Das Menderes Massiv im Westen der Türkei stellt eine große Kulmination metamorpher Gesteine dar. Das Untersuchungsgebiet ist im Zentralen Menderes Massiv (Ödemis Submassiv) gelegen, das von den beiden aktiven Gräben, dem Gediz Graben im Norden und dem Büyük Menderes Graben im Süden begrenzt wird. <br /> Die Untersuchungen der Eklogit Relikte im zentralen Menderes Massiv haben ergeben, dass sich im Menderes Massiv Hochdruckrelikte in unterschiedlichen tektonischen Positionen befinden. Zum einen existieren Eklogit-Blöcke in der obersten Einheit (Selcuk Einheit) des zentralen Menderes Massivs und zum anderen Hochdruck-Relikte in der strukturell mittleren Birgi - Tire Decke. Die Granate der quarzfreien Eklogit-Blöcke weisen große Ähnlichkeiten mit denen der HP/LT Gesteine von Sifnos und Syros auf. Die Entwicklung der Eklogit-Blöcke in der Olistostrom-Einheit lässt sich jedoch nicht mit den Eklogit Relikten in der strukturell mittleren Birgi Tire Decke vergleichen. <br /> Für die Eklogit-Relikte in der Birgi Tire Decke wurde eine polymetamorphe Entwicklung mithilfe petrologischer Untersuchungen und chemischen und Pb-Pb Datierungen herausgearbeitet. Die Eklogit Relikte gehören zu einem metamorphen Teilpfad, der durch eine Amphibolitfazies 1 - Hochdruck - Amphibolitfazies 2/Granulitfazies charakterisiert ist. Der Endpunkt dieses Teilpfades ist mit Temperaturen zwischen 700 und 750 &#176;C und Drücken von 1.2 - 1.4 GPa belegt. Für diese Bedingungen konnte ein minimales Alter von 520 Ma durch chemische Datierungen an Monaziten einer Augengneisprobe und Pb-Pb Datierungen an Zirkonen einer Augengneis- und Metagabbroprobe bestimmt werden. Dieser amphibolit/granulitfazieller Endpunkt wird mit den Granitintrusionen des zentralen und südlichen Menderes Massiv korreliert, die in einem Zeitraum zwischen 520 Ma bis 550 Ma stattfanden. <br /> Sowohl die Amphibolitfazies 1 als auch das Hochdruckereignis werden der Panafrikanischen Orogenese zugeordnet. Für die Hochdruckbedingungen wurden maximale Temperaturen zwischen 680&#176;C und 720&#176;C und bei einem Druck von 2.2 GPa bestimmt. In den untersuchten Metasedimenten konnte eine prograde metamorphe Entwicklung abgeleitet werden, die amphibolitfazielle Bedingungen von 660&#176;C bei 0.6 GPa erreichte. Das Metamorphosealter dieser Metasedimente konnte mit < 100 Ma mittels chemischer Mikrosondendatierung bestimmt werden. Die in den Metasedimenten herausgearbeiteten Druck- und Temperaturbedingungen wurden ebenfalls in den metabasischen Gesteinen bestimmt. Diese Ergebnisse werden als Krustenstapelung der metabasischen Gesteine, Augengneise und Metasedimente interpretiert, die mit der alpinen Orogenese im Zusammenhang stehen. <br /> Durch die Ergebnisse dieser Arbeit lässt sich die Birgi-Tire Decke im zentralen Menderes Massiv genauer charakterisieren. Sie besteht aus Metasedimenten, pelitischen Gneisen, Augengneisen und metabasichen Gesteinen. Die Gneise (pelitische und Augengneise) und die metabasischen Gesteine stellen panafrikanische Relikte dar, die einen amphibolit- eklogit- amphibolit/granulitfaziellen Metamorphosepfad gespeichert haben. Die amphibolit- bis granulitfazielle Metamorphose hängt mit den Granitintrusionen zusammen und fand in einem Zeitraum zwischen 520 - 550 Ma statt. Große Teile der Metasedimente der Birgi Tire Decke haben jedoch nur eine alpine metamorphe Entwicklung durchlaufen, wo sie unter amphibolitfazielle Bedingungen Krustentiefen erreichten, bei denen sie mit den panafrikanischen Relikten zusammen gestapelt wurden und eine gemeinsame Exhumierung erfahren haben. / The Menderes Massif in western Turkey is a large culmination of metamorphic rocks. The investigation area is bounded by two active graben systems, the Gediz Graben in the north and the Büyük Menderes Graben in the south. One result of our investigation in the central Menderes Massif is the occurrence of eclogite relicts in different tectonic positions. On one hand eclogite blocks exist in the structurally highest nappe (Selcuk unit) of the central Menderes Massif, and on the other hand the high pressure relicts exist in the structurally middle Birgi-Tire nappe. The garnets of the quartz-free eclogite blocks in a metaolistostrome unit show large similarities with those which indicate the HP/LT rocks of Sifnos and Syros. The occurrence of the eclogite blocks in the metaolistostrome unit can not be