Lynch's Crater () formed about 230,000 years ago during an explosive volcanic eruption, creating a maar on the eastern edge of the Atherton Tableland in

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

, Australia. Located at an altitude of about 760 m, the crater is about 80 m deep and has been heavily worn by erosion. Following its formation, a crater lake formed in the depression that was gradually filled in with deposits, so that the surface is now an average of 45 m beneath the rim. The present day interior is filled with swampy ground that is maintained by a stream flowing in from the eastern side. This water exits the crater to form a tributary of the North Johnstone River. The mean annual rainfall at this site is 2,500 mm. Sedimentary deposits in the crater provide pollen samples covering most of the last 200,000 years of vegetation growth in the region; spanning the last two

glacial period A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

s. During the interglacial epochs, the crater was occupied by mesic

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...

rainforest. In the cooler glacial periods, this was replaced by rain forests prevalent in drier climes. From 40,000 years ago, the crater was gradually occupied by

sclerophyll Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...

vegetation such as ''

Casuarina ''Casuarina'' is a genus of 17 tree species in the family Casuarinaceae, native to Australia, the Indian subcontinent, southeast Asia, islands of the western Pacific Ocean, and eastern Africa. It was once treated as the sole genus in the fa ...

'' and ''

Eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as e ...

'', with the transition being completed 26,000 years ago. Around 10,000 years ago, evergreen vegetation once more regained dominance. Particles of charcoal dated from up to 38,000 years ago are believed to be the result of fires lit by

Aboriginal Australians Aboriginal Australians are the various Indigenous peoples of the Australian mainland and many of its islands, such as Tasmania, Fraser Island, Hinchinbrook Island, the Tiwi Islands, and Groote Eylandt, but excluding the Torres Strait Isl ...

, and are coincident with the appearance of the sclerophyll vegetation and loss of regional megafauna.

References

{{Reflist, refs= {{Citation , first1 = A. P. , last1 = Kershaw , title = A Late Pleistocene and Holocene Pollen Diagram from Lynch's Crater, North-Eastern Queensland, Australia , journal = New Phytologist , pages = 469–498 , volume = 77 , issue = 2 , year = 1976 , jstor=2433618 , postscript= . , doi=10.1111/j.1469-8137.1976.tb01534.x {{Citation , first1 = Uwe , last1 = Rieser , first2 = Raphael A. J. , last2 = Wüst , title = OSL chronology of Lynch's Crater, the longest terrestrial record in NE-Australia , journal = Quaternary Geochronology , pages = 233–236 , volume = 5 , issue = 2–3 , date=April–June 2010 , doi = 10.1016/j.quageo.2009.05.014 , postscript= . {{Citation , first1 = Jeremy , last1 = Russell-Smith , first2 = Peter , last2 = Stanton , editor1-first = Ross Andrew , editor1-last = Bradstock , editor2-first = Jann Elizabeth , editor2-last = Williams , editor3-first = Arthur Malcolm , editor3-last = Gill , chapter = Fire regimes and fire management of rainforest communities , title = Flammable Australia: The Fire Regimes and Biodiverstiy of a Continent , publisher = Cambridge University Press , page = 333 , year = 2002 , isbn = 0521805910 , chapter-url = https://books.google.com/books?id=4f8anIoS33MC&pg=PA333 , postscript= . {{Cite journal , last1 = Rieser , first1 = Uwe , last2 = Wüst , first2 = Raphael A.J. , title = OSL chronology of Lynch's Crater, the longest terrestrial record in NE-Australia , journal = Quaternary Geochronology , volume = 5 , issue = 2–3 , pages = 233–236 , year = 2010 , doi = 10.1016/j.quageo.2009.05.014 Maars of Australia Landforms of Far North Queensland