Dear Dr. Al-Obaidi:

Residual means it formed in place or in-situ. It is commonly used for ore mineralization be it created by mechanical or chemical weathering on top of a fertile bedrock (parent rock). It can be a placer or a kaolin deposit. In soil sciences it makes little sense because soil is an autochthonous cover on top of different types of parent material from almost organic free oxisols to organic rich ones with well – defined horizons. You should not use this technical term anymore. There is something similar called paleosol which is a soil intercalated into a stratigraphic sequence with all hallmarks of a special modern soil type but subjected to soil-diagenesis so that it comes closer a chemical sediment like silcretes or ferricretes. In this case the transition into sediments is not sharp. There is another type of soil called soil-sediment. It is a former soil which was reworked by water and shows the features of clastic sediments.

For examples and distinction see:

DILL, H.G. (2020) A geological and mineralogical review of clay mineral deposits and phyllosilicate ore guides in Central Europe - A function of geodynamics and climate change.- Ore Geology Reviews 119 (in print)

DILL, H.G. (2017) Residual clay deposits on basement rocks: The impact of climate and the geological setting on supergene argillitization in the Bohemian Massif (Central Europe) and across the globe.- Earth Sciences Reviews 165: 1-58.

DILL, H.G., BUZATU A., and MAFTEI A.E. (2017) Capturing digital data with handheld devices to determine the redox regime, lithology and provenance of siliciclasticsediments and residual deposits - A review and field manual.- Arabian Journal of Geosciences 10: 188-217 (plus supplementary data).

DILL, H.G. (2016) Kaolin: soil, rock and ore From the mineral to the magmatic, sedimentary, and metamorphic environments.- Earth Sciences Reviews 161: 16-129.

Kind regards

H.G.Dill

Dear Dr. Qasim Abdulkarem Al-Obaidi

The main properties of residual soil are:

1. The mineralogical composition is closely related to the original rock.

2. Non transported soil.

Regards

Dear Mr. Ali Al-Shamoosi for your valuable answer.

Regards

Dear Dr. Al-Obaidi:

Residual means it formed in place or in-situ. It is commonly used for ore mineralization be it created by mechanical or chemical weathering on top of a fertile bedrock (parent rock). It can be a placer or a kaolin deposit. In soil sciences it makes little sense because soil is an autochthonous cover on top of different types of parent material from almost organic free oxisols to organic rich ones with well – defined horizons. You should not use this technical term anymore. There is something similar called paleosol which is a soil intercalated into a stratigraphic sequence with all hallmarks of a special modern soil type but subjected to soil-diagenesis so that it comes closer a chemical sediment like silcretes or ferricretes. In this case the transition into sediments is not sharp. There is another type of soil called soil-sediment. It is a former soil which was reworked by water and shows the features of clastic sediments.

For examples and distinction see:

DILL, H.G. (2020) A geological and mineralogical review of clay mineral deposits and phyllosilicate ore guides in Central Europe - A function of geodynamics and climate change.- Ore Geology Reviews 119 (in print)

DILL, H.G. (2017) Residual clay deposits on basement rocks: The impact of climate and the geological setting on supergene argillitization in the Bohemian Massif (Central Europe) and across the globe.- Earth Sciences Reviews 165: 1-58.

DILL, H.G., BUZATU A., and MAFTEI A.E. (2017) Capturing digital data with handheld devices to determine the redox regime, lithology and provenance of siliciclasticsediments and residual deposits - A review and field manual.- Arabian Journal of Geosciences 10: 188-217 (plus supplementary data).

DILL, H.G. (2016) Kaolin: soil, rock and ore From the mineral to the magmatic, sedimentary, and metamorphic environments.- Earth Sciences Reviews 161: 16-129.

Kind regards

H.G.Dill

Dear Prof. Dr. Harald G. Dill ,

thanks a lot for your valuable and detailed answer and for useful information.

I should add that this type of soil is very important for geotechnical engineering application due to the following properties:

1- The mineralogical composition is closely related to the original bedrock beneath the soil.

