Glasgow (bentonite)

Montana, United States

Otherbentonite

Type: Bentonite (Na, Ca)

Smectite bentonite deposit. Mainly marine deposition: distal offshore marine setting, parent material likely rhyolitic ash, or andesitic to dacitic; diagenesis or seawater alteration; Late Campanian to Maastrichtian (74.5 to 69 Ma). Köster et al. (2019): δ11B of purified smectites and fluid δ11B calculated for trigonal or tetrahedral boron at 25 and 90 °C.

δ11B in ‰ (per mil) Values of the same system

Standard : NIST SRM 951

Value	Range	n	Mineral or matrix	Source
22.4 ± 6.8 ‰	16.6 / 28.4 ‰		smectite (< 0.2 µm) treated with mannitol Mean and standard deviation recalculated from the means of 2 samples: SB01-M +17.6 (2SD 1.6, +16.6 to +19.3, 64.3 µg/g B); SB02-M +27.2 (2SD 2.4, +24.8 to +28.4, 49.1 µg/g B).	Köster et al. (2019), The boron isotope geochemistry of smectites from sodium, magnesium …
7.1 ± 6.7 ‰	2.2 / 12.1 ‰		smectite (< 0.2 µm) treated with mannitol and ammonium-exchanged, structural boron Mean and standard deviation recalculated from the means of 2 samples: SB01-A +2.3 (2SD 0.2, +2.2 to +2.4, 36.6 µg/g B); SB02-A +11.8 (2SD 0.5, +11.4 to +12.1, 47.1 µg/g B).	Köster et al. (2019), The boron isotope geochemistry of smectites from sodium, magnesium …

Deposits of the same type

Central African Copperbelt (whole province) DR Congo and Zambia
Witwatersrand basin South Africa
Stelvio Italy
Oris Italy
Kupferschiefer, Lubin-Sieroszowice district Poland
Timna Israël
Datangpo-type manganese (Gaolou, Minle, Zhenxing) China
Eyller Bruch bog iron ore Germany

Cite this page

IsoFind Atlas (2026). Glasgow (bentonite), isotope signatures. https://www.isofind.tech/isotopes/en/deposits/glasgow-bentonite/ (accessed 2026-10-20).

@misc{isofind2026glasgowbentoniteisotopesignat,
  title = {Glasgow (bentonite), isotope signatures},
  author = {{IsoFind Atlas}},
  year = {2026},
  url = {https://www.isofind.tech/isotopes/en/deposits/glasgow-bentonite/},
  note = {Accessed 2026-10-20}
}

Updated : 2026-10-20