DOI: 10.1016/j.quascirev.2016.06.008
Scopus记录号: 2-s2.0-84979071862
论文题名: Late Pleistocene-Holocene alluvial stratigraphy of southern Baja California, Mexico
作者: Antinao J.L. ; McDonald E. ; Rhodes E.J. ; Brown N. ; Barrera W. ; Gosse J.C. ; Zimmermann S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2016
卷: 146 起始页码: 161
结束页码: 181
语种: 英语
英文关键词: Alluvial fans
; Baja California
; Holocene
; Late Pleistocene
; Mexico
; North America
; Sonoran desert
; Tropical cyclones
Scopus关键词: Deposition
; Deposits
; Geochronology
; Hurricanes
; Luminescence
; Storms
; Stratigraphy
; Alluvial fans
; Baja california
; Holocenes
; Late Pleistocene
; Me-xico
; North America
; Sonoran desert
; Tropical cyclone
; Tropics
; alluvial fan
; depositional sequence
; El Nino
; geochronology
; geomorphological mapping
; Holocene
; luminescence
; paleoclimate
; Pleistocene
; proxy climate record
; radiocarbon dating
; sedimentation
; sequence stratigraphy
; tropical cyclone
; Baja California Sur
; Baja California [(PNN) Mexico]
; Jos
; La Paz Bay
; Mexico [North America]
; Nigeria
; Plateau [Nigeria]
; Sonoran Desert
英文摘要: A late Pleistocene to Holocene alluvial stratigraphy has been established for the basins of La Paz and San José del Cabo, in the southern tip of the Baja California peninsula, Mexico. Six discrete alluvial units (Qt1 through Qt6) were differentiated across the region using a combination of geomorphologic mapping, sedimentological analysis, and soil development. These criteria were supported using radiocarbon, optically stimulated luminescence and cosmogenic depth-profile geochronology. Major aggradation started shortly after ∼70 ka (Qt2), and buildup of the main depositional units ended at ∼10 ka (Qt4). After deposition of Qt4, increasing regional incision of older units and the progressive development of a channelized alluvial landscape coincide with deposition of Qt5 and Qt6 units in a second, incisional phase. All units consist of multiple 1-3 m thick alluvial packages deposited as upper-flow stage beds that represent individual storms. Main aggradational units (Qt2-Qt4) occurred across broad (>2 km) channels in the form of sheetflood deposition while incisional stage deposits are confined to channels of ∼0.5-2 km width. Continuous deposition inside the thicker (>10 m) pre-Qt5 units is demonstrated by closely spaced dates in vertical profiles. In a few places, disconformities between these major units are nevertheless evident and indicated by partly eroded buried soils. The described units feature sedimentological traits similar to historical deposits formed by large tropical cyclone events, but also include characteristics of upper-regime flow sedimentation not shown by historical sediments, like long (>10 m) wavelength antidunes and transverse ribs. We interpret the whole sequence as indicating discrete periods during the late Pleistocene and Holocene when climatic conditions allowed larger and more frequent tropical cyclone events than those observed historically. These discrete periods are associated with times when insolation at the tropics was higher than the present-day conditions, determined by precessional cycles, and modulated by the presence of El Niño-like conditions along the tropical and northeastern Pacific. The southern Baja California alluvial record is the first to document a precession-driven alluvial chronology for the region, and it constitutes a strong benchmark for discrimination of direct tropical influence on any other alluvial record in southwestern North America. © 2016 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59522
Appears in Collections: 过去全球变化的重建
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作者单位: Division of Earth and Ecosystem Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV, United States; National Research Center for Integrated Natural Disaster Management, CIGIDEN, Santiago, Chile; Earth and Space Sciences Department, UCLA, Los Angeles, CA, United States; Dalhousie Geochronology Centre, Dalhousie University, Halifax, NS, Canada; Center for Accelerator Mass Spectrometry, Lawrence Livermore National LaboratoryCA, United States
Recommended Citation:
Antinao J.L.,McDonald E.,Rhodes E.J.,et al. Late Pleistocene-Holocene alluvial stratigraphy of southern Baja California, Mexico[J]. Quaternary Science Reviews,2016-01-01,146