2- The soil grains are irregular, sharp, and lack roundness.

3- The soil contains fragments of the original rock.

4- The soil thickness depends upon the depth of weathering, climatic conditions, nature of rocks, topography, and time.

5- The presence of a complete soil profile reflecting the gradual change from the original rock at the bottom to topsoil at the surface as shown in the attached figure.

Best regards.

Qasim Al-Obaidi

Ruhr Universitaet Bochum, Germany (PhD)

Agree with Harald G. Dill answere

great dear Qasim Abdulkarem Al-Obaidi

Dear Dr. Abbas,

Thanks a lot for your comments.

Best regards.

Qasim

Thank you Professor Harald G. Dill. You have explained it in details.

Thanks Mr. Rahman for your comment.

The mean of Residual soil, that soil made at the place of weathering (Autochtoneouse) and there is not clear layers. as well as the gravels are angular.

I prefer to use this technical term residual only in mineralogy and economic geology for some supergene deposits.

With kind regards

H.G.Dill

The characteristics of these soils are dependent upon environmental factors of climate, parent material, topography and drainage, and age.

Dear Mr. Rasouli,

thanks for your comment. Yes, residual soil formed in place or in situ, but with long weathering time, all the horizons (layers) A, B and C can be observed.

Regards

dependent upon environmental factors of climate, parent material, topography and drainage, and age

Dear Prof. Harald G. Dill Mr. Mukul Barwant Mr. Hafizullah Rasouli Mr. Md. Mizanur Rahman Mr. Joan Nyika Dr. Abbas F. I. Al-Ameri

Thanks for your useful information and valuable comments.

Best regards

Qasim Al-Obaidi

You are most welcome dear Dr. Qasim Abdulkarem Al-Obaidi , it is my pleasure to be in contact with you

Dear Dr. Qasim,

your question is one of the most important questions if you explore for ore deposits in regolith dominated terrains. Surface anomalies in soil and discriminating its origin (in situ vs transported) can save the exploration budget. Having said that, it is not an easy task to do the job just from the physical description, but you need to use the vertical mineralogical and chemical variationsSoil is in situ if it is formed as an apart of a residual weathering profile on igneous or metamorphic bedrock with little or no chemical and mineralogical variation. Kaolin crystallinity of this soil is well ordered compared to the poorly ordered kaolin in the transported soil (you can use XRD or hyperspectral methods for that). For example, if the soil is transported and derived from mafic source and covered fresh or weathered acidic igneous rocks, elemental ratios such as Ti/Zr or others can be used to determine the unconformity between the in situ and transported.

regards

Walid

You are welcome Qasim Abdulkarem Al-Obaidi

It is dependent upon environmental factors of climate, parent material, topography and drainage...

In engineering geology meaning , Soil is the aggregate of mineral grains that can be seperated by such gentle means as agitation in water for example

Dear Qasim Abdulkarem Al-Obaidi

I think here you do not need to say anything more because Prof. Harald G. Dill gave clear and correct answer two your question... You can clarify your problem in another case too...

Regards,

Laszlo

Dear László,

My respect to you and everyone in this conversation, but we are not here to say that "you do not need to say anything more..). We are listening to different opinions and thoughts from everyone and there is no wrong or correct answers, but different perspectives. Soils studied by different scientists and have different definitions among soil scientists, engineers and geologist. My personal opinion that I have not read yet in the comments about the criteria/characteristics that differentiate the residual from transported soil. I have read more about the processes of soil formation.

