Record of Early to Middle Eocene paleoenvironmental changes from lignite mines, western India

Abstract. Various Eocene hyperthermal events have been recorded from lignite sections of western India in the past decade. To infer the paleoenvironment, during a warm paleotropical climate of India, we have assessed multiple microfossil groups like pollen/spores, dinoflagellates and foraminifera from Early Eocene lignite mine sections from the Cambay (Surkha) and Barmer (Giral) basins and Middle Eocene sections from the Kutch Basin (Matanomadh and Panandhro mines) of western India. The Surkha and Giral sections exhibit a dominance of rainforest elements (Arengapollenites achinatus, Longapertites retipilatus), thermophilic mangrove palm Nypa and (sub)tropical dinoflagellate cyst Apectodinium, Cordosphaeridium and Kenleyia. This palynomorph assemblage is indicative of a marginal marine setting within a hot and humid climate. During the Middle Eocene, the diversity of dinocyst assemblage increased and a decrease in percentage of mangrove elements was observed in the Matanomadh and Panandhro mine sections of the Kutch Basin as compared to the Early Eocene sections of western India. Bloom of triserial planktic (Jenkinsina columbiana) and rectilinear benthic (Brizalina sp., Trifarina advena rajasthanensis) foraminifera indicates eutrophic conditions of deposition during the Late Lutetian–Early Bartonian in the lignite sections of the Kutch Basin which later changed to oligotrophic, open marine conditions towards the Bartonian (planktic E12 zone). This change to oligotrophic conditions coincides with a drastic increase in diversity of planktic foraminifera in the top portion of lignite mines of the Kutch Basin which may be correlated with the Kirthar–Wilson Bluff transgression event in the Bartonian observed across basins in India, Pakistan and Australia potentially linked to sea level rise around the Middle Eocene Climatic Optimum.

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A study on morbidity profile of lignite miners in western India

International Journal of Occupational Safety and Health ◽

10.3126/ijosh.v5i1.16630 ◽

2017 ◽

Vol 5 (1) ◽

pp. 14-16 ◽

Cited By ~ 2

Author(s):

Subroto Nandi ◽

Sarang V Dhatrak ◽

Debasis M Chaterjee ◽

Umesh L Dhumne ◽

Shilpa V Ingole

Keyword(s):

Health Status ◽

Western India ◽

Literacy Rate ◽

Adverse Conditions ◽

Engineering Control ◽

Lignite Mine ◽

Pulmonary Impairment ◽

Function Test ◽

Medical Questionnaire ◽

Lignite Mines

Background: Mining is a hazardous occupation in which workers are exposed to adverse conditions. In India, there are nine working lignite mines, producing about 30 million tons annually. The mines are located in the states of Tamilnadu, Rajasthan and Gujrat. Objective: The present study was carried out in a lignite mine in India to determine the health status of the miners. Methods: 143 workers engaged actively in mining activities were included. The health status of the employees was evaluated by well defined medical questionnaire along with pulmonary function test (PFT) and Audiometry. Result: Findings of the study showed poor literacy rate amongst the miners. Pulmonary impairment was present in 11.88% and noise induced hearing impairment in about 12.15% of the miners. Conclusion: The study findings indicate the need for regular health checkups, health education, personal protective devices and engineering control.

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Lignite deposits of the Kutch Basin, western India: Carbon isotopic and palynological signatures of the early Eocene hyperthermal event ETM2

Journal of Asian Earth Sciences ◽

10.1016/j.jseaes.2017.04.030 ◽

2017 ◽

Vol 146 ◽

pp. 296-303 ◽

Cited By ~ 11

Author(s):

Shailesh Agrawal ◽

Poonam Verma ◽

M.R. Rao ◽

Rahul Garg ◽

Vivesh V. Kapur ◽

...

Keyword(s):

Western India ◽

Early Eocene ◽

Carbon Isotopic ◽

Kutch Basin ◽

Lignite Deposits

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Major perturbations in the global carbon cycle and photosymbiont-bearing planktic foraminifera during the early Eocene

Climate of the Past ◽

10.5194/cp-12-981-2016 ◽

2016 ◽

Vol 12 (4) ◽

pp. 981-1007 ◽

Cited By ~ 18

Author(s):

Valeria Luciani ◽

Gerald R. Dickens ◽

Jan Backman ◽

Eliana Fornaciari ◽

Luca Giusberti ◽

...

