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: 17 (0 ULg)
Magnetic Valley : a knowledge transfer project
; ; et al
in Data Science Journal (2011), 10Detailed reference viewed: 28 (4 ULg)
IGCP 580 - Magnetic susceptibility, correlations and palaeoenvironment.
Da Silva, Anne-Christine ; ; et al
Conference (2009, September)Detailed reference viewed: 15 (2 ULg)
The IGCP Project 580 Application of magnetic susceptibility on Paleozoic sedimentary rocks has been launched: the project outlines, scope and the first results related to Central European region.
; ; Da Silva, Anne-Christine et al
in Regional Devonian Workshop Prague and Graz (2009)Detailed reference viewed: 25 (4 ULg)
Application of magnetic susceptibility on Palaeozoic sedimentary rocks
; Da Silva, Anne-Christine ; et al
in Abstract book of the IAGA 11th Scientific assembly (2009)Detailed reference viewed: 27 (3 ULg)