Palaeoenvironment:Quaternary materials and succession related to climate and sea level change - Essay Example

Palaeoenvironment: Quaternary materials and succession related to climate and sea level change Introduction Understanding of both the sedimentary and environmental responses in the coastal areas to the changes in climate and sea levels is very fundamental for proper management of the coastal areas and land use. Late glacial Holocene back barriers that were formed under the dominant effect of global forcing factors can be a great source of information on the response pattern of the coastal areas to deposition and changes in sea level (Aguzzi et al, 2007). The geochemistry of the wetlands is also very useful in tracing both the palaeoenvironmental changes and impacts of human activities on the changing faces of coastal areas. Normally, a reconstruction of the palaeoenvironment indicates that these areas are characterized by coastal plains, lagoons and alluvial plains (Bard et al, 2000). In this research, a multidisciplinary approach that combines sedimentological and microplaentological analyses will be used to reconstruct the palaeoenvironmental variations.
Equipment
The following equipment was used to gather various data to be used in the research: 5m tape, GPS, compass clino and GS chart.
Discussion
The data that was collected about the core should be analyzed as part of the geological mapping project at a scale of about 1:50,000. A sedimentological report of the core including soil elements such as the mean grain size, structure of the sediments, color, organic matter and peat horizons were included in the geological map (Cearreta et al, 2007). From the sedimentological report, the lowest and uppermost points of the sea level could be established. For further geochemical analysis, evenly distributed samples of sediments were collected at different locations and used for chemical analysis. Determination of the chemical compositions of the sediments can be done using x-ray fluorescence spectrometry.
From the sedimentological report of core analysis, stratigraphic intervals existing in the geology of the coastal areas were identified. The late Pleistocene alluvial faces were identified with an alteration of greyish yellow fine sands and silty clays. Coastal plains on the other hand predominantly consist of grey silty clays and silts and normally have a well-developed layer of peat. Coastal plains usually correspond to a variety of depositional environments developed during the late glacial period in a low gradient coastal plain. The faces of lagoons consist of grey sandy silt and silty clays that are normally organized in a fining upward tendency (Fiorini, 2004). Modern alluvial over backs are characterized by bioturbated yellow silty clays and clayey silts that are organized in a coarsening upward trend (Straaten et al, 2006). The late Pleistocene palaeoenvironment is identified with thick alluvial deposits at the lower stratigraphic portion of the core. This period was marked by relative rises in sea level and frequent oscillations between the supply of sediments and the area under the sea and this led to the evolution of brackish lagoons.
Conclusion
A reconstruction of the paleoenvironment of Mallorca can be identified with various features that are associated with the Pleistocene period and different geochemical characteristics. The palaeoenvironment has undergone great evolution during both the glacial and late glacial periods and this way, only traces of their characteristics remain and have been used to reconstruct the environment.
References
Aguzzi,M.,Amorosi,A.,Colalongo,M.L.,RiccilucchI, M., Rossi, V., Sarti, G. and Vaiani, S. C.. Late Quater-nary climatic evolution of the Arno coastal plain (Western Tuscany, Italy) from subsurface data. Sedimentary Geology, 2007.
Bard, E., Hamelin, B., Fairbanks, R. G. and Zindler, A.Calibration of the 14C time scale over the past 30,000 years using mass spectrometric U–Th ages from Barbados corals. Nature, 2000.
Cearreta, A., Alday, M., Freitas, M. C. and Andrade C. Postglacial foraminifera and paleoenvironments of the Melides lagoon (SW Portugal): towards a regional model of coastal evolution. Journal of Foraminiferal Research, 2007.
Fiorini,F.,.Benthic foraminiferal associations fromUpper Qua- ternary deposits of southeastern Po Plain, Italy. Micro paleontology, 2004.
Straaten,L.M.J.U.Van,Holocene and Late Pleistocene sedimentation in the Adriatic Sea. Geologische Rundschau, 2006. Read More