Anatoly V. Lozhkin, Marina V. Cherepanova, Patricia M. Anderson, Pavel S. Minyuk, Bruce P. Finney
{"title":"Glukhoye Lake: Middle to Late Holocene environments of Kunashir Island (Kuril Archipelago, Russian Far East)","authors":"Anatoly V. Lozhkin, Marina V. Cherepanova, Patricia M. Anderson, Pavel S. Minyuk, Bruce P. Finney","doi":"10.1111/bor.12565","DOIUrl":null,"url":null,"abstract":"<p>A multiproxy analysis of a sediment core from Glukhoye Lake in the southern Kuril Islands indicates that the basin originated <i>c</i>. 8.2 cal. ka BP as a brackish lagoon with the subsequent development of a freshwater lake (<i>c</i>. 4.0 to 3.3 cal. ka BP), a bog (<i>c</i>. 3.3 to 2.4 cal. ka BP) and a second lake (<i>c</i>. 2.4 cal. ka BP to present). The basin history primarily reflects local coastal dynamics and is not related to proposed Archipelago-wide changes in sea level. Between <i>c</i>. 8.2 and 8.0 cal. ka BP, the vegetation of southern Kunashir Island was characterized by <i>Betula–Quercus</i> forest with a secondary component of temperate broadleaf trees. <i>Quercus</i> broadleaf forest established <i>c</i>. 8.0 to 6.5 cal. ka BP and represents the Holocene thermal maximum. The remainder of the record shows a gradual decrease in temperate and an increase in conifer taxa, indicating a gradual cooling from the Holocene thermal maximum to <i>c</i>. 2.3 cal. ka BP. Maxima in <i>Picea</i> and <i>Abies</i> pollen between <i>c</i>. 2.3 and 1.1 cal. ka BP suggest conditions that were slightly cooler than present. Palaeovegetation changes in the Kuril Islands as inferred from lake and section data differ in the timing and/or composition of the vegetation communities, although results from the two types of sites become more similar as the number of sections increases. The lake results do not support a previous conceptual model developed for the southern Russian Far East, which linked changes in sea levels to Holocene climate fluctuations. Rather the depositional environments in the lake cores seem more related to coastal dynamics that are independent of fluctuations in sea levels or climate. The difficulty in developing accurate age models for sites with multiple depositional environments may be the most important obstacle for documenting and understanding the Archipelago’s vegetation and climate histories.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"51 2","pages":"364-384"},"PeriodicalIF":2.4000,"publicationDate":"2021-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12565","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Boreas","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/bor.12565","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOGRAPHY, PHYSICAL","Score":null,"Total":0}
引用次数: 1
Abstract
A multiproxy analysis of a sediment core from Glukhoye Lake in the southern Kuril Islands indicates that the basin originated c. 8.2 cal. ka BP as a brackish lagoon with the subsequent development of a freshwater lake (c. 4.0 to 3.3 cal. ka BP), a bog (c. 3.3 to 2.4 cal. ka BP) and a second lake (c. 2.4 cal. ka BP to present). The basin history primarily reflects local coastal dynamics and is not related to proposed Archipelago-wide changes in sea level. Between c. 8.2 and 8.0 cal. ka BP, the vegetation of southern Kunashir Island was characterized by Betula–Quercus forest with a secondary component of temperate broadleaf trees. Quercus broadleaf forest established c. 8.0 to 6.5 cal. ka BP and represents the Holocene thermal maximum. The remainder of the record shows a gradual decrease in temperate and an increase in conifer taxa, indicating a gradual cooling from the Holocene thermal maximum to c. 2.3 cal. ka BP. Maxima in Picea and Abies pollen between c. 2.3 and 1.1 cal. ka BP suggest conditions that were slightly cooler than present. Palaeovegetation changes in the Kuril Islands as inferred from lake and section data differ in the timing and/or composition of the vegetation communities, although results from the two types of sites become more similar as the number of sections increases. The lake results do not support a previous conceptual model developed for the southern Russian Far East, which linked changes in sea levels to Holocene climate fluctuations. Rather the depositional environments in the lake cores seem more related to coastal dynamics that are independent of fluctuations in sea levels or climate. The difficulty in developing accurate age models for sites with multiple depositional environments may be the most important obstacle for documenting and understanding the Archipelago’s vegetation and climate histories.
期刊介绍:
Boreas has been published since 1972. Articles of wide international interest from all branches of Quaternary research are published. Biological as well as non-biological aspects of the Quaternary environment, in both glaciated and non-glaciated areas, are dealt with: Climate, shore displacement, glacial features, landforms, sediments, organisms and their habitat, and stratigraphical and chronological relationships.
Anticipated international interest, at least within a continent or a considerable part of it, is a main criterion for the acceptance of papers. Besides articles, short items like discussion contributions and book reviews are published.