Interpreting the tectonic significance of high strain zones requires detailed knowledge of the P-T-t-D history of rocks on either side and of tectonized rocks within the shear zone. In-situ monazite geochronology is particularly useful because it generates a time-integrated framework of metamorphism and fabric development. This can be achieved by correlating monazite compositional domains with the growth and consumption of major phases. Furthermore, monazite can be a fabric forming mineral, and can be directly linked to structural fabrics and kinematics. The Cora Lake shear zone (CLsz) represents a major lithotectonic discontinuity within the deep crustal Athabasca Granulite terrain, and preserves intense mylonitic to ultramylonitic fabrics. The 3-5 km wide CLsz strikes ~231°, and dips ~62° to the Northwest, has a moderately plunging stretching lineation (SW trend) with abundant sinistral kinematic indicators. These data indicate oblique extension with NW hanging wall down and to the SW relative to the SE footwall. The NW hangingwall is dominated by the ca. 2.6 Ga charnockitic Mary batholith. The southeastern footwall is primarily underlain by the heterogeneous ca. 3.3-3.0 Ga Chipman tonaite straight gneiss. Although both share common Archean (ca. 2.55 Ga) and Paleoproterozoic (ca. 1.9 Ga) deformation events, the style and P-T conditions of deformation are different. The earliest phase of deformation within the NW hangingwall consists of a penetrative subhorizontal flow fabric at 0.9 GPa and ~725°C (2.56 Ga), but folding in the SE footwall associated with the development of a strong upright axially planar fabric at 1.35 GPa and 850°C. Deformation at ca 1.9 Ga was characterized by upright folding, similar in orientation, in both hangingwall (0.9 GPa; 725°C) and footwall (1.17 GPa; 825°C). Deformation related to the CLsz occurred at 1880 Ma (0.9-1.06 GPa; ~775°C), and is responsible for juxtaposing two levels of lower crust. The Cora Lake shear zone is interpreted to be the culmination of a trend of increased strength, localization, strain partitioning, and vertical coupling. Furthermore, the CLsz overprints fabrics from each wall, marks the development of a major lateral lithotectonic discontinuity, and an introduction of major structural and compositional heterogeneity within the lower continental crust.

Abstract Three dimensional finite strain and kinematic data from the Resolution Island Shear Zone, Fiordland, New Zealand record the progressive evolution of a lower crustal metamorphic core complex. The Resolution Island Shear Zone is a mid-Cretaceous (~114-90 Ma) extensional shear zone that juxtaposes high-pressure (P~17-19 kbar) garnet-granulite and eclogite facies orthogneiss from the lower crust against mid-crustal (P~6-8 kbar) orthogneiss and paragneiss along a low-angle upper amphibolite facies ductile normal fault. In the lower plate of the Resolution Island Shear Zone the high-pressure garnetgranulite and eclogite facies gneissic foliations (S1) are attenuated by granulite facies extensional shear zone foliations (S2). Retrograde metamorphism marked by the breakdown of omphacite and garnet to amphibole and feldspar in S2 foliation records the unloading of the lower plate during extension. Continued extension localized strain into weaker amphibole and feldspar-bearing lithologies. Upper amphibolite facies shear zones anastomose around rigid lenses that preserve the S1 and S2 fabric. Upper amphibolite facies shear zone fabrics (S3/L3) that envelop these pods display a regional-scale domeand- basin pattern. These shear zones coalesce and form the Resolution Island Shear Zone. Coeval with the formation of the Resolution Island Shear Zone, a conjugate, southwest dipping, and lesser magnitude shear zone termed the Wet Jacket Shear Zone developed in the upper plate of the Resolution Island Shear Zone. Three-dimensional strain analyses from S3/L3 fabric in the Resolution Island Shear Zone show prolate-shaped strain ellipsoids. Stretching axes (X) from measured finite strain ellipsoids trend northeast and southwest and are subparallel to L3 mineral stretching lineations. Shortening axes (Y, Z) are subhorizontal and subvertical, respectively, and rotate through the YZ plane of the finite strain ellipsoid. This pattern reflects the dome-and-basin geometry displayed by anastomosing S3 foliations and indicates the Resolution Island Shear Zone developed in the field of constriction. Threedimensional kinematic results indicate a coaxial-dominated rotation of stretching lineations toward the X-axis in both the XZ and XY planes of the finite strain ellipsoid. Results suggest that a lower crustal metamorphic core complex developed in a constrictional strain field with components of coaxial-dominated subvertical and subhorizontal shortening. Mid-Cretaceous (~114-90 Ma) extensional structures exposed in Fiordland, including the Resolution Island, Wet Jacket, Mount Irene and Doubtful Sound shear zones and the Paparoa metamorphic core complex allows the reconstruction of a crustal column that describes the geometry of mid-Cretaceous continental rifting of Gondwana. The overall symmetry of crustal-scale structures during continental extension suggests kinematic links between flow in the lower crust and the geometry and mode of continental extension. This result is consistent with numerical models of lithospheric rifting that predict the lower crust has a primary control on the style of continental extension.

