Premium
THE ZUBAIR FORMATION, EAST BAGHDAD OILFIELD, CENTRAL IRAQ
Author(s) -
Ali A. Jawad,
Aziz Z. R.
Publication year - 1993
Publication title -
journal of petroleum geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 42
eISSN - 1747-5457
pISSN - 0141-6421
DOI - 10.1111/j.1747-5457.1993.tb00344.x
Subject(s) - geology , facies , sedimentary depositional environment , geochemistry , arenite , marine transgression , siltstone , geomorphology , petrology , paleontology , structural basin
A number of depositional cycles have been defined from the Zubair Formation in central Iraq ( East Baghdad field). Each cycle represents the growth of a deltaic lobe (construction phase), followed by a hiatus during which the delta margin was subjected to wave and tidal activity (destruction phase), succeeded by a marine transgressive shale by which the cycle was concluded. When the growth of the deltaic lobe is renewed over a shale base, a new cycle begins. For each depositional cycle, four facies were identified from sections of core samples. These are: low‐sinuosity (distributary) channels (facies A); marsh (facies B); chenier (facies C); and shelf (facies D). Facies A. B and C comprise the lobe, i.e. indicate a marine regression, whereas facies D concludes the cycle and indicates a transgression. The sandstones of the Zubair Formation are classified as quartz arenites: they are mineralogically and texturally mature, fine‐ to very‐fine grained, well‐ to moderately‐well sorted, fine‐ to nearly‐symmetrical, skewed and mesokurtic. The rocks of the source area are acidic‐igneous. The source area, located within the Arabian Shield, underwent successive periods of tectonic renewal giving rise to high values of sediment supply, and lower values during intervening periods. The detrital materials supplied were to a large extent recycled.