气候变化领域集成服务门户(CCPortal): Phytoliths; pollen; and microcharcoal from the Baringo Basin; Kenya reveal savanna dynamics during the Plio-Pleistocene transition

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DOI	10.1016/j.palaeo.2020.109779
	Phytoliths; pollen; and microcharcoal from the Baringo Basin; Kenya reveal savanna dynamics during the Plio-Pleistocene transition
	Yost C.L.; Ivory S.J.; Deino A.L.; Rabideaux N.M.; Kingston J.D.; Cohen A.S.
发表日期	2020
ISSN	0031-0182
英文摘要	As part of the Hominin Sites and Paleolakes Drilling Project (HSPDP), phytoliths, pollen, and microcharcoal were examined from the 228 m (3.29 to 2.56 Ma) Baringo-Tugen Hills-Barsemoi drill core (BTB13). A total of 652 samples were collected at ~10 to 32 cm intervals, corresponding to sub-millennial to millennial scale temporal resolution. Microcharcoal was well-preserved throughout the core and often peaked in abundance ~5 kyr before and after insolation peaks. Phytolith preservation varied between excellent to total dissolution in alternating intervals throughout the core. Pollen was rarely preserved. These combined datasets indicate that prior to ~3.1 Ma, woody cover fluctuated between open savanna (< 40% cover), woodland (40–80% cover), and forest (> 80% cover) at typically precessional (19–23 kyr) periodicities. During the mid-Piacenzian Warm Period (MPWP; 3.26–3.01 Ma), intervals with exceptionally high microcharcoal abundance suggest that regional turnover from wooded to open habitats was driven in part by fire. After ~3.1 Ma, low-elevation woody cover likely never exceeded 40%, with oscillations between mesic tall-grass vs. xeric short-grass savanna at precessional periodicities. Mesic C4 tall-grass (Panicoideae) peaked in abundance during insolation maxima, whereas xeric C4 short-grass (Chloridoideae) peaked during insolation minima. The onset of Northern Hemisphere glaciation (NHG) at ~2.75 Ma coincided with the appearance of deep lake phases and increases in grass density and fire frequency. Spectral analysis and intervals with well-preserved phytoliths indicate that precession and interhemispheric insolation gradients influenced vegetation via their effects on equatorial precipitation and fire. This study fills a crucial gap in Pliocene vegetation reconstructions from the East African Rift Valley and its associated hominin localities. It also provides orbitally resolved regional vegetation data useful in paleodata–model comparisons for the onset of the MPWP (which is often used as an analog for future warming) and NHG. © 2020 Elsevier B.V.
英文关键词	Hominins; Microfossils; Mid-Piacenzian Warm Period; Northern Hemisphere glaciation; Paleofire; Tugen Hills
语种	英语
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150723
作者单位	Department of Geosciences, University of Arizona, 1040 E 4th St., Tucson, AZ 85721, United States; Department of Geosciences, Pennsylvania State University, State CollegePA 16801, United States; Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709, United States; Department of Chemistry, Rutgers University-Newark, Newark, NJ 07109, United States; Department of Anthropology, University of Michigan, 1085 S. University Avenue, Ann Arbor, MI 48109, United States
推荐引用方式 GB/T 7714	Yost C.L.,Ivory S.J.,Deino A.L.,et al. Phytoliths; pollen; and microcharcoal from the Baringo Basin; Kenya reveal savanna dynamics during the Plio-Pleistocene transition[J],2020.
APA	Yost C.L.,Ivory S.J.,Deino A.L.,Rabideaux N.M.,Kingston J.D.,&Cohen A.S..(2020).Phytoliths; pollen; and microcharcoal from the Baringo Basin; Kenya reveal savanna dynamics during the Plio-Pleistocene transition.Palaeogeography, Palaeoclimatology, Palaeoecology.
MLA	Yost C.L.,et al."Phytoliths; pollen; and microcharcoal from the Baringo Basin; Kenya reveal savanna dynamics during the Plio-Pleistocene transition".Palaeogeography, Palaeoclimatology, Palaeoecology (2020).