干旱区生态环境知识资源中心(Arid): Clay mineral diagenesis and red bed colouration: ASEMstudy of the Gercus Formation (Middle Eocene), northern Iraq

Arid

DOI	10.1002/gj.3915
	Clay mineral diagenesis and red bed colouration: ASEMstudy of the Gercus Formation (Middle Eocene), northern Iraq
	Al-Juboury, Ali, I; Hussain, Salim H.; McCann, Tom; Aghwan, Thamer A.
通讯作者	Al-Juboury, AI
来源期刊	GEOLOGICAL JOURNAL
ISSN	0072-1050
EISSN	1099-1034
英文摘要	Detailed high magnification scanning electron microscopic (SEM) study supported by petrographic, mineralogical, and geochemical (major and trace element) analysis of the Gercus Formation clastics (sandstones and mudstones) from northern Iraq shows that the main authigenic components are carbonate (dolomite and calcite), clay and haematite minerals with rare quartz, feldspar, and gypsum. The carbonates and sulphate minerals were the main early diagenetic phase in the Gercus Formation and were produced from the post-depositional breakdown of ferromagnesian minerals. These latter are unstable in the oxidizing conditions of the interstitial waters below the desert surface. The main authigenic clay minerals are illite, illite-smectite, and palygorskite. The presence of tangential illite coating and illite-smectite in the sandstones can be related to their desert origin. Palygorskite is associated with dolomite, calcite, and haematite. These mineral associations may indicate early diagenesis in evaporitic and saline conditions. It also confirms the syndepositional and diagenetic origin for the clayey-haematitic matrix and pigment of the Gercus Formation. Haematite occurs as extremely fine-grained crystals mixed with authigenic clays and exhibits a range of shapes (e.g., fibrous to lath-shaped aggregates, small spherical grains, specularite crystals, blade-shaped, rosette-like clusters, and a lump of bright spheroid-shaped haematite/goethite). The arid to semi-arid conditions together with the oxidizing and alkaline interstitial water favoured the noted mineral assemblage within the Gercus Formation.
英文关键词	Gercus Formation Iraq Middle Eocene red beds scanning electron microscopy
类型	Article ; Early Access
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000552248700001
WOS关键词	KURDISTAN REGION ; IRON-BACTERIAL ; ALLUVIAL-FAN ; THRUST BELT ; ZAGROS ; BASIN ; ORIGIN ; EVOLUTION ; SANDSTONES ; TRANSITION
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/328115
作者单位	[Al-Juboury, Ali, I; Hussain, Salim H.; Aghwan, Thamer A.] Univ Mosul, Coll Sci, Geol Dept, Mosul, Iraq; [McCann, Tom] Univ Bonn, Inst Geowissensch Geol, Bonn, Germany
推荐引用方式 GB/T 7714	Al-Juboury, Ali, I,Hussain, Salim H.,McCann, Tom,et al. Clay mineral diagenesis and red bed colouration: ASEMstudy of the Gercus Formation (Middle Eocene), northern Iraq[J].
APA	Al-Juboury, Ali, I,Hussain, Salim H.,McCann, Tom,&Aghwan, Thamer A..
MLA	Al-Juboury, Ali, I,et al."Clay mineral diagenesis and red bed colouration: ASEMstudy of the Gercus Formation (Middle Eocene), northern Iraq".GEOLOGICAL JOURNAL