ABSTRACT Doubtful Sound, in SW New Zealand, exposes an exhumed section of lower crust that represents the root of an Early Cretaceous magmatic arc. Here, the lower crust underwent a change from contraction to extension and these tectonic cycles are fundamental to the growth of continental crust. Mafic-intermediate granulite gneisses occur below the extensional Doubtful Sound shear zone (DSSZ) which records the retrogression and transposition of granulite fabrics at the upper amphibolite facies. I compared 3D rock fabrics, microstructures and textures within and below the DSSZ to determine the processes involved in the shift from contraction to extension and to infer the sequential processes of transforming L>S granulites to L=S amphibolites. Below the DSSZ, dehydration zones around felsic veins and leucosome in migmatitic orthogneiss record granulite facies metamorphism. Aggregates of clinopyroxene (cpx) and orthopyroxene (opx) that are rimmed by garnet (grt) and interstitial melt are set in a plagioclase (pl) matrix. Peritectic grt, pl-grt symplectites, beads of pl along grain boundaries, and elongate, inclusion-free pl reflect the anatexis. Pl exhibits a crystal preferred orientation (CPO) and evidence of subgrain rotational recrystallization and grain boundary migration, indicating subsolidus deformation outlasted melting. Mafic aggregates are boudinaged and opx developed subgrains. During peak metamorphism high strain was partitioned to locations enriched in melt, producing L>S fabrics and an upward trajectory in the strain path. A comparison of mineral grain shapes indicates that pl accommodated most of the strain. Granulite-amphibolite transitional rocks inside the DSSZ record a heterogeneous retrogression of the granulites to a polyphase metamorphic assemblage of hornblende (hbl), biotite (bt), and fine pl. Also preserved is the resetting of high strain L>S granulite to low strain, L=S amphibolite. Folia of porphyroblastic hbl + bt progressively penetrate the pl matrix via solution mass transfer. Porphyroblastic pl in the rock matrix becomes increasingly transposed to gneissic layering. A path of decreasing gradient from high strain L>S granulite to low strain L=S amphibolite reflects the development of the DSSZ fabric, growth of new minerals and onset to deformation at the amphibolite facies. Inside the DSSZ, amphibolites show an increasing strain gradient from low strain L=S amphibolite to high strain L=S amphibolite. Pl aggregates lack a CPO and are mostly annealed but preserve grain boundary migration microstructures. Hbl is recrystallized and forms asymmetric fish. Evidence of high fluid activity and reaction softening within the DSSZ include increased hbl + bt and bt beards on pl relative to rocks outside the DSSZ. My observations suggest that magma, heat, and melting initially weakened the lower crust, facilitating the development of high strain zones with L>S fabrics. Partially molten regions deformed by suprasolidus flow and solid portions deformed mostly by dislocation creep in pl and boudinage of cpx + opx. Later, the lower crust was weakened and high strain fabrics were reset from overprinting and transposition as retrogression progressed and low strain L=S fabrics formed. During extension there was an upward trajectory in the strain path to high strain L=S fabrics within the DSSZ, where hbl and bt accommodated more strain. My results illustrate the importance of 1) melting, cooling, and hydration in controlling strain partitioning and the rheological evolution of lower crustal shear zones, and 2) the importance of integrating microstructural and fabric analysis to determine strain paths.

