Thin Section Thursday! A transmitted light image of a MORB (mid-ocean ridge basalt) from the Gorda Ridge. A plagioclase ultraphyric basalt.
Contributed by Dr Roger L Nielsen.
See: Lange et al. (2013) doi: 10.1002/ggge.20207
Hewitt et al. (2025) doi.org/10.1029/2024GC011835
#thinsectionthursday
Contributed by Dr Roger L Nielsen.
See: Lange et al. (2013) doi: 10.1002/ggge.20207
Hewitt et al. (2025) doi.org/10.1029/2024GC011835
#thinsectionthursday
November 5, 2026 at 1:32 PM
Thin Section Thursday! A transmitted light image of a MORB (mid-ocean ridge basalt) from the Gorda Ridge. A plagioclase ultraphyric basalt.
Contributed by Dr Roger L Nielsen.
See: Lange et al. (2013) doi: 10.1002/ggge.20207
Hewitt et al. (2025) doi.org/10.1029/2024GC011835
#thinsectionthursday
Contributed by Dr Roger L Nielsen.
See: Lange et al. (2013) doi: 10.1002/ggge.20207
Hewitt et al. (2025) doi.org/10.1029/2024GC011835
#thinsectionthursday
For #thinsectionthursday: a glomerocryst from Mt Ijen’s 1817 eruption. Euhedral augite and plagioclase living together in harmony 🤩
🌋⚒️
🌋⚒️
November 6, 2026 at 12:27 AM
For #thinsectionthursday: a glomerocryst from Mt Ijen’s 1817 eruption. Euhedral augite and plagioclase living together in harmony 🤩
🌋⚒️
🌋⚒️
Halloween Thin Section Thursday!
Chlorite + Fe±Ti-oxide pseudomorph after garnet in a retrogressed eclogite. The matrix is fine-grained intergrowths of amphibole + plagioclase ± diopside after omphacite. FOV ~2 mm, PPL. Contributed by Donna Whitney.
#thinsectionthursday
Chlorite + Fe±Ti-oxide pseudomorph after garnet in a retrogressed eclogite. The matrix is fine-grained intergrowths of amphibole + plagioclase ± diopside after omphacite. FOV ~2 mm, PPL. Contributed by Donna Whitney.
#thinsectionthursday
October 29, 2026 at 11:53 AM
Halloween Thin Section Thursday!
Chlorite + Fe±Ti-oxide pseudomorph after garnet in a retrogressed eclogite. The matrix is fine-grained intergrowths of amphibole + plagioclase ± diopside after omphacite. FOV ~2 mm, PPL. Contributed by Donna Whitney.
#thinsectionthursday
Chlorite + Fe±Ti-oxide pseudomorph after garnet in a retrogressed eclogite. The matrix is fine-grained intergrowths of amphibole + plagioclase ± diopside after omphacite. FOV ~2 mm, PPL. Contributed by Donna Whitney.
#thinsectionthursday
Thin Section Thursday! Andesite from Indonesia with a twinned pyroxene in the center. Taken under cross-polarized light. Contributed by Bernhard W. Seubert.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
October 22, 2026 at 12:47 PM
Thin Section Thursday! Andesite from Indonesia with a twinned pyroxene in the center. Taken under cross-polarized light. Contributed by Bernhard W. Seubert.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Thin Section Thursday! Upper image: XPL. Lower image: Cathodoluminescence. 2.8 Ga tonalite from the Beartooth Mtns, MT with anti-perthitic exsolution of microcline (blue in CL) in a plagioclase host. Contributed by Darrell Henry.
Contact akoziol1 (at) udayton dot edu. #thinsectionthursday
Contact akoziol1 (at) udayton dot edu. #thinsectionthursday
October 15, 2026 at 11:24 AM
Thin Section Thursday! Upper image: XPL. Lower image: Cathodoluminescence. 2.8 Ga tonalite from the Beartooth Mtns, MT with anti-perthitic exsolution of microcline (blue in CL) in a plagioclase host. Contributed by Darrell Henry.
Contact akoziol1 (at) udayton dot edu. #thinsectionthursday
Contact akoziol1 (at) udayton dot edu. #thinsectionthursday
Thin Section Thursday!
