Skip to main content

Paleoenvironmental Analysis and Its Significance in Sedimentology: Case Study of the Conglomerate Facies of the Awi Formation, Calabar Flank, Southeast Nigeria | Chapter 7 | Advances and Trends in Physical Science Research Vol. 2

Pebble morphometry of unbroken quartz pebbles collected from the basal section of Awi Formation exposed around Ewen area, southeastern Nigeria was studied for paleoenvironmental reconstruction. Paleoenvironmental analysis refers to the study or use of ancient geological materials (rocks) to infer the depositional environment or setting within which they were deposited. Pebble morphometric analysis has aided the determination of paleoenvironment during the deposition of Awi Formation. The depositional processes responsible for shaping the pebbles and the environment that prevailed during past geological times was characterised. This involved the measurement of the three orthogonal axes (long, intermediate and short), determination of their corresponding roundness, flatness indices and elongation indices for no less than 200 pebbles. The pebbles were selected from 20 points across four exposed sections of the Awi Formation around Ewen village. The roundness was determined using the standard roundness chart. The results show that the pebbles are sub-rounded to sub-angular and predominantly compact-bladed. The mean values for the following morphometric parameters: Flatness index, elongation ratio, maximum projection sphericity index and oblate-prolate (OP) index are 0.57, 0.78, 0.74 and 15.65 respectively. These values are in agreement with those of modern fluvial pebbles. This result was integrated with the deductions from bivariate plots of roundness against elongation ratio and sphericity against OP index, and they all inferred the deposition of the conglomeratic sandstones in a fluvial setting with subordinate transitional setting. Fluviatile process with some overlapping littoral influence has been shown to be responsible for the variation in clast morphology of the paraconglomerates (matrix-supported) of Awi Formation. Integrating all observations viz; the sediment stratification and grading style (fining upwards successions) and the dominant unidirectional nature of the crudely imbricate pebbles, a typical fluvial setting is inferred. It is possible that the jointing, faulting, sheeting and/or exfoliation of the rocks of the Oban Massif, which is believed to be the principal source of the sediments (provenance), also accounts for the abundance of vein quartz in the area which was eventually adapted for this study. Within sedimentary settings as this one with paraconglomerates associated with high energy flux during deposition and other typical channel lag deposits are locations of good economic deposits (placer deposits) and in some cases hydrocarbon accumulation. Therefore, besides the significance for pebble morphometry in deciphering paleoenvironments, it also gives clues for potential sites of ore bodies and/or characteristics of some targets for hydrocarbon pools. There are obviously several methods for paleoenvironmental reconstruction using sediments as earlier mentioned, grain morphology is one. However, care must be taken when reconstructing paleoenvironment because the shape of grains is a result of so many other factors and for effective utilisation, a careful study and integration of all other parameters are recommended.

Biography of author(s)

Emmanuel Etim Okon
Department of Geology, University of Calabar, P.M.B. 1115, Calabar, Nigeria.

Romeo Akombi Ojong
Department of Geology, University of Calabar, P.M.B. 1115, Calabar, Nigeria.


Popular posts from this blog

A Brief Study of Middleware Technologies: Programming Applications and Management Systems | Chapter 15 | Novel Research Aspects in Mathematical and Computer Science Vol. 1

  Many platforms, services, applications, hardware, and operating systems are connected through the middleware layer. Because the middleware layer abstracts much low-level complexity and makes applications and software systems portable, it allows disparate systems to interface and function together in harmony. Middleware technologies enable software engineers to swiftly construct software systems and applications, allowing developers to focus on more important tasks. This chapter examines several types of middleware systems and discusses middleware capabilities, middleware operation, middleware's function in cloud-based systems, and the best middleware platforms to use. Middleware systems are widely utilised and can be found in practically any software system or application. Middleware programmes provide as a link between many sorts of systems and protocols. They serve as a mechanism for various systems. To successfully exchange information, it runs on a variety of operating system

A Prospective Study about Safety and Efficacy of Perioperative Lidocaine Infusion | Chapter 09 | New Horizons in Medicine and Medical Research Vol. 8

 Opioids cause clinically significant side effects such as respiratory depression, immunosuppression, muscle rigidity, negative inotropism, nausea, vomiting, hyperalgesia, urine retention, postoperative ileus, and drowsiness. Perioperative opioids are a major contributor to the United States' and other countries' opioid epidemics. Non-opioid analgesics, particularly lidocaine, are becoming more common for perioperative use as a result of this. A total of 185 adult patients were randomly assigned to one of two groups: control group I (105 patients) [fentanyl group] or group ii (80 patients) [opioid-free anaesthesia group]. Lidocaine 1.5 mg/kg bolus followed by 1.5 mg/kg/h infusion intraoperatively, and 1.5-2 mg/kg/h infusion for 2-8 hours postoperatively were given to patients in both groups at anaesthetic induction. Intraoperatively, both groups received analgesic adjuvants such as diclofenac 75 mg, paracetamol 1 gm, and mgso4 30-50 mg/kg. If the mean arterial pressure (map)

Scientific values of ECA Ligation | Chapter 06 | New Horizons in Medicine and Medical Research Vol. 8

  Previously, carotid artery ligation was done as an emergency procedure to stop severe haemorrhages in the head and neck. Despite this, it was abandoned because to high patient mortality and morbidity. However, ECA ligation, a more selective branch of the carotid artery, has been popular for the same goal in recent decades due to the lack of or modest postsurgical problems compared to Transarterial embolization (TAE). However, a good surge seal pack, especially in the maxilla, is occasionally required to regulate both collateral circulation and backflow of blood from the internal carotid arteries distal to the carotid arteries (ICA). ECA ligation, on the other hand, might be a superior alternative for controlling life-threatening uncontrolled bleeding in this area. Author(S) Details Jachmen Sultana Department of Oral and Maxillofacial Surgery, Dhaka Dental College and Hospital, Bangladesh. Abul Bashar Department of Paediatrics, Comilla Medical College and Hospital, Bangladesh.