Best regards

Walid

Dear Valid,

Ok, accept you critics: and changed a bit the before made response:

'I think here I do not need to say anything more because Prof. Harald G. Dill gave clear and correct answer two your question... You can clarify your problem in another case too... '

But it should be better to be a bit elegant and try to understand the next sentence of Prof. Harald G. Dill: ' I prefer to use this technical term residual only in mineralogy and economic geology for some supergene deposits. ' He was polite and did not say that the question erroneous asked... The example you have observed my minor mistake but did not observe exist something clear in the question... To have soil we need to have altered rocks and minerals which is transformed by 'biological agent' in soil. So somewhat the term ' residual soil'

So the question should be sound better onto the base of my opinion: What are the main characteristics of the different residuum of altered rocks and minerals in different soil? (This question same is not enough, we have answers to other question to have the response to the real question (really what wanted Qasim Abdulkarem Al-Obaidi to ask.) I hope that you same accept that Prof. Harald G. Dill has given an excellent and polite response to the present question... Example me and my son we could learn a lot from the Professor.

Qasim Abdulkarem Al-Obaidi There are two general groups of soils, 1) residual soils, and 2) transported soils. Residual soils are those that have formed from the weathering of rocks in place or in situ. Examples are basalt soils, granite soils, and limestone soils. These soils generally reflect some characteristics of the parent rocks. Transported soils are those that were derived from transported sediments like alluvial/fluvial, lacustrine, colluvial, and many others. These materials are a mixture of weathered products from several rock materials.--Luz

Dear Dr. Asio,

sorry that I object your definition. Soils are the autochthonous blankets on top of the bedrock they may have allochthonous inputs, e.g., by air fall tuffs or get reworked into soil sediments and form part of a stratigraphic sequence as a paleosols. Soil is a more general term whereas pedon is the precise term or unit reflecting the various horizons typical of the soil-type classified as such after a careful mapping along profile, based on organic and inorganic composition, texture and “soil stratigraphy”.

In the presented way it would sound like a “vitreous glass container”.

With kind regards

H.G.Dill

Harald G. Dill Dear Dr. Dill,

Thank you for your reaction to my earlier answer. My answer was from a pedological point of view, and your's is probably from a geology perspective. The pedon concept was proposed by the American pedologist Simonson in 1960. While it is accepted in pedology, the pedon concept has been criticized because it has no real lateral boundaries since the soil is a continuum (Ruellan, 2002). The soil, in scientific studies, is represented by the soil profile or by the pedon. I agree that soils contain both autochthonous and allochthonous materials depending on their origin. Thanks again for the discussion-- Luz

Dear Mr. László Attila Horváth

Unfortunately your comment "I think here you do not need to say anything more" was NOT acceptable for such academics and scientific discussion.

I appreciate the useful answers, valuable comments, and high qualified clarification by Prof. Dr. Harald G. Dill with all respect and many thanks.

Also, all respect and most welcome for all other researchers such as Luz G. Asio Walid Salama Jaithish John Sandip Kumar Gupta Abbas F. I. Al-Ameri Mukul Barwant Ali Al-Shamoosi and others for their comments and useful participation in this discussion.

Best regards.

Qasim Al-Obaidi

Dear Assistant Prof. Dr.-Ing. Qasim Abdulkarem Al-Obaidi, (University of Technology, Baghdad, Iraq, Department of Civil Engineering),

In case the next sentence you have right:” Unfortunately your comment "I think here you do not need to say anything more" was NOT acceptable for such academics and scientific discussion.'

But you were not ethical!

BECAUSE:

You did not make the correct quotation! The question is: Why?

My sentence has the next form:

‘I think here you do not need to say anything more because Prof. Harald G. Dill gave clear and correct answer two your question.‘

and my sentence refers to:’ because Prof. Harald G. Dill gave clear and correct answer two’ (to)’ your question’. (here needs to read excellent answers of Prof. Harald G. Dill on to this question!)…

The next: your is question is incorrectly asked:’ Residual soil is the product of the weathering processes for rocks. What are the main characteristics of this residual soil?’’

‘Residual soil is the product of the weathering processes for rocks.’- Is this sentence scientifically? (Rest: auto-censored),

Regards,

Laszlo Attila Horvath

Geologist Eng, in Chinese clothes selling shop, Kaba, Hungary.

