چينه شناسي بخش زيرين سازند اميران در شمال غرب و جنوب شرق خرم آباد

Stratigraphy of lower part of Amiran Formation in N.W and S.E of Khorramabad

به منظور مطالعه ي چينه شناسي بخش آغازين سازند اميران، مقاطع چينه شناسي چم سنگر در جنوب شرقي و تنگ شبيخون در شمال غربي خرم آباد انتخاب و در برّرسي هاي ميكروبيواستراتيگرافي، 23 جنس و 35 گونه ي مختلف از روزن بران كف زي در اين برش ها شناسايي و معرّفي شدند كه عبارتند از: Loftusia minor, L. harisoni, L. coxi, L.elongata, L. morgani, L. sp., Dicyclina schlumbergeri, D. sp., Minouxia lobata, M. sp., Cuneolina sp., Antalyna korayi, Psuedolithounella sp., Broekinella sp., Omphalocyclus macroporus, Orbitoides media, O. cancavatus, O. tissoti, O. apiculata, Siderolites calcitrapoides, S. sp., Rotalia trochidiformis, R. sp., Nezzazatinella sp., Vania anatolica, Valvulammina sp., Murciella sp., Trochospirsa sp., Idalina antique, Dictyoconella complanata, Cyclammina sp., Dictyoconus sp., Gavelinella sp., Goupillaudina sp., Miliolids. مطالعات ميكروپاليونتولوژي، سن قسمت آغازين سازند اميران در اين ناحيه را، مايس تريشتين مياني تا پسين نشان دادند. به نظر مي رسد با توجه به كثرت و اندازه ي بزرگ روزن بران، محيط تشكيل فليش هاي سازند اميران در تامين مواد مورد نياز براي ساخت ديواره ي آگلوتينه موثر بوده است.

In order to study of stratigraphy of Lower part of Amiran formation In Northwest and Southeast of Khorramabad, tow stratigraphic sections were chooses consist of Cham sangar section at Southeast and Tang –e shabikhon section at Northwest of Khorram Abad. In microbiostratigraphy investigations were identified 23 genuses and 35 various species of benthic foraminifera in these sections which are identified include: Loftusia minor, L. harisoni, L. coxi, L. elongata, L. morgani, L. sp., Dicyclina shlumbergeri, D. sp., Minouxia lobata, M. sp., Cuneolina sp., Antalyna korayi, Psuedolithounella sp., Broekinella sp., Omphalocyclus macroporus, Orbitoides media, O. cancavatus, O. tissoti, O. apiculata, Siderolites calcitrapoides, S. sp., Rotalia trochidiformis, R. sp., Nezzazatinella sp., Vania anatolica, Valvulammina sp., Murciella sp., Trochospirsa sp., Idalina antiqe, Dictyoconella complanata, Cyclammina sp., Dictyoconus sp., Gavelinella sp., Goupillaudina sp., Miliolids. According to the micropaleontology data, the age of Lower part of Amiran Formation at Northwest and Southeast of Khorramabad is middle to upper Maestrichtian. Micropaleontological data indicate that large quantity and size of agglutinate foraminifers in Lorestan area that seem Amiran formation ?s flysh were effected to the agglutinate shell growing Key words: Amiran Formation, Cham sangar, Khorramabad, Maestrichtian, Tang –e shabikhon