The UPSC Combined Geo-Scientist Examination (GSI) 2026 is a national-level recruitment exam conducted by the Union Public Service Commission (UPSC) to recruit Geologists, Geophysicists, Chemists, and Junior Hydrogeologists for the Geological Survey of India (GSI) and Central Ground Water Board (CGWB).

It is one of India’s most prestigious scientific recruitment exams, consisting of Prelims, Mains, and Personality Test. Candidates with strong academic backgrounds in Geology, Chemistry, Physics, Environmental Science, Hydrology, and related fields often appear for this exam.

Official Website (for notifications & PDFs):
🔗 https://upsc.gov.in

🧭 2. UPSC Combined Geo-Scientist 2026 – Selection Process

The selection process consists of three stages:

Preliminary Examination (Objective) – Screening Test
Main Examination (Descriptive)
Personality Test (Interview)

Final merit is based on Mains + Interview marks only.

📝 3. UPSC Geo-Scientist Exam Pattern 2026 (Updated)

3.1 Prelims Exam Pattern (Objective) – Screening Stage

Mode: Online (CBT)
Type: Objective (MCQs)
Negative Marking: 1/3rd for each wrong answer
Qualifying nature only

Prelims Exam Pattern Table

Post	Paper	Subject	Marks	Duration
Geologist / Junior Hydrogeologist	Paper-I	General Studies	100	2 hrs
	Paper-II	Geology / Hydrogeology	300	2 hrs
Geophysicist / Chemist	Paper-I	General Studies	100	2 hrs
	Paper-II	Geophysics / Chemistry	300	2 hrs

3.2 Mains Exam Pattern (Descriptive)

Post	Paper	Subject	Marks	Duration
Geologist	Paper-I	Geology	200	3 hrs
	Paper-II	Geology	200	3 hrs
	Paper-III	Geology	200	3 hrs
Geophysicist	Paper-I	Geophysics	200	3 hrs
	Paper-II	Geophysics	200	3 hrs
	Paper-III	Geophysics	200	3 hrs
Chemist	Paper-I	Chemistry	200	3 hrs
	Paper-II	Chemistry	200	3 hrs
	Paper-III	Chemistry	200	3 hrs
Junior Hydrogeologist	Paper-I	Geology	200	3 hrs
	Paper-II	Hydrogeology	200	3 hrs
	Paper-III	Hydrogeology	200	3 hrs

3.3 Personality Test (Interview)

Total Marks: 200
Assesses subject knowledge, field understanding, personality, communication, and decision-making skills.

📘 4. UPSC Geo-Scientist Detailed Syllabus 2026 (Section-wise)

4.1 Prelims Syllabus

General Studies (Paper-I)

Current affairs
Indian Polity, Economy
Geography & Environment
General Science
Disaster Management
Scientific developments

Subject Paper (Paper-II)

Depends on post:

Geology

Mineralogy
Petrology
Structural geology
Paleontology
Economic geology
Environmental geology
Hydrogeology basics

Geophysics

Solid Earth
Seismology
Geodynamics
Electromagnetism
Gravity & Magnetic methods
Remote sensing

Chemistry

Inorganic chemistry
Organic chemistry
Physical chemistry
Spectroscopy
Analytical techniques

Hydrogeology

Groundwater flow
Aquifers
Well hydraulics
Groundwater contamination
Surface–groundwater interactions

4.2 Mains Syllabus (Descriptive)

Geology Papers

Crystallography
Structural geology & tectonics
Geochemistry
Economic minerals
Mineral exploration
Sedimentology
Petroleum geology
Engineering geology

Geophysics Papers

Earthquake seismology
Gravity & magnetic fields
Geoelectrical methods
Seismic exploration
Borehole geophysics
Mathematical geophysics

Chemistry Papers

Reaction kinetics
Coordination compounds
Spectroscopy (UV, IR, NMR, Mass)
Quantum chemistry
Periodic properties
Thermodynamics
Electrochemistry

Hydrogeology Papers

Groundwater depletion
Aquifer tests
Water balance studies
Environmental hydrogeology
Groundwater modeling

🧮 5. Final Selection – Marks Weightage

Stage	Marks
Prelims (Qualifying)	Not counted
Mains	600
Interview	200
Final Merit	800 marks

🎯 6. Preparation Tips for UPSC Geo-Scientist 2026

📚 Study Tips

Start with NCERT basics for geology/chemistry/physics.
Use standard university-level textbooks.
Practice previous year question papers (last 10 years).

⏳ Time Management

Allocate more time to Mains (descriptive answers).
Create subject-wise micro notes for revision.

🧠 Concept Clarity

Focus on diagrams, maps, and flowcharts.
Build strong fundamentals in geological and chemical processes.

🌐 Practice

Solve at least 30 mock tests for Prelims.
Write 20+ Mains mock answers for speed + structure.

🔗 7. Useful Resource Links

UPSC Official Website: https://upsc.gov.in
UPSC Geo-Scientist 2026 Notification PDF (when released): Available on UPSC → Examinations → Active Examinations
Syllabus PDF (Official): https://upsc.gov.in/examinations/syllabus

UPSC Combined Geo-Scientist Examination ...

UPSC Combined Geo-Scientist Examination 2026 (GSI) – Complete Guide