For residual soil, soil formed by the weathering process of the rock in place; there is no clear contact between the rock and the soil

Mr. László Attila Horváth

My question was simple and clear "What are the main characteristics of this residual soil?" and the sentence "Residual soil is the product of the weathering processes for rocks" was a brief description (like keyword) to help the readers for understanding the topic of the question.

Also, I didn't cut some of your comments because all (full) answers were published on RG but I tried to focus on this part of your comment "I think here you do not need to say anything more".

Again, you insist to follow non-academic behavior in your reply by saying "But you were not ethical!".

Please let us continue our scientific discussion with the other respectful researchers, therefore I would be thankful if you leave this page.

Thanks for your participation. I wish you all the best in your life and work.

Best regards

Dear Sir Qasim Abdulkarem Al-Obaidi,

Thank you for your ‘polite’ response addressed to me!

From it, I have observed that you want to escape from me, but I am helpful. Observed that you making science in keywords! because at your question you used real keywords:

Soil

Chemical Weathering

Rock Mechanics

And the criticized part by Prof. Harald G. Dill and me and was in ‘question body’ (onto the base of your last response in the question keywords body!)

and the present sentence scientifically prove you can observe in the attachment: (first photo)

If you want really to let this discussion, please prove to me that you are a good scientist and tell me what kind of residual soil exists onto the second photo… Please be scientifically and not use keywords!

The second photo origin: ((Photo origins:www.astro.sunysb.edu/fwalter/AST101/ms2.html)

Please tell me what type of residual soil you observe and every remark should be good if proved with scientific arguments!

Regards,

Laszlo

P.S.:

You have a bit of luck because the photo shows such zone which has common features to some areas of Iraq.

The soil remains near the original source luje weathering rock. Mostly it is collapsible soil and this depends on the layers and period.

Precambrian soils found in metamorphic sequences can be recognized by the chemical composition of the rock. Without an effective intervention by microorganisms in Precambrian times, the record of climatic action in the transformation of the source material by weathering is explicit only when the protolith is of igneous nature. In fact, paleosols, in this case, are layers of paleolaterites and,or paleobauxites, and the final product being foliated metamorphic rocks with minerals rich in aluminum and iron, maintaining, however, the trace elements and REE of the protolith.

I am not a specialist for "astro-geology", but the above picture looks like the undercarriage of a "Mars landing device" with some metal parts around. Is this considered as a hamadah and where is the residual soil ?

Harald G. Dill

Dear Dr. Luz G. Asio and Dr. Walid Salama

Thanks a lot for your comments.

I agree with you that the residual soil formations are a product of the physical, chemical, and biological weathering processes of the rock in situ.

As a Geotechnical Engineers, we are interested in the mechanical properties of this soil due to the complex behavior, especially under wetting and loading processes.

Best Regards

Dear Prof. Dr. Harald G. Dill

Many thanks again for your very useful information and valuable comments.

I work since many years ago in Iraq and at Ruhr Universität Bochum, Germany (Group of Prof. Tom Schanz) on the topic "Hydro-Mechanical Behaviour of Unsaturated Collapsible Soils" especially "Gypseous and Loess Soils".

I would be grateful if you can help me with your opinion regarding the following issue:

As you know the Gypseous soil (CaSo4.2H2O) is a result of the chemical weathering of rock by Hydration of Anhydrite (CaSO4) to Gypsum.

The question is:

• Is the gypseous soil residual or transported soil? There are two opinions in the literature:

-Pedogentic origins include the formation of secondary gypsum in the soil due to the accumulation of gypsum particles within the soil by one or more of the following actions: Dissolution from primary rocks, groundwater evaporation,

windblown gypsum, and cat-ion exchange. (i.e.Transported Soil)

-Geogenetic origins include forms of processes that are of digenetic type (i.e. gypsum formed in place). These can be summarized as the weathering of igneous rocks, seawater evaporation, the chemical origins of gypsum, and the dolomization of calcite. (i.e. Residual Soil)

Best Regards

Qasim Al-Obaidi

Dear Prof. Pedro Angelo Almeida-Abreu

Thanks a lot for your useful comments.

