Mesoproterozoic diamondiferous ultramafic pipes at Majhgawan and Hinota, Panna area, central India: key to the nature of sub-continental lithospheric mantle beneath the Vindhyan basin

Amongst all the perceptible igneous manifestations (volcanic tuffs and agglomerates, minor rhyolitic flows and andesites, dolerite dykes and sills near the basin margins, etc.) in the Vindhyan basin, the two Mesoproterozoic diamondiferous ultramafic pipes intruding the Kaimur Group of sediments at Majhgawan and Hinota in the Panna area are not only the most conspicuous but also well-known and have relatively deeper mantle origin. Hence, these pipes constitute the only yet available ‘direct’ mantle samples from this region and their petrology, geochemistry and isotope systematics are of profound significance in understanding the nature of the sub-continental lithospheric mantle beneath the Vindhyan basin. Their emplacement age (∼ 1100 Ma) also constitutes the only reliable minimum age constrain on the Lower Vindhyan Group of rocks. The Majhgawan and Hinota pipes share the petrological, geochemical and isotope characteristics of kimberlite, orangeite (Group II kimberlite) and lamproite and hence are recognised as belonging to a ‘transitional kimberlite-orangeite-lamproite’ rock type. The namemajhagwanite has been proposed by this author to distinguish them from other primary diamond source rocks. The parent magma of the Majhgawan and Hinota pipes is envisaged to have been derived by very small (<1%) degrees of partial melting of a phlogopite-garnet lherzolite source (rich in titanium and barium) that has been previously subjected to an episode of initial depletion (extensive melting during continent formation) and subsequent metasomatism (enrichment). There is absence of any subduction-related characteristics, such as large negative anomalies at Ta and Nb, and therefore, the source enrichment (metasomatism) of both these pipes is attributed to the volatile- and K-rich, extremely low-viscosity melts that leak continuously to semi-continuously from the asthenosphere and accumulate in the overlying lithosphere. Lithospheric/crustal extension, rather than decompression melting induced by a mantle plume, is favoured as the cause of melting of the source regions of Majhgawan and Hinota pipes. This paper is a review of the critical evaluation of the published work on these pipes based on contemporary knowledge derived from similar occurrences elsewhere

QUALITY FUNTION DEPLOYMENT METHOD FOR ASCERTAINING INFLUENTIAL FACTORS ON TRANSFER OF SAFETY TRAINING SKILLS IN INDIAN CONSTRUCTION ORGANIZATIONS

Safety training is crucial activity of an injury and illness prevention program that can assist management to identify and mitigate workplace hazards. Effective safety training will contribute towards transforming employees competent in health and safety aspects, to minimize accidents and eliminate the costs of accidents. Translating knowledge gained of safety training into the workplace environment by employees will assist the organizations to minimize work-related injuries. Most of the construction organizations in India are imparting safety trainings to all levels of employees and its impact on work place safety is marginal. In order to better understand factors influencing the transfer of safety knowledge acquired during trainings in construction organizations, quality function deployment technique has been applied; the trainee’s expectations and technical requirements were analyzed. The study proposes to identify factors and to assist managements of Indian construction organizations to understand the interaction among trainee’s expectations and technical requirements. Support from superiors, perceived importance and self-efficacy the most important expectation of trainees. Organization culture, management commitment and working environment are the most important technical requirements for better transfer of safety training skills

Enumeration of Triangles in a Divisor Cayley Graph

In this paper a new class of arithmetic Cayley graphs, namely, divisor Cayley graphs associated with the divisor function d ƒvnƒw , n „d1,an integer is introduced. It is shown that this graph is regular, hamiltonian, connected and not bipartite, and when n is odd it is eulerian. The enumeration of triangles in this graph is also presentedKey words: Arithmetic graph, Cayley graph, Hamilton cycle, Fundamental triangle and Triangle

Kimberlites, Lamproites, Lamprophyres, Carbonatites, other Alkaline Rocks, and Mafic Dykes from the Indian Shield: glimpses of research (2012-2016)

