure, stishovite is volume increase, although the grain, preserving the meta- metastable. Stishovite can metamorphic reaction is very stable grain as tectonic forces be separated from quartz by slow at the low temperatures uplift and expose these rock applying hydrogen fluoride of the Earth’s surface. Coesite at the surface. As a result the (HF); and unlike quartz, is a polymorph quartz, that is grains have a characteristic stishovite will not react. formed when very high pres- texture of “A Polycrystalline Until recently, the only sure 20–30 kbar, and moder- Quartz Rim”. known occurrences of stisho- ately high temperature 700 °C Coesite has been identi- vite in nature formed at the , are applied to quartz. fied in UHP metamorphic very high shock In 1960, a natural occur- rocks around the world, pressures more than 100 Kbar rence of coesite was reported including the western Alps of and temperatures more than from Barringer Crater, in Italy at Dora Maira, the Lan- 1200 °C present during Arizona, USA which was terman Range of Antarctica, in hypervelocity meteorite evidence that the crater must the Western Gneiss region of impact into quartz-bearing have been formed by an Norway and the Himalayas of rock. Minute amounts of impact. After this report, the Eastern Pakistan. stishovite has been found presence of coesite in unmeta- within diamonds, and morphosed rocks was taken Stishovite post-stishovite phases were as evidence of a meteorite identified within ultra-high impact. It was not expected Stishovite is an extremely pressure mantle rocks. It is that coesite would survive in hard, dense tetragonal form of second densest polymorph of high pressure metamorphic silicon dioxide. Which is one silica, after Seifertite. rocks. In metamorphic rocks, of the polymorphs of Quartz. coesite was initially described It is very rare on the earth’s in eclogite xenoliths from surface. It may however be a the mantle of the Earth that predominant form of silicon were carried up by ascending dioxide in the earth, especially

42 CONGLOMERATE Other Important Polymorphs within seconds under laser or valid species by the CNMNC, of Quartz electron beams used for stan- [The Commission on New dard Raman spectroscopy or Minerals, Nomenclature and electron beam microanalysis, Classification ] (part of the Seifertite respectively, even at much IMA). It has been mainly Seifertite is a silicate reduced beam intensities. found in dry locales such as mineral with the formula SiO2 Gran Canaria and Lake Maga- and is one of the densest poly- di. It has been reported from a morphs of quartz. It has only Moganite variety of locations in Europe, been found in Martian and Moganite is one of the India and the United States. lunar meteorites. Where, it is polymorphs of quartz that eventually formed from either was discovered in 1984. It Keatite tridymite or cristobalite. It is crystallises in the monoclinic named after Friedrich Seifert crystal system. This mineral Keatite is a silicate min- (born 1941), the founder of is “Virtually indistinguish- eral with the chemical formula the Bayerisches Geoinstitut at able” from chalcedony which SiO2 that first was discovered University of Bayreuth, Ger- is made up of both moganite in 2013. It is a tetragonal poly- many, and is officially rec- and quartz. Physically, it has morph of silica first known ognized by the International a hardness of about 6, a dull as a synthetic phase. It was Mineralogical Association. luster and appears gray in reported as minute inclusions As a result of heating during color but transparent. It was within clinopyroxene (diop- the atmospheric re-entry and named after the municipality side) crystals in an ultra high impact to the Earth, at an of Mogán on Gran Canaria. In pressure garnet pyroxenite estimated minimum pressure 1994, the International Min- body. The host rock is part of 350 kbar. Seifertite forms eralogical Association (IMA) of the Kokchetav Massif in micrometre-sized crystal- had disapproved it as being Kazakhstan. line lamellae embedded into a separate species because it a glassy SiO2 matrix. The was not clearly distinguish- References – lamellae are rather difficult able from quartz. It has only Wikipedia , Earth Materials (Kevin to analyze as they vitrify recently been approved as a Hefferen, John O’Brian)

43 CONGLOMERATE FLUORESCENCE of minerals Vinoy D’souza, Shivaraj Patil TYBSc.

What is a Fluorescent Mineral? Fluorescence

Fluorescence is a phenomenon which causes the Fluorescence in minerals occurs when a minerals to glow when they are subjected to ultra- specimen is illuminated with specific wave- violet Light radiation. This phenomenon is exhibited lengths of light. Ultraviolet light x-rays and only by some minerals and a mineral which pos- cathode rays are the typical types of light that trigger fluorescence. These types of light sesses this property is called a fluorescent mineral. have the ability to excite susceptible electrons These minerals have the ability to temporarily absorb within the atomic structure of the mineral. a small amount of light(ultra-violet) and an instant These excited electrons temporarily jump up later release a small amount of light of a different to a higher orbital within the mineral’s atomic wavelength (Visible spectrum wavelength). structure. When those electrons fall back down to their original orbital a small amount of energy is released in the form of light. This release of light is known as fluorescence. The wavelength of light released from a fluorescent mineral is often distinctly different from the wavelength of the incident light. This produces a visible change in the colour of the mineral. This “glow” continues as long as the mineral is illuminated with light of the proper wavelength. How Many Minerals Fluoresce in UV Light? Most minerals do not fluoresce. Only about 15% of minerals have this ability and Fluorescence of minerals every specimen of those minerals (Image courtesy:www. geology.com) 44 CONGLOMERATE does not fluoresce. Fluores- cence usually occurs when specific impurities known as “activators” are present within the mineral. These activators are typically cations of metals such as: tungsten, molybdenum, lead, boron, titanium, manganese, uranium and responsible for the significantly higher price of chromium. Rare scientific lamps. earth elements Scientific-grade lamps are produced in a such as euro- variety of different wavelengths. The table at pium, terbium, left lists the wavelength ranges that are most dysprosium, often used for fluorescent mineral studies and and yttrium are their common abbreviations. Diagramatic repersentation of also known to interaction between photons contribute to Practical Uses of Fluorescence in and electrons which produce the fluorescence Minerals: the fluorescence phenomena phenomenon. (Image courtesy: Fluorescence Fluorescence has some practical uses in www. geology.com) can also be mining, gemmology, petrology and caused by mineralogy. crystal The mineral scheelite, an ore of tungsten, structural typically has a bright blue fluorescence. Geolo- defects or organic impurities. gists prospecting for scheelite sometimes go Lamps for Viewing Fluorescent Minerals The lamps used to locate and study fluorescent minerals are very different from the ultraviolet lamps (called “black lights”) sold in novelty stores. The novelty store lamps are not suitable for mineral studies for two reasons: 1. They emit long-wave ultraviolet light (most fluorescent minerals respond to short- wave ultraviolet). 2. They emit a significant amount of visible light which interferes with accurate observation, but is not a problem for novelty use. The scientific-grade lamps used for mineral studies have a filter that blocks most of the visible light that will interfere with observation. These filters are very expensive and are partly Fluorescent Mineral Viewing cabinet

