Editing Undara Volcanic National Park (section)

== Geology ==
The Undara Volcanic National Park lies within the McBride Basalt  (Volcanic) Province<ref>{{Cite web|url=https://volcano.si.edu/volcano.cfm?vn=259804|title=Global Volcanism Program {{!}} McBride Volcanic Province|website=Smithsonian Institution {{!}} Global Volcanism Program|language=en|access-date=2020-03-27|archive-date=12 February 2020|archive-url=https://web.archive.org/web/20200212144028/http://volcano.si.edu/volcano.cfm?vn=259804|url-status=live}}</ref> which is one of 11 discontinuous Cenozoic volcanic regions in north Queensland. The McBride Basalt Province is around {{Convert|5,500|km2}} in area.<ref name="whitehead">{{Cite journal |last=Whitehead |first=Peter |date=2010-08-12 |title=The Regional Context of the McBride Basalt Province and the Formation of the Undara Lava Flows, Tubes, Rises and Depressions |url=https://www.researchgate.net/publication/277249112 |journal=Proceedings of the 14th International Symposium on Vulcanospeleology}}</ref>[[File:Undara National Park3.jpg|thumb|right|Geological sketch map of the Undara National Park formations.]]

A total of 164 eruption centres [[Volcano|(volcanoes]], vents and cones) have been identified within the McBride Basalt Province. Remnants of older flows dated at around 8 million years occur outside of the national park. The majority of flows are less than 8 million years.<ref name=":1">{{Cite journal|last1=Cohen|first1=Benjamin E.|last2=Mark|first2=Darren F.|last3=Fallon|first3=Stewart J.|last4=Stephenson|first4=P. Jon|date=2017-04-01|title=Holocene-Neogene volcanism in northeastern Australia: Chronology and eruption history|url=https://eprints.gla.ac.uk/134886/9/134886.pdf|journal=Quaternary Geochronology|language=en|volume=39|pages=79–91|doi=10.1016/j.quageo.2017.01.003|bibcode=2017QuGeo..39...79C |issn=1871-1014|access-date=26 December 2020|archive-date=|archive-url=|url-status=}}</ref><ref name=whitehead/> The volcanic activity that formed the tubes occurred approximately 190,000 years ago<ref name=":1" /><ref>{{Cite web|url=http://volcano.oregonstate.edu/undara|title=Undara {{!}} Volcano World {{!}} Oregon State University|website=volcano.oregonstate.edu|date=28 August 2011 |access-date=2020-03-27|archive-date=31 July 2019|archive-url=https://web.archive.org/web/20190731054739/http://volcano.oregonstate.edu/undara|url-status=live}}</ref> and the Undara volcano expelled massive amounts of [[lava]] onto the surrounding [[Atherton Tableland]], covering about 1550 square kilometres.<ref name=":1" /> In total it was estimated that over {{Convert|23|e9m3}} of lava was released.<ref name=guides/>

Thermal insulation provided by the solidification of a crust above actively flowing magma is required to produce long lava flows. The longest of the Undara flows is approximately {{Convert|160|km}} with an average gradient of 0.3°. Lava tubes occur up to {{Convert|30|km}} from the Undara Crater and up to 5 successive flow units, demarcated by [[Lava|Pahoehoe]] surfaces, have been identified in the walls of some of the caves.<ref name=whitehead/>

Bayliss Cave is the remains of a [[lava tube]] that was once over {{convert|100|km|mi|0}} in length. The cave itself is over {{convert|1300|m|ft|0}} in length, {{convert|11|m|ft|0}} high and {{convert|22|m|ft|0}} wide. It is described as a "bad air cave" with measured [[carbon dioxide]] levels as high as 5.9%.<ref name=":0">{{cite web|url=http://undara.com.au/lava-tubes/tunnels-to-a-wildlife-underworld/|title=Undara Volcanic National Park - Tunnels to the Underworld|year=2010|access-date=2010-08-23|archive-date=16 September 2010|archive-url=https://web.archive.org/web/20100916203127/http://undara.com.au/lava-tubes/tunnels-to-a-wildlife-underworld/|url-status=live}}</ref>