I hope for further academic cooperation especially in the field of Gypseous soil.

I learned that in Brazil there is a large area covered with gypsum layers.

Have a nice day.

Regards

Qasim Al-Obaidi

Dear Dr. Moataz A. Al-Obaydi

Thanks a lot for your useful comments.

Which type of collapsible soil do you mean? and what is the reason behind the collapse deformation?

Have a nice day.

Best regards

Qasim Al-Obaidi

Dear Herald (Prof. Dr. Harald G. Dill),

Yes, you have right!

But I don't want to go on, even if I could have the chance to give an a good resolution recipe to the present problem (this morning I have had an intuitional moment)…

Regards,

L. A.Horvath

Dear Dr. Al-Obaidi,

I will not resume the discussion on residual soils where I have already fixed my position in my first post but only refer to the CaSO4 which in nature starts off with anhydrite and transforms via some intermediate products such as monohydrate into gypsum when hydrating.

The original way of formation goes along with the changing solution product:

(1) Ca-Mg carbonate (calcite, dolomite), (2) Ca-(Mg) sulfate, (3) Na halogenides (4) K halogenides (5) K-Mg-chloride-sulfate (bittern) + special salts such as borates, soda ash, all of them may be associated with Ca-sulfate and halite caused by increasing evaporation

(1) Diagenetic (bacterial) sulfurization of stratiform gypsum deposits

(2) Gypcretes or sulcretes

(3) Sulfur-bearing dune sands (White sands)

The non-marine / continental host environments are: sabkhas, salt pans, salinas, salt lakes (ephemeral lakes)

The marine host environments strictly follow the above sequence and encompass environments from the shallow marine to the deep water basin. The salt mineralization may be texturally very variable (e.g. chevron texture, slumps, layers etc.)

These chemical sediments bearing Ca sulfate are normally found intimately intergrown with authigenic silicates such as smectite s.s.s. and palygorskite and some other sulfates such as celestite, rarely fluorite.

I have worked and studied pedology and some papers of mine may be helpful for you. They are available for download from the RG server:

DILL, H. G. (1988) Diagenetic and epigenetic U, Ba, and base metal mineralization in the arenaceous Upper Triassic "Burgsandstein" (Southern Germany). With special reference to mineralization in duricrusts. - Mineralogy and Petrology, 39: 93-105.

DILL, H.G., PÖLLMANN, H. , BOSECKER, K., HAHN, L. and MWIYA, S.(2002) Supergene mineralization in mining residues of the Matchless cupreous pyrite deposit (Namibia) – A clue to the origin of modern and fossil duricrusts in semiarid climates.- Journal of Geochemical Exploration, 75: 43-70.

DILL, H.G., BOTZ, R. , BERNER, Z., STÜBEN, D., NASIR, S. and AL-SAAD, H. (2005) Sedimentary facies, mineralogy and geochemistry of the sulphate -bearing Miocene Dam Formation in Qatar.- Sedimentary Geology, 174: 63-96.

DILL, H.G., KADIROV, O., TSOY, Y. and USMANOV, A. (2007) Palaeogeography of Neogene red bed sequences along the Aksa-Ata River in the Parkent-Nurekata intermontane basin (Tien Shan Mountains, Uzbekistan): With special reference to the magnetic susceptibility of siliciclastic rocks.- Journal for Asian Earth Sciences, 29: 960-977.

DILL, H.G., WEBER, B. and BOTZ, R. (2013) Metalliferous duricrusts (“orecretes”) - markers of weathering: A mineralogical and climatic-geomorphological approach to supergene Pb-Zn- Cu-Sb-P mineralization on different parent materials.- Neues Jahrbuch für Mineralogie Abhandlungen, 190: 123-195.