45 CONGLOMERATE out at night with fluorescent lamps to look range of colours, from dull-brown for heavy for deposits. They also use fluorescent lamps oils and tars through to bright-yellowish and to examine core specimens and well cuttings. bluish-white for very light oils and conden- These exploration procedures have also been sates. This phenomenon is used in oil explora- used for other minerals. Fluorescent lamps can tion drilling to identify very small amounts of be used in underground mines to identify and oil in drill cuttings and core samples. trace ore-bearing rocks. They have also been used on picking lines to quickly spot valuable Fluorescence shown by the minerals in pieces of ore and separate them from waste. Project done in Flints 2013 Fluorescence of Minerals shown by Using Many gemstones are sometimes fluores- a Blacklight (Long UV light): cent including: ruby, kunzite, diamond and Green Fluorescence Shown by Calcite opal. This property can sometimes be used to [Colour in ordinary light: Colourless] spot small stones in sediment or crushed ore. Bright Red Fluorescence shown by Ruby It can also be a way to associate stones with a in Fuchsite [Colour in ordinary light: Red] mining locality. Blue fluorescence Shown by Fluorite [Colour in ordinary light: Colourless] Crude oil (petroleum) fluoresces in a

46 CONGLOMERATE The Gabbro Intrusions Khopoli,Maharashtra

Mugdha Chimote Dipal Jain Supriya Bahirat T.Y.BSc.

The gabbroic intrusions occur as a River is also controlled by this fracture. This medium grey toned low lying ridge extending clearly indicates that, the magmatic material in ENE-WSW direction about 3 km west of has followed the fracture zone. Khopoli. The country rock wherever exposed The occurrence of dyke near Dheku shows a slightly lighter tone than the ridge. village, having the same ENE-WSW trend, Field works reveal that the ridge is due supports the view that the trend of the fracture to a coarse grained melanocratic rock which pattern is ENW-WSW, and it existed in this has a discordant relationship with the associ- area prior to the intrusion of magmatic ated Deccan Trap Basalt Flows. The intrusive material. body has lenticular outcrops which extend for The gabbro body exhibits typical tor about 3-4 km in length with maximum width topography and probably because of its of about half a km. In the SW direction along nature, the intrusive body has been indicated the gabbroic body, the country rock has been as Stony Waste on Survey of India Toposheet fractured with individual master joints trending in ENE-WSE direction. Further down it is observed that the tributary of Patalganga

Gabbroic intrusions at location 1 Gabbroic body exhibiting tor topography

47 CONGLOMERATE Google image of the area Country rock consisting laths of plagioclase (Left) Location 1 - Olivine Gabbroic ridge (18.788552N, Country rock exhibiting porphyritic texture (Right) 73.304405E) Location 2 – Contact between the country rock and the intrusive body (18.790370N, 73.309388E) Location 3 – Exposed country rock exhibiting porphy- No. 47F/5. ritic texture (18.799830N, 73.316287E) The country rock in this area is amygdaloidal basalt and has become reddish along the boundary of intrusive body due to contact effect. In thin sections under microscope, plagioclase plate encloses pyroxene and olivine giving rise to poikilitic texture. Analysis have shown that olivine is 45%, pyroxene is 25%, plagioclase is 28% and glass, iron ore etc constitute 12%. Olivine commonly alters to iddingsite (Mulay and Peshwa, 1980). Samples of the rock specimens were collected only from the top of this gabbro body. Exposure of intrusive body represents the top of it, is evident from the fact that outcrop is concealed at one place below a ridge and at another by a hammock of basalt flows into which it has intruded. Presence of glass can therefore be attributed to fast cooling near References: the top of intrusive body. Mulay J. G. and Peshva V.V. , “Remote Sens- Hence we can draw conclusion that ing of dykes in Deccan trap area around Khandala there have been intense intrusive activities of and Khopoli (Maharashtra)”, National Space olivine gabbro in the Dheku village. Besides Science Symposium, Varanasi, 1980. the peripheral areas show clear evidences of Oka M. S., “On the occurrence of some gab- gabbro basalt contacts and the gabbros show a broic rocks at Vajrat, District Ratnagiri, Maharash- perfect Tor topography. tra” Jour. Inst. Of Geol. Vikram Univ., 1969, 2, 39.

48 CONGLOMERATE THE MOST EXPENSIVE COCONUTS OF MY LIFE The lighter side of geological fieldwork (a real incidence)

Dr. P. K. Sarkar Associate Prof. Department of Geology, Fergusson College, Pune

This is a true story which What has to be done in accompany me to the field. happened during one of my the field and We went to the field in Ph.D. fieldworks around How different type of the second week of March, Malvan in Sindhudurg district data has to be collected and 1983. The fieldwork was of Maharashtra, India. analyzed. proceeding well as accordance I registered for my Ph.D. I happily returned with to the plan. On the fifth day in Geology at the Depart- my guide back to Pune. we had to take the longest ment of Geology, University After a few days my traverse along a thickly of Pune in 1983. My research guide advised me to go to my vegetated area. We started was to work on the sedi- research area and proceed moving through the dense mentological aspects of the with my research work as vegetation collecting data and Kaladgi Supergroup of rocks, suggested, somewhere in the information. It was very hot which are also known as month of March, 1983. I said and humid on that day and the Konkan Kaladgis. After “Yes Sir”, however, a fear all our energy was getting everything was finalized, started developing within drained by intense sweating. the first field reconnaissance myself that, will it be possible We ultimately came to a spot survey was undertaken along for me to carry out this field- near a small stream, lined with my guide to delineate work alone! Climbing hills, with native vegetation and and formulate the traverses mountains, moving through several coconut trees. We for the fieldwork. Everything dense vegetation, valleys and were exhausted, thirsty, and went on well and I could learn what animals or reptiles I hungry. We thought of taking many new concepts and the would face that would come some rest for a while under a importance of geological map- my way. I was lucky as one of tree and proceed ahead later ping. It took us five to six days my classmates Mr. Ram Kit- for the fieldwork. There was to formulate turkar a.k.a. Ramya, agreed to absolutely no sign of any

