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 16 of 16 for “"migmatite"”.
-
Petrogenesis of a migmatite, Penobscot County, Maine: ultrametamorphism or intrusion?
The Clifton Migmatite crops out between the biotite grade Bucksport Formation (predominantly calcareous pelitic quartzite) on the west, the Lucerne Pluton (biotite granite) on the southeast, and the Parks Pond Pluton (mafic granite to quartz syenite) on the northeast. The Parks Pond crystallized at …
-
Geology and structure of the Serra Do Mar in eastern São Paulo, Brazil
… divided into four formations: the Biritiba-Mirim migmatite, the Jurubatuba migmatite, the Itapanhaú gneiss, and the Guarujá migmatite. Numerous late and post-tectonic granitic bodies occur intrusive into both complexes.</p><p>Metamorphic grade increases from northwest to southeast. In the Suzano …
-
Sobre os recalques superficiais causados pela escavação de um túnel em solo residual
… of the Ferrovia do Aço in residual soil of migmatite, as well as analyses the measurements and compaires them with the values that were gotten by the well-known prediction methods of these settlements. The analysis of the measurements was divided into three parts. The first one, which talks …
-
Impact of accessory minerals on the distribution of trace elements in the continental crust: an integrated petrologic and phase equilibria modeling study of migmatites, The
… the common occurrence of accessory mineral-rich migmatite residues and upper crustal granites that are depleted in incompatible elements (U, Th, and REE) suggests our understanding of the controls on element distribution during recycling is limited. The behavior of key accessory minerals during …
-
Rapid Middle to Late Miocene Slip Along the Zanskar Normal Fault, Greater Himalayan Range, NW, India: Constraints from Low-Temperature Thermochronometry
… data from high-grade (amphibolite-migmatite) Greater Himalayan Sequence (GHS) metamorphic rocks, exposed in the footwall immediately adjacent to the ZF, provide constraints on the middle Miocene to present exhumation history of the footwall. The overlap of these elevation invariant …
-
Crustal melting in the Himalayan orogen : field, geochemical and geochronological studies in the Everest region, Nepal
… to determine the timing of anatexis in a migmatite at the structurally lowest outcrop. Quantitative measurement of REE and Y in monazites and xenotimes, that were later dissolved and dated by U-Pb IDTIMS, revealed monazite growth at temperatures appropriate for crustal melting (>650⁰C) …
-
Mapping, petrological and geochemical explorations of the Massabesic Gneiss Complex in New Hampshire
… of rocks that exposes metasedimentary rocks, migmatites and granites. Early geochronological work indicates that the MGC is Late-Proterozoic, but recent mapping (∼112 mi2, Kerwin, 2000 and ∼130 mil2, this study) of the MGC and surrounding areas has found rock textures indicating that …
-
Mineral Ridge: A Late Cretaceous Orogenic Gold System in the Miocene Silver Peak-Lone Mountain Metamorphic Core Complex
… rocks and Cretaceous peraluminous granite and migmatite. Gold production at Mineral Ridge since discovery in 1864 has been approximately 1 million oz. Gold-bearing veins are concentrated in a major low-angle ductile shear system active during the Late Cretaceous. However, a broadly coincident …
-
Geology, structure and metamorphism of the Chuacús Group, Rio Hondo Quadrangle and vicinity, Guatemala
… San Agustín Formation (cataclastic gneiss and migmatite), the Jones Formation (dominantly phyllite and mica schist), and the San Lorenzo Formation (marble).</p> <p>Chemical study of these rocks suggests that the San Agustín Formation is an orthogneiss of quartz monzonitic composition, while the …
-
The Structure and Behavior of Plate Boundary Regions Through the Wilson Cycle
… a field-based study of low melt fraction migmatites in central New Hampshire. In it, we utilize a unique approach, based on the compaction lengthscale, to calculate the shear viscosity of the migmatite during deformation associated with the Acadian-Neoacadian orogeny and the presence of an …
-
Tectonic significance of the Atnarko complex, Coast Mountains, British Columbia
… Peak metamorphism coincides with generation of migmatite in the Early Cretaceous (~117-115 Ma) and is contemporaneous with penetrative ductile fabrics. The Atnarko complex had cooled below 350°C by the Late. Comparison of the Atnarko complex to equivalent portions of the orogen along strike, …
-
INTO THE STRUCTURE OF THE PERMIAN DEEP CONTINENTAL CRUST: A MULTISCALE APPROACH TO RECONSTRUCT MIGMATIZATION IN THE VALPELLINE SERIES (DENT BLANCHE TECTONIC SYSTEM, WESTERN ITALIAN ALPS)
Granulite and migmatite are widespread across different tectonic settings, such as those associated with collisional crustal thickening during orogenic events and post-collisional or back-arc lithospheric thinning. Studying these rocks provides an exceptional opportunity to observe the deep …
-
Caratterizzazione geo-petrografica, petrologica e geochimica di rocce anatettiche del nord Sardegna
… Sardinia is characterized by the widespread of migmatites. This study is focused on two localities of NE Sardinia (Porto Ottiolu and Punta Sirenella) where ortho- and para-derivates migmatites outcrop. A geological and structural survey was carried out, leading to the realization of a geological …
-
Formation and segregation of melts during deformation : an approach with analogue material
… from natural partial molten systems like migmatites indicate a close relationship between melt segregation and deformation. To study this phenomena we conducted experiments with rock analogues consisting of mixtures of LiNO3 and KNO3 as a melting component and crushed baryte featuring as a …
-
The Damara mobile belt in the south-Western Kaokoveld
… in the deformed mass at the margin of the migmatite zone induced intense shearing and produced belts of mylonite and cataclastic gneiss. At a later stage, the Sesfontein Thrust was buffered against the Otavi dolomite relief and its speed of advancement reduced to match that of the erosion …
-
Association of S-type and I-type granitoids in the Neoproterozoic Cameroon orogenic belt, Bafoussam area, West Cameroon : geology, geochemistry and petrogenesis
… which intruded wall-rocks of gneiss and migmatite during the Pan-African orogeny. The Bafoussam granitoid emplacement was influenced by the N 30 °E strike-slip shear zone in the prolongation of the Cameroon Volcanic Line, but also by the N 70 °E Central Cameroon Shear Zone. In the field, …