Keyword(s):

Carbon Cycle ◽

Northwest Pacific ◽

Early Eocene ◽

Ocean Drilling Program ◽

Low Latitude ◽

Planktic Foraminifera ◽

Early Eocene Climatic Optimum ◽

Carbon And Oxygen Isotope ◽

Hyperthermal Events ◽

Global Carbon

Abstract. A marked switch in the abundance of the planktic foraminiferal genera Morozovella and Acarinina occurred at low-latitude sites near the start of the Early Eocene Climatic Optimum (EECO), a multi-million-year interval when Earth surface temperatures reached their Cenozoic maximum. Stable carbon and oxygen isotope data of bulk sediment are presented from across the EECO at two locations: Possagno in northeast Italy and Deep Sea Drilling Project (DSDP) Site 577 in the northwest Pacific. Relative abundances of planktic foraminifera are presented from these two locations, as well as from Ocean Drilling Program (ODP) Site 1051 in the northwest Atlantic. All three sections have good stratigraphic markers, and the δ13C records at each section can be correlated amongst each other and to δ13C records at other locations across the globe. These records show that a series of negative carbon isotope excursions (CIEs) occurred before, during and across the EECO, which is defined here as the interval between the J event and the base of Discoaster sublodoensis. Significant though ephemeral modifications in planktic foraminiferal assemblages coincide with some of the short-term CIEs, which were marked by increases in the relative abundance of Acarinina, similar to what happened across established hyperthermal events in Tethyan settings prior to the EECO. Most crucially, a temporal link exists between the onset of the EECO, carbon cycle changes during this time and the decline in Morozovella. Possible causes are manifold and may include temperature effects on photosymbiont-bearing planktic foraminifera and changes in ocean chemistry.

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Botryococcus from the early Eocene lignite mines of western India: inferences on morphology, taphonomy and palaeoenvironment

Palynology ◽

10.1080/01916122.2016.1259667 ◽

2017 ◽

Vol 41 (4) ◽

pp. 462-471 ◽

Cited By ~ 4

Author(s):

Madhav Kumar ◽

Priyanka Monga ◽

Anumeha Shukla ◽

R.C. Mehrotra

Keyword(s):

Western India ◽

Early Eocene ◽

Lignite Mines

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Evolutionary trends in coiling of tropical Paleogene planktic foraminifera

Paleobiology ◽

10.1666/0094-8373(2001)027<0327:eticot>2.0.co;2 ◽

2001 ◽

Vol 27 (2) ◽

pp. 327-347 ◽

Cited By ~ 16

Author(s):

Richard. D. Norris ◽

Hiroshi Nishi

Keyword(s):

Mass Extinction ◽

Middle Eocene ◽

Large Body ◽

Tropical Species ◽

Evolutionary Trend ◽

Ancestral State ◽

Early Eocene ◽

Large Body Size ◽

Planktic Foraminifera ◽

Iterative Evolution

Populations of planktic foraminifera display “proportionate” coiling (approximately 50% sinistral and dextral individuals given the data at hand) or may have “biased“ coiling, in which populations are dominated by either sinistral or dextral individuals. The major radiations of planktic foraminifera in the Late Cretaceous, the Paleocene to early Eocene, the middle Eocene, and the Neogene were each initiated by clades with proportionate coiling but subsequently accumulated sinistral and dextral species over time. Upper Maastrichtian foraminifera were predominantly dextral, but only the small number of species with proportionate coiling actually survived the Cretaceous/Paleogene mass extinction. The first Paleocene species with biased coiling appeared about four million years after the extinction and gradually came to represent as much as 50–60% of the tropical species diversity by the latest Paleocene. Tropical taxa with biased coiling suffered a second extinction in the late early Eocene and renewed a trend toward an increased abundance of species with biased coiling in the middle Eocene.Our results for the Paleogene reflect a recurring theme in foraminifer evolution. In each radiation, once the founding species of a clade developed a biased-coiling mode, the descendants tended to maintain biased coiling until the extinction of the clade. The iterative evolution of biased coiling appears to represent an example in which a fundamental feature of development becomes fixed in a clade and inhibits reversion to an ancestral state. Apparently, coiling patterns are heritable in contrast with previous interpretations that coiling is environmentally controlled. On evolutionary timescales, species with proportionate coiling are less susceptible to extinction than species dominated by sinistral or dextral forms. Differential survivorship ensures that each radiation is initiated from founders with proportionate coiling following mass extinction. Hence, coiling preferences represent a case where the establishment of an evolutionary trend is caused by drift away from a “limiting boundary,” much like the evolution of large body size from ubiquitous small ancestors.

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