Geosciences Division
Division Head: Prof. Sanjeev Kumar
Deputy Head 1: Dr. A. K. Sudheer
Deputy Head 2: Prof. Neeraj Rastogi
Overview
The research activities of the Geosciences Division at PRL focus on understanding the physical, chemical, biological, and geological processes that have shaped the Earth since its formation. By applying principles of elemental distribution and isotopic systems in nature, radioactive decay and growth, and the optical luminescence properties of minerals, the division’s scientists use cutting-edge analytical techniques to determine the timescales of key events and explore the evolutionary processes across various Earth reservoirs. The division’s key research areas include Solid Earth Research, Oceanography, Biogeochemistry, Hydrology, Paleoclimate Studies, Quaternary Geology, and Atmospheric Aerosol Chemistry.
Major Research Programmes
Early Earth and Planetary EvolutionThe basic building blocks of the Earth and planets in our solar system are the gases and dust in the solar nebula. Nonetheless, the chemical and isotopic compositions of all solar system bodies are different from each other. It implies that each planet has unique precursors as well as evolution pathways. The research activities of Genesis Lab mainly focus on the origin and evolution of the Earth and planetary objects using element concentrations, mass-dependent, and mass-independent isotope variations in terrestrial as well as extra-terrestrial materials.
Solid Earth Geochemistry
Research in Solid Earth Geochemistry deals with the chemical composition and processes of the Earth's solid components, including the crust, mantle, and core. Studies in this field investigate the distribution, cycling, and interaction of elements and isotopes within Earth's interior and their influence on geological and geophysical processes. The research topics include, but are not limited to, the secular evolution of mantle, crust-mantle interaction, intraplate volcanism, subduction zone processes, and arc volcanism.
Quaternary Environments, Sedimentology, and Terrain response
The QuEST laboratory explores (para- and peri-) glacial, fluvial, aeolian, and coastal environments to understand the terrain response focusing on past-climate trends, especially the extreme events, and changes in the geomorphic processes. Utilising multi-proxy and multi-chronological techniques some of the current focus themes are Himalayan glacier changes (millennial to centennial scales), Himalayan and dryland flash floods, and the Holocene sea-level changes. Human-terrain-climate relationship is explored in the Holocene period to understand the anthropogenic processes as a geomorphic agent.
Paleoclimate Studies
This research focuses on past climate variability, monsoon dynamics, and sea surface temperature fluctuations. By analyzing natural archives like cave deposits and sediments and using isotopic techniques and climate models, we aim to understand both short-term human impacts and long-term natural drivers of climate to improve future predictions.
Hydrology
Hydrology Research at PRL examines the transport of moisture via atmospheric, surface, and sub-surface processes encapsulating- i) Terrestrially-recycled moisture ii) Diagnose moisture transport pathways iii) Detect multi-decadal rainfall trend reversals iv) Investigate surface-groundwater exchange, and v) Extreme precipitation events. We leverage isotopes (stable & radioactive), water table data, AI and ML tools, and statistical modeling to explore long-term changes and dynamics, offering insights into regional hydrology and sustainable water resource management.
Aqueous Geochemistry
Natural waters (rivers, groundwater, lakes) draining the solid earth play a critical role in supporting and maintaining life on the earth. These terrestrial aquatic systems are key to regulating climate, major and trace element cycling, supporting biodiversity and providing water as a resource. Our research under aquatic geochemistry focuses on understanding the chemistry of natural waters to assess the water-rock interactions, river and groundwater dynamics, and human/anthropogenic influence. Novel geochemical and isotopic tools are used to assess these processes.
Oceanography and Paleoceanography
The ocean circulation plays a key role in regulating global climate. Our research focuses on investigating the variability in ocean circulation across both time and space and their interactions with the climate system. By analyzing signals preserved in natural archives, we aim to reconstruct past oceanographic and climatic dynamics, gaining a deeper understanding of the factors that control these systems. Our research spans time scales from decadal to millions of years, to enhance predictions for the Earth's future climate and oceanographic developments.
