tivity on the carmel faul

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Figure 14: Sample DN-7 3.3 Dating of seismite samples 3.3.1 Multiple Collector Inductively Coupled Plasma Mass Spectrometer In this study dating with the U-series decay method was conducted using the MC- ICP-MS (located at the geochemical laboratory of the Geological Survey of Israel in Jerusalem), which measures Uranium and Thorium isotopes after chromatographic separation from the calcite samples in the laboratory. The protocol for the chromatographic separation of Uranium and Thorium from the calcite matrix is explained in detail in Appendix II-I. These measurements are then used to calculate the isotopic ratios needed for U-series age equations (see below). 35
3.3.2 Single sample dating Single sample dating was done using equation [1] according to Broecker and Kaufman (1965): [1] [ 230 Th/ 234 U] = [ 238 U/ 234 U]*(1-e -λ230t ) + {1-[ 238 U/ 234 U]}*{λ 230 /(λ 230 -λ 234 )}*[1-e (-λ230-λ234)t ] As mentioned above (ch. 1.3- Dating of speleothems), this equation is based on the assumption that no initial 230 Th is present in the sample. Any initial 230 Th is always accompanied by a much larger amount of 232 Th, therefore 232 Th is routinely monitored during analysis, and samples containing less than an acceptable threshold of 230 Th/ 232 Th can be identified (Hellstrom, 2007). According to Kaufman et al. (1998) a sample is considered to have a high detrital content, which requires a correction for the contribution of 230 Th by the decay of 232 Th, if this ratio is less than ~30, since for larger ratios the correction becomes negligible compared to the analytical uncertainty. Richards and Dorale (2003) and Li et al. (1989) argued that thresholds of between 100 and 300 for the case of mass spectrometric dating, due to the high-precision analysis of initial 230 Th. Hellstrom (2007) argued that even a value of 230 Th/ 232 Th=300 requires a correction for the derital fraction. Considering these higher values, most ages obtained for Denya Cave seismite samples need to be corrected for initial 230 Th, using as a correction factor the detrital molar ratio of 232 Th/ 238 U. The most common correction factor for crust value rocks is 3.8 (Wedepohl, 1995). Even higher values of 4.2 were determined (e.g. Kuperman, 2005). Haase- Schramm et al. (2003) reported a single sample correction factor for Lake Lisan aragonites detritus of 232 Th/ 238 U atomic ratio=0.85 (i.e. 232 Th/ 238 U detrital molar ratio of 0.83=0.27 ac<strong>tivity</strong> ratio*3.05). They also suggested that some initial 230 Th found in those samples was contributed by hydrogenous Th. In a carbonate terrain the correction factor was calculated by Kaufman et al. (1998), using an isochron method, yielding a value of 1.8±0.25=detrital molar ratio (Soreq cave). In their study Kaufman et al. (1998) showed that all the Th in the speleothems from Soreq cave was associated with detrital material. In their method the slopes of isochrons in a plot of ( 232 Th/ 234 U) vs. ( 230 Th/ 234 U) were used in order to calculate the detrital molar ratio of 232 Th/ 238 U. Those isochron lines are essentially mixing lines between a clean sample (low detrital component) and the DEM within the lamina, since stalagmites often have observable differences in the quantity of detrital material along growth layers (Richards and Dorale, 2003). Following Kaufman et al. (1998) isochron slopes and their intersects with the Y axis ( 230 Th/ 234 U) enables a calculation of a correction factor as follows: 36
Page 1: Dating Paleo-seismic Activi
Page 5 and 6: Abstract Mt Carmel is defined to it
Page 7 and 8: Table of content 1. Introduction...
Page 9: List of Tables Table 1: Isochron sa
Page 12 and 13: 1998; Lacave et al., 2004; Kagan et
Page 14 and 15: statistical study indicated that th
Page 16 and 17: The first step in establishing viab
Page 18 and 19: crystal lattice; (5) when detrital
Page 20 and 21: caused by curved segments along the
Page 22 and 23: 1 2 Yagur Jalame 3 4 Yoqne’am Meg
Page 24 and 25: 1.4.1 Seismicity and paleo-seismici
Page 26 and 27: eferences to Early Bronze Age I and
Page 28 and 29: Figure 5: Earthquakes for the years
Page 30 and 31: 15 30 Figure 7: Geological map of t
Page 32 and 33: a b c Figure 9: Pictures from a qua
Page 34 and 35: 3 1 2 4 5 Figure 11: Seismic featur
Page 36 and 37: the cave can be viewed in Appendix
Page 40 and 41: [3] ( 230 Th)/( 232 Th) d = ( 234 U
Page 42 and 43: extremely high errors for these val
Page 44 and 45: DN-62 Iso-III Iso-II Iso-I Iso-V Is
Page 46 and 47: contribution of 232 Th carried by d
Page 48 and 49: 3.3.3 Cluster dating Osmond isochro
Page 50 and 51: 4. Results A total of 68 speleothem
Page 52 and 53: Table 5: Denya Cave seismite I.D.'s
Page 54 and 55: Figure 17: Dated seismite uncorrect
Page 56 and 57: Table 6: Dated seismite samples' is
Page 58 and 59: 1.14 1.10 1.06 234 U/ 238 U 1.02 0.
Page 60 and 61: Sample name 230/238 err 234/238 err
Page 68 and 69: Seismic events in Denya Cave Broken
Page 70 and 71: isochron of 10.4ka (MSWD = 107), it
Page 72 and 73: data-point error ellipses are 2σ 1
Page 74 and 75: 5. Discussion The purpose of the pr
Page 76 and 77: case, it is not clear which of thos
Page 78 and 79: indicates that there is a possibili
Page 80 and 81: 5.2.1 Considerations for comparison
Page 82 and 83: easonable assumption that whatever
Page 84 and 85: establish a unique correction facto
Page 86 and 87: References Achmon, M., 1986. The Ca
Page 88 and 89:
Hofstetter, A., Feldman, L. and Rot
Page 90 and 91:
acceleration using the parameter of
Page 92 and 93:
I-a. Table of Denya Cave speleothem
Page 95 and 96:
DEN-2 Sample DEN-2 is a type C-1 se
Page 97 and 98:
DN-4 Sample DN-4 is a type C-1 seis
Page 99 and 100:
DN-7 DN-7 appeared to be a stalagmi
Page 101 and 102:
DN-11, 12 and 13 These samples are
Page 103 and 104:
Seismic contact pre 12.51ka DN-17 D
Page 105 and 106:
DN-21 DN-21 is a type C-1 seismite.
Page 107 and 108:
DN-25 DN-25 is a sample of flowston
Page 109 and 110:
Page 111 and 112:
DN-34 DN-34 is a flowstone core of
Page 113 and 114:
DN-37a DN-37a is a flowstone core i
Page 115 and 116:
Page 117 and 118:
DN-43 This stalactite was located c
Page 119 and 120:
Seismic contact DN-45 DN-45 is a ty
Page 121 and 122:
DN-47 DN-47 is a flowstone core of
Page 123 and 124:
DN-51 DN-51 is a stalactite formati
Page 125 and 126:
DN-62 DN-62 is a flowstone sample o
Page 127 and 128:
DN-65 DN-65 is a flowstone sample o
Page 129 and 130:
Seismic contact DN-68 DN-68 is a a
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II-b. Laboratory protocol for the p
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Appendix III: All seismites conside
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,10.4±0.7 שהשאירו את חו
Page 138:
משרד התשתיות הלאומ
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