49 CONGLOMERATE human settlement in the area. knife for making a hole in the asked her if she could give As we were resting, suddenly coconut. We both drank the us some water to drink. The an idea struck me and I said sweet water from the first two lady refused to even look at to Ramya, whether he would coconuts. us or hear out what we were like to have some coconuts as As I was about to cut the saying. After a while a young I knew how to climb a coconut remaining two coconuts, we boy came towards us from tree. I could read my friends got shocked and scared by the nowhere and started shouting face which expressed that, noise of people shouting and towards the direction from what I had said is not pos- running towards us. In the where we came. We later real- sible. Anyways, I had to do panic, we left the remaining ized that he was shouting to what I had committed to my coconuts behind and started the people who were hunting friend. I rolled-up my trousers running towards the stream. for us, telling them that the till my knees and started Unfortunately, there was lots persons they are looking for climbing up slowly and of water flowing in the stream. are in their house. In a short steadily. Somehow, I reached Ramya was even more terri- time all those who were look- the top of a tall coconut tree fied as he could not swim. I ing for us surrounded us. We unharmed. I started plucking asked him not to worry as I got terrified to see them and and throwing the coconuts would take him across. In the felt that we would be trashed one by one. Suddenly, I could panic we entered the stream and beaten up. It took lots of see a small village girl collect- and tried crossing in the flow. time to convince and explain ing wood in the nearby area. I It was about seven feet deep. them. Ultimately the matter was scared and I came down Somehow we crossed to the was settled by paying Rs.Two immediately. other side and started running hundred for the four coconuts. Now, the problem we without any orientation. There is a saying in faced was to cut four large We ran for our life for Hindi “Aasman se gire aur coconuts and drink its sweet about two to three kilome- khajur me atke”. It means that water without a knife. In ters and ultimately we saw someone already in problem such a situation one can use some houses. Exhausted gets more problems from the multipurpose Geological and tired we reached one somewhere. hammer. Hence, the chisel end of those houses. We saw an of the hammer became our old lady sitting in the sun. I

50 CONGLOMERATE The Telltale Fossil Wood of Sattanur, District Perambalur, Tamil Nadu Vidyadhar D. Borkar Visiting Faculty Member, Department Geology, Fergusson College, Pune

Pandit Jawahar Lal Nehru, the first Prime Minis- ter of independent India, was educated in England. He was a science student. Very few are aware of the fact today that the subjects he had opted for his graduation included Geology, Botany and Chemis- try. In 1928, when his daughter, Indira, was just a ten year old school student, went to Mussoorie during the summer holidays. At that juncture he wrote letters to her narrating interesting information from Natural History, Archaeology and Prehistory His friends and relatives suggested that these letters should be published in the form of a booklet. And so they were published. Name of that booklet is ‘Letters from a

51 CONGLOMERATE And then Nehru narrates existence was discerned in the how a pebble lying at some early years of the last cen- remote place can reveal its tury. There was an ocean in journey from a hillside slope between these two continents. through a small streamlet and Scientists called it the Tethys. then through a river. How Remaining surface of the earth erosion wore away its edges was covered by a vast ocean. and corners while it was being It occupied more than 50% of transported. How this ero- the earth’s surface. This was sion gave it a rounded shape, the original expanse of what ultimately polishing it. we know today as the In the same manner, I Pacific Ocean. have attempted to decipher the speechless narrative a In due course of time, huge fossil wood is trying to both the megacontinents convey. Length of this fossil were split into the constitu- wood is more than 18.0 m, ent segments. A chunk of the Father to his daughter’. I do while its girth is to the tune of Laurasia separated apart; and not know if the student read- 1.0 m. It occurs near Sattanur, drifted much to the west. We ers of this e-journal have read a remote village in the Peram- call it North America today. it. But I hope that they have balur District of Tamil Nadu, The remaining segment is at least heard of this lovely and is preserved in the rocks known today by the name and lively booklet. As Nehru deposited some hundred Eurasia. The mega-continent had learnt Geology during his million years ago. It is a rare, Gondwanaland was split into graduation, no wonder that he rewarding and fascinating five segments viz., Australia, writes in his very first letter: marvel of nature, worth con- Antarctica, South America, serving for posterity. There- Africa and Indian Peninsula. “There was a time when no fore, the Geological Survey of Each of these severed seg- kind of life existed on the earth. It India has established a small ments drifted variously to is difficult to imagine this world of national park at Sattanur occupy their present posi- ours, which is so full today of all All of us are well tions. The Indian Peninsula kinds of animals and men, to be versed with the hypothesis very gradually drifted to the without them.. You read history of continental drift, since we north. Finally it got attached in books. But in old times when learn it right from our school to the southern edge of Asiatic men did not exist, surely no books days. Hence we know that part of Eurasia. And now it is could have been written. But the distribution of oceans considered an integral part fortunately we have some things and continents has been of Asia. which tell us as well almost as a changing. Millions of years The Tethys Ocean was book would. We have rocks and ago there were only two receiving sediments from both mountains and seas and stars and megacontinents, one in the these continents for ages. As rivers and fossils of old animals. northern hemisphere and the These and other like things are our other in the southern. Name books for the earth’s early story. of continent in the northern Imagine how fascinating hemisphere is Laurasia, while it is. The real way to understand that in the southern is Gond- this story is not merely to read wanaland. Of course, there about it in other people’s book but was no human being at that to go to the great Book of Nature time, who would designate itself. You will, I hope, soon begin names to those megaconti- to learn how to read this story nents. These names were sug- from the rocks and mountains.” gested by scientists, after their

52 CONGLOMERATE segments of both the mega- encroachments of sea on the continents separated and neighbouring low lying land. drifted towards their destina- This phenomenon is called a tions, Tethys gradually started marine transgression, which narrowing down. The layers lasts for some million years. of sediments which had been The shallow marine seas accumulating for millions of formed due to such marine years were lifted up, thrown transgressions provide a site into gigantic folds and trans- for accumulation of sedi- formed into a lofty mountain ments. It also constitutes an chain. We call it today Alpine- environment extremely suit- Himalayan Mountain chain. able for marine organisms. But Obviously, this mountain such seas cease to exist one chain was not created over- day due to some geological night. It was sometime in the reason or the other. The region Cretaceous Period (120 million covered by marine waters years to 55 million years) that once again becomes a land, the first phase of Himalayan leaving behind sedimentary uplifting took place. When rocks and fossils of Indian Peninsula severed off marine organisms. from the adjacent segments, During the Cretaceous Arabian Sea and Bay of Bengal Period marine transgressions started taking shape. occurred in different parts largest of them being that All these geological of all the continents. One of occurring in the Perambalur activities must have caused the transgressions took place and Ariyalur Districts of reduction in the capacity of in parts of Tamil Nadu and Tamil Nadu oceans for quite some time. Pondicherry. Marine rocks It is a proven fact that when deposited during this geologi- capacity of oceans reduces, cal episode are today exposed there are temporary and local in four major patches, the

