siltstone
Fine-grained sedimentary rock
Siltstone is a sedimentary rock composed mainly of silt-sized particles—finer than sand but coarser than clay.
It forms when mud and silt compact over time, often in riverbeds, lakebeds, or ocean floors.
Siltstone typically appears gray or brown and feels gritty when rubbed.
It falls between sandstone and shale in grain size.
Compacted clay sediment
- mudstoneCompacted clay and silt rock
- claystoneIndurated fine-grained sedimentary rock
- stratigraphyStudy of rock layers
- outcropSurfacing native stone
clastic · sedimentology · petrology · geomorphology · erosion · weathering · deposition · facies
Composed of minute particles
- grittyCoarse or courageous
- compactTightly packed together
- induratedMade physically or emotionally tough
- friableReadily reduced to fragments
fissile · laminated · massive · dense · durable · impermeable · buff · gray
Formal testimony under oath
- fluvialRelating to rivers
- marineRelating to the sea
- deltaicOf river-mouth landforms
- alluviumWater-deposited loose sediment
floodplain · overbank · estuarine · tidal flat · loess · windblown · settling · compaction
Division into distinct levels
- laminationBonding sheets together
- beddingMaterials covering a mattress
- strataParallel geological layers
- cross-beddingAngled layers within strata
shale
Compacted clay sediment
- mudstoneCompacted clay and silt rock
- claystoneIndurated fine-grained sedimentary rock
- stratigraphyStudy of rock layers
outcrop · clastic · sedimentology · petrology · geomorphology · erosion · weathering · deposition · facies · formation
fine-grained
Composed of minute particles
- grittyCoarse or courageous
- compactTightly packed together
- induratedMade physically or emotionally tough
friable · fissile · laminated · massive · dense · durable · impermeable · buff · gray · reddish-brown
deposition
Formal testimony under oath
alluvium · floodplain · overbank · estuarine · tidal flat · loess · windblown · settling · compaction · cementation
stratification
Division into distinct levels
- laminationBonding sheets together
- beddingMaterials covering a mattress
- strataParallel geological layers
cross-bedding · parting · cleavage · sequence
shale
Compacted clay sediment
- mudstoneCompacted clay and silt rock
- claystoneIndurated fine-grained sedimentary rock
- slateFissile metamorphic rock
marlstone · conglomerate · breccia · chert · flint · quartzite · flagstone · brownstone · bluestone · fieldstone
- rocksbasalt, granite, marble, shale, slate
- fossil sourcestar pits, amber, shale, coal beds, peat bogs
- sedimentsand, clay, gravel, mud, pebble
- sedimentary rocksshale, mudstone, conglomerate, claystone, chalk
- sedimentssand, mud, clay, gravel, deposit
- petrologypetrology, igneous rocks, metamorphic rocks, sedimentary rocks, rock cycle