correlated with those of the structural middle nappe (Birgi Tire nappe). By petrological investigations, chemical and Pb-Pb age determinations a polymetamorphic history was found for the eclogite relicts in the Birgi Tire nappe. The eclogite relicts belong to a metamorphic P-T path which is characterized by a amphibolite facies 1 - high pressure - amphibolite facies 2/granulite facies. The last one is characterized by temperatures between 700 and 750 &#176;C and by pressure of 1.2 - 1.4 GPa. A minimum age of 520 Ma was deduced by chemical age determination on monazites and Pb-Pb dating on zircons. The age of the amphibolite/granulite facies condition is correlated with the granite intrusions in the central and southern Menderes Massif which occurred in the range of 520 to 550 Ma. The intrusions belong to the Panafrican orogeny. Therefore the P-T path (amphibolite facies 1 - high pressure - amphibolite facies 2/granulite facies) is assigned to the Panafrican orogeny. The maximum temperatures of the high pressure event are between 680 &#176;C and 720 &#176;C. The pressure amounts to 2.2 GPa. A prograde metamorphic evolution under amphibolite facies conditions was derived for the investigated metasediments. The amphibolite facies conditions took place at a temperature of 660&#176;C and at a pressure of 0.6 GPa. The age of the metasediments was determined as < 100 Ma by means of chemical dating. The same metamorphic conditions could be recognized in the metabasic rocks. The interpretation of this result is that crustal stacking occurred under amphibolite facies conditions during the Alpine orogeny. Due to the presented results, the Birgi Tire nappe in the central Menderes Massif can be characterized more exactly. It consists of metasediments, pelitic and augengneisses, and metabasic rocks. Pelitic and augengneisses and the metabasic rocks represent Panafrican relicts, which have stored an amphibolite - eclogite - amphibolite/granulite facies P-T path. The amphibolite to granulite facies metamorphosis is related to the granite intrusions and took place in a period between 520 - 550 Ma. Parts of the metasediments belonging to the Birgi Tire nappe are influenced by only an alpine metamorphic history. They moved to crustal depths at which they were stacked with the Panafrican relicts under amphibolite facies conditions followed by common exhumation.

This thesis uses various approaches such as observation of satellite images, field investigations, analogue modeling and GPS measurements to constrain deformation of the basement and sedimentary cover of the Zagros fold-thrust belt in time and space. Focal mechanism solutions of most earthquakes indicate that deformation in the Zagros basement is due to shortening and thickening through numerous thrust faults. However, observations of strike-slip faulting recognized on satellite images imply that N-S trending faults in the Zagros, inherited from Pan-African basement, rotated about vertical axes to accommodate the convergence between Arabia and central Iran. Field studies suggest that southwestward advance of the Zagros front has been recorded by syn-sedimentary structures. These structures indicate that deformation started as early as end Eocene in the northeast of the Simply Folded Zone and propagated progressively to the southwest. The deformation front drove the foreland basin to its present position along the Persian Gulf and Mesopotamia. Scaled analogue models suggest that the seismicity due to orogenic shortening depends largely on the friction between the cover and its basement. Models show that fold-thrust belts with low tapers shortened above low friction ductile decollements involve several long-lived thrust faults generating low to moderate earthquakes over wide areas at the same time. By contrast, earthquakes with larger magnitudes are expected to occur along a few short-lived thrust ramps in fold-thrust belts with larger tapers shortened above high-friction decollments. GPS-derived velocities across and along the Zagros suggest that only about one third (10 ± 3 mm/yr) of the current convergence between Arabia and Eurasia is accommodated within the Zagros by thickening to the east of the Kazerun Fault and thickening and lateral movement to the west. The remaining (21 ± 3 mm/yr) is transferred beyond the Zagros suture to central Iran and the northern Iranian mountains.

