SubjectDurationMaximum Marks
Paper – I: General Studies2 Hours100 Marks
Paper-II: Geology / Hydrogeology2 Hours300 Marks
 Total400 Marks


Plan of Examination

The UPSC-GSI Preliminary Examination is according to the plan as follows:

#1 Stage – I: Combined Geo-Scientist – Preliminary Examination (MCQ Type Papers) for the selection of candidates to write the examination of Stage-II.

#2 Stage – II: Combined Geo-Scientist (Main) Examination (Subjective Question type Papers).

#3 Stage – III: Personality Test / Interview

Marking Structure

The marking structure of the exam is as follows:

#1 Stage – I: 400 Marks (100 + 300)

#2 Stage – II: 600 Marks (200 + 200 + 200)

#3 Stage – III: 200 Marks 

Combined Geo-Scientist (Preliminary) Examination Syllabus:

Paper-I in Stage-I General Studies is common to all streams, and its standard will be comparable to that of a graduate in science. Paper-II of Stage-I (Stream specific) and three required papers of Stage-II on Geology and Hydrogeology subjects will be roughly of the M.Sc. degree standard of an Indian university, with questions intended to assess the candidate’s understanding of the basics in each field.

1. Paper – I: General Studies (Common Exam)

#1 Current events of national and international importance.

#2 History of India and Indian National Movement.

#3 Indian and World Geography -Physical, Social, Economic Geography of India and the World.

#4 Indian Polity and Governance -Constitution, Political System, Panchayati Raj, Public Policy, Rights Issues, etc.

#5 Economic and Social Development – Sustainable Development, Poverty, Inclusion, Demographics, Social Sector initiatives, etc.

#6 General issues on Environmental Ecology, Biodiversity and Climate Change – that do not require subject specialisation.

#7 General Science. 

It is advisable to read NCERT Textbooks up to class 12 for all subjects in order to get a grasp of all subjects. Additionally, Current Affairs is an important constituent of the Paper – I and can be covered by following news and updates of about 10-11 months prior to the exam. Monthly magazines and newspapers can be followed for the same.

2. Paper-II: Geology/Hydrogeology

This includes the subjects studied during the bachelor’s and masters in Earth Sciences and equivalent fields.

#1 Physical Geology: Principle of uniformitarianism; origin, differentiation and internal structure of the Earth; origin of the atmosphere; earthquakes and volcanoes; continental drift, sea-floor spreading, isostasy, orogeny, and plate tectonics; geological action of rivers, wind, glaciers, waves; erosional and depositional landforms; weathering processes and products.

#2 Structural Geology: Stress, strain, and rheological properties of rocks; planar and linear structures; classification of folds and faults; Mohr’s circle and criteria for failure of rocks; ductile and brittle shear in rocks; study of toposheets, V-rules and outcrop patterns; stereographic projections of structural elements.

#3 Mineralogy: Elements of symmetry, notations, and indices; Bravais lattices; chemical classification of minerals; isomorphism, polymorphism, solid solution and exsolution; silicate structures; physical and optical properties of common rock-forming minerals- olivine, garnet, pyroxene, amphibole, mica, feldspar, and quartz.

#4 Igneous Petrology: Magma types and their evolution; IUGS classification of igneous rocks; forms, structures and textures of igneous rocks; applications of binary and ternary phase diagrams in petrogenesis; magmatic differentiation and assimilation; petrogenesis of granites, basalts, komatiites and alkaline rocks (carbonatite, kimberlite, lamprophyre and nepheline syenite).

#5 Metamorphic Petrology: Limits, types, and controls of metamorphism; metamorphic structures- slate, schist and gneiss; metamorphic textures- pre, syn and post tectonic porphyroblasts; concept of metamorphic zone, isograd and facies; geothermal gradients, facies series and plate tectonics.

#6 Sedimentology: Origin of sediments; sedimentary textures, grain-size scale; primary sedimentary structures; classification of sandstone and carbonate rocks; siliciclastic depositional environments and sedimentary facies; diagenesis of carbonate sediments.

#7 Paleontology: Fossils and processes of fossilization; concept of species and binomial nomenclature; morphology and classification of invertebrates (Trilobites, Brachiopods, Lamellibranchs, Gastropods and Cephalopods); evolution in Equidae and Hominidae; microfossils-Foraminifera, Ostracoda; Gondwana flora.

#8 Stratigraphy: Law of superposition; stratigraphic nomenclature- lithostratigraphy, biostratigraphy and chronostratigraphy; Archaean cratonic nuclei of Peninsular India (Dharwar, Singhbhum, and Aravalli cratons); Proterozoic mobile belts (Central Indian Tectonic Zone, Aravalli-Delhi and the Eastern Ghats); Purana sedimentary basins (Cuddapah and Vindhyan); Phanerozoic stratigraphy of IndiaSpiti, Kashmir, Damodar valley, Kutch, Trichinopoly, Siwaliks and Indo-Gangetic alluvium.

#9 Economic Geology: Properties of mineral deposits- form, mineral assemblage, texture, rock-ore association and relationship; magmatic, sedimentary, metamorphic, hydrothermal, supergene, and weathering related processes of ore formation; processes of formation of coal, and petroleum; distribution and geological characteristics of major mineral and hydrocarbon deposits of India.

#10 Hydrogeology: Groundwater occurrence and aquifer characteristics, porosity, permeability, hydraulic conductivity, transmissivity; Darcy’s Law in homogenous and heterogeneous media; Bernoulli equation, Reynold’s number; composition of groundwater; application of H and O isotopes in groundwater studies; artificial recharge of groundwater.

Breakdown of Stage – I:

The Paper – I of General Studies is as important as any other section of the exam. The candidates must secure a minimum score in Paper – I and only then the Paper-II of the Preliminary Examination is evaluated. Therefore, due importance must be given to Paper – I. However, since it comprises 100 marks only, a fine balance must be maintained.

Paper-II is a scoring aspect of the whole examination as a good score here doesn’t only mean qualification for Stage – II, but also ensures a good rank. 

This is because the marks obtained in Stage – II (both Paper – I and Paper – II) are added to the final score. 

Tips to prepare for the Examination:

#1: Know when to start the preparation

You need approximately a year for the preparation of the UPSC GSI Examination. It is advisable to start with the subjects that overlap in the Mains and Preliminary Examinations. Dedicated preparation for the Paper – I (General Studies) should ideally start about 4 months prior to the Preliminary Examination.

#2: Have a plan

You should definitely have a plan and a timetable in order to complete the syllabus at least twice for the examination.

#3: Not just facts

There is a myth that geology is all about facts. The UPSC – GSI Examination tests the conceptual knowledge of the candidates and their ability to think and act fast and evaluates their speed of thought since you have to answer 120 questions in 2 hours (about a minute for each question).

#4: Current Affairs

Current Affairs are the most important parameter of Paper – I and must be studied regularly by reading newspapers and magazines and following news.

#5: Practice mock test

No examination preparation is complete without practicing mock tests. The preliminary examination is about solving questions quickly. Only practice and getting familiarized with the questions can help you achieve that speed and accuracy.