Biogeochemistry
Our research focuses on how marine and terrestrial biota respond to global change, examining their impacts on ecosystem functioning and the resulting consequences for biogeochemical cycles. We aim to: (1) develop a mechanistic understanding of key biological processes at the elemental level and their global impact, (2) understand the influence of organismal response to community dynamics and ecosystem structures, shaping trophic interactions and food web efficiencies, (3) investigate how shifts in ecosystem composition and function affect biogeochemical cycling, (4) decipher the impact of anthropogenic modifications on terrestrial aquatic systems, and (5) study distribution of trace elements and isotopes in the past and present oceans.
Aerosol Chemistry
The major focus of this research is to understand how sources and processes affect ambient aerosol concentration, composition, and characteristics over different regions of India and surrounding oceans, and how the atmospheric processing of aerosols affects their implications to atmospheric chemistry, air quality, human health, aquatic ecosystem, and climate change. The chemical and isotopic composition of aerosols measured through state-of-the-art analytical techniques are used as tools to achieve the research objectives.
Facilities
- Accelerator Mass Spectrometer (AMS)
- Multi-collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) equipped with femtosecond laser
- Quadrupole Inductively Coupled Plasma Mass Spectrometer (Q-ICPMS)
- High-Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICP-MS) equipped with laser ablation
- Thermal Ionization Mass Spectrometer (TIMS)
- Isotope Ratio Mass Spectrometer (IRMS)
- Gas Chromatography-Mass Spectrometer (GCMS)
- Thermoluminescence (TL) & Optically Stimulated Luminescence (OSL) dating systems
- Ion Chromatograph
- Alpha, Beta, and Gamma detectors
- Liquid Scintillation Counters (LSC)
- Inductively Coupled Plasma-Atomic Emission Spectrometers (ICP-AES)
- CN-Analyzer
- Thermo-Optical EC-OC Analyzer
- Particle-into-Liquid Sampler (PILS)
- Ambient Ion Monitor coupled to Ion Chromatography (AIM-IC)
- Portable UV-visible spectrometer with liquid waveguide capillary cell (LWCC)
- Atomic Absorption Spectrophotometers
- Total Organic Carbon (TOC) Analyzer
- High Resolution - Time of Flight - Aerosol Mass Spectrometer (HR-ToF-AMS)
- Aethalometer
- Scanning Mobility Particle Sizer (SMPS)
- Particle Size Analyzer and Sieve shaker
- Magnetic Separator
A glimpse of PhD programs offered
- Chemical and isotopic evolution of the Earth through time, Isotope Geochemistry, and Cosmochemistry
- Nitrogen and Carbon Cycling in Marine and Terrestrial Environments
- Isotopic Fingerprinting of Waters of India
- Paleoclimate Studies Using Marine and Terrestrial Proxies
- Marine Geochemistry
- Ocean circulation in the present and past
- Ocean redox dynamics in deep time
- Chemical Weathering and Climate
- Paleomonsoon and Desertification on various time scales
- Spatial and Temporal evolution of various Landforms in India
- Glacial and paraglacial terrain response (Himalayas)
- Human-climate-landform relationship in Holocene
- Evolution of Proterozoic Sedimentary Basins of India
- Subduction Zone Volcanism
- Aerosol Chemistry and Characterization
- Atmospheric deposition fluxes of biogeochemically important species
- Fate of Environmental Microplastics
New Developments/Initiatives/Areas
Marine Biogeochemistry: PRL scientists extensively use stable carbon, oxygen, nitrogen and sulfur isotopes to trace their sources, cycling, and their transformation. These isotopic tools along with trace elements are also used to understand primary productivity, nutrient utilization, food-web structure, water-mass mixing, and past ocean conditions.
