Photos sur le terrain de Novo Cruzeiro

Pourquoi les pegmatites sont importantes dans l'exploration du lithium

Nos géologues recherchent le spodumène — un minéral porteur de lithium présent dans la pegmatite, cette roche claire, souvent blanche, qui recoupe le granite et le schiste (une roche feuilletée façonnée par la chaleur et la pression). Les meilleurs endroits pour l’observer sont les affleurements rocheux et les anciennes mines artisanales qui suivent les veines minérales en profondeur.


Pour trouver du lithium, il faut d’abord rechercher le spodumène — et cela commence par la pegmatite. C’est précisément ce que les équipes de terrain d’Atlantico cartographient et échantillonnent dans l’ensemble du projet Novo Cruzeiro.

Repérez les pegmatites

Mettez en pratique ce que vous avez appris. Sur les deux premières photos, observez les grands corps de pegmatite blanche dans les tunnels artisanaux. La troisième photo montre des bandes plus minces et superposées dans le schiste ; la quatrième présente une pegmatite altérée en surface — qui mérite néanmoins d’être échantillonnée.

Pegmatite vein exposure with internal banding
Pegmatite vein exposure with internal banding
Pegmatite vein exposed against schist in gallery wall
Pegmatite vein exposed against schist in gallery wall
Banded pegmatitic vein with quartz, feldspar, and biotite layers
Banded pegmatitic vein with quartz, feldspar, and biotite layers
Deeply weathered pegmatite with clay-rich and iron-stained zones
Deeply weathered pegmatite with clay-rich and iron-stained zones

Pegmatites sous lumière UV

À l’intérieur de plusieurs tunnels artisanaux, nous observons des veines de pegmatite en profondeur. Les géologues utilisent la lumière UV pour mettre en évidence les minéraux accessoires dont la fluorescence peut correspondre à des zones enrichies en lithium.

Orange fluorescence on pegmatite under UV light
Orange fluorescence on pegmatite under UV light
Blue-green fluorescence on pegmatitic sample under UV light
Blue-green fluorescence on pegmatitic sample under UV light
UV light on pegmatite surface showing faint orange fluorescence
UV light on pegmatite surface showing faint orange fluorescence
Multicolour fluorescence on pegmatite under UV light
Multicolour fluorescence on pegmatite under UV light
Blue fluorescence highlighting possible quartz-rich zones.
Blue fluorescence highlighting possible quartz-rich zones.
Blue-green fluorescence on pegmatite under UV light
Blue-green fluorescence on pegmatite under UV light

Observations dans les mines artisanales

Les galeries historiques creusées à la main suivaient les veines de pegmatite jusqu’à la surface. Ces expositions constituent des observations de terrain utiles pour orienter la cartographie, l’échantillonnage et l’interprétation géologique préliminaire.

