气候变化领域集成服务门户(CCPortal): Biostratigraphic analysis of a Late Pleistocene to Holocene section from Punta Pescador, eastern Venezuela

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DOI	10.1080/01916122.2024.2329582
	Biostratigraphic analysis of a Late Pleistocene to Holocene section from Punta Pescador, eastern Venezuela
	Pocknall, David T.; Jarzen, David M.
发表日期	2024
ISSN	0191-6122
EISSN	1558-9188
英文摘要	A biostratigraphic study was undertaken on a shallow borehole drilled to 90 meters in the easternmost Orinoco Delta, Venezuela. Twenty-eight samples were analyzed for palynomorphs and foraminifera. Palynomorphs were recovered in all except one sample consisting of 178 entities. Foraminifera assemblages of low diversity were recovered in 17 of the 28 samples. The analysis provides some insight into the vegetation, climate, and depositional history allowing comparisons with other Late Pleistocene to Holocene studies in the northern South America region. The Late Pleistocene to Early Holocene transition is marked by an unconformity, where the vegetation changes from a diverse flora of Mauritia flexuosa, grasses (Poaceae), ferns, and mangroves (Rhizophora, Avicennia) to one dominated by Rhizophora around 10,000 years BP. This transition also contains reworked palynomorphs and abundant black wood (inertinite), indicative of erosion and oxidation. The absence of foraminifera suggests an exposed continental shelf and lowering of sea level. The Early Holocene mangrove flora is replaced by vegetation dominated by Mauritia flexuosa, with Symphonia globuliflora, grasses, and ferns. The palynological signature for the upper 42 m of the section compares favorably with a previous study of the Holocene in the Orinoco Delta. Radiocarbon dating indicates there is an unconformity or condensed section at the vegetation change, representing as much as 5500 +/- years. Foraminifera indicate an open shelf environment immediately above this horizon followed by a significant shallowing to nearshore transitional environments near the top of the section. Local climate and/or human influence may have been a factor in the abundance of Mauritia flexuosa as suggested by other studies.
英文关键词	Mangrove; Mauritia; Rhizophora; radiocarbon dates; unconformity
语种	英语
WOS研究方向	Plant Sciences ; Paleontology
WOS类目	Plant Sciences ; Paleontology
WOS记录号	WOS:001194315100001
来源期刊	PALYNOLOGY
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/299849
推荐引用方式 GB/T 7714	Pocknall, David T.,Jarzen, David M.. Biostratigraphic analysis of a Late Pleistocene to Holocene section from Punta Pescador, eastern Venezuela[J],2024.
APA	Pocknall, David T.,&Jarzen, David M..(2024).Biostratigraphic analysis of a Late Pleistocene to Holocene section from Punta Pescador, eastern Venezuela.PALYNOLOGY.
MLA	Pocknall, David T.,et al."Biostratigraphic analysis of a Late Pleistocene to Holocene section from Punta Pescador, eastern Venezuela".PALYNOLOGY (2024).