Pollen Grain Proportions as a Paleoecological Reconstruction Tool: The Correlativity of Zonocostites Ramonae and Monoporites Annulatus in the Niger Delta Basin as a Case Study

Abstract

Zonocostites ramonae and Monoporites annulatus are the most abundant pollen in each of the wells M-1, 2 and 3. They constitute 82.4%, 90.0% and 91.5% of the total pollen respectively. The proportionality of the two taxa was considered for predicting the prevailing paleoecological condition during the deposition of sediments in the studied wells. The mean values of Z. ramonae in the wells were 88.8, 269 and 169 respectively; that of M. annulatus were 5.76, 11.7 and 16.1. The correlation coefficient (rc) were 0.634, 0.666 and 0.189 respectively whilst the regression coefficient values were -0.883, 6.16 and 14.7. The coefficient of variation percent (CV%) were 52.3, 298 and 259 respectively for Z. ramonae and 107, 77.3 and 72.7 respectively for M. annulatus. The coefficient of alienation and index of forecasting efficiency ranged from 0.746 to 0.982 and 0.018 to 0.254 respectively. The percentage of the difference in the occurrence of the two taxa varied greatly; there were five samples with 100%, 96 dominated with >50.0% and one of the remaining two samples had a negative value whilst the other had 0.00%. The correlation coefficient indicated that the occurrence of Z. ramonae and M. annulatus in M-1 and M-2 was very significantly different but not significantly different in M-3 at rc = 0.05. The cross correlation between Z. ramonae and M. annulatus showed that both spectra were generally not coherent which meant that these taxa only slightly shared their source area. This work inferred that whilst Z. ramonae always suggested a mangrove environment, however, using M. annulatus as a simple indicator of arid condition may overstate trends or boundary transitions and also disregard seasonal variation in swamp communities. Predicting the relationship of occurrence in these taxa might be difficult since the reduction in the error of prediction (IFE) ranged from low to very low (0.226, 0.254, 0.018).