Weathering images – where each one came from

Four of these came from Wikimedia Commons on 2026-09-03, each under a licence that permits reproduction; the fifth is Andy’s own photograph. Every one is credited in its caption on the page as well, because attribution that lives only in a repository is not attribution.

If you add one: check the licence yourself, look at the image, and record it here. A picture that shows the wrong mechanism is worse than no picture, and the mechanism is often not visible in the picture – see both Minnesota entries.

corestones-lost-creek-colorado.jpg

Granite corestones and joint-bounded blocks, Lost Creek Wilderness, Colorado.

• Photographer: Adam Baker
• Licence: CC BY 2.0
• Source: https://commons.wikimedia.org/wiki/File:Boulders,_Lost_Creek_Wilderness.jpg
• Processing: resized to 1600 px wide, re-encoded at JPEG quality 82.

corestones-vedauwoo-wyoming.jpg

Turtle Rock, Vedauwoo – weathered Sherman Granite, Medicine Bow-Routt National Forest, Albany County, Wyoming.

• Photographer: Carol M. Highsmith, for the Library of Congress
• Licence: public domain (Highsmith dedicated the collection to the public)
• Source: https://commons.wikimedia.org/wiki/File:Vedauwoo_Turtle_Rock,_a_towering_pile_of_weathered_Sherman_Granite_that_is_the_cornerstone_of_a_3.2-mile_trail_in_the_Medicine_Bow-Routt_National_Forest_between_Laramie_and_Cheyenne_on_the_Albany_LCCN2015632858.tif
• Library of Congress catalogue: https://lccn.loc.gov/2015632858
• Processing: rendered from the master TIFF at 1600 px wide, JPEG quality 82.

corestone-formation-usgs.jpg

“Weathering of joint blocks and stages in the formation of corestones” – the mechanism this exercise models, drawn.

• Source publication: Huber, N.K., 1987, The geologic story of Yosemite National Park: U.S. Geological Survey Bulletin 1595, 64 p. https://doi.org/10.3133/b1595
• Licence: public domain (work of the U.S. Geological Survey)
• Source: https://commons.wikimedia.org/wiki/File:Weathering_of_joint_blocks_and_stages_in_the_formation_of_corestones.jpg
• NOTE: the Commons credit calls this “Professional Paper No. 1595”. That is wrong – 1595 is a Bulletin, confirmed against the USGS publication record and its DOI. The citation above is the corrected one; do not copy Commons’.
• Processing: resized to 1280 px wide, JPEG quality 82.

weathering-rinds-galicia.jpg

Concentric spheroidal weathering rinds in granite, Estaca de Bares, A Coruña, Galicia, Spain. A coin gives the scale.

• Photographer: Wikimedia Commons user PePeEfe
• Licence: CC BY-SA 3.0
• Source: https://commons.wikimedia.org/wiki/File:Concentric_spheroidal_weathering_in_granite.JPG
• Processing: re-encoded at JPEG quality 82; not resized (1024 px original).

corestones-quarry-minnesota.jpg

Corestones in a sand-and-gravel pit, southwestern Minnesota. They weathered in place; the machinery moved them because they were in the way of the Glacial River Warren sand and gravel being mined around them. Two things follow that the caption has to say, because a reader would otherwise take both for natural: the line they sit in is the excavator’s, and the material around them is outwash rather than the grus they weathered out of.

• Photographer: Andy Wickert
• Licence: CC BY 4.0, granted by him for reuse.
• The two people in it are Kerry Callaghan (University of Illinois Chicago) and Fiona Clubb (Durham University), included with their agreement.
• EXIF from the original, recorded here because the web copy is stripped: Sony E5803 (Xperia Z5 Compact), original filename IMG_20171007_101620.jpg, 2017-10-07 10:16:21 GMT-05:00, 1920x1080, 1/2500 s, f/2.0, ISO 40, 4.23 mm.
• No location, and it is not recoverable from what was shared. The file has no GPS IFD, no “GPS” bytes and no XMP; Google Photos’ own info panel for the item shows date, camera and exposure but no place, and there is no map or geocode in the page. So this is not a download stripping it: Google never had one. Only the camera-roll original could still carry it. The pit is therefore recorded as “southwestern Minnesota” on Andy’s word, which is the authority here anyway – he was standing in it.
• Processing: JPEG quality 82, not resized. EXIF dropped on re-encode.

Considered and rejected

• Morton Outcrops Scientific and Natural Area, Minnesota (Morton Gneiss, CC BY-SA 4.0, Tim Kiser). Rejected after looking at it. The outcrop is glacially scoured, so its roundness is ice, not weathering – the opposite of what this page teaches. Nothing suitable for Minnesota turned up on Commons; the quarry photograph above came from Andy instead. Note that settling whether those blocks were weathered in place or transported took asking him – the photograph alone does not show it, which is the same test Morton failed.