Show simple item record  

dc.contributor.authorGreen, John D.
dc.contributor.authorLowe, David J.
dc.date.accessioned2011-04-11T01:35:55Z
dc.date.available2011-04-11T01:35:55Z
dc.date.issued1985
dc.identifier.citationGreen, J.D. & Lowe, D.J. (1985). Stratigraphy and development of c. 17 000 year old Lake Maratoto, North Island, New Zealand, with some inferences about postglacial climatic change. New Zealand Journal of Geology and Geophysics, 28(4), 675-699.en_NZ
dc.identifier.urihttps://hdl.handle.net/10289/5264
dc.description.abstractThe stratigraphy and geomorphology of Lake Maratoto and its surrounds were investigated as part of a programme of paleolimnological studies based on sediment cores from lakes in northern North Island. Changes in the lake and catchment were inferred from variations in sediment character, the correlation and timing being determined from distinctive tephra layers in the sediments and by radiocarbon dating. Nineteen new C-l4 dates, on gyttja or peat, are reported (old T½, years B.P,): 11 on tephras (Mamaku Ash 6830 ±90. Wk227; Rotoma Ash 8370 ± 90, Wk522; 8350 ± 100, Wk523; Opepe Tephra 9370 ± 210, Wk230; Mangamate Tephra 9700 ± 140, Wk23l; 10000 ± 120, Wk232; Waiohau Ash 12 200 ± 230, Wk233; 12500 ± 190, Wk234; 12450 ± 200, Wk5l5; 12300 ± 190,Wk516; RotoruaAsh 13450 ± 120, Wk511); 5 on the deposition of Hinuera Formation alluvium (16 300 ± 250, Wk239; 16 900 ± 470, Wk240; 17050 ± 200, Wk358; 16200 +360 -340, Wk509; 15 850 ± 130, Wk510); and 3 on basal peat of the Rukuhia bog (10 250 ± 90, Wk114; 15200 ± 130, Wk534; 10600 ± 90, Wk553). Lake Maratoto originated c. 17 000 years ago when a small valley was dammed by volcanogenic alluvium (Hinuera Formation). From c. 17 000 to c. 14 000 years ago the lake was about 2 m deep with clear water. Marginal peat first developed at c. 15000 years ago, reducing the area of the lake by about one-half by c. 13 000 years ago. Lake area then expanded, possibly because of marginal erosion and/or oxidation of the peat, to its maximum size at the present day. The adjacent Rukuhia peat bog grew rapidly from c. 11 000 years ago and is now 8 m thick immediately to the west of the lake. As a result of this growth, the lake became dystrophic and deepened (3.5 m at c. 7000 years ago, 6.4 m at c. 2000 years ago, and 7. 1 m today). The developmental history suggests that net precipitation increased at c. 15 000 years ago, increased further at c. 11 000 years ago, remaining high to c. 7000 years ago at least, but with a decline at or before c. 2000 years ago. There may have been a distinctly wetter or windier period from c. 10 000 to 9000 years ago. This interpretation is consistent with other reconstructions of postglacial climate in the Southern Hemisphere.en_NZ
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.relation.urihttp://www.royalsociety.org.nz/publications/journals/nzjg/en_NZ
dc.rightsThis article has been published in the journal: New Zealand Journal of Geology and Geophysics. © Crown copyright 1985. Used with permission.en_NZ
dc.subjectpaleolimnologyen_NZ
dc.subjectlake sedimentsen_NZ
dc.subjectdrainage basinsen_NZ
dc.subjectpeaten_NZ
dc.subjectpyroclasticsen_NZ
dc.subjecttephrostratigraphyen_NZ
dc.subjecttephrochronologyen_NZ
dc.subjectC-14en_NZ
dc.subjectabsolute ageen_NZ
dc.subjectferromagnesian mineralogyen_NZ
dc.subjectglass chemistryen_NZ
dc.subjectglass chemistryen_NZ
dc.subjectHoloceneen_NZ
dc.subjectClimateen_NZ
dc.subjectlake-level fluctuationsen_NZ
dc.subjectHamilton Basinen_NZ
dc.subjectHinuera Formationen_NZ
dc.subjectLake Maratotoen_NZ
dc.subjectRukuhiaen_NZ
dc.subjectbogsen_NZ
dc.titleStratigraphy and development of c. 17 000 year old Lake Maratoto, North Island, New Zealand, with some inferences about postglacial climatic changeen_NZ
dc.typeJournal Articleen_NZ
dc.identifier.doi10.1080/00288306.1985.10422541
dc.relation.isPartOfNew Zealand Journal of Geology and Geophysicsen_NZ
pubs.begin-page675en_NZ
pubs.elements-id84365
pubs.end-page699en_NZ
pubs.issue4en_NZ
pubs.volume28en_NZ


Files in this item

This item appears in the following Collection(s)

Show simple item record