Kaliş oluşumu ve özellikleri
Kaliş genel bir terim olup, kurak ve yarı kurak iklim koşullarında gevşek çökeller, tortul kayaçlar ve topraklar içindeki ikincil kalsiyum karbonat (CaCO3) yığışımlarını tanımlamaktadır. Kalişler mikrit (< 4 m) ve mikrosprarit (5-15 m) boyutundaki küçük kalsit kristallerinden oluşmakta ve küçük miktarlardaki diyajenetik mineral oluşumları (sepiyolit, paligorskit, magnezyum kalsit, dolomit gibi) kalsiyum karbonat oluşumlarına (düşük Mg-kalsit) eşlik etmektedir. Kalişler; kireç tozu, yumru, tüp, laminalı kabuk ve sert kabuk gibi farklı oluşum şekillerine sahiptir. Kalişlerde makroskopik kök yapıları ve mikroskopik alfa ve beta dokusal özellikleri yaygın olarak bulunmaktadır. Kalişlerin oluşumu üzerine başlıca iki hipotez önerilmiştir. Bunlar; (a) sızma modeli (per descensum; pedojenik model); çözünmüş CaCO3'ün sızan sulardan çökelimini tanımlamakta ve (b) yeraltı suyunun kapiler yükselim (per ascensum; yeraltısuyu modeli) modelidir. Kaliş oluşumunda kalsiyum değişik kaynaklardan sağlanır.
Caliche formation and features
Caliche is a general term that describes a secondary carbonate accumulation in unconsolidated sediments, sedimentary rocks and soils under semi-arid and arid climate conditions. Caliches are composed dominantly of small calcite crystals in micrite (< 4 m) and microsparite (5-15 m) size. Small amount ofdiagenetic minerals such as sepiolite, palygorskite, magnesium calcite and dolomite etc. are associated with calcium carbonate (low Mg-calcite) occurrences. Caliche appears in a variety of forms such as chalky powdery, nodular, tubular, laminated crust, hardpan (indurated crust). In caliche, macroscopic rhizolithic structures and microscopic alfa and beta fabric constituents are common. Two main hypotheses which explain the origin of caliche. These are; (a) downward movement of dissolved CaCO3 (per descensum; pedogenetic); and (b) capillary rise from groundwater (per ascensum; groundwater) models. During caliche formation, calcium is provided from varied sources.
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- Aristarain, L. F., 1970. Chemical analyses of caliche profiles from the high plains, New Mexico. Journal of Geology, 78,201-212.
- Demicco, R.V. and Hardie, L.A., 1994. Sedimentary structures and early diagenetic features of shallow marine carbonate deposits. SEPM Atlas Series 1, Tulsa, Oklahoma, 265 p.
- Eren, M., Kadir, S., Hatipoğlu, Z., ve Gül., M., 2004. Mersin yöresinde kaliş gelişimi. TÜBİTAK Projesi YDABAG-102Y036, 13 6 s., (Yayınlanmamış).
- Esteban, M. and Klappa, C.F., 1983. Subaerial exposure environment. In: Scholle, P.A., Bebout, D.G., and Moore, C.H., (eds.), Carbonate Depositional Environments, Association of American Petroleum Geologists Memoir 33, Tulsa, Oklahoma, p. 1-54.
- Goudie, A. S., 1973. Duricrusts in Tropical and Subtropical Landscapes. Clarendon Press, Oxford, 174 p.
- Goudie, A. S., 1983. Calcrete. In: Goudie, A.S. and Pye, K., (eds.), Chemical sediments and geomorphology. Academic Press, London, p.93-131.
- Goudie, A. S., 1996. Organic agency in calcrete development. Journal of Arid Environment, 32,103-110.
- James, N.P. and Choquette, P.W., 1984. Diagenesis 9. Limestones- The meteoric diagenetic environment. Geoscience Canada 11,161-194.
- Klappa, C.F., 1980. Rhizoliths in terrestrial carbonates: classification, recognition, genesis and significance. Sedimentology, 27,613-629. Machette, M.N., 1985. Calcic soils of the southwestern United States. Geological Society of America, Special Paper No. 203, 1-21.
- Semeniuk, V., and Meagher, T.D., 1981. Calcrete in Quaternary coastal dunes in South western Australia: a capillary-rise phenomenon associated with plants. Journal of Sedimentary Petrology 51,47-68.
- Tucker, M.E., and Wright, V.P., 1990. Carbonate sedimentology. Blackwells, Oxford, 482 p.
- Tucker, M.E., 1991. Sedimentary petrology: an introduction to the origin of sedimentary rocks. Blackwell Science, Oxford, 260 p.
- Watts, N.L., 1980. Quaternary pedogenic calcretes from the Kalahari (Southern Africa): mineralogy, genesis and diagenesis. Sedimentology, 27,661-686.
- Wright, V.P., 1990. A micromorphological classification of fossil and recent calcic and petrocalcic microstructures. In: Douglas, L.A. (ed.), Soil Micromorphology: A Basic and Applied Science, Elsevier, Amsterdam, v. 19, 401-407.
- Wright, V. P., and Tucker, M. E. (Eds.), 1991. Calcretes. Blackwell Scientific Publications, Oxford, 351 p.
- ISSN: 1016-9172
- Başlangıç: 1977
- Yayıncı: TMMOB Jeoloji Mühendisleri Odası