Artisanal tunnel within weathered rock at Novo Cruzeiro.
Artisanal tunnel within weathered rock at Novo Cruzeiro.
Entrance to artisanal working in weathered pegmatite
Entrance to artisanal working in weathered pegmatite
Atlantico field geologist collecting samples from an artisanal tunnel exposure at Novo Cruzeiro.
Atlantico field geologist collecting samples from an artisanal tunnel exposure at Novo Cruzeiro.
Pink saprolite exposure with biotite and tourmaline textures
Pink saprolite exposure with biotite and tourmaline textures
Six-metre artisanal excavation exposing a lenticular pegmatite vein.
Six-metre artisanal excavation exposing a lenticular pegmatite vein.
Géologue sur le terrain à l'entrée d'une petite excavation artisanale
Géologue sur le terrain à l'entrée d'une petite excavation artisanale
Ouverture de mine artisanale exposée le long d'un affleurement en bord de route
Ouverture de mine artisanale exposée le long d'un affleurement en bord de route
Geologist examining a small artisanal tunnel developed in weathered granitic rock.
Geologist examining a small artisanal tunnel developed in weathered granitic rock.
Intérieur de galerie artisanale illuminé par une lampe de poche
Intérieur de galerie artisanale illuminé par une lampe de poche
Shallow mine entrance with oxidized pegmatitic material
Shallow mine entrance with oxidized pegmatitic material
Hand-dug subsurface gallery exposing a pegmatitic zone within weathered host rock at Novo Cruzeiro.
Hand-dug subsurface gallery exposing a pegmatitic zone within weathered host rock at Novo Cruzeiro.
Geologist examining weathered pegmatite at mine entrance
Geologist examining weathered pegmatite at mine entrance
Veine de pegmatite dans le roche hôte schiste, exposée à l'intérieur d'une galerie artisanale.
Veine de pegmatite dans le roche hôte schiste, exposée à l'intérieur d'une galerie artisanale.
Pegmatite vein exposed against schist in gallery wall
Pegmatite vein exposed against schist in gallery wall
Pegmatite vein parallel to foliation in schist.
Pegmatite vein parallel to foliation in schist.
Rust-stained pegmatite wall inside an artisanal excavation
Rust-stained pegmatite wall inside an artisanal excavation
Pegmatite vein cutting schist exposed within a gallery.
Pegmatite vein cutting schist exposed within a gallery.
Rust-colored bands in a weathered pegmatitic wall within a shallow excavation.
Rust-colored bands in a weathered pegmatitic wall within a shallow excavation.
Crosscutting pegmatite vein in gallery wall
Crosscutting pegmatite vein in gallery wall
Hand sample from pegmatite vein in gallery
Hand sample from pegmatite vein in gallery
Pegmatite vein exposure with internal banding
Pegmatite vein exposure with internal banding
Pegmatite and schist contact showing textural contrast
Pegmatite and schist contact showing textural contrast
Pink saprolite in gallery with biotite and tourmaline patches
Pink saprolite in gallery with biotite and tourmaline patches
UV light showing bright blue fluorescence in a weathered quartz-rich sample.
UV light showing bright blue fluorescence in a weathered quartz-rich sample.
Layered pegmatitic vein with quartz-feldspar and mica bands
Layered pegmatitic vein with quartz-feldspar and mica bands
Pink saprolite with tourmaline and biotite traces
Pink saprolite with tourmaline and biotite traces
Fines veines de pegmatite en orientation parallèle à la foliation
Fines veines de pegmatite en orientation parallèle à la foliation
Light-colored clay-altered pegmatite exposed near artisanal workings.
Light-colored clay-altered pegmatite exposed near artisanal workings.
Banding in weathered pegmatitic material inside an artisanal mine
Banding in weathered pegmatitic material inside an artisanal mine
Folded, weathered pegmatitic layering in an artisanal mine
Folded, weathered pegmatitic layering in an artisanal mine
Banded pegmatitic vein with quartz, feldspar, and biotite layers
Banded pegmatitic vein with quartz, feldspar, and biotite layers
Cluster of shallow artisanal diggings along a weathered hillside in Novo Cruzeiro.
Cluster of shallow artisanal diggings along a weathered hillside in Novo Cruzeiro.
Collapsed artisanal adit opening on forested slopes at Novo Cruzeiro.
Collapsed artisanal adit opening on forested slopes at Novo Cruzeiro.
Collapsed artisanal tunnel with pale clay-rich material at the entrance.
Collapsed artisanal tunnel with pale clay-rich material at the entrance.
Collapsed artisanal tunnel with weathered clay-rich walls near the entrance.
Collapsed artisanal tunnel with weathered clay-rich walls near the entrance.
Collapsed artisanal working exposing soft, clay-rich saprolite at Novo Cruzeiro.
Collapsed artisanal working exposing soft, clay-rich saprolite at Novo Cruzeiro.
Deep, narrow artisanal working in weathered rock near Novo Cruzeiro.
Deep, narrow artisanal working in weathered rock near Novo Cruzeiro.
Geologist examines an overgrown artisanal tunnel entrance in the Novo Cruzeiro hills.
Geologist examines an overgrown artisanal tunnel entrance in the Novo Cruzeiro hills.
Narrow artisanal shaft opening in weathered terrain.
Narrow artisanal shaft opening in weathered terrain.
Narrow artisanal tunnel in reddish saprolite at Novo Cruzeiro.
Narrow artisanal tunnel in reddish saprolite at Novo Cruzeiro.
Shallow collapsed entrance of an artisanal working in reddish saprolite.
Shallow collapsed entrance of an artisanal working in reddish saprolite.
Steep, narrow tunnel entrance cut by artisanal miners into the Novo Cruzeiro hillside.
Steep, narrow tunnel entrance cut by artisanal miners into the Novo Cruzeiro hillside.
Twin artisanal tunnel openings within the Novo Cruzeiro project area.
Twin artisanal tunnel openings within the Novo Cruzeiro project area.
Vegetation-covered artisanal tunnel concealed within the Novo Cruzeiro hillside.
Vegetation-covered artisanal tunnel concealed within the Novo Cruzeiro hillside.
Weathered face with white clay and feldspar textures
Weathered face with white clay and feldspar textures
Well-preserved artisanal mine entrance cut into a weathered hillside at Novo Cruzeiro.
Well-preserved artisanal mine entrance cut into a weathered hillside at Novo Cruzeiro.
Wide artisanal tunnel through reddish-brown saprolite.
Wide artisanal tunnel through reddish-brown saprolite.

