Abandonment ages of alluvial landforms in the hyperarid Negev determined by luminescence dating

Porat, Naomi; Amit, Rivka; Enzel, Yehouda; Zil'berman, E. N.; Avni, Yoav; Ginat, Hanan; Gluck, Daniel

doi:10.1016/j.jaridenv.2009.10.018

Cited by 52 publications

(37 citation statements)

References 49 publications

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“…Other studies report OSL ages in alluvial sediments which are entirely consistent with the stratigraphic order, indicating that inconsistencies are not a general problem of the dating technique (e.g. Porat et al, 1996;Toms et al, 2004;Fattahi et al, 2006;Porat et al, 2010). Several authors mentioned that an overestimation of OSL ages may be the result of incomplete bleaching, i.e.…”

Section: Introductionmentioning

confidence: 85%

Optical dating of alluvial deposits at the orogenic front of the andean precordillera (Mendoza, Argentina)

et al. 2011

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Abstract:Well constrained numerical ages of alluvial fan sediments are key to understanding the chronology of alluvial episodes and tectonic activity at the front of the Andean Precordillera. We tested the application of radiocarbon and optically stimulated luminescence (OSL) dating in the distal part of an alluvial fan five kilometers north of Mendoza. For OSL dating a large number of aliquots (n > 70) -each composed of ~50 quartz grains -were measured in order to obtain reliable burial ages despite scattered dose distributions. Owing to a feldspar contamination in all samples, an infrared stimulation was inserted before each OSL measurement, which reduced the feldspar OSL signal successfully. By using the minimum age model we obtained stratigraphically consistent burial ages of alluvial deposits in a depth profile. The uppermost ~1 m of sediment is composed of debris flow deposits buried 770±76 years ago. Three plant remnants used for radiocarbon dating from the same layer, however, yielded ages younger than 350 years, which are interpreted to underestimate the depositional age. Underneath the debris flow, a major unconformity cuts a series of distal alluvial fan sediments with interstratified floodplain deposits, which are composed of sandy and calcite-rich silt layers, respectively. Three samples from this unit which were distributed over one meter of sediment thickness yielded statistically concordant OSL ages of 12.3±1.2 ka, 12.3±1.2 ka, and 11.7±1.1 ka. The deposition of these sediments during the latest Pleistocene coincides with a phase of cool and humid climate, which occurred before the alluvial fan propagated farther into the foreland. The overlying debris flow sediments are associated with alluvial fan incision during the arid Late Holocene.

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Section: Introductionmentioning

confidence: 85%

Optical dating of alluvial deposits at the orogenic front of the andean precordillera (Mendoza, Argentina)

et al. 2011

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“…These ages indicate that the development of the studied talus flatiron sequences is not specifically associated with the temporal scale of glacial-interglacial cycles. The soils developed in the talus flatirons are cumulative and polygenetic gypsic and saline soils which are proxies for hyperarid climate conditions through most of the Quarternary (Dan and Yaalon, 1982;Amit and Gerson, 1986;Amit et al, 1993Amit et al, , 2006Amit and Yaalon, 1996;Porat et al, 2010). No evidence was found for calcic horizons that would have indicated somewhat wetter conditions in the topsoil, The tops of all samples were exposed at the surface excluding ZRA7 which were collected from a depth range of 200-310 m.We use an average of 255 m for the calculations.…”

Section: Paleoclimatic Significance Of Talus Flatiron Formationmentioning

confidence: 99%

Quaternary-scale evolution of sequences of talus flatirons in the hyperarid Negev

et al. 2011

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“…KF, Khunayzir Fault. Circled numbers show locations of the study sites of (1) Porat et al [2010], (2) Niemi et al [2001] and Klinger et al [2000a] (Early Holocene), and (3) Klinger et al [2000a] (Late Pleistocene).…”

Section: Introductionmentioning

confidence: 99%

Early Holocene and Late Pleistocene slip rates of the southern Dead Sea Fault determined from ¹⁰Be cosmogenic dating of offset alluvial deposits

Béon¹,

Klinger²,

Al-Qaryouti³

et al. 2010

J. Geophys. Res.

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[1] Two sites located along the Wadi Araba Fault (WAF) segment of the Dead Sea Fault are targeted for tectonic-morphological analysis. 10 Be cosmogenic radionuclide (CRN) dating of embedded cobbles is used to constrain the age of offset alluvial surfaces. At the first site a 48 ± 7 m offset alluvial fan, for which 10 Be CRN model ages average 11.1 ± 4.3 ka, yield a slip rate of 5.4 ± 2.7 mm/a, with conservative bounds of 1.3-16.4 mm/a. At the second site the scattered distributions of the 10 Be CRN ages from an offset bajada attest to the complex processes involved in sediment transport and emplacement. There, two offsets were identified. The 160 ± 8 m offset of an incised alluvial fan dated at 37 ± 5 ka shows a slip rate of 4.5 ± 0.9 mm/a, with a conservative minimum value of 3.2 mm/a. A larger offset, 626 ± 37 m, is derived from a prominent channel incised into the bajada. Cobbles from the bajada surface have ages from 33 to 141 ka, with a mean of 87 ± 26 ka. A slip rate of 8.1 ± 2.9 mm/a is derived from the mean age, with conservative bounds of 3.8-22.1 mm/a. These results and other published slip rates along the linear WAF segment, from GPS to geological time scales, lack the resolution to fully resolve the question of temporal variations versus consistency of the fault slip rate of the WAF. Yet, given the uncertainties, they are not inconsistent with each other.

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Abandonment ages of alluvial landforms in the hyperarid Negev determined by luminescence dating

Cited by 52 publications

References 49 publications

Optical dating of alluvial deposits at the orogenic front of the andean precordillera (Mendoza, Argentina)

Optical dating of alluvial deposits at the orogenic front of the andean precordillera (Mendoza, Argentina)

Quaternary-scale evolution of sequences of talus flatirons in the hyperarid Negev

Early Holocene and Late Pleistocene slip rates of the southern Dead Sea Fault determined from ¹⁰Be cosmogenic dating of offset alluvial deposits

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Abandonment ages of alluvial landforms in the hyperarid Negev determined by luminescence dating

Cited by 52 publications

References 49 publications

Optical dating of alluvial deposits at the orogenic front of the andean precordillera (Mendoza, Argentina)

Optical dating of alluvial deposits at the orogenic front of the andean precordillera (Mendoza, Argentina)

Quaternary-scale evolution of sequences of talus flatirons in the hyperarid Negev

Early Holocene and Late Pleistocene slip rates of the southern Dead Sea Fault determined from 10Be cosmogenic dating of offset alluvial deposits

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Early Holocene and Late Pleistocene slip rates of the southern Dead Sea Fault determined from ¹⁰Be cosmogenic dating of offset alluvial deposits