Thesis advisor: Seth C. Kruckenberg / In the earth’s lithosphere there exists both homogeneous and heterogeneous deformation on a variety of scales. The lower crust specifically plays a critical role in lithospheric deformation; however, the lower crust does not deform homogenously but rather heterogeneously in space and time. One of the best avenues for addressing heterogeneous lower crustal deformation is through an integrated study of shear zones. While many studies have identified factors such as strain rate and temperature as key actors in lower crustal strain localization, more studies are needed to characterize the dominant grain-scale mechanisms that accommodate the development of lower crustal shear zones. The primary aim of this research is to investigate the dominant mechanisms that lead to strain localization in the lower crust. The Capricorn Ridge Shear Zone (CRSZ), Central Australia, is an ideal location for study because it is a lower crustal shear zone that contains discrete zones of strain localization, primarily adjacent to major lithological boundaries. Previous studies conclude that competency contrast caused strain to localize at the lithologic boundaries of the CRSZ, a hypothesis that is tested in this study. Using microstructural, textural, and rheologic analysis, as well as field-based mapping and grain size piezometry, this study finds that differential stresses in Capricorn Ridge range from 17-27 MPa for quartz, 31-42 MPa for plagioclase, and 2.8-7.6 MPa for enstatite. Monophase aggregate strain rates range from 1.6 x 10-15 to 1.7 x 10-14 s-1 for quartz, 4.5 x 10-15 to 3.3 x 10-14 s-1 for plagioclase, and 6.0 x 10-20 to 1.2 x 10-18 s-1 for enstatite; corresponding effective viscosities 0.3-1.7 x 1021 Pa.s, 0.3-1.5 x 1021 Pa.s, and 0.2-1.8 x 1025 Pa.s for quartz, plagioclase, and enstatite, respectively. Data across the CRSZ show that while strain rate (viscosity) in monophase aggregates of quartz and plagioclase are generally similar across the shear zone, they do decrease at lithologic boundaries. In contrast to a previous study’s finding that competency contrast caused strain to localize at these boundaries, both quartz and plagioclase appear to record strain accumulation through grain size reduction. However, the observations made in previous studies are not negated by this study, as it is possible that grain size reduction in the mylonite zones near the boundaries caused strain to accumulate over time and therefore produce the observed pattern of increasing fabric intensity with proximity to the lithologic boundaries. / Thesis (MS) — Boston College, 2021. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

The Bohemian Massif was consolidated during the Variscan orogeny (~400-300 Ma), which involved several oceanic subductions and collisions of continental micro-plates. The central part of the Bohemian Massif, the Moldanubian domain, shows a large accumulation of felsic high-pressure metamorphs. We present a numerical model of exhumation of these rocks due to continental collision and underthrusting. The key feature of the model is a felsic (light, rheologically weak and rich in radioactive elements) material in the lower crust of one of the colliding blocks. We examine the influence of the rate of convergence of the two blocks, radiogenic heating in the felsic lower crust and efficiency of erosion, on the model evolution and pressure-temperature conditions in the lower-crustal material. The models where the material is sufficiently weakened due to radiogenic heating show formation of an orogenic plateau, sedimentation in a foreland basin, and crustal thickening accompanied by gravity-driven exhumation of the lower crust and subsequent sub-horizontal flow in the middle crust. In colder and/or faster models, the thickening is dominated by folding. We correlate the tectonic style of these two types of models with differences between the high-grade rocks in the southern (Moldanubian) and northern (Sudetic) parts...