53 CONGLOMERATE the floral assemblage. growth of these huge cycads. There were, of course One very huge cycadean tree certain other non-flow- trunk had its destination near ering plants like ferns Sattanur, which was eventu- and bryophytes. In ally fossilized there. some of the sedimen- The Cretaceous Sea tary rocks, we do get receded in due course of time. excellently preserved The sediments deposited there fossils of these plants. were exposed and became The several plant part of land. All exposed lands species that flour- are subjected to the process ished on the hill of erosion. Erosion helped in slopes included huge exposing the huge fossil log cycadean trees. After to be finally noticed by geolo- the trees lived for gists. many years, we can Every outcrop, every imagine, were attacked rock, every mineral and by fungi and insect every fossil has a story to tell. Green colouredpatches are exposures pests. There must have Would you like to develop of marine Cretaceous rocks of Tamil been certain worms the skill of deciphering their Nadu and Pondicherry. One near Than- and arthropods which language? Believe me. It is javur is to the south of this map and were parasites on indeed very fascinating. hence not roots of the cycads. included here Cycadean trees then were getting uprooted. Acknowledgements: Ms A number of trees Amrita Paranjape, a Research therefore must have collapsed Student in the Geology and Pal- Very close to the on the slopes. Presumably, aeontology Department of the exposures of these marine numerous trees rolled down Agharkar Research Institute, has Cretaceous rocks, to their the slopes and were buried assisted in preparing illustrations west, occur steep hill slopes. in the marine sediments, and accompanying this article, Though these hill slopes are were thus deposited in the an eroded version of what temporary Cretaceous seas. they must have been during Many wood logs are found the Cretaceous, anybody can in a particular layer. It can guess that those hills were not be deduced that when this under marine waters then. particular layer was being Their height from the mean deposited, there was luxuriant sea level during Cretaceous must have prevented farther inward encroachment of the invading marine waters. .During the Creta- ceous period, when marine Steep slopes, very close to the transgression was rampant, exposures of Cretaceous rocks the hill slopes by the sea- in Perambalur District, to their shore supported flora which west. They were just by the side existed then. Those days of seashore 100 million years ago, gymnosperms (Cycadales supporting entirely different flora, and Coniferales) dominated which existed during Cretaceous.

54 CONGLOMERATE Hello my student friends of physical, optical, electri- of Geology…. Many of you cal and thermal properties must be aware of the glamour making it indispensible for its associated with the mesmer- various industrial uses and izing diamond jewellery applications in the anthropo- displayed in majestic show- logical world. Whenever you rooms of major cities of India; see diamond jewellery worn their impressive and haunting by anybody, just appreciate advertisements in leading the age of diamond in that magazines, newspapers, ornament. It will be anywhere television channels, at prime- between 1.0 to 3.33 billion locations on high ways and in years! All such jewellery pieces should be priceless for their antiquity……. You are in possession of that time of this beautiful planet’s- MOTHER FOR EARTH’s life preserved in that tiny faceted crystal of diamond. DIAMONDS These diamonds formed D beneath the old, cold and Dr. Tanuuja Marathe stable cratons at depths of Associate Professor, 120-150 km are brought up Department of Geology, on the earth’s surface via fast Fergusson College, Pune and forceful kimberlite or lamproite eruptions taking place along the deep-seated, mantle reaching, long-lived hotspot areas of main cities; fractures which develop on must have seen the photo- or near cratons. The stable graphs of cine artists, models, interior portions of continents, elite women from business characteristically composed of world and society wearing ancient crystalline basement beautifully crafted, enchanting rocks that have been stable and hypnotic diamond jewel- for over a billion years are lery. That is the dazzling side termed as cratons. Kimberlites of diamonds- a gemmy or gem are a group of volatile rich, quality diamond! dominantly CO2 rich, potas- Diamond is a mineral sic, ultrabasic rocks exhibiting made up only of carbon, it is a distinctive inequigranular a mineral found in the native texture. Kimberlitic magmas element form. It is formed formed at even greater depths under high temperature than those required for the (9000C to 12000C) and high formation of diamonds. Dur- pressure (60-80 kbar) condi- ing their upward journey tions existing at great depths while erupting, if kimber- below the earth’s surface, litic magma passed through slowly crystallized into a overlying diamondiferous covalently bonded, transpar- regions, then resulting kim- ent cubic crystal of carbon berlitic pipes became diamond having a unique combination bearing, else they remained

55 CONGLOMERATE 1 2 3

4 5 7 1. Kimberlite eruption and mining stages 2. Rough diamonds 3. Gem quality rough diamonds 4.Primary diamond deposit Weathering of kimberlite 5. Sieving of gravel in Tertiary diamond deposits 6.Names of facets in brilliantcut of diamond 7.Profile view of brilliant cut of diamonds 8.Cutting and polishing

6 igneous rocks which are rich is only 0.2gm. I think, this in incompatible elements. The should explain the cause of eruptions of kimberlites and high price of diamonds. lamproites have taken place There are many dia- in the various cratonic parts mond producing countries of the world during different on the world map today such geologic time since Palaeo- as South Africa, Botswana, proterozoic till Recent. Only Angola, Namibia, Congo, 15% of such eruptions are Ghana, Lesotho, Sierra Leone, diamondiferous i.e. diamond Russia, Australia, Canada, bearing. Moreover, not all China and others. Several diamondiferous kimberlites or global mining giants such as lamproites are economically De Beers, Rio Tinto, Alrosa, 8 viable for undertaking dia- BHP Billiton, Petra Diamonds, mond mining activities. Also, Gem non-diamondiferous. They for obtaining one carat gem Diamonds, Debswana etc are are named after town Kim- quality diamond nearly 250 busy mining the precious berley in South Africa where tons of kimberlite or lamproite treasure of the earth either first occurrence of kimberlite needs to be unearthed. Rough via open cast mining or via was detected. Lamproites are diamonds further need to be underground mining. Prior mantle derived ultrapotassic, cut and polished before being to modern methods of min- mafic volcanic and hypabyssal set in jewellery. One carat ing, age-old alluvial mining

56 CONGLOMERATE 1. Kohinoor 2. Hope Diamond 3. Regent Diamond

4. Darya-i-Noor 5. Dresden green Diamond 6. Shah Diamond methods (which involves loose gravels, from beaches diamonds are cut and pol- digging, sieving and sifting are termed as tertiary dia- ished they are ready to be for collection of gemstones mond deposits. set in various metals such as from mud, sand and gravel At mines, rough dia- gold, silver, gold of different in the stream/river deposits) monds after separation are colours such as white, pink, were applied in the palaeo sorted as per their crystal red, green, violet, blue, grey and present river channels forms, clarity, colour and etc and in platinum with draining the diamondifer- weight. Then they are auc- mind alluring designs. This is ous areas and also along the tioned to the site holders who a mine to market journey of beaches. Diamonds mined are mainly in the business diamonds. from Kimberlite or lamproite of diamond manufacturing Since times immemo- pipes by open cast or under- (cutting and polishing of rial, India has been the only ground mining method is diamonds). diamond producing country known as primary diamond Diamond mines which in the world till the discovery deposit. Those mined from are operated by De Beers of diamonds in Brazil (1725) conglomarates, where in they have a subsidiary known as and South Africa (1867). Many are eroded from source rocks Diamond Trading Company, famous legendary diamonds, and deposited in congloma- which looks after the sales of that too differently coloured rates are termed as secondary their produce i.e. rough dia- with remarkable sizes have deposits and those mined monds. been produced from old from river channels, from After the rough mines of south India falling in