River and Lake Biogeochemistry: An extensive research program has recently been initiated to quantify the nitrogen budget and greenhouse gas emissions from freshwater systems. This work is especially important as rivers and lakes are increasingly affected by anthropogenic disturbances such as river engineering, dam construction, salinization, and changes in lake volume.
Paleomonsoon reconstruction: Understanding variability of Indian Summer Monsoon is very important as it directly impacts the socio-economy of India. Both natural archives and model-based approaches form an integral part of PRL’s research on monsoon dynamics.
Recycling of rainwater: Estimating moisture recycling over India is essential for understanding how much of the rainfall originates from local evaporation versus transported moisture. This research helps quantify the contribution of land-atmosphere feedback to the Indian Summer Monsoon and improves predictions of regional rainfall.
Aerosol chemistry: The major focus of this research is to understand how sources and processes affect ambient aerosol concentration, composition, and characteristics over different regions of India and surrounding oceans, and how the atmospheric processing of aerosols affects their implications to atmospheric chemistry, air quality, human health, aquatic ecosystem, and climate change.
Solid Earth Studies: Research in Solid Earth Geochemistry explores the chemical composition and dynamic processes within Earth’s interior, encompassing the crust, mantle, and core. Researchers at PRL investigate the distribution, cycling, and interaction of elements and isotopes to understand their influence on geological and geophysical phenomena. Various research topics/themes address key Earth system processes, including the secular evolution of the mantle, crust-mantle interaction, intraplate and arc volcanism, and subduction zone dynamics.
Earth Surface Processes: Earth surface processes shape the landscape through the combined action of weathering, erosion, sediment transport, and deposition driven by water, wind, ice, and biological activity. At PRL, these processes are studied to understand how the landscapes may respond to climate change and human activities.
Understanding ocean circulation and redox state: The oceans compose a large reservoir on the Earth in terms of storage and distribution of heat, oxygen and nutrients. Thus, it becomes important to assess ocean circulation in the present as well as in the past. Further, the redox state of the oceans fundamentally controls marine biology by determining the availability of oxygen and nutrients. Thus, by understanding the ocean circulation and redox some of these critical aspects can be understood.
Future Research Themes
Earth and Planetary Evolution
The study of the origin and evolution of Earth and planetary bodies in the solar system is fundamental to understanding the unique chemical and isotopic signatures of different planets. Research at PRL will focus on unraveling the processes that shaped Earth and its planetary neighbors, utilizing mass-dependent and mass-independent isotopic variations in both terrestrial and extraterrestrial materials. By investigating the early Earth and planetary evolution, we aim to gain deeper insights into the building blocks of our planet and their implications for future planetary exploration and resource management.
Surface and Solid Earth Geochemistry
Geochemistry explores the chemical composition and processes of Earth’s solid components—crust, mantle, and core. Future research will delve deeper into the interactions between elements and isotopes within Earth's interior, advancing our understanding of mantle evolution, crust-mantle dynamics, and volcanic & sedimentary processes. By focusing on subduction zones, intraplate volcanism, and mantle-crust interactions, the goal is to better understand the geological forces driving tectonic activity and contribute to future advancements in seismic and geological hazard prediction.
Climate, Hydrology, and Biogeochemical Cycles
We aim to explore how past climate dynamics, water reservoirs, and biological processes shape Earth's environment. Research will focus on past climate variability, hydrological changes, Himalayan and Arctic permafrost, and their impact on global biogeochemical cycles. Through the use of multi-proxy data, trace elemental composition, isotopic analysis, and advanced neural network modeling, PRL’s future research will aim to improve predictions for future climate shifts, regional hydrological patterns, and ecosystem resilience. Understanding water-rock interactions, surface-groundwater exchanges, and extreme precipitation events will provide critical insights for sustainable water management and climate adaptation strategies.
Oceanography and Paleoceanography
Research in this area will aim to understand the evolution of ocean circulation and its influence on global climate, both in the past and future. By reconstructing past oceanographic conditions using natural archives and isotopic tools, PRL will enhance