Lower Carboniferous ramp sedimentation of the Central Alborz Basin, North Iran: integrated sedimentological and rock–magnetic studies.
Sardar Abadi, Mehrdad ; Da Silva, Anne-Christine ; et al
in Special Publication - Geological Society of London (2015), 414
The Lower Carboniferous Mobarak Formation in the Alborz Basin (northern Iran) was deposited along the northeastern margin of Gondwana in a carbonate ramp setting. This paper focuses on the Tournaisian ... [more ▼]
The Lower Carboniferous Mobarak Formation in the Alborz Basin (northern Iran) was deposited along the northeastern margin of Gondwana in a carbonate ramp setting. This paper focuses on the Tournaisian stratigraphic interval of this formation that crops out at the Jaban section in the southwestern Central Alborz Basin. The following facies associations, representing different ramp palaeoenvironments, have been identified: (1) mudstone–wackestone outer-ramp facies; (2) crinoidal to skeletal grainstone–packstone mid-ramp facies; (3) peloidal to crinoidal grainstone–packstone inner-ramp facies; and (4) coastal facies, which include a variety of microbial laminated to oncoidal grainstones and mudstones with evaporitic pseudomorphs. This ramp profile was affected by frequent storms that were responsible for the formation of several skeletal to non-skeletal shoals in the distal mid-ramp to the most proximal inner-ramp areas. The development of the skeletal to non-skeletal shoals along the sea side of the ramp formed a semi-enclosed lagoon sensitive to the influence of both high tides and storm surges.The magnetic susceptibility (xin) of all the samples was measured and compared with that of the facies from which the sample was taken. There is a clear link between xin and the facies; the average xin values were higher for the distal facies than for the proximal facies. The xin profile of this Lower Carboniferous carbonate sequence reflects stratigraphic variations in response to relative changes in sea level and the input of detrital materials. In the context of the sequence stratigraphic framework, the average xin values for lowstand and transgressive systems tract deposits are higher than for the highstand systems tract deposits. The clear link between xin and facies indicates at least a partly preserved primary xin signal related to the detrital inputs. However, to obtain a better understanding of the nature and origin of the minerals carrying the xin, we performed hysteresis measurements on selected samples. It appears that the xin signal is mainly carried by lowcoercivity ferromagnetic minerals such as magnetite, with a mixture of relatively coarse grains (detrital fraction) and ultra-fine grains (probably formed during diagenesis). [less ▲]Detailed reference viewed: 24 (0 ULg)
Magnetic susceptibility as a high-resolution correlation tool and as a climatic proxy in Paleozoic rocks - merits and pitfalls: examples from the Devonian in Belgium.
Da Silva, Anne-Christine ; ; Boulvain, Frédéric et al
in Marine & Petroleum Geology (2013), 46Detailed reference viewed: 88 (19 ULg)
Depositional facies and magnetic susceptibility of Mobarak formation (Lower Carboniferous in central and eastern Alborz Mountains, North of Iran).
Sardar Abadi, Mehrdad ; Da Silva, Anne-Christine ; Boulvain, Frédéric et al
in Geologica Belgica Meeting 2012; Moving plates and melting icecaps. Processes and forcing factors; Abstract book (2012)Detailed reference viewed: 87 (13 ULg)
Magnetic Susceptibility and sedimentology techniques applied to unravel the interaction between eustasy and tectonic activity from the Jurassic Kashafrud Fromation (Koppeh Dagh Basin, NE Iran).
Sardar Abadi, Mehrdad ; Da Silva, Anne-Christine ; et al
in Kido, E; Suttner, T; Piller, W (Eds.) et al IGCP-580, 4th annual meeting, 24-30th June 2012, Graz, Austria, Abstract book (2012)Detailed reference viewed: 13 (1 ULg)
Diagenetic factors controlling reservoir quality in the Faraghan Formation (Lower Permian), Darang Field, Southern Iran
; ; Sardar Abadi, Mehrdad et al
in Energy Exploration & Exploitation (2011), 29(2), 109-128
The role of diagenesis in affecting (reduction or enhancement) reservoir quality in the Faraghan Formation in Darang #1 well was investigated. The Faraghan Formation is mainly composed of sandstone facies ... [more ▼]
The role of diagenesis in affecting (reduction or enhancement) reservoir quality in the Faraghan Formation in Darang #1 well was investigated. The Faraghan Formation is mainly composed of sandstone facies along with minor mudstone and siltstone and grades upward into mixed carbonate –siliciclastic facies and then to Dalan Formation carbonates. Depositional environment of this formation comprises various sub-environments of a delta setting in the lower part of the formation which grades upward into a shallow marine clastic environment in the upper part. The processes enhancing reservoir quality include dissolution of carbonate grains and cements and alteration of feldspar grains. Burial history diagram shows that after deposition during Lower Permain, the formation underwent a rapid burial up to 1000 meters below sea level in Upper Permian. Then a slight uplift (about 100 meters) and gradual burial followed up to Mid- Jurassic. Afterwards the formation experienced a series of rapid and moderate uplift from Mid-Jurassic to Tertiary when the formation uplifted to around 2500 meters above sea level. The suitable conditions resulting in dissolution took place in shallow buried sandstones. These conditions occurred two times during burial history: at the early stages of eodiagenesis and during telodiagenesis. The major processes deteriorating reservoir quality include compaction and cementation. Major cement types include carbonate cements (dolomite, siderite), clay cements (kaolinite, sericite, chlorite), silica cement and pyrite cement. The most abundant cement is the carbonate cement especially dolomite. The dolomite cement occurs as intergranular and poikilotopic forms. The most frequent clay cement is sericite which dominates in sitstones and lithicarenites. Silica cement, where present, fills all the pore spaces. The least frequent cement type is pyrite which is found in two forms of poikilotopic and framboidal. Where it is found in the form of poikilotopic cement, it massively fills the pore spaces and deteriorates the porosity and permeability of the sandstones. [less ▲]Detailed reference viewed: 23 (0 ULg)
Delta and deep basin Jurassic deposits from Iran: relationship between magnetic susceptibility and facies
Sardar Abadi, Mehrdad ; Da Silva, Anne-Christine ;
in Abstract 4eme Congrès Français de Stratigraphie, Strati2010, Paris, France, 30 Augustus – 2 September (2010)Detailed reference viewed: 21 (9 ULg)