Conventional geophysics have been deployed and observed to be the methods of choice (magnetics and electrical sounding). Is it possible to distinguish the different types of iron ores from the identified anomaly, eg can one distinguish magnetite from hematite? The correct answer and contributions to this question will be greatly appreciated...
Magnetite is ferromagnetic, hematite [alpha-Fe2O3] and martite are not. But one of their modifications called maghemite [gamma-Fe2O3] is also magnetic but rather seldom. Geophysical methods are used to detect and delineate ore bodies. As you might conclude from this set of Fe oxides, geophysical methods are not the methods of choice to make any assumptions on the mineralogical composition, because textural affects, the influence by the wall and host rocks ....can obliterate the petrophysical characteristics as they are described in the textbooks. Therefore, there is no method to get a true overview of the mineral association others than diamond drill holes (DDH)or cuttings obtained from percussion drilling operations. I would not waste my time in checking out this but directly head for the core and cuttings. This is the most efficaceous method to receive precise mineralogical data and the samples are suitable for all kinds of applications from the ore microscopy to the MLA.
HGD
@ Herald Dill, many thanks for your comments .
I was hoping that the signals could be refined to characterize the various limits of the ores in terms of spectral affinities, sometimes the though of improving a tool births newer concepts, just maybe any working group is in that trajectory, I will be glad to keep track of their findings. Such novelties are strongly limited in our climes here (Nigeria) with great brains to venture but limited opportunities for achieving the scholarships. We always often break the jinx when we find ourselves outside our shores associated with research teams that dare to take the leap. Albeit, many thanks, your comments always come with wealth of experience we often like to tap from.
Never adjust a method to your needs and wants as there exist a better method easily available: MINERALOGY. You will always be discontented with your approach in comparison with the results of existing more effective methods.
This is economic geology.
HGD
Good morning
For a field survey the best method is geology coupled with the use of magnetic field survey tools. Hematite is not magnetic while magnetire is magnetic. Ilmenite is slightly magnetic. These three iron ore minerals have different crystallographic system and therefore would not have the same crystal shape. Other iron ore are siderite, goethite. You can use mineralogical lab study to confirm the existence of each mineral and its proportion.
It is better to first have good knowledge on the metallogenesis of each type of iron ore deposits. Or you work in collaboration with an iron ore geologist.
Thanks for you comment Kanouo Sylvester, what i am dealing with an area where secondary or what is called lateritic iron ore is hosted. The deposit is concealed by overburden soil material. Should the samples have been exposed, the geochemical studies could be carried out to differentiate between them. At the moment, you are faced with a wide expanse of land, this is not the books but practically searching for a concealed deposit in the subsurface and how the tropic can be oftentimes, thick weathering and soil cover. The plan is to carryout electrical resistivity survey and then to isolate any observable anomaly and then target the anomaly through drilling and then geochemical studies can follow. the challenge and the reason for the question is the choice of geophysics. Again, its important to note that its the hematite - type iron ore that has been mined in some 7km west of the study area and is suspected to be underlying the area, I hope i have an opportunity to share the results with us as we progress. Cheers and many thanks for all the contribution, especially from Prof Dill.
- Badges
- Science topic
- Similar topics
- Social Science
- Media
- Journalism