Mukund is interested in understanding the evolution of early life on the Earth. His endeavors are targeted on Archaean and Proterozoic rocks to find its clues. Besides, he is collaborating with the forces in the field for biogeochemistry of palaeobiological evidence, early diversification of prokaryotic metabolisms, radiation of eukaryotic forms and large complex megascopic remains.
The paper deals with the problem of fungal contamination in palaeopalynological preparations spec... more The paper deals with the problem of fungal contamination in palaeopalynological preparations specially from the Precambrian sediments. The vegetative and reproductive structures of extant fungal groups show a broad similarity in morphology with the morphotypes described from the Precambrian. The recent fungi when subjected to chemical treatment similar to palynological preparations (maceration) do not show major physical and morphological changes. Nine common fungal genera were selected for this study. It has been observed that they withstand hydrochloric acid and hydrofluoric acid treatment without losing much of their morphocharacters. As these are common in soil profiles, one can easily be misled when they occur amongst macerated residues. This data serves as a cautionary note to all palaeobiologists and specially dealing with Precambrian material, where every new evidence is important in adding to the meagre knowledge.
Boron (B) and Tungsten (W) are often found enriched in high-temperature geothermal waters associa... more Boron (B) and Tungsten (W) are often found enriched in high-temperature geothermal waters associated with the development of subduction-related mafic to felsic arc magma. However, knowledge about the sourcing and transportation of these elements from such hydrothermal systems is sparse and ambiguous. Being the only active continental collision site in the world, the Trans-Himalaya offers a unique chance to study how continental collision sources the high boron and tungsten concentrations in geothermal fluids. This study investigated the distribution of trace elements, major cations, and anions in three physicochemically distinct hotspring sites in the Ladakh region. The results were integrated with the existing geochemical and isotopic data to address the research problem more effectively. This study exhibits that the extreme concentrations of boron, sodium, chlorine, potassium, and tungsten in the hotspring waters were primarily governed by magmatic fluid inputs. In addition, this ...
Systematics of the stromatolites of the Proterozoic Kaladgi Basin is attempted. The main purpose ... more Systematics of the stromatolites of the Proterozoic Kaladgi Basin is attempted. The main purpose is to document the diversity and distribution of the various stromatolite forms occurring in the Bagalkot Group of the Kaladgi Supergroup. An assemblage of six taxa is recognized from the Bagalkot Group. The forms Asperia digitata (=Yelma digitata), Ephyaltes edingunnensis, Eucapsiphora leakensis, Kussoidella karalundiensis, Pilbaria deverella and Yandilla meekatharrensis are described. These forms are not recorded from any other Proterozoic Sequence of India of the Palaeoproterozoic age. Similar forms are recorded from Africa, Australia, Canada and China. Asperia digitata, a digitate stromatolite, is known from the Proterozoic Sequence of the Palaeoproterozoic age in other parts of the world. Poorly constrained age of the Bagalkot Group of the Kaladgi Supergroup can be ascertained on the basis of the reported assemblage as Late Palaeoproterozoic to Early Mesoproterozoic (Orosirian-Stath...
Based on previously obtained and new materials, the association of organ-walled microfossils repr... more Based on previously obtained and new materials, the association of organ-walled microfossils represented by morphologically complex and large forms from the Kaltasa Formation is considered. In general, the Kaltasa microbiota resembles many associations of Neoproterozoic microfossils (late Riphean and Vendian). It was mistakenly interpreted as Late Riphean in its initial description, although the late Riphean index taxons were absent, and geological data indicated its early Riphean age. The early Riphean age of the Kaltasinskaya Formation has been confirmed in a series of studies in recent years using Re–Os, U–Pb and other modern methods of isotopic geochronology. Additionally, the low ratios of 87 Sr/ 86 Sr and almost invariant ō13C values in the surrounding sediments are comparable with the isotopic characteristics of Mesoproterozoic strata that are older than 1300 million years. The use of geochemical methods using high-reagent iron (FeHR), as well as carbon and sulfur isotopes sh...
The geological timescale before 720 Ma uses rounded absolute ages rather than specific events rec... more The geological timescale before 720 Ma uses rounded absolute ages rather than specific events recorded in rocks to subdivide time. This has led increasingly to mismatches between subdivisions and the features for which they were named. Here we review the formal processes that led to the current timescale, outline rock-based concepts that could be used to subdivide pre-Cryogenian time and propose revisions. An appraisal of the Precambrian rock record confirms that purely chronostratigraphic subdivision would require only modest deviation from current chronometric boundaries, removal of which could be expedited by establishing event-based concepts and provisional, approximate ages for eon-, era- and period-level subdivisions. Our review leads to the following conclusions: (1) the current informal four-fold Archean subdivision should be simplified to a tripartite scheme, pending more detailed analysis, and (2) an improved rock-based Proterozoic Eon might comprise a Paleoproterozoic Era...
The present paper deals with the systematics, morphogenesis and depositional environment of a new... more The present paper deals with the systematics, morphogenesis and depositional environment of a new stromatolite morphotype Batiola indica from the ~ 2.6 Ga old Archaean sediments of the Chitradurga Group, Dharwar Craton, India. It has been grouped under family Cryptophytonidae. Its morphological features are attributed to both biotic and environmental factors and considered to have been formed in a tidal regime.
Indian subcontinent with extensive Archaean and Proterozoic sedimentary successions has number of... more Indian subcontinent with extensive Archaean and Proterozoic sedimentary successions has number of stromatolites occurrences which offers avenues of stromatolites studies. The present paper traces the efforts, strengths and gaps in stromatolites studies in India and summarizes significant Indian contributions made in the past in the country and briefly mentions the global advancements made in this field. The overview covers the period of active research from 1908-2005.
