Amitai Katz | The Hebrew University of Jerusalem (original) (raw)
Papers by Amitai Katz
Geochimica Et Cosmochimica Acta, Apr 1, 2003
... Soc. Spec. Pub. 78, 151175. Herut, B., Starinsky, A., Katz, A. and Bein, A., 1990. ... Howel... more ... Soc. Spec. Pub. 78, 151175. Herut, B., Starinsky, A., Katz, A. and Bein, A., 1990. ... Howell, D., Sieger, MJ and Dowdeswell, JA, 2000. Modelling the influence of glacial isostasy on Late Weichselianice sheet growth in the Barents Sea. J. Quat. Sci 15, pp. 475486. ...
Chemical Geology, Nov 1, 1989
Geochimica Et Cosmochimica Acta, Feb 1, 2002
... Foraminiferal study suggests that Li/Ca in seawater has remained essentially constant for the... more ... Foraminiferal study suggests that Li/Ca in seawater has remained essentially constant for the last 40 Ma (Delaney and Boyle, 1986). ... (Delaney and Boyle, 1986), the Li enrichment cannot be attributed to variability in the Li balance in the ocean. ...
Limnology and Oceanography, 1989
Journal of Sedimentary Research, Mar 1, 1965
Abstract A method is described for the preparation of acetate peels of stained carbonate rocks. T... more Abstract A method is described for the preparation of acetate peels of stained carbonate rocks. The stains transferred are: Alizarin red-S (for the detection of calcite), potassium ferricyanide (for the detection of ferrous iron-bearing calcite or dolomite), and Feigl's ...
The Journal of Geology, 1971
Quaternary Science Reviews, 2004
The paleosalinity of the Late Pleistocene Lake Lisan during its highstand between ∼27,000 and 15,... more The paleosalinity of the Late Pleistocene Lake Lisan during its highstand between ∼27,000 and 15,000 years B.P. is evaluated from biological data (diatoms, cyanobacteria, fish and ostracods) and chemical data (Sr/Ca and Na/Ca ratios) in authigenic aragonite. The data indicate a zone of maximum salinity at the southern part of the lake, in the vicinity of the present Dead Sea basin. While most of the freshwater input to Lake Lisan originated from the Jordan River in the north and runoff from the eastern and western parts of the drainage basin, our analysis indicates a significant additional contribution from a southern freshwater source. At present, the contribution of the southern source to the Dead Sea is minimal. Hence, it appears that in addition to the prevailing rain originating from the Mediterranean, an additional, southern source of rain, was more active during the Last Glacial than today. This may be explained by migration of rain tracks, whose moisture originated in the Atlantic, from the Mediterranean southwards.
Nature, 1968
THE dedolomitization process, first named in 1847 (ref. 1), has recently found increasing recogni... more THE dedolomitization process, first named in 1847 (ref. 1), has recently found increasing recognition, and has been reviewed briefly by Friedman and Sanders2.
Geological Society of America Bulletin, 2014
ABSTRACT Using cosmogenic isotopes and solute load analysis, we quantify chemical weathering (sol... more ABSTRACT Using cosmogenic isotopes and solute load analysis, we quantify chemical weathering (solutional erosion) and denudation rates over variable time scales in a tectonically stable, moderate-relief, carbonate terrain (Soreq drainage, Judea Hills, Israel), located in a semihumid Mediterranean climate. Long-term (>10(4) yr) denudation rates were calculated from Cl-36 concentrations in 51 bedrock and sediment samples. Bedrock samples range in elevation (340-850 m), hillslope gradient (0 degrees-30 degrees), and mean annual precipitation (MAP; 500-630 mm) and vary in soil cover thickness (0-75 cm), Mg/Ca ratio (0.0-1.0 mol), clay mineral contents (0-6 wt%), and mechanical strength (41-58 Schmidt hammer rebound units). Soil pCO(2) values at a single location during the course of 1 yr, range between 0.4 and 9.0 mmol mol(-1). Average long-term denudation rate of exposed bedrock samples is 21 +/- 7 mm k.y.(-1). Field observations and Cl-36 measurements indicate that soil pockets undergo cycles in the rate of deepening, and that over 10(5) yr time scale, average denudation rates beneath soil pockets are similar to those of exposed bedrock. Sediment samples yield even higher denudation rates, which are probably anthropogenically induced, but could also indicate that the sediment source is soil pockets. Long-term denudation rates are decoupled from hillslope gradient, elevation, and rock strength. Denudation rates show a positive correlation with present-day MAP values, exhibit a complex relation with rock Mg content, and show a weak correlation with clay content. Annual chemical weathering rates were calculated from modern-day solute load measured in waters of perched springs and the regional carbonate aquifer. Our results indicate that on annual, decadal, and 10(4) yr time scales, chemical weathering and denudation are controlled by carbonate dissolution, while mechanical processes are far less significant. Overlap between the distributions of HCO3- concentrations measured in runoff, springs, and the regional aquifer water suggests that chemical weathering focuses at the bedrock surface and therefore is comparable with solutional denudation. This result is in contrast to the features of ancient fluvial and colluvial activity (steep nonconcave hillslopes and stream profiles and knick-zones in the streams) preserved in the present landscape. Such features were formed in response to mid-Pleistocene uplift and could have been preserved due to a decrease in stream power following the formation of subsurface drainage and the lowering in abrasive clast supply that followed the stabilization of hillslopes in the drainage. Long-term denudation rates calculated from exposed bedrock samples are higher by factor of 1.4 relative to annual, contemporary chemical weathering rates. Increased precipitation by a similar factor, averaged over the last glacial and present interglacial, can explain this difference.
Geochimica et Cosmochimica Acta, 1997
Precise strontium isotope ratios, combined with chemical analyses and sedimentological informatio... more Precise strontium isotope ratios, combined with chemical analyses and sedimentological information, are used to monitor the water sources and the evolution of the Dead Sea and its late Pleistocene precursor, Lake Lisan (70-18 kyr B.P.). The materials analyzed include bulk aragonite, water-leached soluble salts, and residual aragonite and gypsum from the Lisan Formation in the Perazim Valley (near the SW
Geochimica et Cosmochimica Acta, 1973
Calcite crystals were grown in a closed system by recrystallization of synthetic and natural arag... more Calcite crystals were grown in a closed system by recrystallization of synthetic and natural aragonite crystals, in the presence of various CaCl 2 -MgCl 2 solutions with and without NaCl. The distribution of Mg 2+ between calcite and solution at the entire temperature range is heterogeneous, closely following the ( and , 1925) distribution law. Mg 2+ C is strongly
Geochimica et Cosmochimica Acta, 1989
Earth and Planetary Science Letters, 1976
Title: Comment on ``Excess 234 U: An aging effect in confined waters'' by J. Kronfeld, ... more Title: Comment on ``Excess 234 U: An aging effect in confined waters'' by J. Kronfeld, E. Gradsztajn, HW Müller, J. Radin, A. Yaniv and R. Zach. Authors: Starinsky, A.; Kolodny, Y.; Katz, A. Affiliation: AA(Department of Geology ...
Geochimica Et Cosmochimica Acta, Apr 1, 2003
... Soc. Spec. Pub. 78, 151175. Herut, B., Starinsky, A., Katz, A. and Bein, A., 1990. ... Howel... more ... Soc. Spec. Pub. 78, 151175. Herut, B., Starinsky, A., Katz, A. and Bein, A., 1990. ... Howell, D., Sieger, MJ and Dowdeswell, JA, 2000. Modelling the influence of glacial isostasy on Late Weichselianice sheet growth in the Barents Sea. J. Quat. Sci 15, pp. 475486. ...
Chemical Geology, Nov 1, 1989
Geochimica Et Cosmochimica Acta, Feb 1, 2002
... Foraminiferal study suggests that Li/Ca in seawater has remained essentially constant for the... more ... Foraminiferal study suggests that Li/Ca in seawater has remained essentially constant for the last 40 Ma (Delaney and Boyle, 1986). ... (Delaney and Boyle, 1986), the Li enrichment cannot be attributed to variability in the Li balance in the ocean. ...
Limnology and Oceanography, 1989
Journal of Sedimentary Research, Mar 1, 1965
Abstract A method is described for the preparation of acetate peels of stained carbonate rocks. T... more Abstract A method is described for the preparation of acetate peels of stained carbonate rocks. The stains transferred are: Alizarin red-S (for the detection of calcite), potassium ferricyanide (for the detection of ferrous iron-bearing calcite or dolomite), and Feigl's ...
The Journal of Geology, 1971
Quaternary Science Reviews, 2004
The paleosalinity of the Late Pleistocene Lake Lisan during its highstand between ∼27,000 and 15,... more The paleosalinity of the Late Pleistocene Lake Lisan during its highstand between ∼27,000 and 15,000 years B.P. is evaluated from biological data (diatoms, cyanobacteria, fish and ostracods) and chemical data (Sr/Ca and Na/Ca ratios) in authigenic aragonite. The data indicate a zone of maximum salinity at the southern part of the lake, in the vicinity of the present Dead Sea basin. While most of the freshwater input to Lake Lisan originated from the Jordan River in the north and runoff from the eastern and western parts of the drainage basin, our analysis indicates a significant additional contribution from a southern freshwater source. At present, the contribution of the southern source to the Dead Sea is minimal. Hence, it appears that in addition to the prevailing rain originating from the Mediterranean, an additional, southern source of rain, was more active during the Last Glacial than today. This may be explained by migration of rain tracks, whose moisture originated in the Atlantic, from the Mediterranean southwards.
Nature, 1968
THE dedolomitization process, first named in 1847 (ref. 1), has recently found increasing recogni... more THE dedolomitization process, first named in 1847 (ref. 1), has recently found increasing recognition, and has been reviewed briefly by Friedman and Sanders2.
Geological Society of America Bulletin, 2014
ABSTRACT Using cosmogenic isotopes and solute load analysis, we quantify chemical weathering (sol... more ABSTRACT Using cosmogenic isotopes and solute load analysis, we quantify chemical weathering (solutional erosion) and denudation rates over variable time scales in a tectonically stable, moderate-relief, carbonate terrain (Soreq drainage, Judea Hills, Israel), located in a semihumid Mediterranean climate. Long-term (>10(4) yr) denudation rates were calculated from Cl-36 concentrations in 51 bedrock and sediment samples. Bedrock samples range in elevation (340-850 m), hillslope gradient (0 degrees-30 degrees), and mean annual precipitation (MAP; 500-630 mm) and vary in soil cover thickness (0-75 cm), Mg/Ca ratio (0.0-1.0 mol), clay mineral contents (0-6 wt%), and mechanical strength (41-58 Schmidt hammer rebound units). Soil pCO(2) values at a single location during the course of 1 yr, range between 0.4 and 9.0 mmol mol(-1). Average long-term denudation rate of exposed bedrock samples is 21 +/- 7 mm k.y.(-1). Field observations and Cl-36 measurements indicate that soil pockets undergo cycles in the rate of deepening, and that over 10(5) yr time scale, average denudation rates beneath soil pockets are similar to those of exposed bedrock. Sediment samples yield even higher denudation rates, which are probably anthropogenically induced, but could also indicate that the sediment source is soil pockets. Long-term denudation rates are decoupled from hillslope gradient, elevation, and rock strength. Denudation rates show a positive correlation with present-day MAP values, exhibit a complex relation with rock Mg content, and show a weak correlation with clay content. Annual chemical weathering rates were calculated from modern-day solute load measured in waters of perched springs and the regional carbonate aquifer. Our results indicate that on annual, decadal, and 10(4) yr time scales, chemical weathering and denudation are controlled by carbonate dissolution, while mechanical processes are far less significant. Overlap between the distributions of HCO3- concentrations measured in runoff, springs, and the regional aquifer water suggests that chemical weathering focuses at the bedrock surface and therefore is comparable with solutional denudation. This result is in contrast to the features of ancient fluvial and colluvial activity (steep nonconcave hillslopes and stream profiles and knick-zones in the streams) preserved in the present landscape. Such features were formed in response to mid-Pleistocene uplift and could have been preserved due to a decrease in stream power following the formation of subsurface drainage and the lowering in abrasive clast supply that followed the stabilization of hillslopes in the drainage. Long-term denudation rates calculated from exposed bedrock samples are higher by factor of 1.4 relative to annual, contemporary chemical weathering rates. Increased precipitation by a similar factor, averaged over the last glacial and present interglacial, can explain this difference.
Geochimica et Cosmochimica Acta, 1997
Precise strontium isotope ratios, combined with chemical analyses and sedimentological informatio... more Precise strontium isotope ratios, combined with chemical analyses and sedimentological information, are used to monitor the water sources and the evolution of the Dead Sea and its late Pleistocene precursor, Lake Lisan (70-18 kyr B.P.). The materials analyzed include bulk aragonite, water-leached soluble salts, and residual aragonite and gypsum from the Lisan Formation in the Perazim Valley (near the SW
Geochimica et Cosmochimica Acta, 1973
Calcite crystals were grown in a closed system by recrystallization of synthetic and natural arag... more Calcite crystals were grown in a closed system by recrystallization of synthetic and natural aragonite crystals, in the presence of various CaCl 2 -MgCl 2 solutions with and without NaCl. The distribution of Mg 2+ between calcite and solution at the entire temperature range is heterogeneous, closely following the ( and , 1925) distribution law. Mg 2+ C is strongly
Geochimica et Cosmochimica Acta, 1989
Earth and Planetary Science Letters, 1976
Title: Comment on ``Excess 234 U: An aging effect in confined waters'' by J. Kronfeld, ... more Title: Comment on ``Excess 234 U: An aging effect in confined waters'' by J. Kronfeld, E. Gradsztajn, HW Müller, J. Radin, A. Yaniv and R. Zach. Authors: Starinsky, A.; Kolodny, Y.; Katz, A. Affiliation: AA(Department of Geology ...