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LITHOEN

Deposit

Nkamouna

Also known as Mada

A mineral deposit recorded by the USGS Ni-Co laterite database, at Cameroon. The compilation classifies it as the Mg hydrous silicate subtype. Minerals reported present include asbolane, ernienickelite, garnierite, gibbsite, goethite, hematite, kaolinite, kerolite.

Classification

recognition basis
authoritativeDatabase
realm
multiple

What this record is, and who says so

Recognised on the basis of

Authoritative database

A curated deposit database published by a scientific institution, in which inclusion is itself a documented editorial decision with stated criteria.

A deposit is an occurrence of sufficient size and grade that it might, under the most favourable circumstances, be considered to have economic potential. Lithoen records that a named authority made that judgement. It is not a statement that anything here is recoverable, and it is not a resource or a reserve.

How it is interpreted

A deposit is not a mineral system. A source interprets it as an example of one, and interpretations change while the rock does not.

  • Interpreted as an example of Nickel-cobalt laterite system

    By — Membership of the USGS Ni-Co laterite database, which is a compilation of deposits of this class.

    Inclusion in a compilation of this deposit class is the compilation’s own interpretation of this deposit. It is not an independent genetic study.

Commodities documented here

  • Cobalt (commodity)documented association

    The compilation reports a grade for this metal at this deposit. Lithoen records the documented association and infers nothing about how it would be worked.

  • Nickel (commodity)documented association

    The compilation reports a grade for this metal at this deposit. Lithoen records the documented association and infers nothing about how it would be worked.

Reported figures, and what each one is

A sample assay, a deposit average, a compiler total and a reported reserve are different quantities. Each figure below carries which one it is; none of them is a current resource or reserve.

0.25 wt%m Cobalt

Reserve grade

A grade reported inside a formal ore-reserve estimate, which additionally embeds modifying factors — mining, processing, economic, legal.

The usgs ni-co laterite database reports a cobalt grade of 0.25 weight percent for Nkamouna, stated with respect to the reported reserve tonnage.

0.69 wt%m Nickel

Reserve grade

A grade reported inside a formal ore-reserve estimate, which additionally embeds modifying factors — mining, processing, economic, legal.

The usgs ni-co laterite database reports a nickel grade of 0.69 weight percent for Nkamouna, stated with respect to the reported reserve tonnage.

The source records behind this

What one row of a published dataset was taken to mean, and why. The original record stays traceable after reconciliation.

  • Ni-Co laterite deposits of the world (USGS OFR 2011-1058), record 30

    Named there
    Nkamouna
    The source calls it
    deposit
    Lithoen reads it as
    deposit (stated)

    The usgs ni-co laterite database states what one of its rows is, and this row is read as the deposit the compilers named. The compilation excludes occurrences and prospects, so the row is a deposit by its own definition.

    Merged into this row by the compilers: Mada. Those names were combined under the dataset’s own two-kilometre rule before Lithoen read it.

    Read and refused

    • grade and tonnage columns with no value — The compilation writes "(no value)" or leaves the field empty where the information was not available. Reading an empty field as zero would publish a measurement nobody made.
    • processing-route columns (atmospheric leach, Caron, HPAL, ferronickel smelting) — These describe industrial treatment of the ore, not the geology of the deposit. Lithoen models deposits, not operations.

How this is mapped

One published representation of where Nkamouna is. Each is one interpretation, by one identified source, at one scale — not the shape of the thing itself.

  • Representative point

    Point · 1 positionspreferred for publication

    A single position standing for something that is not a point. It exists so a feature can be shown on a map or listed by location, and it asserts NOTHING about extent. A representative point for a 2,000 km province is a label anchor, not a location.

    A representative point for Nkamouna from the USGS Ni-Co laterite database. It marks where the compilation places the deposit; it is not a boundary, not a shaft, and implies nothing about the body's extent.

    Boundary certainty
    ApproximateThe position is known only within a distance much larger than the line width on any map that shows it. Drawing it thinner does not make it better known.
    Status of this geometry
    inferredThe status of the geometry, which need not match the status of what the entity’s claims assert.
    Dataset
    Ni-Co laterite deposits of the world (USGS OFR 2011-1058)Berger, V.I., Singer, D.A., Bliss, J.D., and Moring, B.C., 2011, Ni-Co laterite deposits of the world: Database and grade and tonnage models: U.S. Geological Survey Open-File Report 2011-1058, doi:10.3133/ofr20111058.

    What was done to this geometry

    • By Lithoen — Rounded to 4 decimal places. The compilation computed its decimal degrees from authored degrees-minutes-seconds columns, and the further digits are conversion residue rather than knowledge.
    • Before it reached Lithoen — The compilation computed these decimal degrees from the degrees-minutes-seconds columns its compilers authored.

How this record is known

7
Settled consensus
Cited as the accepted position of the discipline.

7 of 7 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.

What Lithoen records

Each claim states how it is known and cites its evidence.

Establisheddeparea=8; deplength=4; depwidth=2.1; depthick=?71

Reported for this deposit

The compilation records dimensions for the Nkamouna ore body: deparea 8, deplength 4, depwidth 2.1, depthick ?71. These describe the size of a body and place no outline on the ground; Lithoen publishes a point for this deposit and no extent.

  • precision note: Dimensions of an ore body are not a boundary. No polygon is derivable from them and none is published.
  • assertion basis: SOURCE_REPORTED

Evidence support: Supported by the cited evidence 2 sources, single source

Evidence: V.I. 2011 Primary authority

Establishedthe Mg hydrous silicate subtype

How a source classifies it

The usgs ni-co laterite database classifies Nkamouna as the Mg hydrous silicate subtype.