The paper deals with the problem of fungal contamination in palaeopalynological preparations spec... more The paper deals with the problem of fungal contamination in palaeopalynological preparations specially from the Precambrian sediments. The vegetative and reproductive structures of extant fungal groups show a broad similarity in morphology with the morphotypes described from the Precambrian. The recent fungi when subjected to chemical treatment similar to palynological preparations (maceration) do not show major physical and morphological changes. Nine common fungal genera were selected for this study. It has been observed that they withstand hydrochloric acid and hydrofluoric acid treatment without losing much of their morphocharacters. As these are common in soil profiles, one can easily be misled when they occur amongst macerated residues. This data serves as a cautionary note to all palaeobiologists and specially dealing with Precambrian material, where every new evidence is important in adding to the meagre knowledge.
Boron (B) and Tungsten (W) are often found enriched in high-temperature geothermal waters associa... more Boron (B) and Tungsten (W) are often found enriched in high-temperature geothermal waters associated with the development of subduction-related mafic to felsic arc magma. However, knowledge about the sourcing and transportation of these elements from such hydrothermal systems is sparse and ambiguous. Being the only active continental collision site in the world, the Trans-Himalaya offers a unique chance to study how continental collision sources the high boron and tungsten concentrations in geothermal fluids. This study investigated the distribution of trace elements, major cations, and anions in three physicochemically distinct hotspring sites in the Ladakh region. The results were integrated with the existing geochemical and isotopic data to address the research problem more effectively. This study exhibits that the extreme concentrations of boron, sodium, chlorine, potassium, and tungsten in the hotspring waters were primarily governed by magmatic fluid inputs. In addition, this ...
Systematics of the stromatolites of the Proterozoic Kaladgi Basin is attempted. The main purpose ... more Systematics of the stromatolites of the Proterozoic Kaladgi Basin is attempted. The main purpose is to document the diversity and distribution of the various stromatolite forms occurring in the Bagalkot Group of the Kaladgi Supergroup. An assemblage of six taxa is recognized from the Bagalkot Group. The forms Asperia digitata (=Yelma digitata), Ephyaltes edingunnensis, Eucapsiphora leakensis, Kussoidella karalundiensis, Pilbaria deverella and Yandilla meekatharrensis are described. These forms are not recorded from any other Proterozoic Sequence of India of the Palaeoproterozoic age. Similar forms are recorded from Africa, Australia, Canada and China. Asperia digitata, a digitate stromatolite, is known from the Proterozoic Sequence of the Palaeoproterozoic age in other parts of the world. Poorly constrained age of the Bagalkot Group of the Kaladgi Supergroup can be ascertained on the basis of the reported assemblage as Late Palaeoproterozoic to Early Mesoproterozoic (Orosirian-Stath...
Based on previously obtained and new materials, the association of organ-walled microfossils repr... more Based on previously obtained and new materials, the association of organ-walled microfossils represented by morphologically complex and large forms from the Kaltasa Formation is considered. In general, the Kaltasa microbiota resembles many associations of Neoproterozoic microfossils (late Riphean and Vendian). It was mistakenly interpreted as Late Riphean in its initial description, although the late Riphean index taxons were absent, and geological data indicated its early Riphean age. The early Riphean age of the Kaltasinskaya Formation has been confirmed in a series of studies in recent years using Re–Os, U–Pb and other modern methods of isotopic geochronology. Additionally, the low ratios of 87 Sr/ 86 Sr and almost invariant ō13C values in the surrounding sediments are comparable with the isotopic characteristics of Mesoproterozoic strata that are older than 1300 million years. The use of geochemical methods using high-reagent iron (FeHR), as well as carbon and sulfur isotopes sh...
The geological timescale before 720 Ma uses rounded absolute ages rather than specific events rec... more The geological timescale before 720 Ma uses rounded absolute ages rather than specific events recorded in rocks to subdivide time. This has led increasingly to mismatches between subdivisions and the features for which they were named. Here we review the formal processes that led to the current timescale, outline rock-based concepts that could be used to subdivide pre-Cryogenian time and propose revisions. An appraisal of the Precambrian rock record confirms that purely chronostratigraphic subdivision would require only modest deviation from current chronometric boundaries, removal of which could be expedited by establishing event-based concepts and provisional, approximate ages for eon-, era- and period-level subdivisions. Our review leads to the following conclusions: (1) the current informal four-fold Archean subdivision should be simplified to a tripartite scheme, pending more detailed analysis, and (2) an improved rock-based Proterozoic Eon might comprise a Paleoproterozoic Era...
The present paper deals with the systematics, morphogenesis and depositional environment of a new... more The present paper deals with the systematics, morphogenesis and depositional environment of a new stromatolite morphotype Batiola indica from the ~ 2.6 Ga old Archaean sediments of the Chitradurga Group, Dharwar Craton, India. It has been grouped under family Cryptophytonidae. Its morphological features are attributed to both biotic and environmental factors and considered to have been formed in a tidal regime.
Indian subcontinent with extensive Archaean and Proterozoic sedimentary successions has number of... more Indian subcontinent with extensive Archaean and Proterozoic sedimentary successions has number of stromatolites occurrences which offers avenues of stromatolites studies. The present paper traces the efforts, strengths and gaps in stromatolites studies in India and summarizes significant Indian contributions made in the past in the country and briefly mentions the global advancements made in this field. The overview covers the period of active research from 1908-2005.
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Papers by Dr. Mukund Sharma