DILL, H.G., DOHRMANN, R., KAUFHOLD, S. and TECHMER, A. (2014) Provenance analysis and thermo-dynamic studies of multi-type Holocene duricrusts (1700 BC) in the Sua Salt Pan, NE Botswana.- Journal of African Earth Sciences, 96: 79-98

HAMZEHPOUR, N., EGHBAL, M.K., ABASIYANA, S.M.A. and DILL, H.G. (2018) Pedogenic evidence of Urmia Lake's [Iran] maximum expansion in the late Quaternary.- Catena 171: 398-415.

DILL, H.G. , KAUFHOLD, S., TECHMER, A. , BARITZ, R., and MOUSSADEK, R. (2019) A joint study in geomorphology, pedology and sedimentology of a Mesoeuropean landscape in the Meseta and Atlas Foreland (NW Morocco). A function of parent lithology, geodynamics and climate.- Journal of African Earth Sciences 158: (in print).

DILL, H.G., BUZATU A., BALABAN S.-I. , UFER K., GÓMEZ TAPIAS J., BÎRGĂOANU D. and CRAMER T. (2020) The “badland trilogy” of the Desierto de la Tatacoa, Upper Magdalena Valley, Colombia, a result of geodynamics and climate: With a review of badland landscapes.- Catena 194 (on-line)

As you might have learnt from this briefing it is only to little extent a pedological issue but the more so a geochemical, mineralogical and sedimentological one.

Mit herzlichem Glückauf Harald G. Dill

Sehr geehrter Prof. Harald G. Dill

Vielen Dank für Ihre interessierte Antwort.

Schönes Wochenende

Sehr geehrter Herr Dr. Al-Obaidi,

es war mir ein Vergnügen. Ich hoffe der Gedankenaustausch war hilfreich für Ihre Studien.

Mit herzlichem Glückauf

Harald G. Dill

Dear Qasim,

Residual soil is the material resulting from the in situ weathering of the parent rock. It is distributed throughout many parts of the world, such as Africa, South Asia, Australia, Southeastern North America, Central and South America, and few regions of Europe. The largest areas and thickness of these soils occur normally in humid tropical regions, such as Brazil, Nigeria, South India, Singapore, and the Philippines. The existence of residual soil on the surface of the land can cause geological engineering problems, especially related to the strength and carrying capacity of the soil. The most frequent land movement disasters have been linked to the residual soil on the hills. The diversity exhibited by residual soils is due, not so much to the lithology of the original rock, but mainly to external factors such as solar radiation, slope, climate, topography, and vegetation cover.

Coming back to your specific question. The specific characteristics of residual soils are generally attributed either to the presence of clay minerals specific to residual soils (physical composition and mineralogical composition), or to particular structural characteristics of soil in its undisturbed in situ state, such as: (i) Macrostructure: includes the presence of unweathered or partially weathered rock, and relic discontinuities or other weakness planes and structures inherited from the original rock mass; Microstructure – includes rock fabric, interparticle bonds or cementation, particle aggregates, dimension and shape of micropores

Also for more detailed information, you can have a look at:

Wesley, L. D. (2009). Fundamentals of soil mechanics for sedimentary and residual soils. John Wiley & Sons.

I hope I made it clear.

Cheers

Ankur

Ore mineralisation from remnants magnetism

Los suelos residuales productos de la meteorización no han sufrido transporte.

Dependen del clima y pluviometría, además del tipo de roca y geomorfología o relieve del terreno.

Pueden concentrar metales pesados y estables liberados.

También pueden representar un riesgo para el movimiento de tierras.

Dear Dr. Ankur Srivastava

Thanks a lot for your useful answer and valuable details.

Wish you al the best.

regards

Qasim

Dear Mr. Adamu Abubakar

Dear Mr. Agustín Velez

Thanks a lot for your answers.

Unfortunately, I can't understand your comments.

I would be thankful if you re-write by the English language.

Best regards

Qasim

Residue soil are remains of weathered rock material that seems to be highly concentrated with heavy minerals when compared with their parental rock material.