Not stated verbatim by the source — derived: deptype 2 -> “Mg hydrous silicate subtype”

The compilation records a one-character subtype code; its own metadata enumerates what the three codes mean, and that metadata was retrieved and read. The expansion comes from the authority, not from general knowledge about laterite deposits.

  • definition basis: Deposit-type field of the USGS Ni-Co laterite database, whose values are enumerated in the dataset itself.
  • assertion basis: SOURCE_CLASSIFICATION

Evidence support: Derived from the cited evidence 2 sources, single source

Evidence: V.I. 2011 Primary authority

Established0.25 wt%m Cobalt

Reported for this deposit

The usgs ni-co laterite database reports a cobalt grade of 0.25 weight percent for Nkamouna, stated with respect to the reported reserve tonnage.

  • scope: reserveGrade
  • definition basis: Grade with respect to reserve tonnage, as the compilation defines the field.
  • assertion basis: SOURCE_REPORTED
  • reporting framework: None stated. The compilation calls this a grade with respect to reserve tonnage and names no reporting code — no JORC, NI 43-101 or equivalent classification, and no competent-person sign-off. A reserve reported without a framework cannot be compared with one reported under a code, and Lithoen supplies no framework it was not given.
  • precision note: This claim corrects the scope of claim:nkamouna-deposit-cobalt-grade, which published the figure as a resource grade. The compilation defines the field as a grade with respect to RESERVE tonnage, and a resource is not a reserve: the reserve is the part shown to be economically mineable, and the resource is not. The number is unchanged; what it means is not. Note also that the reserve tonnage this grade is stated against is not itself published in this corpus, so the grade is carried without the quantity it qualifies.

Evidence support: Supported by the cited evidence 2 sources, single source

Evidence: V.I. 2011 Primary authority

Establishedasbolane; ernienickelite; garnierite; gibbsite; goethite; hematite; kaolinite; kerolite; limonite; maghemite; montmorillonite; nontronite; serpentine; talc; chalcedony; chromite; magnetite; olivine; quartz

Reported for this deposit

The compilation reports 19 distinct minerals present at Nkamouna, of which the first twelve alphabetically are asbolane, ernienickelite, garnierite, gibbsite, goethite, hematite, kaolinite, kerolite, limonite, maghemite, montmorillonite, nontronite. Of these the compilation marks asbolane, ernienickelite, garnierite, gibbsite, goethite as nickel-bearing at this deposit. It records presence only: no abundance, no paragenesis and no assay follows from it.

  • precision note: The compilation's mineral table holds 19 entries for this row, and the claim counts all 19 of them. The prose names 12 because a sentence of 19 mineral names is not readable; the count is stated so the list is never mistaken for the whole. Presence is not abundance, and the alphabetical order carries no paragenetic meaning.
  • assertion basis: SOURCE_REPORTED

Evidence support: Supported by the cited evidence 2 sources, single source

Evidence: V.I. 2011 Primary authority

Established0.69 wt%m Nickel

Reported for this deposit

The usgs ni-co laterite database reports a nickel grade of 0.69 weight percent for Nkamouna, stated with respect to the reported reserve tonnage.

  • scope: reserveGrade
  • definition basis: Grade with respect to reserve tonnage, as the compilation defines the field.
  • assertion basis: SOURCE_REPORTED
  • reporting framework: None stated. The compilation calls this a grade with respect to reserve tonnage and names no reporting code — no JORC, NI 43-101 or equivalent classification, and no competent-person sign-off. A reserve reported without a framework cannot be compared with one reported under a code, and Lithoen supplies no framework it was not given.
  • precision note: This claim corrects the scope of claim:nkamouna-deposit-nickel-grade, which published the figure as a resource grade. The compilation defines the field as a grade with respect to RESERVE tonnage, and a resource is not a reserve: the reserve is the part shown to be economically mineable, and the resource is not. The number is unchanged; what it means is not. Note also that the reserve tonnage this grade is stated against is not itself published in this corpus, so the grade is carried without the quantity it qualifies.

Evidence support: Supported by the cited evidence 2 sources, single source

Evidence: V.I. 2011 Primary authority

EstablishedRecorded as a deposit by the USGS Ni-Co laterite database, record 30.

How a source classifies it

Nkamouna is recorded as a deposit because the USGS Ni-Co laterite database includes it, as record 30. The compilation states that it excludes occurrences and prospects that are less well known, so every row is a deposit by the compilers' own definition.

  • source record: usgs-ni-co-laterite-deposits-of-the-world record 30
  • assertion basis: SOURCE_CLASSIFICATION

Evidence support: Supported by the cited evidence 2 sources, single source

Evidence: V.I. 2011 Primary authority

EstablishedCretaceous to early-mid Tertiary

Reported for this deposit

The USGS laterite database places the laterite-forming weathering at Nkamouna in the Cretaceous to early-mid Tertiary age group. What that dates is the weathering that made the deposit, not the ultramafic parent rock it formed on.

  • temporal basis: Age group of the laterite-forming weathering processes, as the compilation enumerates them.
  • precision note: A group, not a date. The compilation offers three periods and assigns each deposit to one; no geochronology follows from it.
  • assertion basis: SOURCE_REPORTED

Evidence support: Supported by the cited evidence 2 sources, single source

Evidence: V.I. 2011 Primary authority

In the knowledge graph

Record last updated 2026-09-07. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.