Dear Mr. Beyene,

this seems to me asking for the solution for an equation with several unknowns. You speak about secondary material and paleofluids. There are many processes from early to late diagenesis into epigentic hydrothermal processes which may be simple pore-filling fluids or cut-and-fill structure fillings. They may , however, also interact with the host during what we call replacement. You have first and foremost categorize your lithogenetic processes not only in terms of type of formation but also age of formation. You must expect in each of these processes referred to several generations which may be separated from each other by means of mineralogical and structural studies or by radiometric age dating. So far we have not yet touched any source mineralizing fluids. You realized this. Your question means putting the cart before the horse. There is a lot of preparatory work to be done prior to deal with this question; maybe you have solved that all. If so please disclose this information and you will certainly get some answers helpful for your work. Under the current circumstance I cannot imagine to receive any reliable answer.

With kind regards

H.G.Dill

Well,

In nature, the scarcity of chemical noble gases (He, Ar, Ne, Kr, and Xe) is preserved, which makes their tracking an ideal procedure in hydrological systems.

Noble gases have a number of advantages, including:

- Do not engage in any chemical or biological activity.

- It infiltrates groundwater from two main sources: from air and soil air during filtering or leaking from a deep zone, including the entry of radiation products from underground reservoir rocks and from gases derived from the mantle. These various sources can be identified through the isotope components.

The initial concentration of noble gases in the atmosphere and recharge water can be predicted by the annual ambient temperature relationships and the elevation of the recharge zone.

Regards

Thank you very much for the important answer, Prof. Harald G.Dill. I learned a lot from your response.

I am actually not in the area of expertise, but I need to deal with it in my future career.

I asked this question because, I just found cracks filled with secondary materials in Limestones during my field excursions in Blue Nile Basin, Ethiopia. Some of the materials seem precipitated materials due to fluid circulations. For example, the growth of the chert together within the limestone seems like a diagenetic chert. This may be due to the dissolution of the carbonate materials and precipitation of this chert from a solution (?). So, my question was does the chemistry of such deposits (e.g. chert in this case) or materials tells us about the nature of the solution or fluid type? I understand the complexity if the secondary materials are a mixture of different sources.

Your answer is very clear and I noted it.

Thank you for the response once again!

Dear Bayan Hussien,

That is nice suggestion and I noted it!!!!

Dear Mr. Beyene,

Based upon the information you revealed I suggest that you precisely describe your rock slaps as to texture and composition in the field together with the dip and strike of tectonic planar elements. During your office work it would be helpful to conduct some examinations of thin sections to get an idea of the rock and determine maybe with XRD minerals in joints , fissure and vugs. If you have achieved this you will have a much better overview of your potential fluid system.

I wish you much success

H.G.Dill

Addendum to previous good answers in Oil exploration-exploitation exists a simple method to determine the nature of paleo fluids in the sandstone-carbonate environment, determination of NaCl contains...

So from the before made sentence can be observed that two important things exist:

- the origin of the carbonate environment.

- How does the paleoenvironment evolved.

So before beginning the thorough testing of carbonate you need detailed knowledge about the area where the carbonate environment positioned and how is it evolved.

Regards,

L. A. H.

Some additional suggestions along the lines of what Dr. Dill was talking about. Get as much of a comprehensive picture (3D) of what the geologic setting, sedimentology, stratigraphiy, and paleoenvironments are to develop a framework for context. Use field and petrographic (plain light, CL) data to develop a detailed paragenetic sequence of events from deposition through the last diagenetic event using cross cutting relationships, superposition, and distribution patterns. Getting absolute age dates is great if possible. Doing cement stratigraphy is very useful to trace specific cements and get an idea of fluid flow patterns. All of the above provide a framework then in which you can place elemental and isotope geochemistry data. Collecting fluid inclusion data is extremely useful in getting temperature, pressure, and fluid composition (e.g. salinity) for fluids associated with cements.

Article Silica Diagenesis: origin of Inorganic and Replacement Cherts

Article Silicification of continental carbonates

Above, some references on cherts and silification that could help you in you research. Cheers, Raphaël

Dear Prof. Harald G.Dill,

Thank you! It seems clear now! I will dig on this.

Regards,

Shambel B.

Dear L. A. H,

Very nice! It is a very good input to what Prof. Harald has outlined!

Thank you Prof. Franseen for the answer! I will take this seriously!

Regards,

Shambel B

Dear Prof. Bourilot,

The paper seems very interesting. Do you have it?

Help if you have!

Regards,

Shabel B

Dear Mr. Beyene

further suggestions, you might need to check the petrophysical data such as porosity and permeability in addition to the lithological variations throughout the investigated carbonate section (better if you plot them against depth) then you would able to see the anomalies within your section, then investigate these anomalously intervals (if found) via making thin sections (of course thin section covering the whole unit is also required)to know what is behind.

All the best

Mostafa Monged