Thesis advisor: Seth C. Kruckenberg / Quantitatively describing the deformational behavior (i.e. the rheology) of lower crustal materials has proven challenging due to the highly variable nature of structural and compositional fabrics in the lower crust. Further, many flow laws describing the rheology of monophase aggregates are experimentally derived and do not necessarily apply to polyphase materials, such as gabbro, that dominate the lower crust. Here, we present the results of integrated microstructural analysis and electron backscatter diffraction (EBSD) textural analysis from exhumed lower crustal granulites in the Mount Hay block of central Australia. The preservation of heterogeneous mafic and felsic granulites containing monophase and/or polyphase mixtures of anorthite, pyroxene, and quartz (interlayered on the mm- to m-scale) make this region uniquely suited for advancing our knowledge of the processes that affect deformation and the rheology of the lower crust. Forty-two samples from distinct structural and compositional domains were chosen to compare the microstructural record of deformation, the development of crystallographic textures, and to provide estimates of lower crustal rheology and deformation conditions. Full thin-section maps of crystallographic texture were produced using EBSD methods. The resultant orientation maps were processed to characterize crystallographic textures in all constituent phases, and all other quantifiable aspects of the rock microstructure (e.g., grain size, grain shape, misorientation axes). The EBSD analysis reveals the presence of strong crystallographic preferred orientations (CPO) in nearly all constituent phases, suggesting deformation dominated by dislocation creep. Differential stresses during deformation are calculated using grain size piezometry for all major phases, and range between 34-54 MPa in quartz within monophase layers. Two-pyroxene geothermometry was used to constrain deformation temperatures to ca. 780-810 C. Based on the estimated CPO patterns, stress, and temperature, we quantify strain rates and effective viscosities of all major phases through application of monophase flow laws. Monophase strain rates range from 2.10 x 10-12 s-1 to 1.56 x 10-11 s-1 for quartz, 4.68 x 10-15 s-1 to 2.48 x 10-13 s-1 for plagioclase feldspar, 1.56 x 10-18 s-1 to 1.64 x 10-16 s-1 for enstatite, and 5.66 x 10-16 s-1 to 1.00 x 10-14 s-1 for diopside. The determined flow law variables used for monophase calculations were subsequently applied to two different models – the Minimized Power Geometric model of Huet et al. (2014) and the Asymptotic Expansion Homogenization (AEH) method of Cook (2006) – in order to calculate a bulk aggregate viscosity of the polyphase material. At a strain rate of 10-14 s-1, polyphase effective viscosities for our samples range from 3.07 x 1020 to 2.74 x 1021 Pa·s. We find that the bulk viscosity of heterogeneous, gabbroic lower crust in the Mount Hay region lies between that of monophase plagioclase and monophase quartz, and varies as a function of composition. These results are consistent with past modeling studies and geophysical estimates. / Thesis (MS) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

The rheology and strength of the lower crust play a key role in lithosphere dynamics, influencing the orogenic cycle and how plate tectonics work. Despite their geological importance, the processes that cause weakening of the lower crust and strain localization are still poorly understood. Through microstructural analysis of naturally deformed samples, this PhD aims to investigate how weakening and strain localization occurs in the mafic continental lower crust. Mafic granulites are analysed from two unrelated continental lower crustal shear zones which share comparable mineralogical assemblages and high-grade deformation conditions (T > 700 °C and P > 6 Kbar): the Seiland Igneous Province in northern Norway (case-study 1) and the Finero mafic complex in the Italian Southern Alps (case-study 2). Case-study 1 investigates a metagabbroic dyke embedded in a lower crustal metasedimentary shear zone undergoing partial melting. Shearing of the dyke was accompanied by infiltration of felsic melt from the adjacent partially molten metapelites. Findings of case-study 1 show that weakening of dry and strong mafic rocks can result from melt infiltration from nearby partially molten metasediments. The infiltrated melt triggers melt-rock reactions and nucleation of a fine-grained (< 10 µm average grain size) polyphase matrix. This fine-grained mixture deforms by diffusion creep, causing significant rheological weakening. Case-study 2 investigates a lower crustal shear zone in a compositionally-layered mafic complex made of amphibole-rich and amphibole-poor metagabbros. Findings of case-study 2 show that during prograde metamorphism (T > 800 °C), the presence of amphibole undergoing dehydration melting reactions is key to weakening and strain localization. Dehydration of amphibole generates fine-grained symplectic intergrowths of pyroxene + plagioclase. These reaction products form an interconnected network of fine-grained (< 20 µm average grain size) polyphase material that deforms by diffusion creep, causing strain partitioning and localization in amphibole-rich layers. Those layers without amphibole fail to produce an interconnected network of fine grained material. In this layers, plagioclase deforms by dislocation creep, and pyroxene by microfracturing and neocrystallization. Overall, this PhD research highlights that weakening and strain localization in the mafic lower crust is governed by high-T mineral and chemical reactions that drastically reduce grain size and trigger diffusion creep.

