气候变化领域集成服务门户(CCPortal): Seismic imaging of the Olduvai Basin; Tanzania

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DOI	10.1016/j.palaeo.2019.109246
	Seismic imaging of the Olduvai Basin; Tanzania
	Lu K.; Hanafy S.; Stanistreet I.; Njau J.; Schick K.; Toth N.; Stollhofen H.; Schuster G.
发表日期	2019
ISSN	0031-0182
卷号	533
英文摘要	A 5.6-km-long line of refraction and reflection seismic data spanning the Pliocene-Pleistocene fill of the Olduvai Basin, Tanzania is presented. The line is oriented along a northwest-southeast profile through the position of Olduvai Gorge Coring Project (OGCP) Borehole 2A. Our aims are to (1) delineate the geometry of the basin floor by tracing bedrock topography of the metaquartzitic and gneissic basement, (2) map synsedimentary normal faults and trace individual strata at depth, and (3) provide context for the sequence observed in OGCP cores. Results with refraction tomography and poststack migration show that the maximum basin depth is around 405 m (±25 m) in the deepest portion, which quadruples the thickness of the basin-fill previously known from outcrops. Variations in seismic velocities show the positions of lower density lake claystones and higher density well-cemented sedimentary sequences. The Bed I Basalt lava is a prominent marker in the refraction seismic results. Bottom-most sediments are dated to >2.2 Ma near where Borehole 2A bottoms out at the depth of 245 m. However, the seismic line shows that the basin-fill reaches a maximum stratigraphic thickness of around 380 m deep at Borehole 2A, in the western basin where the subsidence was greatest. This further suggests that potential hominin palaeoenvironments were available and preserved within the basin-fill possibly as far back as around 4 Ma, applying a temporal extrapolation using the average sediment accretion rate. © 2019
语种	英语
scopus关键词	accretion; bedrock; borehole geophysics; fault; hominid; imaging method; paleoenvironment; Pliocene-Pleistocene boundary; sedimentary sequence; seismic data; seismic reflection; seismic refraction; seismic velocity; seismicity; topography; Arusha [Tanzania]; Olduvai Gorge; Tanzania
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/150831
作者单位	King Abdullah University of Science and Technology, Division of Physical Science and Engineering, Thuwal, 23955-6900, Saudi Arabia; King Fahd University of Petroleum and Minerals, Collage of Petroleum Engineering and Geosciences, Dhahran, 31261, Saudi Arabia; Department of Earth, Ocean and Ecological Sciences, University of Liverpool, Brownlow Street, Liverpool, L69 3GP, United Kingdom; The Stone Age Institute, 1392 W Dittemore Road, Gosport, IN 47433, United States; GeoZentrum Nordbayern, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Schloßgarten 5, Erlangen, 91054, Germany; Department of Earth & Atmospheric Sciences, Indiana University, Bloomington, IN 47405, United States
推荐引用方式 GB/T 7714	Lu K.,Hanafy S.,Stanistreet I.,et al. Seismic imaging of the Olduvai Basin; Tanzania[J],2019,533.
APA	Lu K..,Hanafy S..,Stanistreet I..,Njau J..,Schick K..,...&Schuster G..(2019).Seismic imaging of the Olduvai Basin; Tanzania.Palaeogeography, Palaeoclimatology, Palaeoecology,533.
MLA	Lu K.,et al."Seismic imaging of the Olduvai Basin; Tanzania".Palaeogeography, Palaeoclimatology, Palaeoecology 533(2019).