Ahmed Hassan Ahmed

6 Questions 30 Answers 0 Followers

Questions related from Ahmed Hassan Ahmed

How to convert the log-bar unit deviation fO2 from FMQ buffer to normal fO2?

I have calculated the oxygen fugacity (fO2) as delta LogfO2 (FMQ) from the olivine-spinel pairs by the method of Balhaus et al. (1991). The results of this calculation is related to the FMQ buffer...

13 October 2018 327 0 View

Is there any example for magmatic Al-spinel (Cr-poor) deposits?

I am wonder if there is any scientific or economic study for Al-spinel deposits (mostly Cr-poor, Cr2O3 < 1 wt.%). In most known cases the chromite deposit is a Cr-rich or Al-rich chromitites...

29 March 2015 5,496 7 View

Does anyone know of a way to estimate mineral proportions based on whole rock analysis?

Is there any software or excel sheet to calculate the mineral proportions (modal % of minerals) based on bulk-rock analysis. Your kind help is highly appreciated.

24 February 2015 1,680 31 View

Do anyone have a spreadsheet for P-T-depth estimation of mantle rocks?

Will appreciate very much if anyone can send me an excel spreadsheet for estimating P-T-depth of mantle rocks using mineral chemistry of olivine, opx, cpx and spinel

05 February 2015 5,305 6 View

How can we differentiate between ophiolitic gabbros and layered intrusion gabbros using geochemistry and/or mineral chemistry?

Gabbros exist as layers in both ophiolite and mafic-ultramafic layered intrusions. How can we differentiate between these modes using geochemistry?

23 April 2014 9,558 4 View

Does anybody have a spreadsheet for calculating the chlorite formula?

How to differentiate between different chlorite types, and how to estimate the octahedral and tetrahedral Al?

26 March 2014 8,467 15 View