57 CONGLOMERATE region then known as Rayal- Kremlin, Moscow) and many The only working mine of dia- seema. During British rule, others such as Nassak, Orlov, monds is at Majhgawan, Pan- these mines were under Brit- Sancy, Agra, Great Mughal na, Madhya Pradesh. How- ish company- Golkonda Dia- etc. Diamond, considered as ever, there are three distinct mond Mining Co. Hence the symbol of power, courage and diamond producing regions two terms –Indian diamonds virility, till fifteenth century in India where diamonds have and Golkonda remained was worn mostly by Rulers been found. Roughly they are inseparable for a long period. and military men. Possession known as southern region, The famous legendary dia- of such invaluable gems was eastern region and northern monds are Kohinoor ( colour- always a matter of pride and region. Southern region less, 105.6 carats, oval brilliant prestige and many a wars includes parts of Krishna, cut, at present in Tower of were fought for them; frauds, Anantpur, Cuddapah, London), Hope (blue, 45.52 murders and treacheries were Kurnool, Mehboobnagar, carats, cushion shaped bril- not uncommon. These stones West Godavari and Guntur liant cut, now in Smithsonian exchanged several hands, districts. Earlier this area Institution, Washington D.C.), travelled many continents for formed state of Golkonda. It Regent diamond (140.50 many centuries. Today, we includes the region drained carats, blue tint, cushion find them silently resting at by Godavari, Krishna and shaped brilliant cut, cur- their terminuses. There are Pennar rivers. Eastern region rently in Louvre Museum, fascinating stories associated comprises of area spread Paris), Darya-i-noor( approx. with many of them….. stories from Chhotanagpur plateau 185 carats, pale pink, table in Ranchi district, Jharkhand; cut, now in National Jewels next time…. parts of kalahandi, Boudh and Museum, Tehran), Dresden Today, India is seen Sambalpur districts in Odisha, Green (40.70 carats, apple prominently on Diamond parts between Mahanadi and green, pear shaped brilliant Map of the world, but for Godawari rivers and Mainpur cut, at present in Albertinium manufacturing of diamonds, Kimberlite Field of Raipur dis- Museum, Dresden,Germany), closely chased by Israel and trict, Chhattisgarh. Northern Shah (88.70 carats, pale yel- China; and not as prominent region mainly comprises of low, uncut, nowadays in diamond producing country. ENE-WSW stretching belt in Madhya Pradesh near Panna.

Majhgawan Diamond Mine, Panna, Madhya Pradesh, An open cast mine

58 CONGLOMERATE Diamond mines here are laid across on an area of 80 km belt, starting from the Pahari- khera in North-East to Majh- gawan to South-West with breadth of around 30 kms. At Majhgawan, lamproite is hosting diamonds which are mined by NMDC(Nationa Mineral Development Cor- poration). It is an open cast mine. Diamonds are also mined from conglomerates of Vindhyan Supregroup and from loose gravels in the neighbouring areas. T.Y.B.Sc. Satellite picture of Majhgawan Geology students of the year diamond mine, Panna 2004-05 batch were fortunate enough to visit Majhgawan Diamond mine in Decem- ber,2004 and observe all the stages of mining right from ore extraction, prosessing plants for crushing and mill- ing to various rough diamond separation techniques such as washing, screening, heavy media separator, Grease belt and X-ray separator to tai- lends disposal. Recently, new diamond deposit has been found in northern region i.e. in Bundelkhand region, to south- west of Majhgawan mine. It Satellite picture of Bunder was discovered in 2004 by Project. M indicates location of Rio Tinto and is known as Majhgawan. Bunder Project. It is a seven times richer deposit than References: Majhgawan and is proposed Maillard Robert (1980) : Diamonds- Myth, Magic and Reality,. Editor– to be operational in 2016. That in–Chief, Crown Publishers, Inc., New York, 287p. definitely will bring India on Marathe Tanuuja (2005) : Global Occurrences of Primary Host Rocks of world map once again as an Diamonds, Indian Gemmologist, Vol.XIII, No. 1-2, pp 50-53. important diamond producing Marathe Tanuja Santosh (2004): Geological Studies of Diamond and country as well…………. other Gemstones of Raipur District of Chhattisgarh by integrated Clas- sical and Remote Sensing Methods, Unpublished Ph.D. Thesis, Bar- katullah University, Bhopal. Internet Google Earth

59 CONGLOMERATE Causative Factors of Malin Landslide Pune District, Maharashtra Prof.S.S.Thigale Symbiosis International University

Introduction information on physical set disposed basaltic flows, till The landslide event at up of the mountains chain, 1967. A belief that the entire Malin village in Pune district causative factors, symptoms Deccan plateau is safe from on the morning of 30th July, and mechanism of landslides seismicity was shattered after 2014 was the most disastrous drawn after studying Konkan Koyna earthquake of Decem- one, in the landslide history landslide episode of 1983 ber, 1967. Since then the area of western mountain chain (Thigale, 1989), Maval land- is experiencing tremors of (popularly known as Sahya- slide episode of 1989 (Thigale, varying magnitudes, their epi- dri) of Maharashtra. This is so 1989), Satara and Thane land- centres being mostly shallow not only because it has killed slide episode of 1993 (Thigale, and confined mainly around 151 people but also because an 1995; Thigale et al, 1996; Koyna, Bhatsa and Chandoli. entire village vanished from Thigale and Khandge, 2000, A perusal of data of the map of India. 2004), Mahad episode of 2005 Konkan landslide episode of A literature review (Thigale and Umrikar, 2007, 1983 (Thigale, 1989) revealed indicates that fairly compre- Thigale, 2009) and Patan- that huge cracks were devel- hensive literature is available Mahabaleshwar episode of oped on slopes at many places on the landslide episodes 2006 (G. S. D. A., 2006). during Koyna earthquake. A and events that occurred in number of ephemeral springs the western mountain chain Background Information: were developed at the base of of Maharashtra. It is in the these cracks during monsoon. form of reports, publications Evidences collected The data also revealed slow and Ph.D. thesis, and mainly during episodes and events creeping along the cracks. It is includes work carried out in mentioned above indicate that interesting to note that major- the Department of Geology, problem of land sliding was ity of landslides occurred University of Pune (now not so intense in the western precisely along these cracks Savitribai Phule Pune Uni- mountain chain, which is during incessant rains. Land- versity) since 1983. It covers constituted of horizontally slide episodes and events

