Wikipedia:Map data/South Island Volcanics/key

<-Map data/South Island Volcanics In use the following applies:

Modified volcanics by erosion, alluvial action and sedimentary rocks are not shown to minimise complexity. Presently most plutonic rocks, undersea volcanic fields and the Southern Alps dyke field are not shown. Other volcanic features such as off shore volcanic fields may be selectively shown in white shading. Many of the inland, now surface, volcanic features have been subjected to the considerable uplift in last 100 million years of the Pacific plate and are associated therefore with sedimentary deposits and can therefore manifest as flank deposits on mountains or have sedimentary deposits that are not shown around the volcanic centre. The data is complimentary to Map data/Northern North Island Volcanics.

The data on distribution and volcanic rock type is by default from NZ 1:250K Geological GNS science but where ever possible detail is from original academic work and updates of this. Some simplification was undertaken and distribution diagrams are approximate but could sometimes improve on these standard sources as some minor data inaccuracy in original sources was apparent. The mapping terminology is pretty much in line with Le Maitre 2002 as most of the relevant academic work has been updated in last two decades, which was not the case with the companion work to support North Island surface volcanism. Names for flows where a volcanic vent is unnamed or use could be confusing is based on a nearby feature in NZTopoMap and authors own knowledge of likely usual access routes. General age context from the University of Waikato 2015 - Cenozoic sedimentary and volcanic rocks of New Zealand: A reference volume of lithology, age and paleoenvironments with maps (PMAPs) and database compilation. Other specific academic references include:

Not all data uses the TAS nomenclature of Le Maitre 2002 Igneous rocks: a classification and glossary of terms: recommendations of the IUGS, Subcommission on the Systematics of Igneous rocks. University Press. Ages have hopefully been assigned to correct formations which has meant multiple ages where geo coords not definite not assigned. Where multiple specimens with more than one age these are given - there are definite centres with more than 5 million years between volcanic layers ! Clicking on the map enlarges it, and enables panning and mouseover of volcano name/wikilink and ages before present. Key for the volcanics that are shown with panning is: (shades of brown/orange),, , , ,   (basalts shades of olive),  (pale salmon), ,  (shades of red), , , (ignimbrite is lighter shades of violet), and  (gray) - so dolerite/diabase/microgabbro will have shadings towards gray compared to erupted basalt.