Major highlights of researches carried out on kimberlites, lamproites, lamprophyres, carbonatites, other alkaline rocks and mafic dykes from the Indian shield during 2012-2016 are presented. New findings involving field mapping, petrology, geochemistry (including high quality mineral based in situ isotopic studies) and geophysics have provided remarkable insights on the mode of their occurrence, timing of emplacement, mineralogy and bulk-rock composition, redox conditions, relative contribution of the lithosphere and asthenosphere, as well as their economic potential. Several large-scale geodynamic aspects such as plume-lithosphere interactions, ancient subduction events, layered structure of the sub-continental lithospheric mantle, spatial extent of the Precambrian large igneous provinces and supercontinent configurations could be unraveled from these studies on deep-mantle derived small-volume magmatic rocks

New Ar-Ar ages of southern Indian kimberlites and a lamproite and their geochemical evolution

The kimberlites and lamproites of southern India are thought to have formed in the most prolific known period of Precambrian ultramafic/ultrapotassic magmatism at around 1100 Ma. This study reports new age data for southern Indian ultrapotassic rocks (kimberlites and lamproites), a controversial topic due to the wide range of published age data and disagreements over the reliability of previously published ages. In this study we obtained new high-precision Ar–Ar data that better constrain the ages of southern Indian ultrapotassic rocks. Dates from three samples are presented, including two kimberlites from Wajrakarur kimberlite field and one lamproite from the Krishna lamproite field. These age data are then combined with bulk-rock geochemical and Nd isotopic data to provide further constraints on the source region and primary magma composition of southern Indian kimberlites and lamproites. Previously, the Chelima lamproite (ca. 1400 Ma) was considered to be one of the oldest lamproites in the world. However, our age data suggest that at least one lamproite (Pochampalle) was generated in the same region 100 Ma before the Chelima event. The Pochampalle lamproite was emplaced around ~1500 Ma as shown by the Ar–Ar data in this study, roughly 250 Ma before the other Krishna lamproites. It would seem that the Pochampalle lamproite was also derived from an isotopically distinct source region with a lower 143Nd/144Nd ratio than other lamproites in the Krishna field. These findings not only have implications for regional ultramafic/ultrapotassic magmatism, but also demonstrate that the mantle processes for producing lamproitic melts existed earlier than previously thought

An analysis of accident trends and modeling of safety indices in an Indian construction organization

Construction industry has been recognized as a hazardous industry in many countries due to distinct nature of execution of works.The accident rate in construction sector is high all over the world due to dynamic nature of work activities. Occurrence of accidents and its severity in construction industry is several times higher than the manufacturing industries. The study was limited to a major construction organization in India to examine the trends in construction accidents for the period 2008-2014. In India, safety performance is gauged basing on safety indices; frequency, severity and incidence rates. It is not practicable to take decisions or to implement safety strategies on the basis of indices. The data used for this study was collected from a leading construction organization involved in execution of major construction activities all over India and abroad. The multiple regression method was adopted to model the pattern of safety indices wise .The pattern showed that significant relationships exist between the three safety indices and the related independent variables.

A LITERARY REVIEW ON MERCURY W.S.R. TO ITS MEDICINAL ASPECT

Rasasastra is a branch of Ayurvedic medicine dealing with metals and minerals having higher therapeutic efficacy. Recent world wide discussions on hazardous nature of Mercury have led to the global ban on Mercury through Minamata Convention. This is a crisis situation for Ayurveda as Parada (Mercury) is the heart of Rasasastra. An attempt has been made to educate the readers regarding the medicinal aspects of Mercury. Rasasastra texts starting from Rasendra mangalam to Rasatrangini have been analyzed for relevant verses regarding Mercurial formulations with respect to its disease curing property. Mercury has qualities similar to ambrosia. Mercurial medications prepared from purified Mercury can readily treat even Asadhya rogas (incurable diseases). Purified Mercury samples were tested for their therapeutic efficacy through alchemy. A systematic classification regarding types of Mercury, their impurities and purification procedures are mentioned after extensive research in Rasasastra. Method of intake, Pathya (wholesome), Apathya (unwholesome), complications during Mercurial medication have been cited in classical verses. Paribhasha (definitions) regarding basics of Rasasastra have been described for better understanding of Mercurial processes. Procedures like Jarana (digestion), Astadasa samskara (eighteen purification procedures), Dhruti (stable liquid metal), Satwapatana (extracting the essence), Bandhana, etc have been elaborately described in the texts, but their techniques are still unclear in practical aspect. A special clause should be created for the use of Mercury in Ayurvedic medicines with respect to its health benefits and disease curing properties. Also there is a need to intensify research in the field of Rasasastra.