Pegmatites et corps pegmatoïdes

Les pegmatites peuvent contenir du spodumène et donc du lithium. Nous en cartographions l’épaisseur, la continuité et l’orientation afin de cibler les zones les plus prometteuses, puis nous vérifions ces observations au moyen d’analyses.

Bagged pegmatite samples with coarse biotite, quartz, and feldspar fragments.
Bagged pegmatite samples with coarse biotite, quartz, and feldspar fragments.
Collected pegmatite samples showing coarse mica, quartz, and feldspar fragments.
Collected pegmatite samples showing coarse mica, quartz, and feldspar fragments.
Dark pegmatite mineral fragments collected from surface exposures.
Dark pegmatite mineral fragments collected from surface exposures.
Close-up of weathered pegmatitic rock with pink feldspar and milky quartz.
Close-up of weathered pegmatitic rock with pink feldspar and milky quartz.
Coarse-grained pegmatitic rock with quartz, feldspar, and red garnet crystals.
Coarse-grained pegmatitic rock with quartz, feldspar, and red garnet crystals.
Contact between dark biotite-rich granite and light pegmatitic material, with hammer for scale.
Contact between dark biotite-rich granite and light pegmatitic material, with hammer for scale.
Deeply weathered pegmatite with clay-rich and iron-stained zones
Deeply weathered pegmatite with clay-rich and iron-stained zones
Field geologist examining oxidized pegmatite with quartz-feldspar banding
Field geologist examining oxidized pegmatite with quartz-feldspar banding
Gently dipping outcrop with a light-coloured vein in darker biotite-rich host rock.
Gently dipping outcrop with a light-coloured vein in darker biotite-rich host rock.
Geologist sampling an oxidized saprolite exposure with pale veins
Geologist sampling an oxidized saprolite exposure with pale veins
Close view highlighting dark tourmaline clusters within an iron-stained pegmatitic matrix. The red-brown kaolinized textures reflect intense tropical weathering of an originally quartz-feldspar-tourmaline assemblage — typical of lithium-fertile granitic pegmatites.
Hammer-scale view of weathered pegmatite with dark tourmaline and iron-stained zones.
Oxidized exposure showing a banded pegmatitic vein with quartz, feldspar, and muscovite.
Oxidized exposure showing a banded pegmatitic vein with quartz, feldspar, and muscovite.
Panoramic view of a large weathered pegmatitic exposure within an old open-pit cut.
Panoramic view of a large weathered pegmatitic exposure within an old open-pit cut.
Pegmatitic vein exposure with quartz-feldspar bands and iron-stained weathering, hammer for scale.
Pegmatitic vein exposure with quartz-feldspar bands and iron-stained weathering, hammer for scale.
Prominent light-toned pegmatite vein cutting darker country rock along a vertical roadcut face.
Prominent light-toned pegmatite vein cutting darker country rock along a vertical roadcut face.
Quartz and pegmatite veins in oxidized weathered rock
Quartz and pegmatite veins in oxidized weathered rock
Quartz vein in weathered granitic wall rock, Novo Cruzeiro area.
Quartz vein in weathered granitic wall rock, Novo Cruzeiro area.
Red saprolite exposure with pale weathered pegmatite zones
Red saprolite exposure with pale weathered pegmatite zones
Weathered exposure showing pegmatite and schist with iron staining and tourmaline relics.
Weathered exposure showing pegmatite and schist with iron staining and tourmaline relics.
Weathered pegmatite with quartz, feldspar, and iron staining
Weathered pegmatite with quartz, feldspar, and iron staining
Weathered pegmatitic face with iron staining and quartz-rich zones in outcrop.
Weathered pegmatitic face with iron staining and quartz-rich zones in outcrop.
Veine pegmatoïde avec quartz, biotite et tourmaline
Veine pegmatoïde avec quartz, biotite et tourmaline
Affleurement de saprolite granitique pegmatitique altérée
Affleurement de saprolite granitique pegmatitique altérée

Échantillons de sédiments de cours d’eau

Les ruisseaux transportent des signaux provenant de l’amont. Les anomalies en Li (accompagnées de Cs, Rb et Ta) permettent de remonter jusqu’à la source pegmatitique probable.

