Karadeniz'in Güncel Çökellerinin Jeokimyası

Yıl 1987, Cilt: 11 Sayı: 1, 47 - 67, 15.04.1987

Namık Çağatay Taner Saltoğlu Abdullah Gedik

Öz

Karadeniz'de yaklaşık son 30.000 yılda çökelen, kokolit, sapropel ve lutit birimlerinin jeokimyası, Karadeniz'in kendine özgü morfolojik, jeolojik, biyolojik ve kimyasal özellikleri ile denetlenmiştir. Karadeniz çökellerindeki iz elementler, istatistiksel dağılımları, üç değişik birimdeki bollukları ve alansal dağılım özellikleri açısından "iç kökenli" (autigenic) ve "dış kökenli" (allogenic) olmak üzere, iki grupta toplanır. Basen içinde, çökellerle eş zamanlı olarak oluşan minerallere ve organik maddeye bağlı, Mo, Cu, U, B, Ni, Co, V ve Ba gibi iç kökenli elementler, organik madde ve demir sülfidlerce zengin sapropel biriminde, diğer birimlerdekine göre daha bol bulunur. Bu elementler, çökelme hızının genel olarak düşü k olduğu derin düzlüklere doğru artan değerler gösterirler. Öte yandan lutit birimi, Ti, Zr ve Cr gibi daha çok kırıntı minerallere bağlı dış kökenli elementler olarak gözüken V ve Ni; kokolit ve lutit biriminde dış kökenli elementlere özgü dağılım biçimi sunarlar. Diğer iki birime göre biyolojik kökenli olarak yüksek Ca ve Sr içeren kokolit birimi; ayrıca sapropel biriminden daha yüksek SİO2, AI2O3 ve TİO2 içeriğine sahiptir. Karadeniz'in güncel çökellerinin ortalama bileşimi, derindeniz çökellerinin bileşimine göre Cu, Ni, Co, Ba, Mn ve V yönünden çok fakirdir. Ortalama bir şeyi bileşimine genelde bir benzerlik sunmasına karşın, Karadeniz çökelleri, şeyl veya siyah şeyl bileşimine göre daha yüksek Ca, daha düşük V, Pb, Cu, Ba ve Y içerirler.

Anahtar Kelimeler

Jeokimya, Çökel, Karadeniz

Geochemistry of the Recent Black Sea Sediments

Öz

Geochemistry of the Recent Black Sea sediments comprising the Coccolithic, Sapropelic and Lutite units is largely governed by the special characteristics of the Black Sea, related to its geology, morphology, biology and chemistry. According to their statistical distribution, their abundance in the three units, and their areal distribution, the trace elements in the Black Sea sediments fall into the "authigenic" and "allogenic" element groups. The authigenic elements occur as associated largely with the authigenic minerals and organic matter, and have been syngenetically incorporated into the sediments. The Sapropelic unit is relatively more enriched in the authigenic elements such as Mo, U, Cu, B, Ni, Co, V and B than the other two units. These elements show trends of increasing concentration towards the abyssal plains of the Black Sea basin, which are generally characterized by low rates of sedimentation. On the other hand, the allogenic elements such as Ti, Zr, and Cr which are dominantly of detrital mineral origin, occur in higher concentrations in the Lutite unit than the Sapropelic and Coccolithic units. Vanadium and Ni, which appear as authigenic elements in the Sapropelic unit, present a characteristic allogenic distribution pattern in the Coccolithic and Lutite units. Compared with the Lutite and Sapropelic units, the Coccolithic unit is relatively elevated in Ca and Sr, which is widely due to the Coccolithic shells made up of CaCOj. Moreover, the Coccolithic unit is more enriched in SİO2, AI2O3 and TİO2 than the Sapropelic unit. A comparison of the average composition of the Black Sea sediments with that of the deep sea sediments shows that the former are considerably depleted in many elements including Cu, Ni, Co, B, Mn and V. On the other hand, the average composition of the Black Sea sediments is similiar to that of shales except for the higher content of Ca, and relatively lower contents of V, Pb, Cu, Ba and Y.

