boulder
Let an agent define boulders by size and origin, identify kinds by transport process, explain their use as evidence in geology and geomorphology, and relay their roles in landscape, hazard and culture.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent define boulders by size and origin, identify kinds by transport process, explain their use as evidence in geology and geomorphology, and relay their roles in landscape, hazard and culture.
A rock fragment larger than a cobble, conventionally over 256 millimetres across, detached from bedrock and moved by gravity, ice, water or waves, or left in place by weathering as a corestone; boulders include glacial erratics carried far from their source, tsunami and storm boulders on coasts, and ploughing blocks that move slowly downslope, and they serve as landscape features, climbing objects and, when inscribed, as monuments.
What it is for: Not applicable; a natural rock fragment.
It can be define by size and origin; identify kinds by process; explain use as geological evidence; relay landscape and cultural roles.
Distinguishing features
Size class
Transport or in-place origin
Evidence of past processes
Landscape and cultural roles
What it looks like
A large detached rock, rounded or angular, from about a quarter metre to many metres across.
Physical character
minimum size: 256 mm - Wentworth scale
largest erratics: over 10000 tonnes - such as the Big Rock in Alberta
How it is recognised
Rock fragment over 256 mm
Detached and moved, or weathered in place
Cobbles are smaller; bedrock outcrops are not detached
Related models
is a kind of - the largest class
is a kind of - in registry terms
is larger than - the next size class
is moved by - in the case of erratics
In practice
Families and kinds
glacial erratics
tsunami and storm boulders
corestones from spheroidal weathering
ploughing blocks on slopes
boulders in rivers, screes and rockfalls
inscribed boulders and boulder plaques as monuments
Standards and regulation
Wentworth grain size scale
Geoheritage protection for notable boulders
Rockfall hazard regulations
Failure modes and hazards
Rockfall and boulder hazards
Misidentifying origin
Damage to protected boulders
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Identify What boulder this is.
Identity.
Definition
Definition and size.
Definition
Definition.
- What defines a boulder, and how is it classed by size? definition
- Is the object a boulder, a cobble or bedrock? boundary
Origin
Origin and transport.
Origin
Origin.
- How can the origin of a boulder be identified, from erratic to corestone? definition
- Which entry fits the specific kind? action
Science Geological evidence.
Science.
Evidence
Evidence of processes.
Evidence
Evidence.
- What do boulders reveal about glaciation, tsunamis, storms and weathering? provenance
- Which entry fits geomorphology? action
Dating
Dating.
Dating
Dating.
- How are boulder deposits dated, such as by cosmogenic nuclides? provenance
- Which references are standard? provenance
Hazard Hazards and engineering.
Safety.
Rockfall
Rockfall.
Rockfall
Rockfall.
- How are boulder and rockfall hazards assessed and managed? provenance
- Is the question site-specific, which needs an engineer? boundary
Construction
Construction.
Construction
Construction.
- How are boulders handled in construction and used in coastal defences? provenance
- Which entry fits coastal engineering? action
Culture Landscape and culture.
Context.
Monuments
Monuments and heritage.
Monuments
Monuments.
- How are boulders used as monuments, inscribed stones and geoheritage sites? provenance
- Which entry fits geoheritage? action
Recreation
Bouldering and landscape.
Recreation
Recreation.
- How are boulders used in climbing and valued in landscapes? provenance
- Which entry fits bouldering? action
What the second pass must settle
- Should glacial erratic be a separate entry?
- How should geoheritage registers be linked?
- The registry entry has merged aliases naming kinds and monuments; should they be split off?