Granite bedrock exposure along a cascading stream near Novo Cruzeiro.
Granite bedrock exposure along a cascading stream near Novo Cruzeiro.
Field geologist collecting a stream sediment sample below a waterfall cutting through granitic bedrock.
Field geologist collecting a stream sediment sample below a waterfall cutting through granitic bedrock.
Shaded creek with moss-covered boulders cutting through the forest floor.
Shaded creek with moss-covered boulders cutting through the forest floor.
Ruisseau coupant un dôme granitique exposé avec petite caractéristique de chute d'eau.
Ruisseau coupant un dôme granitique exposé avec petite caractéristique de chute d'eau.
Stream descending over weathered granite steps within a forest channel.
Stream descending over weathered granite steps within a forest channel.
Geologist inspecting an oxidized drainage channel where surface water interacts with exposed granitic bedrock.
Geologist inspecting an oxidized drainage channel where surface water interacts with exposed granitic bedrock.
Waterfall exposing granitic bedrock along a forested stream channel.
Waterfall exposing granitic bedrock along a forested stream channel.
Field geologist standing beside a shallow oxidized drainage channel cutting through exposed granitic bedrock.
Field geologist standing beside a shallow oxidized drainage channel cutting through exposed granitic bedrock.
Stream flowing over weathered granite with orange-brown staining.
Stream flowing over weathered granite with orange-brown staining.
Small pond beside a weathered red-soil slope near an access trail.
Small pond beside a weathered red-soil slope near an access trail.
Small drainage channel used for stream sediment sampling in dense forest at Novo Cruzeiro.
Small drainage channel used for stream sediment sampling in dense forest at Novo Cruzeiro.
Stream channel over weathered granitic bedrock with iron staining and hammer for scale.
Stream channel over weathered granitic bedrock with iron staining and hammer for scale.
Streamside granitic outcrop beside active surface drainage.
Streamside granitic outcrop beside active surface drainage.
Exposed granite dome with shallow drainage and saprolitic weathering at the base.
Exposed granite dome with shallow drainage and saprolitic weathering at the base.
Exposed granitic bedrock along a shallow creek channel, showing fracture-controlled weathering and sediment transport.
Exposed granitic bedrock along a shallow creek channel, showing fracture-controlled weathering and sediment transport.
Geologist collecting stream sediment samples from a shallow creek cutting through granitic terrain at Novo Cruzeiro.
Geologist collecting stream sediment samples from a shallow creek cutting through granitic terrain at Novo Cruzeiro.
Shallow creek flowing over exposed granitic bedrock, suitable for sediment and structural observation.
Shallow creek flowing over exposed granitic bedrock, suitable for sediment and structural observation.
Stream sediment sample NCZ-SS-0001 collected from a small drainage at Novo Cruzeiro.
Stream sediment sample NCZ-SS-0001 collected from a small drainage at Novo Cruzeiro.
Waterfall cutting through granitic basement rock in the Novo Cruzeiro region.
Waterfall cutting through granitic basement rock in the Novo Cruzeiro region.
Waterfall partly obscured by forest vegetation along a shaded drainage.
Waterfall partly obscured by forest vegetation along a shaded drainage.

Systèmes de granit et roches hôtes

À mesure que les magmas granitiques évoluent, les fluides tardifs forment des pegmatites. Comprendre cette architecture et cette fertilité aide à prévoir où les corps les plus volumineux peuvent se trouver.

