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اصول مطالعه میکروفسیل های گیاهی | ||
| نشریه دانشکده فنی | ||
| مقاله 6، دوره 24، شماره 0 - شماره پیاپی 1000187، دی 1351 اصل مقاله (930.27 K) | ||
| نویسنده | ||
| عباس کیمیائی* | ||
| عنوان مقاله [English] | ||
| PRINCIPLES~IN STUDY OF PLANT MICROFOSSILS | ||
| چکیده [English] | ||
| The study of plant microfossils (palynology) has increased in past ten years. This paper reviews briefly the importance of these microscopic particles, the geo logic occurrence, methods of preparation, factors affecting observation and study, identification and classification , and finally the interpretation of palynological results Plant microfossils include any type of fossil plant of microscopic dimensions. A great variety of microfossils is presented. Most of these fossils are related to plant kingdom, and are resistant to common acids. These include cutinous membrances , seed coats, planktonic organisms, the cellulosic coenobia of desmids, the thecal armor plates of Dinophyceae, Charophyte oogonia ,siliceous frustules of diatoms, statospores of chrysophytes, and spore and pollen coates referable to higher plants. A small group of animal microfossils are commonly found associated with the fragments of higher plants and planktonic representatives. These include the chitinous sacs, Tasmanites, hystrichosphers, scolecodonts , and representing types ofannelid worms and graptolite remains. Plant microfossils are not limited to specific facies of sedimentary rocks . Medium to fine textured grey siltstones , shales , and some types of claystones are among the most favorable sources for plant microfossils. In spite of their carbona ceous composition, plant microfossils are commonly durable. They usually become coalified rather than mineralized Preparation and study techniques differ from other types of microfossils • Laboratory functions centered around three essential stages: 1) storage of samples; 2) the chemical and physical disaggregation ; 3) microscopical study and photo micrography. Illustrations and drawings of microfossils are essential for showing structural interpretation Depositional environments of microfossils differ greatly and diagenetic changes affect occurrence in the rocks. Plant microfossils provide detailed stratigraphic and ecologic information. | ||
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