Dear Mr. Hassan,

I agree with Dr. Towe, that the anomalies of Ce and Eu play a significant part, particularly Ce which responds to redox changes that are fundamental in the mobilization (organo-metallic complexes), thransort (chelat complex) and concentration of iron. You will find a lot of case studies of  these anomalies, also in papers dealing with a different set of elements or metal deposits. I would like to refer also to the classical studies covering Fe-bearing ochres of the deep sea, BIF and ironstone deposits quoted in Maynard (Geochemistry of Sedimentary Ore Deposits). He listed some of the REE elements. Investigations of the isotopes should not only focus on oxygen but also on carbon which is present in the afore-mentioned carriers of Fe and also in one of the most important Fe host minerals siderite (+ ferroan dolomite), both of which show up in  ironstones too.

Best regards

Harald G. Dill

Dear Jubril Hassan

My suggestion try to look moreover on Agaki studies on theory of  "leftover" in

Akagi T., 2013 Rare earths element silicic acid complexes in seawater to explain the incorporation REEs in opal and the leftover REEs in surface water- new interpretation of REEs in dissolved distribution profiles. Geochimica et cosmochimica acta.113. 174-192

May be this could help your deep interpretation and research design

Best regard's

Zolhizir bin Daud

You could try looking at Precambrian Great Oxidation Event papers on BIFs and other iron-rich sediments. They have had a slew of analytical work done on them - see for example Planavsky's work on the Gunflint Formation.

Planavsky, N., Rouxel, O., Bekker, A., Shapiro, R., Fralick, P., Knudsen, A., 2009. Iron-oxidizing microbial ecosystems thrived in late Paleoproterozoic redox-stratified oceans. Earth and Planetary Science Letters 286, 230–242.