Short Note Extraction of calcified Radiolaria and other calcified microfossils from micritic limestone utilizing Acetic acid
ABSTRACT: Micrite nodules are the only source of Radiolaria within the upper Tithonian to Aptian (Upper Jurassic-Lower Cretaceous) interval of Great Valley Supergroup (GVS), California Coast Ranges. Radiolaria recovered from GVS micrite nodules are either calcified or pyritized. This paper describes...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.114.1313 http://www.utdallas.edu/~smk736/mypapers/Karaminia.pdf |
| Summary: | ABSTRACT: Micrite nodules are the only source of Radiolaria within the upper Tithonian to Aptian (Upper Jurassic-Lower Cretaceous) interval of Great Valley Supergroup (GVS), California Coast Ranges. Radiolaria recovered from GVS micrite nodules are either calcified or pyritized. This paper describes a method of extracting well preserved calcified radiolaria from micrites utilizing acetic acid. The same method resulted in the extraction of well preserved Upper Cretaceous planktonic foraminifera from indurated micrite within the Khoy ophiolitic complex of northwestern Iran; from micrite in the Green Horn Formation, Pueblo Colorado; from indurated chalk in the Austin Chalk, Dallas Texas, and from indurated micrite in Albian Duck Creek Formation of Texas. The preservation of extracted radiolaria and planktonic foraminifera from the indurated micrites and chalk is excellent and is often comparable to that found in most DSDP/ODP samples. Assumedly the clay content of the rock, and the chemical homogeneity of the calcified test are the principal reasons for differential solution of the acetic acid. TEXT-FIGURES 1-4 1-2. Surface of the rock sample etched with HCl, note the pits on the rock fragments surface, representing calcified radiolarian, and Planktonic foraminifera dissolved faster than matrix. 3. Radiolarians at the rock surface after dissolving, and removing the disaggregated matrix with this method. 4. Planktonic foraminifera at the rock surface after dissolving, and removing the matrix with this new method. micropaleontology, vol. 50, no. 3, pp. xxx-xxx, text-figures x-xx, plates x-x, tables x-x, 2004 1 Seyed Mohsen Karaminia: Extraction of calcified Radiolaria and other calcified microfossils from micritic limestone utilizing Acetic acid |
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