Holmquistite in Mica Schist
Crossed polars, horizontal length: 7 mm
Xinjiang, Uygur Autonomous Region
#ThinSectionThursday
You can contribute too. Send images and captions to akoziol1 at udayton dot edu.
Holmquistite in Mica Schist
Crossed polars, horizontal length: 7 mm
Xinjiang, Uygur Autonomous Region
#ThinSectionThursday
You can contribute too. Send images and captions to akoziol1 at udayton dot edu.
October 8, 2026 at 12:56 PM
Thin Section Thursday!
Holmquistite in Mica Schist
Crossed polars, horizontal length: 7 mm
Xinjiang, Uygur Autonomous Region
#ThinSectionThursday
You can contribute too. Send images and captions to akoziol1 at udayton dot edu.
Holmquistite in Mica Schist
Crossed polars, horizontal length: 7 mm
Xinjiang, Uygur Autonomous Region
#ThinSectionThursday
You can contribute too. Send images and captions to akoziol1 at udayton dot edu.
Thin Section Thursday:
A. oolite-bearing sample (PPL). B. in (XPL). The sample of black talc is from the late Neoproterozoic Dengying Formation in Guangfeng County, Jiangxi Province, southeastern China. (DOI: dx.doi.org/10.2138/am-2...). Contributed by Huifang Xu.
#thinsectionthursday
A. oolite-bearing sample (PPL). B. in (XPL). The sample of black talc is from the late Neoproterozoic Dengying Formation in Guangfeng County, Jiangxi Province, southeastern China. (DOI: dx.doi.org/10.2138/am-2...). Contributed by Huifang Xu.
#thinsectionthursday
October 1, 2026 at 12:37 PM
Thin Section Thursday:
A. oolite-bearing sample (PPL). B. in (XPL). The sample of black talc is from the late Neoproterozoic Dengying Formation in Guangfeng County, Jiangxi Province, southeastern China. (DOI: dx.doi.org/10.2138/am-2...). Contributed by Huifang Xu.
#thinsectionthursday
A. oolite-bearing sample (PPL). B. in (XPL). The sample of black talc is from the late Neoproterozoic Dengying Formation in Guangfeng County, Jiangxi Province, southeastern China. (DOI: dx.doi.org/10.2138/am-2...). Contributed by Huifang Xu.
#thinsectionthursday
Thin Section Thursday! Chalcopyrite in galena (or sunset in a wintery forest, slightly askew), reflected light. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday #galena
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday #galena
September 24, 2026 at 7:22 PM
Thin Section Thursday! Chalcopyrite in galena (or sunset in a wintery forest, slightly askew), reflected light. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday #galena
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday #galena
T.S. Thursday!
Pyroxene: Murun, Yakutia, Russia. Digitally worked optical photograph inkjet printed on canvas. Contributed by Roger Mitchell.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Pyroxene: Murun, Yakutia, Russia. Digitally worked optical photograph inkjet printed on canvas. Contributed by Roger Mitchell.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
September 17, 2026 at 4:01 PM
T.S. Thursday!
Pyroxene: Murun, Yakutia, Russia. Digitally worked optical photograph inkjet printed on canvas. Contributed by Roger Mitchell.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Pyroxene: Murun, Yakutia, Russia. Digitally worked optical photograph inkjet printed on canvas. Contributed by Roger Mitchell.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Thin Section Thursday!
Mica and quartz, XPL. Mica is brightly colored.
Contributed by Bernhard Seubert.
You can contribute too! Send image(s) and short explanation to akoziol1 at udayton dot edu.
#thinsectionthursday
Mica and quartz, XPL. Mica is brightly colored.
Contributed by Bernhard Seubert.
You can contribute too! Send image(s) and short explanation to akoziol1 at udayton dot edu.
#thinsectionthursday
September 10, 2026 at 12:43 PM
Thin Section Thursday!
Mica and quartz, XPL. Mica is brightly colored.
Contributed by Bernhard Seubert.
You can contribute too! Send image(s) and short explanation to akoziol1 at udayton dot edu.
#thinsectionthursday
Mica and quartz, XPL. Mica is brightly colored.
Contributed by Bernhard Seubert.
You can contribute too! Send image(s) and short explanation to akoziol1 at udayton dot edu.