The geology of the Sierra Mojada silver-lead-zinc mining district gives new insights into the stratigraphic evolution of the Coahuila Block and the Coahuila Folded Belt and the history of deformation along the basement-rooted San Marcos Fault Zone. Sierra Mojada provides the opportunity for substantial data collection relevant to the interaction of regional tectono-stratigraphic elements in a generally data-poor region of northeastern Mexico. Active mineral exploration has produced an extensive database of closely spaced drill core. Expansive underground workings facilitate subsurface geologic mapping. Sierra Mojada is situated at the northwestern edge of two tectono-stratigraphic provinces, the Coahuila Block, to the south, and the Coahuila Folded Belt, to the north. The San Marcos Fault, a west-northwest-trending regional structure extends through Sierra Mojada and is the informal boundary between these two provinces. Sierra Mojada is situated on uplifted and deformed late Paleozoic Ouachita siliciclastic strata intruded by Triassic diorites. This basement is diagnostic of the Coahuila Block. Basement rocks are overlain by an immature conglomerate that is interpreted to be the updip equivalent of the Jurassic La Casita Formation. The stratigraphy of Sierra Mojada principally consists of a continuous succession of Barremian through Albian carbonates unconformably overlying the basal conglomerate. The Barremian-Aptian Cupido Formation locally records deepening conditions from a clastic-influenced evaporitic interior to high energy, open water conditions. The shale and lime mudstone of the La Pena Formation were deposited during a Gulf-wide transgression that signals the end of the Aptian. The Sierra Mojada region of the Coahuila Block was inundated throughout the Aptian and was affected by the late Aptian transgression. The Albian Aurora Formation constitutes the bulk of the Cretaceous section. Sierra Mojada exposes the Aurora shelf rim, progressing from platform margin to shelf rim and platform interior facies. The structural features of Sierra Mojada affect the entire Cretaceous section. The high angle San Marcos Fault was reactivated with reverse motion during the Paleogene as a result of Laramide shortening. This juxtaposed basement and Jurassic conglomerate against the Cretaceous carbonates consistent with offset observed along the southern trace of the San Marcos Fault. A local colluvial unit suggests a lag in Laramide deformation. The carbonate strata and colluvial unit were overridden by a low angle, northeast-dipping thrust fault that placed a Neocomian through Aptian sequence atop the autochthonous Aptian-Albian carbonates. The allochthonous San Marcos Formation suggests regional-scale tectonic transport of this immature fluvial conglomerate from a downdip depozone within the Sabinas Basin. Kinematic indicators are consistent with the southwest-northeast axis for maximum compression established for Paleogene shortening throughout the Coahuila Folded Belt. The thrust fault bisects the principal ore zone within the Lower Aurora and upper La Pena Formations. This relation constrains the minimum age of ore emplacement to the Paleogene and suggests mineralization was genetically tied to the late stages of the Laramide Orogeny. / text

Alkalic porphyry style Au-Cu deposits of the Cadia district are associated with Late-Ordovician monzonite intrusions, which were emplaced during the final phase of Macquarie Arc magmatism at the end of the Benambran Orogeny. N-striking faults, including the curviplanar, northerly striking, moderately west-dipping basement thrust faults of the Cadiangullong system, developed early in the district history. NE-striking faults formed during rifting in the late Silurian. Subsequent E-W directed Siluro- Devonian extension followed by regional E-W shortening during the Devonian Tabberabberan Orogeny dismembered these intrusions, thereby superposing different levels porphyry Au-Cu systems as well as the host stratigraphy. During the late Silurian, the partially exhumed porphyry systems were buried beneath the Waugoola Group sedimentary cover sequence, which is generally preserved in the footwall of the Cadiangullong thrust fault system. The Waugoola Group is a typical rift-sag sequence, deposited initially in local fault-bounded basins which then transitioned to a gradually shallowing marine environment as local topography was overwhelmed. Basin geometry was controlled by pre-existing basement structures, which were subsequently inverted during the Devonian Tabberabberan Orogeny, offsetting the unconformity by up to 300m vertically. In the Waugoola Group cover, this shortening was accommodated via a complex network of minor detachments that strike parallel to major underlying basement faults. For this reason, faults and folds measured at the surface in the sedimentary cover can be used as a predictive tool to infer basement structures at depth.