Broad granite dome exposure overlooking forested slopes in the Novo Cruzeiro region.
Broad granite dome exposure overlooking forested slopes in the Novo Cruzeiro region.
Expansive granitic exposure on a weathered bedrock high near Novo Cruzeiro.
Expansive granitic exposure on a weathered bedrock high near Novo Cruzeiro.
Geologist examining a broad weathered granite exposure with faint pale banding.
Geologist examining a broad weathered granite exposure with faint pale banding.
Granite équigranulaire moyen avec fines veines de pegmatite croisées
Granite équigranulaire moyen avec fines veines de pegmatite croisées
Porphyritic granite with flow fabric and fine pegmatite veins
Porphyritic granite with flow fabric and fine pegmatite veins
Leucogranite grossier équigranulaire avec orientation de biotite
Leucogranite grossier équigranulaire avec orientation de biotite
Granitic outcrop exposure showing subtle mineral banding.
Granitic outcrop exposure showing subtle mineral banding.
Geologist examining a foliated outcrop with dark biotite-rich bands and surface weathering.
Geologist examining a foliated outcrop with dark biotite-rich bands and surface weathering.
Isolated granitic boulders and domal outcrops across gentle hills
Isolated granitic boulders and domal outcrops across gentle hills
Geologist examining a prominent granite outcrop with light-coloured veins in rolling terrain.
Geologist examining a prominent granite outcrop with light-coloured veins in rolling terrain.
Field geologist examining weathered granite with surface cavities and vegetation cover.
Field geologist examining weathered granite with surface cavities and vegetation cover.
Granite block with multiple fine pegmatite veins
Granite block with multiple fine pegmatite veins
Geologist examining foliated granitic rock with dark and light bands.
Geologist examining foliated granitic rock with dark and light bands.
Weathered granite outcrop showing sheet-like exfoliation and faint pale vein traces.
Weathered granite outcrop showing sheet-like exfoliation and faint pale vein traces.
Field geologist examining a coarse-grained granite boulder with visible feldspar and quartz.
Field geologist examining a coarse-grained granite boulder with visible feldspar and quartz.
Fresh coarse-grained granite with feldspar and quartz crystals
Fresh coarse-grained granite with feldspar and quartz crystals
Granitic hand sample with quartz-feldspar intergrowths and iron staining.
Granitic hand sample with quartz-feldspar intergrowths and iron staining.
Coarse-grained granite with thin pegmatite veinlets
Coarse-grained granite with thin pegmatite veinlets
Coarse-grained granite with fine garnet grains
Coarse-grained granite with fine garnet grains
Coarse-grained granite with quartz, feldspar, and biotite shown beside a pencil tip.
Coarse-grained granite with quartz, feldspar, and biotite shown beside a pencil tip.
Coarse-grained granite sample showing feldspar, quartz, biotite, and minor weathering.
Coarse-grained granite sample showing feldspar, quartz, biotite, and minor weathering.
Coarse-grained leucogranite with quartz and feldspar
Coarse-grained leucogranite with quartz and feldspar
Garnet-bearing granite with coarse quartz, feldspar, and biotite texture.
Garnet-bearing granite with coarse quartz, feldspar, and biotite texture.
Hand sample of coarse-grained granite displaying feldspar-rich texture with minor biotite and iron-oxide staining.
Hand sample of coarse-grained granite displaying feldspar-rich texture with minor biotite and iron-oxide staining.
Granite exposure with coarse feldspar, quartz, and biotite minerals.
Granite exposure with coarse feldspar, quartz, and biotite minerals.
Medium- to coarse-grained granite with visible feldspar, quartz, and biotite.
Medium- to coarse-grained granite with visible feldspar, quartz, and biotite.
Freshly exposed granitic surface showing coarse intergrowth of feldspar, quartz, and biotite.
Freshly exposed granitic surface showing coarse intergrowth of feldspar, quartz, and biotite.
Granitic outcrop showing coarse feldspar and quartz textures exposed at surface, with a rock hammer for scale.
Granitic outcrop showing coarse feldspar and quartz textures exposed at surface, with a rock hammer for scale.
Coarse-grained granite with quartz, feldspar, and dark accessory crystals.
Coarse-grained granite with quartz, feldspar, and dark accessory crystals.
Oxidized granitic outcrop showing iron-stained surface weathering over coarse feldspar and quartz textures.
Oxidized granitic outcrop showing iron-stained surface weathering over coarse feldspar and quartz textures.
Granitic outcrop with dark biotite-rich foliation and light quartz-feldspar veinlets.
Granitic outcrop with dark biotite-rich foliation and light quartz-feldspar veinlets.
Coarse-grained granitic outcrop with visible quartz and feldspar.
Coarse-grained granitic outcrop with visible quartz and feldspar.
Weathered granitic outcrop with coarse feldspar crystals
Weathered granitic outcrop with coarse feldspar crystals
Vue rapprochée de granite riche en feldspath affichant une altération incipient et une ségrégation minérale.
Vue rapprochée de granite riche en feldspath affichant une altération incipient et une ségrégation minérale.
Granite porphyrique à texture grossière montrant des phénocristaux de feldspath dans une matrice plus sombre de biotite-quartz.
Granite porphyrique à texture grossière montrant des phénocristaux de feldspath dans une matrice plus sombre de biotite-quartz.
Fine- to medium-grained granitic exposure showing dark biotite-rich layering and light felsic mineral bands.
Fine- to medium-grained granitic exposure showing dark biotite-rich layering and light felsic mineral bands.
Granite outcrop with aligned feldspar crystals and a field hammer for scale.
Granite outcrop with aligned feldspar crystals and a field hammer for scale.
Outcrop of dark biotite-rich granite showing foliation and compositional banding.
Outcrop of dark biotite-rich granite showing foliation and compositional banding.
Porphyritic granite exposure with aligned feldspar phenocrysts, hammer for scale.
Porphyritic granite exposure with aligned feldspar phenocrysts, hammer for scale.
Rock hammer on a darkened granitic outcrop showing fracture-controlled oxidation and light surface water flow.
Rock hammer on a darkened granitic outcrop showing fracture-controlled oxidation and light surface water flow.

