Molasse
Traditionally an Alpine foreland association of largely clastic deposits produced during erosion of rising mountain belts.
Language and route: International geoscience borrowing from French molasse / Franco-Provençal mollasse, a regional building-stone word. International geoscience borrowing from French molasse / Franco-Provençal mollasse, a regional building-stone word
Literal gloss: regional name for workable/soft building sandstone; origin contested
The name and its history
Regional vernacular predates H.-B. de Saussure’s geological writing · Local pre-geological attestations; geological 1779 de Saussure attestation
- What does the word literally mean?
- Immediate borrowing/formation pathway: International geoscience borrowing from French molasse / Franco-Provençal mollasse, a regional building-stone word. Linguistic gloss: ‘regional name for workable/soft building sandstone; origin contested’. This is not automatically the original namer’s stated reason.
- What did the original author mean?
- Local Franco-Provençal stone vocabulary predates geological classification; H.-B. de Saussure recorded molasse in his 1779 Alpine geological writing, decades before later tectonic associations.
- Why was the name needed?
- Alpine observers needed to name extensive soft, commonly sandstone-rich basin deposits and contrast them with older or more deformed mountain successions.
- What evidence supported the original concept?
- Quarry properties and regional lithostratigraphic occurrence originally; modern foreland-basin interpretations require sediment provenance, facies and structural timing.
- How has geology changed the concept?
- The later flysch–molasse orogenic contrast is useful but not a universal depositional law; its regional terms cannot alone date deformation or prove foreland setting.
Further historical context
Local Franco-Provençal stone vocabulary predates geological classification; H.-B. de Saussure recorded molasse in his 1779 Alpine geological writing, decades before later tectonic associations.
Alpine observers needed to name extensive soft, commonly sandstone-rich basin deposits and contrast them with older or more deformed mountain successions.
Quarry properties and regional lithostratigraphic occurrence originally; modern foreland-basin interpretations require sediment provenance, facies and structural timing.
The later flysch–molasse orogenic contrast is useful but not a universal depositional law; its regional terms cannot alone date deformation or prove foreland setting.
Editorial qualification
Do not say de Saussure invented molasse in 1779; vernacular forms predate him and deep etymology debated.
Related names
Flysch · Sandstone · Conglomerate · Facies
Sources
- CNRTL / Trésor de la langue française, molasse etymology — Franco-Provençal local borrowing; 1669 lexical, 1779 de Saussure; etymological uncertainty
- British Geological Survey, Rock Classification Scheme, Volume 3 overview — Modern descriptive sedimentary classification; does not establish historical first use
- Alpine flysch and molasse historical comparison — Retrospective on tectofacies and changing inferred depositional setting
- Flysch (Bernhard Studer) historical overview (French) — Secondary account of Studer 1827 original Alpine application; original pages unverified