Sedimentology and mineralogical characteristics of the coastal sediments in the southern part of the Caspian Sea (Iran)
Subject Areas : Marine Biology
1 - Iranian national institute for oceanographic and atmospheric sciences
Keywords: Sediment, Mineralogy, sedimentology, Caspian Sea Coasts,
Abstract :
Caspian Sea isa unique laboratory, for studying all aspects of oceanography and coastal geology. The main aim of this study was to investigate: textural andmineralogicalcharacteristics ofcoastlinedeposits in the south Caspian Sea. Initially, 100 sediment sampleswere taken in summer2014, along 700 km of the southern Caspian Sea coasts (from HosseinGholi Bay to Astara, one sample per 5-8 km).In addition, after sampling, coastal geomorphology and structures were evaluated and manypictures were taken. Optical mineralogy and grain size analysis were performed on sediments. Heavy mineralsincluding ilmenite, magnetite and goethite, pyroxene, apatite, zircon and garnet and also light minerals included quartz, plagioclase, orthoclase, carbonate fragments and bivalveswere identified. Mapping the distribution of minerals showed that eastern coastline sediments are rich in light minerals and carbonate fragments derived mainly from the erosion of Kopeh-Dagh Mountains. The central and western coast is dominated by heavy minerals, primarily ilmenite and magnetite that are supplied by the Sefidrud River. The moderate abundance of light minerals in the central region results from the sediment flux of the rivers that drain the Cenozoic and Quaternary volcanic coverage and Mesozoic sedimentary deposits.A closer look and compliance with regional geological maps, mineral distribution and beach slope,it was found that in the regions of the study area that the sea slope in the shallow parts are steep and slope of the beach is gentle (east Mazandaran and central parts of gilan province) distribution of heavy minerals such as magnetite and goethite is higher than other areas, while the distribution of Gabbro-Dioritic, and carbonate fragments are more in steep beachareas andareas of sea bed with gentle slope (West of Gilan and Mazandaran). Also gravely coasts are formed in the steep sea bed and beach areas, as the small particles and light mineralsare washed away in these areas.
منابع
باقری،ح.،کاکرودی،ع. و لاهیجانی،ح. 1390. کانی‌شناسی رسوبات کواترنری پایانی در شبه جزیره میانکاله. گزارش نهایی طرح. پژوهشگاه ملی اقیانوس شناسی و علوم جوی، ایران.
پالوسکا،و. ووگنر،آ.ت. 1370. زمین شناسی کواترنر کرانه های دریای خزر. ترجمه شهرابی،م. (۱۳۷۱).سازمان زمین شناسی کشور. گزارش شماره۶0. ایران.
سبحانی،ا.۱۳۴۷. دریای خزر و بررسی مقدماتی رسوب های عهد حاضر سواحل چالوس تا رامسر. سازمان زمین شناسی کشور. ایران.
Abrantes, A., Pinto, F.& Moreira, M. 1999. Ecology of PolychaeteNereisdiversicolor, in the Canal de Mira (Ria de averio, Portugal). Population dynamics, production and oogenic cycle. Acta Oceanology, 20 (4): 267–283.
Baturin, V.P.&Konilova, E.K. 1956. Geological features of south and middle Caspian modern sediments. USSR Academy of Science. Moscow.
Berberian, M. 1983.The southern Caspian: a compressional depression floored by a trapped, modified oceanic crust. Canadian Journal of Earth Science, 20: 163–183.
Blott, S.J.&Pye, K. 2001. A grain size distribution and statistics package for the analysis of unconsolidated sediments. Earth Surface Processes and Landforms, 26: 1237-1248.
Blott, S.J., Croft, D.J., Pye, K., Saye, S.E.& Wilson, H.E. 2004. Particle size analysis by laser diffraction. In: Pye, K., Craft, D.J. (Eds.), Forensic Geoscience: principles, Techniques and Applications.Geological Society.Special publication, vol. 232. London.
Bjorlykke, J.1974. Geochemical and mineralogical influence of Ordovician island arcs on epicontinental clastic sedimentation: a study of lower Paleozoic sedimentation in the Oslo Region, Norway. Sedimentology, 21(2):251 – 272.
Folk, R.L. 1966. A review of grain size Parameters.Sedimentology, 6: 73-93.