Saprolite et zones d'altération

L’altération tropicale crée une saprolite qui peut masquer les pegmatites de roche dure, mais elle fait aussi ressortir des contrastes de couleur et de texture qui orientent la cartographie.

Field geologist examining a weathered profile with vein traces
Field geologist examining a weathered profile with vein traces
Roadcut exposure showing thick saprolitic weathering profile with hematitic and kaolinitic zoning over granitic bedrock.
Roadcut exposure showing thick saprolitic weathering profile with hematitic and kaolinitic zoning over granitic bedrock.
High saprolite wall with pink, tan, and cream weathering zones
High saprolite wall with pink, tan, and cream weathering zones
Geologist sampling reddish-brown residual soil over weathered schist
Geologist sampling reddish-brown residual soil over weathered schist
Geologist sampling a weathered saprolitic exposure showing alternating kaolinite-rich and oxidized bands derived from granitic bedrock.
Geologist sampling a weathered saprolitic exposure showing alternating kaolinite-rich and oxidized bands derived from granitic bedrock.
Roadcut exposure of pink to red saprolitic material in weathered granitic terrain.
Roadcut exposure of pink to red saprolitic material in weathered granitic terrain.
Eroded roadcut showing thick saprolitic cover over granitic rock.
Eroded roadcut showing thick saprolitic cover over granitic rock.
Geologist collecting samples from a red clay-rich weathered roadcut.
Geologist collecting samples from a red clay-rich weathered roadcut.
Red lateritic access road through weathered terrain with small drainage ponds nearby.
Red lateritic access road through weathered terrain with small drainage ponds nearby.
Field geologist sampling red-brown lateritic saprolite at Novo Cruzeiro.
Field geologist sampling red-brown lateritic saprolite at Novo Cruzeiro.
Geologist examining a kaolinite-rich saprolitic exposure with distinct bleaching and oxidation zones derived from granitic weathering.
Geologist examining a kaolinite-rich saprolitic exposure with distinct bleaching and oxidation zones derived from granitic weathering.
Roadcut exposure with red oxidized saprolite in weathered granitic terrain.
Roadcut exposure with red oxidized saprolite in weathered granitic terrain.
Geologists collecting saprolite samples from a weathered granitic outcrop.
Geologists collecting saprolite samples from a weathered granitic outcrop.
Geologist examining a weathered outcrop with reddish and pale clay-rich zones.
Geologist examining a weathered outcrop with reddish and pale clay-rich zones.
Vertical roadcut exposing a deeply weathered saprolitic profile
Vertical roadcut exposing a deeply weathered saprolitic profile
Field examination of a weathered outcrop with iron-rich bands
Field examination of a weathered outcrop with iron-rich bands
Layered saprolite profile with yellow, purple, and brown weathering colours.
Layered saprolite profile with yellow, purple, and brown weathering colours.
Roadside exposure of weathered granitic saprolite with pink to red oxidation zones.
Roadside exposure of weathered granitic saprolite with pink to red oxidation zones.
Kaolinized granitic saprolite with quartz-rich zones and iron staining.
Kaolinized granitic saprolite with quartz-rich zones and iron staining.
Yellow-grey saprolite with relict foliation and rock hammer scale
Yellow-grey saprolite with relict foliation and rock hammer scale
Exposed saprolite face with pink, orange, and pale-yellow weathering bands.
Exposed saprolite face with pink, orange, and pale-yellow weathering bands.
Roadcut exposure of weathered saprolitic material overlying granitic to pegmatitic bedrock.
Roadcut exposure of weathered saprolitic material overlying granitic to pegmatitic bedrock.
Affleurement de saprolite granitique-pegmatitique sous couverture superficielle
Affleurement de saprolite granitique-pegmatitique sous couverture superficielle