60 CONGLOMERATE which occurred in 1993, 2005 order streams and 2006 indicate that the which meet process of developing and the south- widening cracks, gradual westerly creeping and ultimate trigger- main stream. ing during incessant rains is This stream still on all along the mountain is mapped chain (Thigale and Umrikar, as fractured 2007; Thigale, 2009). controlled on the sat- The data also suggests ellite-based that the areal extent of land- groundwater Wide view of main scarp and crown slide-prone zones and severity potential map are on the rise. It is mainly prepared by MRSAC, Nagpur. which continue to yield water because of metamorphosis of The village was located on up to January/February every slopes due to anthropogenic moderate slope backed by year. Water table and land activities all along and across steep one as evident from the intersection points naturally the western mountain chain. toposheet. should lie along the banks of These activities are housing, Geological map of Malin the streams. But in mountain- terracing, trenching, defores- prepared by MRSAC using ous terrain they even lie up tation, transportation routes, data of Geological Survey of slope due to human induced quarrying and change in India shows five horizontally modifications such as con- agricultural practices. Such disposed basaltic flows of struction of transportation human induced changes are vesicular, mixed and massive routes or levelling of slopes. responsible for shifting slopes type. These flows are covered It was noted two such springs from equilibrium to in-equi- by moderate to thick soil layer were aligned along the road librium state. (0.5 to 2.5 m) which grades passing through the Malin downward into weathered to village. Malin Event: moderately jointed basalt and There is no seismic then hard basalt. Outcrops of history for Dimbhe reservoir. Physical Setup: The fresh rock are intermittently Structured interviews of observations made dur- seen on the surface of the inhabitants, however, revealed ing field investigations and spurs. The banks of fracture- that the region experienced evidences collected through controlled streams are consti- the shaking of ground after structured interviews of tuted of valley fill material. Koyna and Latur earthquakes stakeholders including The area receives heavy in the year 1967 and 1993 affected inhabitants, school rainfall of the order of over respectively. teachers, local NGO and Chief 3700 mm annually. It is com- of National Disaster Reduc- monly observed that upper Human-induced tion Force involved in Malin soil and weathered portion, changes: Google Earth image rescue operation on 22nd and being porous and permeable, of Malin (19.61°, 73. 69°) 23rd September, 2014 about permit rainwater to infiltrate of February, 2014 (http:// Malin landslide (Toposheet and percolate up to the inter- blog.agu.org/landslide- No.47E/12) are outlined face of pervious and impervi- blog/2014/07/31/malin-land- below: ous bed rock. The base flow slide) shows the clustering of so developed travels laterally houses on hill slope and other Malin village was located down slope and emerges out man-made changes, terracing on the spur portion, at an ele- in the form of springs where for paddy cultivation being vation approximately between water table intersects with dominant along the streams 730 m and 780 m, between two land surface. These springs and upland slope of the vil- south-easterly flowing lower are essentially ephemeral lage. It is worth mentioning

61 CONGLOMERATE here that terracing for paddy Survey of India. Dimbhe and structured interviews, it cultivation has been a tradi- dam is constructed on river can be inferred that steep to tional practice all along the Ghod which is considered to moderate slope, adverse geo- streams in western mountain be fractured controlled and logical and tectonic settings, chain. Apart from terracing shows evidences of uplifting and excessive rainfall are and housing other changes (Powar, 1993; Radhakrishna, natural, and metamorphosis made on the slope include 1993; Valdiya, 2001; Peshwa of slope due to housing, ter- i) cutting the trench close to and Kale, 1997; Kale and racing, trenching, were human the row of houses located in Shejwalkar, 2008). Higher induced causes responsible the upper reach for diverting order streams contributing for bringing slope under water in the paddy fields, ii) to the river are also fractured geologic threshold. Signatures levelling of slope for bringing controlled. The village Malin of instability of slope such as more land under paddy culti- is located on one such stream cracks to the walls of houses vation upland, and iii) cutting flowing in southerly direction and ground, and oozing of of trees during levelling. and meeting the main stream groundwater in houses at least Inhabitants were expe- flowing in south-east direction a decade before the calamity riencing oozing of water in a and ultimately emptying its were adequate to support this few houses particularly those water in Ghod river. Thigale fact. Incessant rains during close to the southern part of and Umrikar (2007) while the event ensured percolation the scar. The yield of water investigating the Mahad of large quantity of rainwater during excessive rains used to landslide episode observed in already shattered pervious be so high that pipes were laid that seismicity of the region surfaces which helped increas- to remove it. appears to be responsible for ing weight of the slope by Toe of the slide is located developing fissures parallel to displacing air and increasing along the road which was N-W to NNW-SSE trending pore-water pressure. The con- washed out in the landslide. streams on the slopes along dition conducive for ultimate The springs at lower reaches which majority of landslides triggering was developed dur- are mostly ephemeral in occurred. Although there is no ing incessant rains from 28th nature which yield water up convincing evidence of devel- to 30th July as a consequence to February/March. opment of cracks on slopes huge mass of debris collapsed during the Koyna and Latur making rumbling noise. Discussion: earthquakes, the tectonic set- ting is conducive to develop The area under inves- them. tigation falls in Zone III of From all the evidences seismic map (moderate inten- collected through previous lit- sity) prepared by Geological erature, maps, field evidences

