نویسندگان
1 استادیار، گروه زمین شناسی، دانشکده علوم، مجتمع آموزش عالی گناباد، گناباد، ایران
2 دانشجوی دکتری، رسوب شناسی و سنگ شناسی رسوبی، دانشگاه بوعلی سینا، همدان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In this research, the processes of diagenesis, elemental geochemistry and dolomitization model of Talehzang Formation in the northeast of Kohdasht have been studied. This formation extends to the middle Paleocene-Eocene age in the sedimentary basin of Lorestan. In this area, a 51-meter-thick subsurface section has been selected at the 18 kilometers north of Kohdasht city. In the studied area, the Talehzang Formation is placed on the Amiran Formation as a slope and is covered by the red clastic of the Kashkan Formation as a continuous discontinuity. The petrographic studies led to the identification of several diagenesis processes, including micriteization, neomorphism, cementation, compression, dissolution, and replacement, and the replacement process of dolomitization is more widespread in this formation .Based on this, the paragenetic sequence of the Talehzang Formation deposits in this section has been interpreted in four marine, burial, upwelling and fresh water environments, and during three stages of initial (eugenesis), middle (mesogenesis) and final (telogenesis) diagenesis has fallen The elemental analysis of the samples by EDS and EPMA method (with accuracy of 0.01%) on 12 samples of dolomites showed that the low amount of Fe and the high amount of Sr and Na in dolomicrites and the high concentration of Fe and Mn in dolomicrosparite, and dolosparites along with the existence of some evidences such as algal intraclasts, fenestral porosity and the absence of evaporite minerals indicate the formation of these dolomites from the tidal flat model, seepage and reflux and then shallow to medium and deep burial.
کلیدواژهها [English]
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