| Article Details : |
|
| | | Article Name : | | | Provenance and Depositional Environment of
Sediments of the Awi Formation, Calabar Flank,
Southeastern Nigeria | | Author Name : | | | UKPONG, Aniediobong. Jonah, EKHALIALU, Ogie Macaulay, OGIDI, Anthony Odama, OSUNG, Wilson Edet | | Publisher : | | | Bridge Center | | Article URL : |  | | | Abstract : | | | The Awi Formation is a significant ancient deposit of fluvial
origin and provides a comprehensive record of the geomorphologic and
sediment history that occurred during their deposition. Five (5)
sediment samples and four hundred (400) pebbles were collected from
the Awi Formation for heavy mineral and pebble morphometric
analysis respectively in order to determine their provenance and
depositional environment. A total of six hundred and seven (607) nonopaque heavy mineral grains were counted and their properties were
studied. The dominant heavy mineral grains in the study area based
on the analyzed sample include: tourmaline (34.7%), zircon (21.9%)
and rutile (21.3%). The Zircon Tourmaline Rutile (ZTR) index of the
study area was calculated and ranged from 45% to 85%. This implies
that the sediments of the Awi Formation ranged from mineralogically
mature – mineralogically immature sediments. Most of the heavy
mineral grains (tourmaline and zircon) are sub-rounded while others
(staurolite, garnet, kyanite and apatite) are angular. This implies that
sediments of the Awi Formation have multiple sources. The heavy
mineral grains studied are tourmaline (34.7%), zircon (21.9%), rutile
(21.3%), staurolite (9.8%), garnet (7.3%), kyanite (2.9%) and apatite (2.1%). These heavy mineral assemblages indicate that the igneous and
metamorphic rocks of the Nigerian basement complex (particularly the
Oban Massif) are the source of these sediments. The flatness ratio (FR)
for the pebbles has a range of 0.28-1.44 while the mean elongation
ratio (ER) evaluated for the pebbles of Awi Formation falls within 0.39
- 0.83. The forms of the pebbles in the studied area are Compact (C),
compact bladed (CB), Bladed (B) and compact elongate (CE) which
indicate a fluvial setting with little beach influence. The average
roundness value of the pebbles from the study area is 57.6 % with a
range of 38.2% - 73.3%. This further confirms the beach influence on
the environment. Most of the sphericity values for the pebbles in the
study area are greater than 0.66 and therefore indicative of a fluviatile
origin with minor beach influence. The bivariate plot of sphericity
versus oblate-prolate index indicates that the pebbles were dominantly
from a river environment with little beach influence. Bivariate plot of
elongation versus roundness indicates littoral influence on the pebbles
while bivariate plot of maximum projection sphericity versus oblateprolate index is suggestive of a dominant river environment with
minor beach influence. The deductions from the bivariate plots of
pebbles of the Awi Formation are a pointer to the fact that the Awi
Formation was deposited by fluvial processes with little littoral
influence. | | Keywords : | | | Awi Formation, Calabar Flank, Depositional
environment, Fluvial, Heavy mineral, Littoral, Pebble morphometry,
Provenance.
|
|
|
|
|
|
|
|
| Announcements
|
- Volume 9, issue 5, August issue - publishing in progress
- Volume 9, Issue 2/ May 2021 publishing IN PROGRESS
- Call for Papers: open. Articles will be uploaded constantly, once the evaluation process is complete.
- The Certificates of Publication can be downloaded from RECEIVED ARTICLES section.
- COVER - VOLUME 2, ISSUE 12 / MARCH 2015
- COVER - VOLUME 3, ISSUE 2 / MAY 2015
- COVER - VOLUME 3, ISSUE 3 / JUNE 2015
- COVER - VOLUME 3, ISSUE 4 / JULY 2015
- COVER - VOLUME 3, ISSUE 8/ NOVEMBER 2015
- COVER - VOLUME 4, ISSUE 4 / JULY 2016
- COVER - VOLUME 4, ISSUE 5 / AUGUST 2016
- COVER - VOLUME 7, ISSUE 11/ FEBRUARY 2020
- Volume 9, issue 3, June 2021 publishing in progress
|
|
|
| New Launched Project |
 |
|
|
| Recommend & Share
|
|