Alkalic porphyry style Au-Cu deposits of the Cadia district are associated with Late-Ordovician monzonite intrusions, which were emplaced during the final phase of Macquarie Arc magmatism at the end of the Benambran Orogeny. N-striking faults, including the curviplanar, northerly striking, moderately west-dipping basement thrust faults of the Cadiangullong system, developed early in the district history. NE-striking faults formed during rifting in the late Silurian. Subsequent E-W directed Siluro- Devonian extension followed by regional E-W shortening during the Devonian Tabberabberan Orogeny dismembered these intrusions, thereby superposing different levels porphyry Au-Cu systems as well as the host stratigraphy. During the late Silurian, the partially exhumed porphyry systems were buried beneath the Waugoola Group sedimentary cover sequence, which is generally preserved in the footwall of the Cadiangullong thrust fault system. The Waugoola Group is a typical rift-sag sequence, deposited initially in local fault-bounded basins which then transitioned to a gradually shallowing marine environment as local topography was overwhelmed. Basin geometry was controlled by pre-existing basement structures, which were subsequently inverted during the Devonian Tabberabberan Orogeny, offsetting the unconformity by up to 300m vertically. In the Waugoola Group cover, this shortening was accommodated via a complex network of minor detachments that strike parallel to major underlying basement faults. For this reason, faults and folds measured at the surface in the sedimentary cover can be used as a predictive tool to infer basement structures at depth.

Typescript (Photocopy) / Copies of 4 published papers co-authored by author, and 7 maps, in back cover pocket. / Bibliography: leaves 203-218. / [232] leaves : ill., maps (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology and Geophysics, 1989

Alkalic porphyry style Au-Cu deposits of the Cadia district are associated with Late-Ordovician monzonite intrusions, which were emplaced during the final phase of Macquarie Arc magmatism at the end of the Benambran Orogeny. N-striking faults, including the curviplanar, northerly striking, moderately west-dipping basement thrust faults of the Cadiangullong system, developed early in the district history. NE-striking faults formed during rifting in the late Silurian. Subsequent E-W directed Siluro- Devonian extension followed by regional E-W shortening during the Devonian Tabberabberan Orogeny dismembered these intrusions, thereby superposing different levels porphyry Au-Cu systems as well as the host stratigraphy. During the late Silurian, the partially exhumed porphyry systems were buried beneath the Waugoola Group sedimentary cover sequence, which is generally preserved in the footwall of the Cadiangullong thrust fault system. The Waugoola Group is a typical rift-sag sequence, deposited initially in local fault-bounded basins which then transitioned to a gradually shallowing marine environment as local topography was overwhelmed. Basin geometry was controlled by pre-existing basement structures, which were subsequently inverted during the Devonian Tabberabberan Orogeny, offsetting the unconformity by up to 300m vertically. In the Waugoola Group cover, this shortening was accommodated via a complex network of minor detachments that strike parallel to major underlying basement faults. For this reason, faults and folds measured at the surface in the sedimentary cover can be used as a predictive tool to infer basement structures at depth. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The Kinsevere mine is a copper deposit located in the Democratic Republic of Congo (DRC), within the Central African Copperbelt. This area is situated in the Katangan basin within the SE portion of the Lufilian Arc, which is a large, arcuate structure that extends from SE Angola, across the DRC, and into NW Zambia. The purpose of this study is to characterise the brittle deformation observed around the Kinsevere copper deposit to lead to an understanding of the deformation history of the area. This is accomplished by analysing fault-slip and fold data to help understand the relationship between regional palaeostress, faulting and folding present in the mine vicinity. This study also attempts to characterise