Weathered granite blocks in red saprolitic clay
Weathered granite blocks in red saprolitic clay
Weathered outcrop with vertical oxidation bands and clay-rich zones
Weathered outcrop with vertical oxidation bands and clay-rich zones
Roadcut exposure showing deeply weathered pink to red saprolite.
Roadcut exposure showing deeply weathered pink to red saprolite.
Vertical saprolite wall with pink, yellow, and white weathering zones.
Vertical saprolite wall with pink, yellow, and white weathering zones.
Field sample collected from an oxidized saprolite horizon at Novo Cruzeiro.
Field sample collected from an oxidized saprolite horizon at Novo Cruzeiro.
Labeled sample bag with kaolinized saprolite from a weathered granitic exposure.
Labeled sample bag with kaolinized saprolite from a weathered granitic exposure.
Atlantico field sample NCZ-CR-0001 beside a kaolinized saprolite roadcut.
Atlantico field sample NCZ-CR-0001 beside a kaolinized saprolite roadcut.
Field sample NCZ-CR-0004 from weathered granitic saprolite
Field sample NCZ-CR-0004 from weathered granitic saprolite
Fine-grained pale saprolite with kaolinized texture, photographed with a pencil for scale.
Fine-grained pale saprolite with kaolinized texture, photographed with a pencil for scale.
Weathered hillside exposure with clay-rich saprolite and embedded coarse rock fragments at Novo Cruzeiro.
Weathered hillside exposure with clay-rich saprolite and embedded coarse rock fragments at Novo Cruzeiro.
Clay-altered saprolite with iron-oxide staining and relict pegmatitic texture.
Clay-altered saprolite with iron-oxide staining and relict pegmatitic texture.
Close-up of oxidized saprolite with relict granitic textures
Close-up of oxidized saprolite with relict granitic textures
Close-up of saprolitic weathering with granular granitic fabric
Close-up of saprolitic weathering with granular granitic fabric
Dark band exposed within weathered saprolitic material, showing remnant quartz and biotite-rich textures.
Dark band exposed within weathered saprolitic material, showing remnant quartz and biotite-rich textures.
Dark red lateritic profile along a weathered hillside exposure.
Dark red lateritic profile along a weathered hillside exposure.
Deeply weathered roadcut with layered saprolitic soil over granitic bedrock.
Deeply weathered roadcut with layered saprolitic soil over granitic bedrock.
Field hammer beside an iron-stained weathered outcrop with clay-rich zones.
Field hammer beside an iron-stained weathered outcrop with clay-rich zones.
Fine-grained lateritic saprolite with clay-rich matrix and iron oxide mottling.
Fine-grained lateritic saprolite with clay-rich matrix and iron oxide mottling.
Fresh roadcut exposing a pale saprolitic profile developed over granitic bedrock.
Fresh roadcut exposing a pale saprolitic profile developed over granitic bedrock.
Iron-oxidized outcrop with clay-rich material and quartz-feldspar textures
Iron-oxidized outcrop with clay-rich material and quartz-feldspar textures
Iron-stained lateritic profile in weathered granitic saprolite.
Iron-stained lateritic profile in weathered granitic saprolite.
Iron-stained saprolite with mottled red and yellow-brown weathering textures.
Iron-stained saprolite with mottled red and yellow-brown weathering textures.
Iron-stained weathered exposure along a vegetated slope.
Iron-stained weathered exposure along a vegetated slope.
Kaolinized and iron-stained saprolite with pink to yellow banding.
Kaolinized and iron-stained saprolite with pink to yellow banding.
Kaolinized and iron-stained saprolite with quartz-feldspar banding
Kaolinized and iron-stained saprolite with quartz-feldspar banding
Kaolinized saprolite horizon with pink and white weathering bands.
Kaolinized saprolite horizon with pink and white weathering bands.
Kaolinized, iron-stained saprolite with remnant feldspar textures.
