Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 10 of 10 for “"Crustal growth"”.
-
The Global Detrital Zircon Database: Quantifying the Timing and Rate of Crustal Growth
… This project entailed three subprojects: 1. crustal growth/crustal recycling patterns, 2. a provenance study of the Triassic Dry Fork Formation of the Danville-Dan River Rift basin of Virginia and North Carolina, and 3. sample size issues in detrital zircon studies. The global detrital zircon …
-
Evolution of continental crust in the Proterozoic : growth and reworking in orogenic systems
To understand the growth of continental crust, the balance between juvenile mantle derived extraction, infracrustal reworking and crustal recycling, needs to be estimated. Since the beginning of the century, the use of coupled in situ zircon U–Pb, Lu–Hf and O isotope analyses as a tool to address …
-
Geodynamic evolution and petrogenesis of the neoarchaean Francistown granite-greenstone complex in NE Botswana, SW margin of the Zimbabwe craton
… Neoarchaean granitoids and mafic dominated-supracrustal assemblages. All the supracrustal rocks and mafic intrusions have undergone greenschist to lower amphibolite facies metamorphism, but most mafic intrusions have preserved original igneous textures. The Francistown Granite Greenstone Complex …
-
Geochemical characterisation of Archaean granitoids in eastern Finland
… of the Karelian craton spans about 1000 Ma of crustal growth and evolution and forms the core of the Fennoscandian shield. The Karelian province is a complex patchwork of different rock types. The individual formations are of small territorial extent in accordance with often postulated small …
-
Modeling target rock composition of two impact events
… a rare opportunity to investigate early Earth's crustal evolution. Spherule layers, formed through condensation of vaporized target rock and bolide material during meteorite impacts, represent a unique window into this time. This study models target rock compositions of two …
-
Rates of tectonic and magmatic processes in the North Cascades continental magmatic arc
… the processes of magma generation, ascent and crustal growth. The primary goal of this research is to determine rates of tectonic and magmatic processes in the mid to deep crustal levels of the crystalline core of the Cretaceous North Cascades arc. This region was selected for study because it …
-
Pan-African magmatism and regional tectonics of South Brazil
… the basement schists corresponding to garnet growth during D3 deformation. Three phases of granite intrusion are recognized in the Santana Metamorphic Belt The Santana Granite (8oom.y.) represents the first phase intruding the basement and it is folded by 02 and 03. The Campinas Granite …
-
Geochemical Insights into Crustal Melting in the Bhutan Himalaya
Crustal melting and granitic intrusions are characteristics of many continental collision zones. The processes, sources and timing of melt generation in collision zones are critical to understanding crustal and tectonic evolution. In the Himalaya, multiple Oligocene-Miocene leucogranite bodies …
-
Source Constraints of Ore Metals in Mississippi Valley-type Deposits in Central and Eastern Tennessee using Pb Isotopes
… covariation diagrams with respect to the average crustal growth curve from Stacy and Kramers (1975) and the orogene curve from Zartman and Doe (1981). Lead isotope data from both Central and East TN plot beyond the present day age (0 m.y. ago) indicative of a crustal source of Pb-Zn. Central TN …
-
Granite petrogenesis and crustal evolution studies in the Damara Pan-African orogenic belt, Namibia
… three geochemically distinct granitoid groups, - crustal-melt granitoids, calc-alkaline granitoids and within-plate granitoids. The overwhelming majority of the Oamara granitoids are peraluminous crustal-melt leucogranites which have elevated <sup>87</sup>Sr/<sup>86</sup>Sr ratios (> 0.710) and …