fracture-controlled copper mineralisation within the interpreted geodynamic context of the area. The broader objective of this study is to relate the structural observations from Kinsevere to the deformation history of the Lufilian Arc. This study uses the right dihedral method to analyse four categories of brittle structures. The structural types analysed include slickensided faults, mineralised joints, and unmineralised joints and shear fractures. The data suggests that the palaeostress associated with the formation of brittle structures in the Kinsevere area occurred during three deformation events. The first event is characterised by a compressional stress regime which occurred during the early stage of the Kolwezian phase (D1). The second event is characterised by a strike-slip stress regime that formed as the result of clockwise rotation of the earlier (D1) compressional regime. Two fault-slip vectors were observed on the strike-slip fault planes, indicating that a reactivation occurred during the Monwezian phase (D2). The final structural event was characterised by the development of an extensional stress regime. This was associated with North-South oriented extension and is related to the East African Rift System (D3). These interpreted events correlate well with the geodynamic context related to the Lufilian orogeny. Another line of evidence that supports this structural interpretation is the presence of evaporitic minerals observed in the stratigraphic units surrounding the brecciated zones such as the RAT and the CMN. The structural association of these evaporitic minerals may be related to pre-existing, salt-bearing units, which were dissolved during an early compressive (D1) phase of the Lufilian orogeny. However, the contact between the Grey RAT and the Red RAT (distal from the breccia zones) does not show any evidence of faulting, and in the Kinsevere area the Grey RAT is always observed above the Red RAT. This suggests that the Grey RAT may be the uppermost stratigraphic unit of the RAT subgroup, which contradicts some previously published interpretations. Thus, the current structural architecture was probably formed from a combination of two separate mechanisms, including compression-related salt extrusion and the development of thrust faults and folding resulting from the shortening of the Katangan basin. Based on an analysis of the fracture-controlled mineralisation in the study area, it is shown here that most of the stress tensors indicate that these fractures were induced within the compressional stress regime generated by the Lufilian orogeny. This conclusion supports studies which suggest a multiphase origin for the mineralizing fluids active in the Katangan basin. Thus, the age of the copper mineralisation associated with fractures is interpreted to correlate with the timing of the folding event that occurred during the Lufilian orogeny between 540-550Ma. / Dissertation (MSc)--University of Pretoria, 2012. / Geology / unrestricted

Diploma thesis - Kateřina Schlöglová - 2011 1/2 English abstract Granulites of the Rychleby Mts. represent relics of high-pressure eclogite-facies metamorphic rocks that are scattered in various crustal and mantle segments of the Variscan orogen in central Europe. These rocks may provide important insights into early stages of Variscan plate convergence and burial as well as exhumation mechanisms. We use mineral assemblages and chemistry to reconstruct the pressure-temperature paths, mechanisms of melting, and conditions of mineral preservation of high-pressure granulites, as well as whole- rock geochemistry to aid in interpretation of granulite precursors and their geodynamic setting. The mafic granulites consist of garnet, omphacite, two feldspars, and quartz with accessory rutile and zircon. The peak assemblage was partly replaced by pargasitic amphibole and biotite. Garnet grains are zoned from Grs36Py10Alm54 (core) to Grs20Py38Alm42 (rim), and host inclusions of phengite, omphacite, unmixed feldspars, kyanite, and rutile. Omphacite composition varies from Di44Hd14Jd42 (inclusions in garnet) through Di63Hd20Jd17 (porphyroblasts) and Di63Hd24Jd13 (symplectitic intergrowths with plagioclase). Reintegrated composition of the feldspar porphyroblasts is Or43Ab53An04. The felsic granulite variety is composed...