Folk, L. 1980. Petrology of Sedimentary Rocks. Hemphill.Austin, Texas.
Firozfar, A., Bromhead, E.N., Dykes, A.P. &LashtehNeshaei, M.A. 2011. Southern Caspian Sea coasts, morphology, sediment characteristics, and sea level change. Proceedings of 27th Annual International Conference on Soils, Sediments, Water& Energy, Massachusetts, USA.
Heiri,O., Lotter, A.&Lemcke, G.2001.Loss on ignition as a method for estimating organic and carbonate content in sediments: reproducibility and comparability of results. Journal of Paleolimnology, 25:101–110.
Kakroodi, A.A., Kroonenberg, S.B., Hoogendoorn, R.M., MohammdKhani, H., Yamani, M., Ghassemi, M.R. &Lahijani, H.A.K. 2012. Rapid Holocene sea-level changes along the Iranian Caspian coast, Quaternary International, 30: 1-11.
Klenova, M.V. 1948. Geology of the Sea.Uchpedgiz. Moscow. (In Russian).
Klenova, M.V., Solovev, V.F., Aleksina, F.A., Vikhrenko, I.M., Kulakova, L.C., Maev, E.G., Rikhter, V.G.&Skorhiakova, N.S. 1962. Geological structure of the Caspian Sea shelf and slope. Soviet Academy of Science. Moscow. (In Russian).
Khaatbari-jafari, M.,Jutean,T.&Cotton, J. 2006. Petrological and geochemical study of the late cretaceous ophiolite of khoy (NW Iran) and related geological formations. Journal of Asian Earth Sciences, 27: 465-502.
Lahijani, H.1997. Riverine sediments and stability of Iranian coast of the Caspian Sea.PhD Thesis, Russian Acd. Sciences.Russia.
Lahijani, H., Rahimpour- Bonab, H.&Tavakoli, V. 2007. Evidence for late holocenehighstands in central Guilan- East Mazandaran, South Caspian Coast Iran.Quaternary International, 197: 55-71.
Lahijani, H. &Tavakoli, V. 2012. Identifying provenance of South Caspian coastal sediments using mineral distribution pattern.Quaternary International, 261: 128–137.
Morton, A.C.&Hallsworth, C. 1994. Identifying provenance specific features of detrital heavy mineral assemblages in sandstones. Sedimentary Geology, 90: 241–256.
Morton, A.C.&Hallsworth, C.R.1999. Processes controlling the composition of heavy mineral assemblages in sandstones. Sedimentary Geology, 124: 3 –29.
NaderiBeni, A., Lahijani, H., MoussaviHarami, R., Leroy, S.A.G., Shah-hosseini, M., Kabiri, K. &Tavakoli, V. 2012. Development of spit-lagoon complexes in response to Little Ice Age rapid sea level changes in the central Gilān coast, South CS, Iran. Journal of the Persian Gulf, 5(16):27-48.
NaderiBeni A., Lahijani, H., MousaviHarami, R., Arpe, K., Leroy, S.A.G., Marriner, N., Berberian, M., Andrieu-Ponel, V., Djamali, M., Mahboubi, A. & Reimer, P.J. 2013. Caspian sea-level changes during the last millennium: historical and geological evidence from the south Caspian Sea.Climate of the Past, 9:1645–1665.
Stöcklin, J. 1974.Northern Iran: Alborz mountains, in Mesozoic- Cenozoic Orogenic Belts: Data for Orogenic Studies. Spencer, A.(Ed.). Geological Society of London Special Publications, 4: 213-234.
Strakhov, N.M. 1954. Sediment formation in Caspian Sea. In: Sediment formation in modern basins. USSR Academy of Science Pub.Ruusia.
Sussli, P.E.1976. The geology of the lower Haraz valley area, central Alborz, Iran: Geological Survey of Iran, 38: 116.
Tucker, M. E.1988. Techniques in sedimentology. Black Wells. Oxford.
Wong, F. L. 2002. Heavy mineral provinces of the Palos Verdes marginSouthern California. Continental Shelf Research,22:899–910.
Zenkovich, V.P .1957. Structure of the south-east coast of the Caspian Sea.USSR Academy of Sciences, Oceanographic CommissionWorks, vol. II. Russia.