Precise multi element- isotopic analysis at micrometer scale is paramount to understand basic geochemical processes that are generally controlled by ionic diffusion at submicron scale. Compared to the conventional isotopic analysis, the advancements in the SIMS instrumentation combine efficient ion transmission and high mass resolution capable of precise in-situ isotope ratio measurements with high-spatial resolution of the order of ~ 1 micro meter on selective analysis directly in solid samples. This technique now provides for unprecedented precision and rapidity in in-situ isotope analysis of virtually the entire isotopic Periodic Table. These developments have significantly broadened the scope and application of isotope geochemistry in encompassing themes, virtually from “stars to life”.
In this context, it is proposed to set up a National Facility for High-resolution Secondary Ionization Mass Spectrometry to take up contemporary cutting-edge research in isotope geochemistry and geochronology pertaining to earth, atmospheric, oceanic and planetary sciences. The facility is expected to support several new lines of research in the areas of multi-element Isotope geochemistry and geochronology which are currently at the fore front of basic and applied research across the world. Some of the scientific questions that could be addressed using the facility are:
- U-Pb dating of zircon and several other accessory minerals at a high spatial resolution to decipher complex growth histories related to magmatic, metamorphic, sedimentary and diagenetic processes.
- Resolving basic issues of metallogeny and finger printing a variety of ore deposits.
- In situ stable isotope geochemistry such as C, O, S, N relevant to themes in palaeoclimate research through rapid analysis of growth layers in corals, speleothems, etc.
- Chronostratigraphy of sedimentary basins.
- In situ study of sulphur and oxygen isotope compositions of Indian ore deposits.
- Deep earth processes from the isotopic analysis of inclusions in diamonds.
- Volatile contents and halogen isotope chemistry of basaltic glasses from the Indian ocean ridge systems.
- Stable isotope studies related to cosmochemistry.
Indian Earth and Planetary Scientists depend largely on foreign laboratories to undertake advanced research in Isotope Geochemistry especially using instrumentation such as ASI-Sensitive High Resolution Ion Micro Probe (SHRIMP) or the Cameca-IMS 1280-HR SIMS. Though over 40 such facilities were established around the world including China in the last decade, India, this new technology is yet to reach India.
It is pertinent to note that Indian research institutions are capable of establishing such a facility. Conventional SIMS and nano-SIMS laboratories are operational at the Physical Research Laboratory, Ahmedabad. A new insitu isotope analytical facility (LAM-MC-ICPMS) has been established recently at the National Geophysical Research Institute (CSIR-NGRI), Hyderabad with partial support from the Department of Science and Technology, Government of India. The new National Facility shall serve as a centre for excellence in isotope geochemistry and geochronology with a great scope for not only advanced research but also for turning out excellent human resources in the fields of Earth, Atmospheric, Oceanic and Planetary Sciences.
- Insitu U-Pb dating of zircons and precise geochronology of important rock formations of the Indian shied; implications to crust evolution, and economic geology.
- Hf isotopic compositions in zircons and ultramafic – mafic rocks with implications to crust-mantle dynamics and evolution of the Indian shield through its>3.5 billion year geologic history and the regional metallogeny.
- Sr, Nd, Pb and Hf - Isotopic characterization of mafic - ultramafic rocks from the Carlsberg and Central Indian Ridge systems and the Andaman back arc basin, understanding magmatism and geodynamic processes at the Indian plate margins.
- Isotopic studies on Ocean sediments, particulates and waters: implications to present and past climates and surface processes.
- Geochronology and Isotopic systematics of mantle xenoliths in Indian diamond bearing kimberlites: insights into the deep mantle and diamond exploration.
- Isotopic compositions of elements such as Fe, Cr, Cu and Zn to understand the genetic controls of Indian base metal deposits.
- To initiate Fe isotopic studies with implications to bio-geochemical processes and palaeoclimates.
b) Participating Institutions:
- National Centre for Antarctic & Ocean Research, Goa
- National Centre for Seismology
c) Implementation Plans:
- Finalization of the specifications of the equipment and accessories
- Floating of Global tenders, evaluation of the response.
- Finalization of the vendor, placing of order
- Identification of key personnel, Training of scientists
- Preparation of civil structure to house the equipment, obtaining clearances from BARC etc ,commissioning of the HR-SIMS,
- Test run on standards.
- Development of cutting edge science pertaining to characterization , origin and evolution of extra terrestrial objects (meteorites & inter-planetary dust, evolved Martian meteorites and relatively unevolved Lunar meteorites etc.
- Window to the interior of earth will be provided by isotopic and trace element characterization of exhumed material such as ultramafic rocks and xenoliths in rocks ( e.g. kimberlites ).
- Estimation of deep earth processes.
- Isotopic and geochemical characterization including insitu micro characterization of the heterogeneities of ocean sediments and other geological archives (sediments, minerals and fossils) would be correlated with the cryosphere evolution , especially in Himalaya to yield data on uplift and tectonics vs sedimentation and palaeo-monsoons..
- Isotopic characterization of Sr, Nd, Pb ,Hf etc will yield conclusive data on understanding of magmatism and geodynamic processes at the Indian plate margins and fill information gap in the structure of Andaman-Nicobar subduction zone and other similar regions.
- The facility will help in studies on genetic aspects of mineral deposits and thus open new directions for exploration strategies.
e) Budget requirement : 115 crores.
(Rs. In crores)
|Name of the Scheme