Thesis (M.Sc.)--Memorial University of Newfoundland, 1989. / Typescript. Bibliography: leaves 436-465. Also available online.

Thesis--Northwestern University. / Vita. Includes bibliographical references (p. 212-225).

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1982. / Supervised by William J. Jenkins. Includes bibliographical references (leaves 265-290).

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1993. / "June 1993." At head of title: Woods Hole Oceanographic Institution, Massachusetts Institute of Technology, Joint Program in Oceanography/Applied Ocean Science and Engineering. "Doctoral dissertation." Includes bibliographical references.

University, Diss., 2002--Mainz.

Universiẗat, Diss., 2005--Heidelberg.

Univ., Diss., 2002--Frankfurt (Main) / Zsfassung in dt. und engl. Sprache

The Karoo basalt outliers between Molteno and Jamestown in the north-eastern Cape Province are associated with two central volcanic vent complexes, referred to in the text as the Brosterlea and the Modderfontein complexes. The basalts, particularly those associated with the Brosterlea complex, show geochemical variations throughout the sequence, a factor which has facilitated the subdivision of the Brosterlea basalts into a series of discrete units, each having its own chemical characteristics. Most of the basalt units at Brosterlea can be correlated with units identified in the Barkly East basalt suite. As is the case around Barkly East, the Brosterlea basalt units cannot be related to one another by any simple crystal fractionation or partial melting process, and the most feasible alternative explanation lies in the existence of inhomogeneities in the upper mantle at the time of generation of the magmas. New electron microprobe data are presented for the silicate phases in the Karoo basalts. Analyses of augites from a limited number of slides indicate that pyroxenes from different basalt units define different trends on the Ca - Mg - Fe triangular diagram. The plagioclases in the Brosterlea basalts are fairly Ca-rich (average 70% An), and the K-content of the plagioclases is shown to vary with the K-content of the parent basalt. A comparison of the Karoo Central Province with the younger Columbia River and Deccan Trap Provinces shows many similarities in the evolutionary history of the three provinces. The Karoo Province, however, is distinct from the other two provinces in some aspects of the geochemistry. Broadly speaking, the Karoo basalts are depleted in the incompatible elements relative to the Columbia River and Deccan basalts, and often enriched in the transition metals, most specifically Cr

Dreibus and Wänke (1985) calculated a bulk composition for the interior of Mars (DW model) based on eight Martian meteorites. Since then, experiments on the Martian interior have used this model, or similar models, to understand processes that may influence basalt genesis within the Martian mantle. Recent experiments have shown that the DW model does not fit with the current, now greater number of Martian meteorites (132 including paired stones as of April 2014) and surface basalt compositions. One of the parameters that does not match is the Mg # (atomic [Mg2+/(Mg2+ + Fe2+)]*100); the current data show that Mars is not as iron rich as once thought and needs a higher bulk Mg # for the mantle to produce Martian basaltic compositions. This project involves experiments using a new bulk composition with an Mg # of 80 to update the compositions of a partially melted Martian mantle. A melt produced by this new bulk composition consists of MgO and FeO levels that match well with the primitive Martian meteorite Yamato-980459. Additionally, this composition was produced with 37% melt. Melts produced with this bulk composition match poorly with Na2O composition of Martian meteorites and match better, but still not particularly well, with CaO and Al2O3 compositions. However, lower-temperature partial melts of the Mg # 80 mantle match well with CaO, Al2O3, FeO, and Na2O compositions of Martian surface basalts. This shows that the source of the surface basalts is represented well by the model in this study.

Isostasy, flexure and dynamic processes all influence the shape of the Earth’s surface. While the first two processes are well understood, dynamic topography remains controversial. On the continents, dynamic uplift is often expressed by positive long-wavelength gravity anomalies, radial drainage patterns, and slow seismic velocity anomalies within the upper mantle. Volcanic activity and elevated heat flow are also often observed. The aim of this study is to investigate the link between geochemical compositions of intracontinental magmatism and geophysical, geomorphological and geodetic observations of dynamic uplift. Three volcanic regions are considered in detail: western North America, northeast Brazil and Madagascar. The combined database includes 348 new whole-rock geochemical analyses. Rare earth element concentrations of mafic, asthenospheric-derived volcanic samples are exploited to calculate the depth and temperature of melt generation by inverse modelling. A sensitivity test of this modelling scheme is carried out. Lithospheric thickness and mantle temperature are independently determined from shear wave velocity models. Beneath western North America, a negative correlation between shear wave velocities at depths of 70–150 km and degree of melting is observed. Temperatures obtained from igneous compositions and from shear wave velocity profiles beneath volcanic fields closely agree. Melts are produced within, or close to, the spinel-garnet transition zone at depths shallower than $\sim$70 km, yielding mantle potential temperatures of up to 1380$^{\circ}$C. Calculated uplift and heat flow based upon these results match observed surface elevation and heat flow measurements. In northeast Brazil, Jurassic, Cretaceous and Cenozoic phases of mafic igneous activity are recognised. Jurassic magmatic activity probably resulted from spinel-field melting at potential temperatures of $\sim$1380$^{\circ}$C. This episode is associated with regional magmatism during break-up of the Central Atlantic Ocean. Cretaceous compositions record melting at potential temperatures of 1330–70$^{\circ}$C at similar depths. This activity is linked to extension at the time of break-up of the equatorial and South Atlantic Ocean. Cenozoic volcanism comprises low-degree melts within the spinel-garnet transition zone at ambient potential temperature. Shear wave velocity models support these results. Cenozoic volcanism in Madagascar is predominantly alkaline and records small-degree melting with minor temperature anomalies within the spinel-garnet transition zone. Rare tholeiitic basalts record temperatures up to 1360$^{\circ}$C. Analysis of global and regional shear wave velocity models closely matches these results. The principal control on continental magmatism appears to be temperature anomalies within the upper mantle beneath thin lithosphere. Highest mantle potential temperatures correlate with largest dynamic uplift. Mantle potential temperatures $ < $1350$^{\circ}$C are matched with minimal or negative dynamic topography.