Kaolinized, iron-stained saprolite with remnant feldspar textures.
Layered weathering profile with pale saprolite beneath red lateritic soil.
Layered weathering profile with pale saprolite beneath red lateritic soil.
Pale kaolinitic layer exposed beneath red-brown lateritic soil.
Pale kaolinitic layer exposed beneath red-brown lateritic soil.
Pinkish-weathered granitic saprolite with quartz and feldspar relicts
Pinkish-weathered granitic saprolite with quartz and feldspar relicts
Red-weathered granitic exposure with quartz-rich veinlets and hammer for scale.
Red-weathered granitic exposure with quartz-rich veinlets and hammer for scale.
Profil saprolitique rougeâtre montrant un horizon de désagrément riche en fer et une formation d'argile résiduelle.
Profil saprolitique rougeâtre montrant un horizon de désagrément riche en fer et une formation d'argile résiduelle.
Roadcut exposure of deeply weathered saprolite over granitic rock.
Roadcut exposure of deeply weathered saprolite over granitic rock.
Roadcut exposure of pink to reddish saprolite in weathered granitic rock.
Roadcut exposure of pink to reddish saprolite in weathered granitic rock.
Saprolitic granite profile with in-situ weathering and quartz-feldspar layers at Novo Cruzeiro.
Saprolitic granite profile with in-situ weathering and quartz-feldspar layers at Novo Cruzeiro.
Saprolitic granite profile with quartz-feldspar banding and red matrix
Saprolitic granite profile with quartz-feldspar banding and red matrix
Sharp contact between pale granitic saprolite and red laterite
Sharp contact between pale granitic saprolite and red laterite
Sharp transition between red saprolitic clay and pale granitic core, showing an advanced weathering profile.
Sharp transition between red saprolitic clay and pale granitic core, showing an advanced weathering profile.
Vertical roadcut exposure showing kaolinized saprolite with quartz-rich bands and ferruginous staining.
Vertical roadcut exposure showing kaolinized saprolite with quartz-rich bands and ferruginous staining.
Vertical roadcut showing deeply weathered granitic saprolite with visible textural relics of the parent rock.
Vertical roadcut showing deeply weathered granitic saprolite with visible textural relics of the parent rock.
Vertical saprolite exposure showing pale and iron-stained weathering layers.
Vertical saprolite exposure showing pale and iron-stained weathering layers.
Vertical saprolite profile with pale clay-rich and iron-stained zones
Vertical saprolite profile with pale clay-rich and iron-stained zones
Weathered exposure with red-brown saprolite, pale clay-rich material, and quartz fragments.
Weathered exposure with red-brown saprolite, pale clay-rich material, and quartz fragments.
Weathered granitic outcrop with kaolinized zones and quartz-feldspar remnants
Weathered granitic outcrop with kaolinized zones and quartz-feldspar remnants
Weathered granitic saprolite with bleached feldspar and iron staining
Weathered granitic saprolite with bleached feldspar and iron staining
Weathered granitic saprolite with bleached feldspar and iron staining
Weathered granitic saprolite with bleached feldspar and iron staining
Weathered roadcut with oxidized saprolite and preserved granitic texture.
Weathered roadcut with oxidized saprolite and preserved granitic texture.
Weathered saprolite with red and beige clay-rich zones exposed along a roadcut.
Weathered saprolite with red and beige clay-rich zones exposed along a roadcut.
Banded weathering pattern in granitic saprolite
Banded weathering pattern in granitic saprolite
Pink schist saprolite with quartz-feldspar veins
Pink schist saprolite with quartz-feldspar veins
Quartz vein exposed in granitic soil
Quartz vein exposed in granitic soil
Whitened granitic saprolite with feldspar weathering
Whitened granitic saprolite with feldspar weathering
Yellow-reddish weathered saprolite horizon
Yellow-reddish weathered saprolite horizon