Anahtar Kelimeler

Geochemistry, Sediment, Karadeniz

Kaynakça

• AGAMIROV, S.SH., 1963a, Precipitation of uranium in the bottom of the Black Sea: Geochemistry International, 1,104-106.
• AGAMIROV, S.SH., 1963b, Geochemical balance of the radioactive elements in the Black Sea Basin: Geochemistry International, 6, 630-633.
• AKSARAY, F., 1978, Karadeniz şelfinin yapısı: Türkiye 4. Petrol Kongresi.
• ARMANDS, G., 1972, Geochemical studies of uranium, molybdenum and vanadium in a Swedish alum shale: Stockholm Contrib. Geol., 27, 148 s.
• BATURIN, G.N., 1973, Uranium and sedimentation in Black and Azov Seas: Litologiya; Poleznye Iskopaemye: 5, 21-32.
• BATURIN, G.N. ve KOCHENOV, A.V., 1968, Relation between some rare metals and organic material in marine sediments: Oceanology, 7 (6), 792-809.
• BATURIN, G.N., KOCHENOV, A.V., ve KOVALEVA, S.A., 1965, Some features of uranium distribution in Black Sea water: Doklady Akad. Nauk SSR, 166, 172-174.
• BELL, R.T., 1978., Uranium in black shales- a review- M.M.
• KIMBERLEY (ed.). Short Course in Uranium Deposits, Mineralogical Association of Canada, Toronto, S. 307-329.
• BURGER, K., 1953, Mikro-Elementaranalyse. Industrieverfahren zur Bestimmung von Kohlenstoff und Wasserstoff. W.C. Heraeus GMBH. ABT Elektrowaerme. Hanau.
• ÇAĞATAY, N., 1983, Karadeniz'in güncel çökellerinde değişik uranyum analiz ve çözümleme yöntemlerinin karşılaştırılmas ı: T.J.K. Bülteni, 26, 187-196.
• ÇAĞATAY, N., SALTOĞLU, T., GEDİK, A., 1986, Karadeniz güncel çökellerinin jeokimyası: MTA rapor no 7844 s. 14-34.
• DEGENS, E.T., KHOO, F. ve MİCHALEİS, W., 1977, Uranium anomaly in Black Sea: Nature, 269, 566-569.
• DEGENS, E.T., ve ROSS, D.A. (Ed)., 1974, The Black Sea Geology, Chemistry, and Biology: AAPG Memoir 20, 633 s.
• DEUSER, W.G., 1974, Evolution of anoxic conditions in Black Sea during Holocene: Degens, E.T. ve Ross, D.A. (ed), 133-136.
• FLOROVSKAYA, V.N., ve GURSKIY, YU. N., 1966 Organic material in deep-water sediments of Black Sea: Geochemistry, 3(1), 78-83.
• GEDİK, A., SALTOĞLU, T. ve KAPLAN, H., Karadeniz güncel çökelleri ve uranyum içerikleri: M.T.A. Enstitüsü Dergisi, 92, 97-119.
• GLAGOLEVA, M.A., 1961, Regularities in distribution of chemical elements in modem sediments of the Black Sea: Am. Geol. Inst., 135 (1-6)
• GREEN, J., 1959, Geochemical table of the elements of 1959: Geol. Soc. America Bull., 70 (9), 1127-1183.
• GUNDLACH. H ve MARCHİG, V., 1982, Ocean floor "metalliferous sediments" two possibilities for genesis: Amstutz v. d. (ed.). Ore Genesis the State of the Art, S. 200-210, Springer-Verlag.
• HIRST, D.M., 1974, Geochemistry of sediments from eleven Black Sea cores: Degens, E.T. ve Ross, D.A. (ed), 430-455.
• HUNT, J.M.,1974, Hydrocarbon geochemistry of Black Sea: Degens, E.T. ve Ross, D.A. (ed.) 499-504.
• KOCHENOV, A.V., BATURIN, G.N., KOVALEVA, S.A., EMEL’YANOV, E.M. ve SHIMKUS, K.M., 1965, Uranium and organic matter in the Sediments of the Black and Mediterranean Seas: Geochemistry, 3, 302-313.
• KOCHENOV, A.V., KOROLEV, K.G., DUBINCHUK, V.T. ve MEDVEDEV, YU.L., 1977, Experimental data on the conditions of precipitation of uranium from aqueous solutions: Geochemistry International, 14(4), 82-87.
• KOCYZ, F.F., TOMlC, B. ve HECHT, F., 1957, Zur Geochemie des urans im Ostseebecken: Geochimica Acta, 11 (1/2), 86-102.
• KORNFELD, J.A. 1964, Geochemistry of uranyl oxides in Devonian marine black shales of North America; Colombo, U. ve Hobson, G.D. (ed). Advances in Organic Geochemistry, Pergamon Press, Oxford, 261-262.
