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Morphometric analysis of pebbles in verification of transport processes and interpretation of palaeoenvironment: A case study from the Ogwashi Formation (Oligocene), Niger Delta Basin, Nigeria

Ogbe Ovie B., Osokpor Jerry, Emelue Chukwunomso V., Ocheli Azuka

Geologos

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2023

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Vol. 29, No. 1

21--31

EN

The present paper discusses a palaeoenvironmental interpretation of the Oligocene Ogwashi Formation (Niger Delta Basin, Nigeria) through morphometric analysis of pebbles, a research method essentially depending on the quantitative evaluation of pebble size and shape which change during transport processes in a range of depositional environments. The relationship of bivariate and ternary-diagram plots of independent functions was determined from freshly exposed sandstone sections in quarries at Ibusa, near Asaba, Nigeria. The grain size of pebbles ranges from fine (11.00 mm) to very coarse (41.33 mm), with a mean size of 21.05 mm (coarse pebbles). A bivariate plot of the flatness index vs maximum projection sphericity index shows 37% of the pebbles to fall within a beach (marine) environment, and 33% within a fluvial environment; the remaining 30% are uncertain. The maximum projection sphericity index vs oblate-prolate index bivariate plot indicates that 47% of pebbles fall within a marine environment and 22% within a fluvial environment, while the remaining 31% are uncertain. The sphericity-form ternary diagram plot shows that the pebbles primarily comprise bladed, platy, very bladed and very platy of near-equal proportions with minor elongate and very elongate stones, which suggests that the pebbles are diverse in origin. The sphericity-form bivariate plot indicates that the pebbles are largely of disc and blade shapes with a minor number of spherical and rod shapes. The near-equal proportion of pebbles in different segments of the bivariate and ternary diagram plots, and the wide distribution of the pebble grain sizes and shapes suggest the Ogwashi Formation is composed of redeposited sediments that likely were transported and deposited in a mix of marine and fluvial settings with possible transitional environments. In other words, the pebbles can be interpreted as marine-influenced fluvial sediments in marginal-marine settings.

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Some comments on compositional analysis in management and production engineering

Vives-Mestres M., Martín-Fernández J. A.

Management and Production Engineering Review

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2015

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Vol. 6, No. 2

63--72

EN

This paper introduces the most basic concepts of the compositional analysis of data with a simple but real example form the Management and Production Engineering (MPE) field. Compositional Data (CoDa) are vectors of positive elements that represent parts of a whole and are widely found in MPE, i.e. production times, resource composition, percentage utilization of work stands, waste components. . . The need for an analysis based on ratios of components (or better log-ratios of components) is illustrated step by step, and findings are compared to the corresponding standard methods applied to raw compositions. The paper also exposes the principles of CoDa analysis and presents two basic descriptive tools suitable for CoDa: the clr-biplot and the CoDa dendrogram. The example is a time series, from 1994 to 2013, of motor vehicle production in 8 countries and regions.

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Removal of lindane from wastewater using liquid-liquid extraction process

Patil I. D., Patil Y. S., Pangarkar B. L.

Polish Journal of Chemical Technology

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2013

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Vol. 15, nr 3

81-84

EN

Pesticide pollution is a serious problem being faced. Harmful levels of pesticides are found in the water which is used for daily purposes. In the event of such a scenario, this paper presents a working solution for bringing down the Pesticide levels in the water to safe levels by using the method of liquid-liquid extraction. The experimental liquid-liquid equilibrium data on pesticide-water-solvent ternary mixtures at a temperature of 288.15 K are presented here. The pesticide used here is a chlorinated hydrocarbon called lindane found in the water (underground, land), beverages and foods. The solvents used are Petro-ether-Chloroform (1:1), Ethylene di chloride and n-hexane. The equilibrium generation diagram, triangular diagram, tie lines and bimodal curves as well as the distribution coefficient have been determined and reported. The petro-ether-chloroform was found to be the right solvent for the separation of lindane from wastewater because of high selectivity (25.36) and distribution coefficient (4). The extraction process is simulated into ‘C’ language.