#thinsectionthursday
Thin Section Thursday:
Primary Olivine in Picritic Tadipatri Sill, Cuddapah Basin in Eastern Dharwar craton, XPL
Contributed by Dr P V Sunder Raju.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Primary Olivine in Picritic Tadipatri Sill, Cuddapah Basin in Eastern Dharwar craton, XPL
Contributed by Dr P V Sunder Raju.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
September 3, 2026 at 11:39 AM
Thin Section Thursday:
Primary Olivine in Picritic Tadipatri Sill, Cuddapah Basin in Eastern Dharwar craton, XPL
Contributed by Dr P V Sunder Raju.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Primary Olivine in Picritic Tadipatri Sill, Cuddapah Basin in Eastern Dharwar craton, XPL
Contributed by Dr P V Sunder Raju.
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Thin Section Thursday!
concentric aggregates of chalcopyrite, galena and pyrite in sphalerite. Reflected light. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
concentric aggregates of chalcopyrite, galena and pyrite in sphalerite. Reflected light. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
August 27, 2026 at 12:45 PM
Thin Section Thursday!
concentric aggregates of chalcopyrite, galena and pyrite in sphalerite. Reflected light. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
concentric aggregates of chalcopyrite, galena and pyrite in sphalerite. Reflected light. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Thin Section Thursday!
False-colored Backscatter Electron image of a clinopyroxene in a Galapagos MOR basalt. Features a sector zoned more calcic core, a resorption event followed by concentric overgrowth. Photo by Alice Colman. Contributed by Thomas Shea.
#thinsectionthursday #clinopyroxene
False-colored Backscatter Electron image of a clinopyroxene in a Galapagos MOR basalt. Features a sector zoned more calcic core, a resorption event followed by concentric overgrowth. Photo by Alice Colman. Contributed by Thomas Shea.
#thinsectionthursday #clinopyroxene
August 20, 2026 at 12:57 PM
Thin Section Thursday!
False-colored Backscatter Electron image of a clinopyroxene in a Galapagos MOR basalt. Features a sector zoned more calcic core, a resorption event followed by concentric overgrowth. Photo by Alice Colman. Contributed by Thomas Shea.
#thinsectionthursday #clinopyroxene
False-colored Backscatter Electron image of a clinopyroxene in a Galapagos MOR basalt. Features a sector zoned more calcic core, a resorption event followed by concentric overgrowth. Photo by Alice Colman. Contributed by Thomas Shea.
#thinsectionthursday #clinopyroxene
Happy #ThinSectionThursday! Hope you enjoy this thin section of a bryozoan-crinoid dominated grainstone from the Permian of Western Australia.
August 13, 2026 at 2:34 PM
Happy #ThinSectionThursday! Hope you enjoy this thin section of a bryozoan-crinoid dominated grainstone from the Permian of Western Australia.
Thin Section Thursday!
Spinifex texture (olivine) in a komatiite. XPL. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Spinifex texture (olivine) in a komatiite. XPL. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
August 13, 2026 at 12:45 PM
Thin Section Thursday!
Spinifex texture (olivine) in a komatiite. XPL. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
Spinifex texture (olivine) in a komatiite. XPL. Photo by Ingrid Kjarsgaard (c)
You can contribute too! Send image(s) and short caption to akoziol1 (at) udayton dot edu. #thinsectionthursday
If I would be a content creator my content would be cathodoluminescence images revealing cryptic zoning in magmatic-hydrothermal quartz.
This one from an Iceland gabbro. #heyarewestilldoing #thinsectionthursday
This one from an Iceland gabbro. #heyarewestilldoing #thinsectionthursday
February 15, 2024 at 5:51 AM
If I would be a content creator my content would be cathodoluminescence images revealing cryptic zoning in magmatic-hydrothermal quartz.
This one from an Iceland gabbro. #heyarewestilldoing #thinsectionthursday
This one from an Iceland gabbro. #heyarewestilldoing #thinsectionthursday
@allochthonous.bsky.social I'm following your geohashtags feed, but it doesn't look like it's picking up any of the #thinsectionthursday posts.
January 30, 2025 at 4:50 PM
@allochthonous.bsky.social I'm following your geohashtags feed, but it doesn't look like it's picking up any of the #thinsectionthursday posts.
A multicoloured treat for #ThinSectionThursday!
