Thesis and Guide details:
Details of CSIR Fellowship/ Associateship held, if any or from other sources/ agencies.
Significant foreign assignments:
(a) Significant contributions to science and/ or technology development by the nominee
based on the work done in India during most part of last 5 years:
Dr. Ray is a versatile isotope geochemist who works on wide range of topics in Geosciences.
His approach to research is multidisciplinary and quantitative. He formulates his own projects,
does fieldwork and collects samples, generates most of his experimental data using indigenous
facilities and develops mathematical models to explain the data. Except for three of his
publications which came out of two overseas postdoctoral assignments [16(e)], all his research
has been carried out in India. He has made significant contributions to the study of stable
isotope fractionation in high and low temperature processes, origin and evolution of mantle
derived magmas, isotope stratigraphy, geochronology, subduction zone processes and
provenances of sediments in ancient and modern ocean basins. The most important
contributions of Dr. Ray are summarized below in three broad topics.
Chronology of Major Geologic Events
Using multiple radioisotope dating techniques (Sm-Nd, Rb-Sr, Pb-Pb and Ar-Ar) Dr. Ray has
resolved some of the important chronological issues in Indian Geology and in the history of
volcanism in the South Pacific Ocean and Andaman Sea. I. One of his landmark contributions has been the dating of volcaniclastic sediments and
carbonates from the Semri Group of the Vindhyan Supergroup of India that resolved a major
scientific controversy of recent times. His work established that the lower Vindhyans were
deposited between ~1750 Ma and ~1600 Ma and therefore, cannot contain fossils of
Cambrian or younger age. (Publication nos. 16(a)-4 & 5) (The project was conceived and
carried out by Dr. Ray as part of his postdoctoral research in Canada)
II. His work established that the carbonatite-alkaline complexes of the Deccan and Sylhet-
Rajmahal Traps represent either initial or terminal phase magmatic activity of the flood
basalt eruptions. Specifically, his work revealed that Amba Dongar and Sung Valley
carbonatite complexes were emplaced at ~65 Ma and ~107 Ma, respectively. (Publication
nos. 16(a)-2; 16(d)-4: work entirely done in India)
III. His work established that the Sylhet Traps were emplaced rapidly at ~116 Ma and are linked
to the initiation of the Kerguelen hotspot and the break-up of Gondwanaland. (Publication
no. 16(a)-6: work entirely done in India)
IV. His work revealed that the Newania carbonatite complex of Rajasthan, one of the few
primary dolomite carbonatites of the world, was emplaced at ~1473 Ma and got affected by
a thermal event at ~904 Ma. It reported evidences for heterogeneous incorporation of Pb
during the thermal event – the reason for an older Pb-Pb date (~2400 Ma). (Publication no.
16(a)-8: work entirely done in India)
V. His work established a genetic link between the Nazca Ridge and the Easter Seamount
Chain – two chains of volcanoes in the South Pacific and showed that these belong to a ~30
Ma hotspot trail of the Salas y Gomez (and not Easter Island) hotspot. (Publication no.
16(b)-2: data were generated in USA but the interpretations, modeling work and paper
writing were done at PRL, India)
(b) Impact of the contributions in the field concerned:
I. Dr. Ray‟s timely contributions to the resolution of the long-standing issue on the age of
deposition of the Vindhyan Supergroup have led to thorough re-investigations of its
purported fossil record, which have implications for the evolution of animal life on Earth.
These studies also formed a basis for reorganization of the Proterozoic stratigraphy of India.
II. The seawater Sr-isotope ratio curve for the Proterozoic as suggested by his work became
the basis of numerous isotope-stratigraphic age determinations of Proterozoic carbonate
sequences worldwide.
III. Evidences shown by his work that carbonatites incorporate recycled inorganic carbon
resolved the problem of uninterrupted supply of carbon in the mantle for generation of
carbonatites throughout the geologic history by suggesting continuous replenishment
through carbonate subduction. His proposal that lower crust plays an important role in the
diversification of carbonatites has revolutionized thinking on the carbonatite-alkaline rock
associations and his mathematical model has been successfully used to explain the large
variations observed in Sr and Nd isotopic compositions in the associated alkaline silicate
rocks.
IV. The multi-component Rayleigh isotopic fractionation model developed by him has become
the basis for explaining C and O isotope ratio variations in carbonatites, fluid-deposited
graphite and many such systems where fluids play a significant role.
V. The chronological information provided by his work on the Sylhet Traps and 29 volcanoes of
Nazca Ridge and Easter Seamount Chain reaffirmed the validity of the hypothesis of
hotspots fixity beneath moving lithospheric plates.
VI. The findings of his work that the carbonatites associated with flood basalts are
contemporaneous with stratigraphic boundaries and are capable of injecting much large
quantities of green house gases than the flood basalts themselves led to a rethinking on the
role of smaller magmatic activities on climate change and mass extinctions.
VII. The recent results of his work on the Barren Island volcano that it is at least 1.6 Ma old and
lies on a > 106 Ma oceanic crust are bound to reshape the evolutionary models for the
Andaman Sea and the Andaman Islands – which have implications for the breakup of the
Gondwanaland and India‟s northward journey.
VIII. The geochemical investigation of Dr. Ray and his collaborators on Late Quaternary
sediments in the Andaman Sea reaffirmed the southward shifting of the ITCZ during the
LGM and provided a clear evidence, contrary to earlier belief, that the Andaman Sea was
well connected to the Bay of Bengal though the south Preparis Channel
Places where work of last 5 years has been referred/ cited in Books, Reviews:
Names of the industries in which the technology (ies) has (have) been used :
The achievements already been recognised by Awards by any learned body:
The Awardee a fellow of the Indian National Science Academy/Indian Academy of Sciences/National
Academy of Sciences/Others:
The Awardee delivered invited lecture(s) in India/abroad and/or chaired any scientific
Internatiional Conference Symposium:
List of Awardee's 10 most significant publications.
List of Awardee's 5 most significant publications during the last 5 years
List of Awardee's 5 most significant publications from out of work done in India
during the last five years:
Complete list of publications in standard refereed journals:
Complete list of publications with foreign collaborators (indicating your status
as author):
List of papers published in Conferences /Symposia/ Seminars, etc:
List of the most outstanding Technical Reports/ Review Articles:
Statement regarding collaboration with scientists abroad:
Dr. Ray has only 3 journal publications with scientists abroad [see 16(e)] – which came out of
his postdoctoral research done during 1999-2002 in Canada and USA. For his research activities in India, he has no collaborations outside the country and he does not use laboratory
facilities abroad to generate his experimental data.
Total number of patents granted in last five years.
Details of Books published: