WorldCat Identities

DePaolo, Donald J. 1951-

Works: 36 works in 62 publications in 1 language and 716 library holdings
Genres: Conference papers and proceedings 
Roles: Author, Editor
Publication Timeline
Most widely held works by Donald J DePaolo
Neodymium isotope geochemistry : an introduction by Donald J DePaolo( Book )

13 editions published between 1988 and 2012 in English and held by 447 WorldCat member libraries worldwide

This monograph was begun with two objectives in mind. The first was to provide a review of research involving the application of neodymium isotopic measurements to pro blems in earth science. In the process of organizing to do this, I realized that the research in this field had produced a need for an updated review of the underlying paradigms. This need had arisen because of the special properties of the samarium-neodymium isotopic system, and because the research had transgressed the traditional boundaries be tween the subfields of earth science. Without such a review, the significance of the results seemed likely to remain un necessarily obscure to interested scientists from related disciplines. Consequently, the second objective became the provision of a theoretical framework for the application of neodymium isotopic studies. Much of what this contains is not new, but it is drawn together here for the first time. At the time the writing was initiated, the literature of the field was still relatively limited. Over the past 5 years it has grown enormously. Considering the rate at which the writing progressed, it became clear that this could not be a fully up-to-date review and still reach completion. The selection of material for the review sections is biased toward earlier studies. Part I presents most of the background information
Geochemistry of geologic CO₂ sequestration( Book )

10 editions published in 2013 in English and held by 191 WorldCat member libraries worldwide

Using Pb and Sr isotopes to assess Asian aerosol impacts in urban and interior California by Donald J DePaolo( )

2 editions published in 2012 in English and held by 27 WorldCat member libraries worldwide

Study of magna sources, mantle structure and the differentiation of the earth from variations of ¹⁴³Nd/¹⁴⁴Nd in igneous rocks by Donald J DePaolo( )

4 editions published between 1978 and 1980 in English and held by 11 WorldCat member libraries worldwide

Special issue in honour of G.J. Wasserburg : isotope tracers in geochemistry and cosmochemistry( Book )

2 editions published in 2000 in English and held by 6 WorldCat member libraries worldwide

Isotopic Tracers for Waste Fluid Tracking and Fluid-Soil Interactions : Hanford, Washington( )

1 edition published in 2004 in English and held by 5 WorldCat member libraries worldwide

The objective of this research is to develop and advance isotopic approaches for characterizing fluid flow and chemical transport through the vadose zone to groundwater. Previous research has been concentrated on developing and comparing different isotopic systems (e.g., hydrogen, oxygen and strontium isotopes) for determining fluid infiltration rates and pathways in the vadose zone (e.g., Maher et al., 2003; DePaolo et al., 2004; Singleton et al., in press). The results demonstrate the unique advantage of studies of multiple isotopic systems for distinguishing short-term versus long-term processes. The focus of our current efforts is on using the isotopic compositions of different chemical phases (e.g., uranium, nitrate) to track their movement through the vadose zone. Preliminary results indicate that this will be a powerful tool for assessing environmental risks associated with vadose zone contamination
Rates of tectonometamorphic processes from rubidium and strontium isotopes in garnet by J. N CHRISTENSEN( )

1 edition published in 1989 in English and held by 2 WorldCat member libraries worldwide

Hawaii Scientific Drilling Project : core logs and summarizing data, 1999 by Hawaii Scientific Drilling Project( Book )

1 edition published in 1999 in English and held by 2 WorldCat member libraries worldwide

Chemical and isotopic evidence for lithospheric thinning beneath the Rio Grande rift by F. V PERRY( )

1 edition published in 1988 in English and held by 2 WorldCat member libraries worldwide

A mantle plume initiation model for the Wrangellia flood basalt and other oceanic plateaus by M. A Richards( )

1 edition published in 1991 in English and held by 2 WorldCat member libraries worldwide

Age and oxygen isotope data for bulk carbonate from DSDP Sites 41-366 and 72-516 and ODP Sites 111-677A and 130-807, supplementary data to: Schrag, Daniel P; DePaolo, Donald J; Richter, Frank M (1995): Reconstructing past sea surface temperatures; correcting for diagenesis of bulk marine carbon. Geochimica et Cosmochimica Acta, 59(11), 2265-2278 by Daniel P Schrag( )

in English and held by 1 WorldCat member library worldwide

A numerical model which describes oxygen isotope exchange during burial and recrystallization of deep-sea carbonate is used to obtain information on how sea surface temperatures have varied in the past by correcting measured d18O values of bulk carbonate for diagenetic overprinting. Comparison of bulk carbonate and planktonic foraminiferal d18O records from ODP site 677A indicates that the oxygen isotopic composition of bulk carbonate does reflect changes in sea surface temperature and d18O. At ODP Site 690, we calculate that diagenetic effects are small, and that both bulk carbonate and planktonic foraminiferal d18O records accurately reflect Paleogene warming of high latitude surface oceans, biased from diagenesis by no more than 1?C. The same is likely to be true for other high latitude sites where sedimentation rates are low. At DSDP sites 516 and 525, the effects of diagenesis are more significant. Measured d18O values of Eocene bulk carbonates are more than 2? lower at deeply buried site 516 than at site 525, consistent with the model prediction that the effects of diagenesis should be proportional to sedimentation rate. Model-corrections reconcile the differences in the data between the two sites; the resulting paleotemperature reconstruction indicates a 4?C cooling of mid-latitude surface oceans since the Eocene. At low latitudes, the contrast in temperature between the ocean surface and bottom makes the carbonate d180 values particularly sensitive to diagenetic effects; most of the observed variations in measured d18O values are accounted for by diagenetic effects rather than by sea surface temperature variations. We show that the data are consistent with constant equatorial sea surface temperatures through most of the Cenozoic, with the possible exception of the early Eocene, when slightly higher temperatures are indicated. We suggest that the lower equatorial sea surface temperatures for the Eocene and Oligocene reported in other oxygen isotope studies are artifacts of diagenetic recrystallization, and that it is impossible to reconstruct accurately equatorial sea surface temperatures without explicitly accounting for diagenetic overprinting
Silicate hyperhalmyrolysis Grande Saline, St. Bartholomew, Lesser Antilles by Donald J DePaolo( )

1 edition published in 1973 in English and held by 1 WorldCat member library worldwide

Study of magma sources, mantle structure and the differentiation of the earth from variations of ¹⁴³Nd/¹⁴⁴Nd in igneous rocks by Donald J DePaolo( Book )

1 edition published in 1978 in Undetermined and held by 1 WorldCat member library worldwide

The decay of 147Sm to 143Nd allows 143Nd/144Nd to be used to trace Sm/Nd fractionation in long time-scale geologic processes. Since Sm/Nd is a sensitive indicator of many aspects of the overall chemistry of rocks, the Sm-Nd system provides an excellent tool for the study of the chemical evolution of the earth's crust and mantle. 143Nd/144Nd has been measured in terrestrial rock samples of different ages to establish the characteristics of Nd isotopic evolution in the crust and mantle. The evolution of 143Nd/144Nd in the mantle indicates Sm/Nd equal to that of chondrites, and implies a chondritic REE distribution for the earth. Young basalts show a significant dispersion in 143Nd/144Nd indicating the existence of distinct mantle reservoirs with characteristic 143Nd/144Nd. 143Nd/144Nd in average crustal rocks today is much lower than in mantle samples and reflects their age and low Sm/Nd. Continental flood basalts and mid-ocean ridge (MOR) tholeiitic basalts have distinctly different 143Nd/144Nd which may permit a priori distinction between "continental" and "oceanic" igneous rocks. Ocean island basalts have 143Nd/144Nd intermediate between MOR and continental flood basalts. Initial 143Nd/144Nd of many continental igneous rocks through time fall on a Sm/Nd evolution curve with chondritic REE abundance ratio. Oceanic igneous rocks are derived from a different ancient reservoir which has Sm/Nd higher than chondritic. These observations indicate that many continental igneous rocks are derived from a reservoir with chondritic REE pattern which may represent primary undifferentiated material remaining since the formation of the earth, while oceanic igneous rocks are derived from highly differentiated reservoirs. The mantle beneath the oceans appears to be more depleted in crustal components than is the mantle which is subjacent to the continental crust. In general, basalts are not derived from mantle reservoirs which have been light REE-enriched for long times. Initial 143
Calcium concentrations and isotopic composition in carbonates and porefluids from ODP Hole 130-807A, supplementary data to: Fantle, Matthew S; DePaolo, Donald J (2007): Ca isotopes in carbonate sediment and pore fluid from ODP Site 807A; the Ca2+(aq)-calcite equilibrium fractionation factor and calcite recrystallization rates in Pleistocene sediments. Geochimica et Cosmochimica Acta, 71(10), 2524-2546 by Matthew S Fantle( )

in English and held by 1 WorldCat member library worldwide

The calcium isotopic compositions (d44Ca) of 30 high-purity nannofossil ooze and chalk and 7 pore fluid samples from ODP Site 807A (Ontong Java Plateau) are used in conjunction with numerical models to determine the equilibrium calcium isotope fractionation factor (a_s-f) between calcite and dissolved Ca2+ and the rates of post-depositional recrystallization in deep sea carbonate ooze. The value of a_s-f at equilibrium in the marine sedimentary section is 1.0000+/-0.0001, which is significantly different from the value (0.9987+/-0.0002) found in laboratory experiments of calcite precipitation and in the formation of biogenic calcite in the surface ocean. We hypothesize that this fractionation factor is relevant to calcite precipitation in any system at equilibrium and that this equilibrium fractionation factor has implications for the mechanisms responsible for Ca isotope fractionation during calcite precipitation. We describe a steady state model that offers a unified framework for explaining Ca isotope fractionation across the observed precipitation rate range of 14 orders of magnitude. The model attributes Ca isotope fractionation to the relative balance between the attachment and detachment fluxes at the calcite crystal surface. This model represents our hypothesis for the mechanism responsible for isotope fractionation during calcite precipitation. The Ca isotope data provide evidence that the bulk rate of calcite recrystallization in freshly-deposited carbonate ooze is 30-40%/Myr, and decreases with age to about 2%/Myr in 2-3 million year old sediment. The recrystallization rates determined from Ca isotopes for Pleistocene sediments are higher than those previously inferred from pore fluid Sr concentration and are consistent with rates derived for Late Pleistocene siliciclastic sediments using uranium isotopes. Combining our results for the equilibrium fractionation factor and recrystallization rates, we evaluate the effect of diagenesis on the Ca isotopic composition of marine carbonates at Site 807A. Since calcite precipitation rates in the sedimentary column are many orders of magnitude slower than laboratory experiments and the pore fluids are only slightly oversaturated with respect to calcite, the isotopic composition of diagenetic calcite is likely to reflect equilibrium precipitation. Accordingly, diagenesis produces a maximum shift in d44Ca of +0.15? for Site 807A sediments but will have a larger impact where sedimentation rates are low, seawater circulates through the sediment pile, or there are prolonged depositional hiatuses
Special issue in honour of G. J. Wasserburg : isotope tracers in geochemistry and cosmochemistry by International Union of Geological Sciences. Commission for Igneous and Metamorphic Petrology( )

in English and held by 1 WorldCat member library worldwide

Chemical and Sr isotopic compositions of pore fluids and marine carbonates from ODP Hole 130-807A, supplementary data to: Fantle, Matthew S; DePaolo, Donald J (2006): Sr isotopes and pore fluid chemistry in carbonate sediment of the Ontong Java Plateau; calcite recrystallization rates and evidence for a rapid rise in sea water Mg over the last 10 million years. Geochimica et Cosmochimica Acta, 70(15), 3883-3904 by Matthew S Fantle( )

in English and held by 1 WorldCat member library worldwide

The 87Sr/86Sr ratios and Sr concentrations in sediment and pore fluids are used to evaluate the rates of calcite recrystallization at ODP Site 807A on the Ontong Java Plateau, an 800-meter thick section of carbonate ooze and chalk. A numerical model is used to evaluate the pore fluid chemistry and Sr isotopes in an accumulating section. The deduced calcite recrystallization rate is 2% per million years (%/Myr) near the top of the section and decreases systematically in older parts of the section such that the rate is close to 0.1/age (in years). The deduced recrystallization rates have important implications for the interpretation of Ca and Mg concentration profiles in the pore fluids. The effect of calcite recrystallization on pore fluid chemistry is described by the reaction length, L, which varies by element, and depends on the concentration in pore fluid and solid. When L is small compared to the thickness of the sedimentary section, the pore fluid concentration is controlled by equilibrium or steady-state exchange with the solid phase, except within a distance L of the sediment-water interface. When L is large relative to the thickness of sediment, the pore fluid concentration is mostly controlled by the boundary conditions and diffusion. The values of L for Ca, Sr, and Mg are of order 15, 150, and 1500 meters, respectively. L_Sr is derived from isotopic data and modeling, and allows us to infer the values of L_Ca and L_Mg. The small value for L_Ca indicates that pore fluid Ca concentrations, which gradually increase down section, must be equilibrium values that are maintained by solution-precipitation exchange with calcite and do not reflect Ca sources within or below the sediment column. The pore fluid Ca measurements and measured alkalinity allow us to calculate the in situ pH in the pore fluids, which decreases from 7.6 near the sediment-water interface to 7.1+/-0.1 at 400-800 mbsf. While the calculated pH values are in agreement with some of the values measured during ODP Leg 130, most of the measurements are artifacts. The large value for L_Mg indicates that the pore fluid Mg concentrations at 807A are not controlled by calcite-fluid equilibrium but instead are determined by the changing Mg concentration of seawater during deposition, modified by aqueous diffusion in the pore fluids. We use the pore fluid Mg concentration profile at Site 807A to retrieve a global record for seawater Mg over the past 35 Myr, which shows that seawater Mg has increased rapidly over the past 10 Myr, rather than gradually over the past 60 Myr. This observation suggests that the Cenozoic rise in seawater Mg is controlled by continental weathering inputs rather than by exchange with oceanic crust. The relationship determined between reaction rate and age in silicates and carbonates is strikingly similar, which suggests that reaction affinity is not the primary determinant of silicate dissolution rates in nature
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Alternative Names
Donald J. DePaolo American geochemist

Paolo, Donald J. de

English (45)