Crown Cracks Crown

62 CONGLOMERATE Debris of earlier landslides from the area View of the Malin Landslide Sight

References: India, Abst. Internat. Geo. Con- AS (2000) Landslides in the Groundwater Survey and gress, Washington, 3:232-233. Western Ghats of Maharashtra, Development Agency (2006). In: Pathan, A.M. and Thigale, S.S. Expert Committee’s Report on Thigale, S.S. (1989) Pre- (Eds) Contributions To Environ- Landslide Episode of July 2006 in liminary Geotechnical report mental Geoscience, Arvalli Books Satara District, p.32. on Landslide Episode of Maval International, New Delhi, pp Kale Vishwas and She- Taluka, Pune District, Maharash- 161-174. jwalkar Nikhil (2008), Uplift tra, report submitted to Govern- along the western margin of the ment of Maharashtra, p 12. Thigale S.S. and Khandge Deccan Basalt Province: Is there A.S. (2004). Coping with land- any geomorphometric evidence?, Thigale, S S (1995) A review slide disasters in western ghats. Jour. Earth Syst. Sci.117 (6), of landslides along the Western In: Coping with Natural Hazards December 2008, pp. 959–971, Ghats of Maharashtra, In: Proc. (Eds Valdiya K.S. and Kale V.S.), retrieved from, http://www.ias. National Seminar on Landslides Orient Longman, Hyderabad, pp ac.in/jess/dec2008/jess57.pdf in Western Ghats, CESS, 269-315. Trivandrum, pp 248-251. Thigale S.S. and Umrikar Peshwa, V. V. and Kale, V. S. Bhavana (2007) Disastrous Land- 1997. Neotectonics of the Dec- Thigale, S S and Khandge, slide episode of July, 2005 in the can Trap Province: focus on the AS (1996) Generation of data- Konkan Plain of Maharashtra, Kurduwadi lineament. Jour. of base for preparation of Landslide India with special reference to Geophysics, 18(1): 77-86 Hazard Zonation map of the tectonic control and hydrother- Western Ghats of Maharashtra, mal Anomaly, Current science, Powar, K.B. (1993) Geomor- India, Geoinformatics, 7 (1-2): Vol. 92 (3), pp 383-386. phic Evolution of Konkan Coastal 61-68. Belt and adjoining Sahyadri Thigale, S S (2009) Report Uplands with reference to qua- Thigale S.S., Khandge on Geological Investigations in ternary uplift, Current Science, A.S., Thigale M., Bhokare M. the Landslide Affected Villages Vol. 64, pp 793-796. Afor Landslides and Sawarkar in Mahad Taluka, Raigad District, A. (1998). Causative Factors as Maharashtra Radhakrishna B.P. (1993) Applicable to GIS: A Case study Neogene uplift and geomorphic of western mountain chain of Dr. Dave (2014) retrieved rejuvenation of the Indian Penin- Maharashtra. In: Proceedings from http:// blog.agu.org/ sula. Current Science, Vol. 64, pp International Symposium on landslideblog/2014/07/31/malin- 787-793. Application of RS-GIS to Disaster landslide Thigale, S S (1989) Process- Reduction, Geol. Survey Japan, es conducive for slope failure in Tsukuba, pp 197-213. Western Ghats of Maharashtra, Thigale, S S and Khandge,

63 CONGLOMERATE ROLLING STONES

History of the Universe Part 3- Formation of the earth

Earths formation was turbulent and spectacular. Begin- ning in the Hadean Era, early Earth had lots of frightening scenes with Mars sized collisions, humongous meteors and a surface completely filled with boiling magma.

Inside the Earth

The Earth’s interior is composed of four layers, three solid and one liquid—not magma but molten metal, nearly as hot as the surface of the sun.The deepest layer is a solid iron ball, about 1,500 miles (2,400 kilometers) in diameter. Although this inner core is white hot, the pressure is so high the iron cannot melt. The iron isn’t pure—scientists believe it contains sulfur and nickel, plus smaller amounts of other elements. Estimates of its temperature vary, but it is probably somewhere between 9,000 and 13,000 degrees Fahrenheit (5,000 and 7,000 degrees Celsius). Above the inner core is the outer core, a shell of liquid iron. This layer is cooler but still very hot, perhaps 7,200 to 9,000 degrees Fahrenheit (4,000 to 5,000 degrees Celsius). It too is composed mostly of iron, plus substantial amounts of sulfur and nickel. It creates the Earth’s magnetic field and is about 1,400 miles (2,300 kilometers) thick.

64 CONGLOMERATE The Planet that smashed into the Earth

That old theory that the Moon was formed out of fragments of Earth blasted into space after a massive planetary collision 4.5 billion years ago has gained support from two new studies. Boffins have tried to figure out exactly how a giant impact in our solar system made the Moon. Previous theories have suggested that the celestial body could have been made from pieces of the mysterious planet that crashed into Earth, but recent studies showing that Earth and the Moon have the same isotopic composition pour water on that idea.

Earth’s Interior and Plate Tectonics

Animated Earth and its interior layers. Description of plate tectonics and tectonic boundaries.

65 CONGLOMERATE View of Fingal’s cave from outside Where giants walked…. Chinmay Thite Department of Geology

Geomythology is very interesting and explanation, and that which is the garbled new branch of geology which is lesser known. explanation of some actual geologic event, It is the study of alleged references to geologi- usually a natural catastrophe’.” cal events in mythology. The term was coined Vitaliano (1973) in 1968 by Dorothy Vitaliano, a geologist at Oral traditions about nature are often Indiana University. expressed in mythological language and may “Geomythology indicates every case in contain genuine and perceptive natural knowl- which the origin of myths and legends can edge based on careful observation of physical be shown to contain references to geological evidence about the geological events that phenomena and aspects, in a broad sense have taken place in the past. Before the birth including astronomical ones (comets, eclipses, of the modern science in last 400 or so years meteor impacts, etc.).’Primarily, there are two the events or other scientific things commonly kinds of geologic folklore, that in which some known to us now were given explanations geologic feature or the occurrence of some with the help of myths and stories, which may geologic phenomenon has inspired a folklore have been about the gods and demons and

66 CONGLOMERATE View of Giants Causeway and Google map of Giant’s causeway and Isle of Staffa

giants etc. Geomythology alleges to provide shout insults and hurl abuse from across the valuable information about past from these channel. In anger Finn lifted a clod of earth myths about the past events like earthquakes, and threw it at Benandonnar as a challenge, tsunamis, floods, impact events, fossil discov- the earth landed in the sea. eries, and other events, which are otherwise scientifically unknown or difficult to trace. Benandonnar retaliated with a rock In August 2004, the 32nd International thrown back at Finn and shouted that Finn Geological Congress held a session on “Myth was lucky that he wasn’t a strong swimmer or and Geology”, which resulted in the first peer- he would have made sure he could never fight reviewed collection of papers on the subject. again. View of Fingal’s cave from outside Here I have attempted to discuss one of the popular examples related to it. Finn was enraged and began lifting huge Recently I had an opportunity to visit one clumps of earth from the shore, throwing them of the most popular tourist destination associ- so as to make a pathway for the Benandonnar, ated with geology – The Giant’s Causeway Scottish giant to come and face him. However in Northern Ireand UK and its lesser famous by the time he finished making the crossing counterpart from Scotland called as Fingel’s he had not slept for a week and so instead Cave belonging to a very small island called as devised a cunning plan to fool the Scot. Isle of Staffa . It is a strange rock formation that has a spellbinding effect on the multitude of Finn disguised himself as a baby in a tourists that arrive by the busload. The striking cot and when Benandonnar came to face him and at times, like the day of our visit when the Finn’s wife Una told the Giant Benandon- mist hung low over the shore, eerie perfection nar, that Finn was away but showed him his of the precise geometric columns has led many son sleeping in the cradle. The Scottish giant a traveler to believe that it must have been cre- became apprehensive, for if the son was so ated by human or supernatural forces. There huge, what size would the father be? are many myths and legends surrounding the origin of such a mysterious feature, the most In his haste to escape Benandonnar sped prominent of them being the Legend of Finn. back along the causeway Finn had built, tear- ing it up as he went. He is said to have fled to The Legend of Finn McCool. a cave on Staffa which is to this day named ‘Fingal’s Cave’. “Finn McCool (Fionn mac Cumhail) an Irish Giant lived on an Antrim headland and Other versions of the legend include Finn one day when going about his daily business throwing a huge piece of earth which then a Scottish Giant named Benandonnar began to became the Isle Of Man and the hole which it

