BGS Rock Classification Scheme

Agglomerate, trachytic

Code	AGTR
Description	Agglomerate, trachytic
Qualifiers	trachytic
Definition	Unimodal well sorted rock, clastic material (>10% debris) formed by volc processes; >75% pyroclastic frags, >75% >64mm bombs (rounded) >blocks, <25% 2-64mm lapilli + <2mm ash. Composition qtz <5% of QAPF, felds 65-90% alk felds, TAS SiO2 57.6- 69wt%.
Linked data	http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/AGTR

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CAVEAT

"Thumbnail" definitions attached to some of the table entries are an interim attempt to provide simple short descriptions of the "unqualified" rock types presented within the BGS Rock Classification Scheme. Every effort has been made to ensure accuracy and consistency but minor contradictions or omissions might be present. The BGS welcomes any feedback pointing out such minor imperfections and/or providing constructive comment and suggestions for improvement of the definitions. In the first instance such feedback should be directed to Dr Tim McCormick.