>Magister Scientiae - MSc / The Sea Point contact, Cape Town, South Africa, exposes the contact between the Neoproterozoic Malmesbury Group metasedimentary rocks of the Pan-African Saldania belt and the intrusive S-type Peninsula Granite of the Neoproterozoic-Paleozoic Cape Granite Suite (CGS). The exposure outcrops over an area of approximately 170 m × 60 m with the northern end of the exposure being characterized by the country rock–microgranite intrusive contact. Heading further south, the outcrop transitions to the main contact zone, which is a predominantly gradational zone marked by sheets of compositionally variable granitic injections (collectively referred to as hybrid granite phases) concordant to the country rock structure, before reaching the main pluton area comprising the voluminous coarse-grained porphyritic granite. Using a combined study incorporating field, structural, geochemical, isotopic and U-Pb geochronological data, the intrusive contact is investigated to determine the construction history of the pluton and delineate possible emplacement mechanisms. The granitic phases, which vary from fine-grained leucocratic, medium-grained porphyritic to coarse-grained porphyritic, are peraluminous, magnesian to ferroan, and alkali-calcic. Based on the linear trends between the whole-rock major and trace element content of the granites vs. maficity (molar Fe + Mg), their initial Sr ratios and εNd(t) values, the granites of the study area are consistent with the currently proposed petrogenetic model for the CGS (e.g. Stevens et al., 2007; Villaros et al., 2009a; Harris & Vogeli, 2010); i.e., they are crustally derived and their chemical variability is controlled primarily by peritectic assemblage entrainment. The fractional crystallization of K-feldspar is identified as the primary mechanism for the local geochemical variability of the granites. The fractionation of K-feldspar as a mechanism of variability was evaluated using binary log-log diagrams of Ba, Sr and Eu and is interpreted to have taken place at levels close to the emplacement site after source entrainment processes. Although there is outcrop evidence, particularly in the main contact zone, to suggest that local assimilation and filter pressing took place, this was not reflected by the whole-rock and isotope geochemistry of the granites. This suggests that these processes are very localized and will need further rigorous testing to ascertain the extent to which they caused variability. Outcrop evidence for assimilation includes gradational country rock-granite contacts and the ductile behaviour of the country rock, whereas the occurrence of K-feldspar megacrysts embedded in the country rock at the main contact zone suggests melt accumulation and escape consistent with the filter pressing mechanism. In the case of the latter, the melt fraction of the granite was easily mobilized and driven out compared to the crystal fraction (K-feldspars) during the emplacement of the granites. Field relationships and the structural interpretation of the Malmesbury Group country rocks and the granites reveal that: (1) the various granites are late syn-tectonic and (2) were emplaced as incrementally assembled, repeated pulses of inclined granitic sheets more or less normal (i.e. at high angles) to the regional NE-SW shortening (D1) of the Malmesbury forearc during the Saldanian orogeny. Given the lack of a controlling shear zone in facilitating granite emplacement in the study area, the pre-existing planar anisotropies (bedding planes and foliations) in the country rock provided preferential pathways for magma emplacement and propagation during deformation. This implies that the tensile strength normal and parallel to the bedding and foliation anisotropy of the country rock was larger than the regional differential stress (σ1 – σ3, with σ1 ≥ σ2 ≥ σ3), allowing for magma emplacement relative to shortening. Sheet propagation is interpreted to have occurred through the balance of the following conditions: (1) density contrasts between host rocks and magmas, (2) the pressure differential along the subvertical fractures/sheets, and (3) the melt pressure equalling the lithostatic pressure to keep the magma pathways open and being sufficiently high such that it exceeds the sum of σ1 and the tensile strength of the rock parallel to σ1. The crystallization ages of the dated granite samples are identical within error and vary between 538.7 ± 3.6 Ma and 542.7 ± 2.9 Ma. They, therefore, cannot prove which granite phase intruded first and which one proceeded and so forth. Field relationships, however, suggests that the microgranites were first to intrude given their fine-grained nature and the localized chilled contacts they show with the country rock. The various coarser-grained and porphyritic phases were next to intrude, with their coarse grain-sizes and lack of chilled margins with the country rock suggesting that the time interval between their successive emplacements was not too long; this prevented the country rock from completely cooling down between each magma batch. Magma stoping and the ductile flow of the host material (owing to highly viscous magma flow) to accommodate granite emplacement are interpreted to be secondary emplacement processes.