67 CONGLOMERATE Columns at Giant Causeway

left behind became Lough Neagh. phenomenon that occurs when the pressure of It is told that Finn was building a Cause- overlying material is reduced. Buried mantle way pathway to Scotland using the hexagonal rocks, under less pressure, will melt and rise rocks, much to the upset of Benandonnar. A to the surface where they either erupt or cool battle ensued. To this day, there remain hex- within the crust. In the case of the Giant’s agonal rocks for all to see at the Isle of Staffa, Causeway basalts, the magma was formed by however, the main breathtaking formations decompression melting of the mantle beneath are situated at the Giant’s Causeway, World the Rathlin trough, a sedimentary basin that Heritage Site, with over 38,000 basalt columns extends from the Antrim to Islay, an island off on display.- “ The Natiomal Trust U.K.” the south coast of Scotland (McCann). The physical properties of columns are Was The Giant’s Causeway actually due to the manner in which cooling occurred. formed by a giant trying to cross the Irish Sea? After magma erupts to the surface it is known Unfortunately, (or maybe fortunately because as lava. As lava cools, it expels dissolved gases, just imagine a world with angry giant’s run- contracts, and solidifies, all of which decrease ning amuck) no. The Giant’s Causeway is its overall volume. In order to accommodate actually a volcanic feature known as columnar the volume loss, the rock begins to crack and basalt. form what are known as joints. Under ideal The columns at the Causeway are a type conditions, joints will form at 120 degrees to of rock called basalt, a mafic igneous rock one another in basalt, creating the hexago- that is made up of the minerals clinopyroxene nal pattern you can see from the top of the and plagioclase. The term mafic describes its columns. However, when walking along the chemical composition and means that it is rich top of the columns you may notice that some in iron and magnesium. Igneous simply means can be five, seven, eight, or even nine sided. that it was formed from molten rock: magma. This is just an example of the imperfections in It is extrusive – it cools at the surface unlike nature. As further cooling ensues, the cracks granite, an intrusive igneous rock, which cools will propagate downward creating vertical in the crust below the surface of the earth– and columns known as columnar jointing. When forms when magma rises from the mantle, this pattern forms in basalt, it is known as erupts onto the surface, cools and becomes columnar basalt. solid rock. Tomkeieff was the first to describe the Magma can be formed by three main Giant’s Causeway basalts as tholeiitic, a term processes: decreasing pressure, increasing used to describe the composition of the mag- temperature, or changing chemical composi- ma. A tholeiitic magma is enriched in iron and tion. Decompression melting is a geologic depleted of magnesium which preferentially

68 CONGLOMERATE crystallizes out of the cooling magma. Geo- Staffa, an entirely volcanic island, is prob- chemical and petrographic analysis of the ably best known for its unique geological fea- basalts led researches to conclude that they tures such as the many caves and the unique were formed by sheet flows contained within shape of the basalt columns which are also the margins of a fault basin (Lyle and Preston). found in the Giant’s Causeway and Rathlin island in Northern Ireland and closer by on the Staffa - A Geological Marvel island of Ulva. It consists of a basement of tuff, underneath colonnades of a black fine-grained Staffa is one of the smallest islands in the Tertiary basalt, overlying which is a third layer Southern Hebrides, located south-west off the of basaltic lava lacking a crystalline structure. isle of Ulva and halfway between the Ross of By contrast, slow cooling of the second layer Mull and the Treshnish Isles. The Vikings gave of basalt resulted in an extraordinary pattern it this name as its columnar basalt reminded of predominantly hexagonal columns which them of their houses, which were built from form the faces and walls of the principal caves. vertically placed tree-logs. Island is very small The lava contracted towards each of a series with only 33 hectares, was once inhabited in of equally spaced centres as it cooled and the 1700s by as much as 16 people but nowa- solidified into prismatic columns. The columns days seabirds and tourists have taken over typically have three to eight sides, six being their place. The 1700s were also the time that most common. Staffa was part of the Ulva Estate but it was The island is not historically important sold in 1777 and via several owners it was but is a wonderful geological marvel and is donated to the National Trust of Scotland by often visited by the tourists who are looking Jock Elliott from New York in 1986. Staffa is for the new experience and geology now a Site of Special Scientific Interest. enthusiasts.

Refernces- www.wikipedia.org http://www.southernhebrides.com/staffa.html geomythology.wordpress.com

View of Fingal’s cave from inside

69 CONGLOMERATE ROCKY TIMES

70 CONGLOMERATE 71 CONGLOMERATE 72 CONGLOMERATE Flash Stones Field photographs of Kaldagi Supergroup around the Bagalkot- Badami Area of Karnataka Aishwarya Chandekar T.Y.B.Sc.

Folded BHQ of Dharwar Super- group at Bagalkot Anticline

Closepet Granite with MME at Bilgi

Basal Conglomerate of Kaladgi Supergroup (Salgundi conglomerate)

Saundatti Quartzite at Bilgi

73 CONGLOMERATE A B

C D A) Ball and Pillow structure B) Load cast C) Calcite filling in fault planes D) Flame Structure in Chikshelikeri Limestone at Gaddankeri Cross

Jallikatti Phyllites at Gaddankeri Cross Parasitic folding in Chikshelikeri limestones near Lokapur

74 CONGLOMERATE Stromatolitic Limestone at Petlur

Petlur Limestone at Petlur

Bevinmatti Conglomerate Gaddankeri Cross Muchkundi Quartzite Gaddankeri Cross

Govindkoppa Argillite at Gaddankeri Cross Niralkeri chert Breccia at Gaddankeri Cross

75 CONGLOMERATE Cave tample arenite at Badami Caves

Lithostratigraphic Classification of Kaladgi Supergroup by Jayprakash et al. (1987)

76 CONGLOMERATE