This rock is from the summit in Cademan Wood - one of many rocks with a volcanic origin in the north of Charnwood Forest🌋
🔬 Thin section = a rock sliver for viewing under microscope
👁️ Field of view about 20 mm
©️ BGS
This rock is from the summit in Cademan Wood - one of many rocks with a volcanic origin in the north of Charnwood Forest🌋
🔬 Thin section = a rock sliver for viewing under microscope
👁️ Field of view about 20 mm
©️ BGS
September 4, 2025 at 9:44 AM
A multicoloured treat for #ThinSectionThursday!
This rock is from the summit in Cademan Wood - one of many rocks with a volcanic origin in the north of Charnwood Forest🌋
🔬 Thin section = a rock sliver for viewing under microscope
👁️ Field of view about 20 mm
©️ BGS
This rock is from the summit in Cademan Wood - one of many rocks with a volcanic origin in the north of Charnwood Forest🌋
🔬 Thin section = a rock sliver for viewing under microscope
👁️ Field of view about 20 mm
©️ BGS
#ThinSectionThursday, larger benthic #foraminifera, coralline algae, and friends in tropical #mesophotic sediments from the western Indian Ocean.
May 16, 2024 at 3:16 PM
#ThinSectionThursday, larger benthic #foraminifera, coralline algae, and friends in tropical #mesophotic sediments from the western Indian Ocean.
#thinsectionthursday Precipitates of ilmenite and apatite in garnet. PPol, fov=1cm, within one growth sector of a single garnet crystal. First generation (coarse) follows included fabric NW-SE, second generation sub micron crystals decorate unannealed growth dislocations. Note depletion haloes.
March 26, 2026 at 7:15 PM
#thinsectionthursday Precipitates of ilmenite and apatite in garnet. PPol, fov=1cm, within one growth sector of a single garnet crystal. First generation (coarse) follows included fabric NW-SE, second generation sub micron crystals decorate unannealed growth dislocations. Note depletion haloes.
Piemontite in phengite-carbonate schist, Lago di Cignana, N. Italy.
#thinsectionthursday
#thinsectionthursday
January 29, 2026 at 4:08 PM
Piemontite in phengite-carbonate schist, Lago di Cignana, N. Italy.
#thinsectionthursday
#thinsectionthursday
Pyrope and minor kyanite in matrix of phengite and palisade-textured quartz from the Dora Maira massif, N. Italy. Section is slightly above standard thickness.
#thinsectionthursday
#thinsectionthursday
January 22, 2026 at 7:30 PM
Pyrope and minor kyanite in matrix of phengite and palisade-textured quartz from the Dora Maira massif, N. Italy. Section is slightly above standard thickness.
#thinsectionthursday
#thinsectionthursday
Olivine- and plagioclase-phyric, vesicular basaltic glass in cross polarised light from Hawaii for #ThinSectionThursday. Olivine shows wide range of interference colours despite uniform composition. Much of the glassy groundmass is devitrified in rosettes around the phenocrysts. 🧪⚒️🌋
May 21, 2026 at 8:51 AM
Olivine- and plagioclase-phyric, vesicular basaltic glass in cross polarised light from Hawaii for #ThinSectionThursday. Olivine shows wide range of interference colours despite uniform composition. Much of the glassy groundmass is devitrified in rosettes around the phenocrysts. 🧪⚒️🌋
Pegmatitic dolerite from Fair Head, County Antrim in XPL for #ThinSectionThursday. Same location as two weeks ago but much coarser grain size. Stunning clinopyroxene showing birefringence progressions at edges and cracks, plus fractured olivine and twinned plagioclase. 🧪⚒️🌋
March 26, 2026 at 9:59 AM
Pegmatitic dolerite from Fair Head, County Antrim in XPL for #ThinSectionThursday. Same location as two weeks ago but much coarser grain size. Stunning clinopyroxene showing birefringence progressions at edges and cracks, plus fractured olivine and twinned plagioclase. 🧪⚒️🌋
Have had a quick look and could not see any with ocelli but a marvellous variety of relationships between olivine, plagioclase, and clinopyroxene. Might have to post the "pegmatite" one for next week's #ThinSectionThursday!
March 5, 2026 at 3:53 PM
Have had a quick look and could not see any with ocelli but a marvellous variety of relationships between olivine, plagioclase, and clinopyroxene. Might have to post the "pegmatite" one for next week's #ThinSectionThursday!