Litharenite
An arenitic sandstone rich in lithic (rock) fragments compared with feldspar, within the relevant QFL classification.
Language and route: English compound lith- from Greek líthos ‘stone’ + arenite ultimately Latin arēna ‘sand’. English compound lith- from Greek líthos ‘stone’ + arenite ultimately Latin arēna ‘sand’
Literal gloss: rock-fragment sandy rock
The name and its history
First geological naming act not verified · First geological printed use not verified
- What does the word literally mean?
- Immediate borrowing/formation pathway: English compound lith- from Greek líthos ‘stone’ + arenite ultimately Latin arēna ‘sand’. Linguistic gloss: ‘rock-fragment sandy rock’. This is not automatically the original namer’s stated reason.
- What did the original author mean?
- Post-war sandstone point-count classifications increasingly distinguished framework rock fragments from isolated mineral grains, enabling hypotheses about tectonic source terrains.
- Why was the name needed?
- Older arkose/greywacke classifications conflated framework lithic content, alteration and matrix; litharenite helps separate these attributes.
- What evidence supported the original concept?
- Modal counts of sedimentary, volcanic and metamorphic rock fragments in thin section; framework fragments require definition and careful point-count rules.
- How has geology changed the concept?
- Litharenite is a compositional class, not proof of a unique tectonic setting; QFL diagrams depend on grain-counting conventions and can be affected by diagenesis.
Further historical context
Post-war sandstone point-count classifications increasingly distinguished framework rock fragments from isolated mineral grains, enabling hypotheses about tectonic source terrains.
Older arkose/greywacke classifications conflated framework lithic content, alteration and matrix; litharenite helps separate these attributes.
Modal counts of sedimentary, volcanic and metamorphic rock fragments in thin section; framework fragments require definition and careful point-count rules.
Litharenite is a compositional class, not proof of a unique tectonic setting; QFL diagrams depend on grain-counting conventions and can be affected by diagenesis.
Editorial qualification
First coinage/priority not independently established; historical narrative is a source-bounded reconstruction.
Related names
Arenite · Sandstone · Quartz arenite · Arkose · Greywacke
Sources
- Pettijohn (1954), Classification of Sandstones — Original 1954 abstract examined; compositional, maturity and matrix criteria
- Hybrid event beds and the greywacke problem revisited (2022) — Retrospective of historical matrix/composition schemes and later debate
- British Geological Survey, Rock Classification Scheme, Volume 3 overview — Modern descriptive sedimentary classification; does not establish historical first use