TY - JOUR ID - TI - PETROGRAPHY, DIAGENESIS AND DEPOSITIONAL ENVIRONMENT OF NAHR UMR FORMATION, FROM SELECTED WELLS IN CENTRAL IRAQ AU - Jassim A. Al-Jassim AU - Beriwan M. Abdul-Kareem AU - Amanj I. Qaradaghi PY - 2008 VL - 4 IS - 1 SP - 67 EP - 94 JO - Iraqi Bulletin of Geology and Mining مجلة الجيولوجيا والتعدين العراقية SN - 18114539 AB - Nahr Umr Formation is a siliciclastic deposit of the Mesopotamian basin. This formation is mainly composed of sandstone interlaminated with siltstone and shale, with occurrence of thin limestone beds. Nahr Umr Formation is subdivided into three lithostratigraphic units of variable thicknesses on the basis of lithological variations and log characters. Mineralogically and texturally, mature quartz arenites and sandstones are the common type of the Nahr Umr Formation. The sandstones are cemented by silica and calcite material and have had a complex diagenetic history and are cemented by silica and calcite. Compaction, dissolution and replacements are the main diagenetic processes.Prodelta; distal bar; distributary mouth bar; distributary channel; over bank and tidal channel are the main depositional environments recognized for the Nahr Umr Formation, within the studied wells. This formation was deposited in shallow marine and fluvial – deltaic environments and exhibit progradational succession of facies.

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