• MASON, B., 1966, Principles of Geochemistry: John Wiley and Sons, Toppan Company; 3. Baskı, 329 s.
• MULLER, G. ve STOFFERS, P., 1974, Mineralogy and petrology of Black Sea sediments: Degens, E.T. ve Ross, D.A. (ed) 200-248.
• PEAKE, E., CASAGRANGE, DJ. ve HOGSON G.W., 1974, Fatty acids, chlorins, hydrocarbons sterols, and carotenoids from a Black Sea core: Degens, E.T. ve Ross, D.A. (ed.) 505-523.
• PELTOLA, E., 1960. On the black schists in the Outokumpu region in Eastern Finland: Finl. Comm. Geol. Bull., 192.
• PHILIPCHUK, M.F. ve VOLKOV, I.I., 1974, Behaviour of molybdenum in processes of sediment formation and diagenesis in Black Sea: Degens, E.T. ve Ross, D.A. (ed) de, 542-553.
• RONA. E. ve JOENSU, O., 1974, 1974 Uranium geochemistry in Black Sea: Degens, E.T. ve Ross, D.A. (ed.) 570-572.
• ROSANOV, A.G., VOLKOV, I.I., ve YAGODINSKAYA, T.A., 1974, Forms of iron in surface layer of Black Sea sediments: Degens, E.T. ve Ross, D.A. (ed.) 542-553.
• ROSS, D.A. ve DEGENS, E.T., 1974, Recent sediments of the Black Sea: Degens, E.T. ve Ross, D.A. (ed), 183-199.
• ROSS, D.A., UCHPI, E., PRADA, K.E. ve MACILVAINE, J.C.,1974, Bathimetry and microtopography of Black Sea: Degens, E.T. ve Ross, D.A. (ed), 1-10.
• ROSS, A.D., STOFFERS, P., ve TRIMONİS, E.S., 1978 Black Sea Sedimentary framework: Initial reports of the Deep Sea Drilling Project, Volume 42, Part 2; Washington (U.S. Government Printing Ofice), s. 359-363.
• ROSLER, H.J. ve LUNGE, H, 1972, Geochemical tables: Elsevier Publ. Co. Amsterdam, 468. s.
• SEVAST'YANOV, V.F. ve VOLKOV, I.I., 1966, Chemical composition of iron-manganese concretions of the Black Sea Am. Geol. Inst., 166 (1-6), 174-176.
• SHIMKUS, K.M. ve TRIMONIS, E.S., 1974, Modem sedimentation in Black Sea: Degens, E.T. ve Ross, D.A. (ed), 249-278.
• SlMONEIT, B.R., 1974, Organic analysis of Black Sea cores Degens, E.T. ve Ross, D.A. (ed), 477-488.
• STARIKOVA, N.D., 1961, Organic Substances in the liquid phase of sea and ocean deposits: Akad. Nauk SSR Inst. Okeanologii Trudy, 50, 130-169.
• TATSUMOTO, M. ve GOLDBERG, E.D., 1959, Some aspects of marien geochemistry of uranium: Geochimica Cosmochimica Acta, 17, 201-208.
• TISSOT, B.P. ve WELTE, D.H., 1978, Petroleum formation and occurrence: Springer-Verlag Berlin, 538 s.
• TOURTELOT, H.A., 1979, Black Shale-its dreposition and diagenesis: Clays and clay minerals, 27(5), 313-321.
• TUREKIAN, K.K., 1969, The Composition of the crust: Origin and Distribution of the Elements, Pergaman Press, Oxford.
• TUREKIAN, K.K. ve WEDEPOHL, K.H., 1961, Distribution of elements in some major units of the earth's crust: Geol. Soc. America Bull., 72, s.186.
• VINE, J.D., SWANSON, V.E. ve BELL, K.G., 1958, The Role of humic acide is the geochemistry of uranium: 2nd Int. Conf. Peaceful Uses, Atomic Energy (Proc. Conf. Geneva) 2. United Nations, New York, 187-191.
• VINE, J.D. ve TOURTELOT, E.B., 1970, Geochemistry of black shale deposits-a summary report: Econ. Geol., 65, 253- 272.
• VOLKOV, I.I. ve FOMNA, L.S., 1974, Influence of organic material and processes of sulfide formation on distribution of some trace elements in deep-water sediments of Black Sea: E.T. ve Ross, B.A. (ed.)., 456-476.
• WEDEPOHL, K.H., DELEVAUX, M.H. ve DOE, B.R., 1978. The potential source of lead in the Permian Kupfreschiefer bed of Europe and some selected Paleozoic mineral deposits in the Federal Rupublic of Germany: contrib. Mineral. Petrol., 65, 273-281.