The Andean Southern Volcanic Zone (SVZ) is a vast and complex continental arc that has been studied extensively to provide an understanding of arc-magma genesis, the origin and chemical evolution of the continental crust, and geochemical compositions of volcanic products. The present study focuses on distinguishing the magma/sub-arc crustal interaction of eruptive products from the Azufre-Planchon-Peteroa (APP 35°15’S) volcanic center and other major centers in the Central SVZ (CSVZ 37°S - 42°S), Transitional SVZ (TSVZ 34.3-37.0°S), and Northern SVZ (NSVZ 33°S - 34°30’S). New Hf and Nd isotopic and trace element data for SVZ centers are consistent with former studies that these magmas experienced variable depths of crystal fractionation, and that crustal assimilation is restricted to the lower crustal depths with an apparent role of garnet. Thermobarometric calculations applied to magma compositions constrain the depth of magma separation from mantle sources in all segments of the SVZ to(70-90 km). Magmatic separation at the APP complex occurs at an average depth of ~50 km which is confined to the mantle lithosphere and the base of the crust suggesting localized thermal abrasion both reservoirs. Thermobarometric calculations indicate that CSVZ primary magmas arise from a similar average depth of (~54 km) which confines magma separation to the asthenospheric mantle. The northwards along-arc Sr-Nd-Hf isotopic data and LREE enrichment accompanied with HREE depletion of SVZ mafic magmas correlates well with northward increasing crustal thickness and decreasing primary melt separation from mantle source regions indicating an increased involvement of lower crustal components in SVZ magma petrogenesis. The study concludes that the development of mature subduction zones over millions of years of continuous magmatism requires that mafic arc derived melts stagnate at lower crustal levels due to density similarities and emplace at lower crustal depths. Basaltic underplating creates localized hot zone environments below major magmatic centers. These regions of high temperature/partial melting, and equilibration with underplated mafic rocks provides the mechanism that controls trace element and isotopic variability of primary magmas of the TSVZ and NSVZ from their baseline CSVZ-like precursors.

Les profils de sismique réflexion de Marges Passives Volcaniques imagent une croûte inférieure réflective formée de deux domaines distincts. Ces réflecteurs sont interprétés comme des intrusions mafiques associées à la formation de la marge. Les observations géophysiques ne permettent pas de comprendre les conséquences associées à la mise en place de ces magmas sur la rhéologie et la déformation effective de la croûte inférieure des marges volcaniques. Cette thèse explore deux exemples géologiques de croûte inférieure à l’affleurement qui ont été affectés par d’importants volumes magmatiques pendant leur histoire extensive : la Zone d’Ivrée (Alpes italiennes) et la province de Seiland (Calédonides finmarkiennes). Une étude approfondie de terrain, associée à des analyses géochimiques et isotopiques ainsi qu’à des expériences de déformation en Presse Paterson permet, (1) de définir la structure synthétique finie d’une croûte inférieure extensive affectée par un ou plusieurs épisodes magmatiques intenses et d'identifier dans la Zone d’Ivrée une croûte moyenne ductile, dans laquelle s’enracinent les failles de la croûte supérieure, (2) de montrer l’évolution de la rhéologie et de la déformation ductile de la croûte inférieure relativement à la mise en place des magmas (3) de caractériser à partir de Seiland l’interface croûte manteau dans un contexte d’extension synmagmatisme mafique. L’ensemble des résultats montre la complexité des relations, à la fois structurales, spatiales et temporelles, entre les magmas et roches mafiques et la déformation en extension dans la croûte inférieure. / Seismic reflection profiles of Volcanic Passive Margins show a two-domain reflective lower crust. The particular reflectors are interpreted as mafic intrusions associated to the margin evolution.From those geophysical observations it is not possible to understand the consequences of mafic magma emplacement on the rheology and effective deformation of volcanic margins lower crust. This thesis explores two geologic examples of outcropping lower crusts affected by important volumes of magma during their extensional story: the Ivrea Zone (Italian Alps) and Seiland (Finmarkian Caledonides). An important field study associated to geochemical and isotopic analyses, and to Patersonapparatus deformation experiences led to (1) define a synthetic structure of an extensional lower crust affected by one or more major magmatic events and to indentify a ductile middle crust in the Ivrea Zone where roots the upper crust faults, (2) show the rheologic and deformation evolution of the lower crust in relation to magma emplacement timing, (3) characterize, from Seiland observations, the crustmantle interface in an extensional System. The whole study shows the complexity of the temporal, spatial and structural relationships between mafic rocks (as magma and as crystallised rock) and extensional deformation in the lower crust.

Pour la première fois, une étude par spectroscopie infrarouge à transformée de Fourrier et par microsonde ionique des minéraux majeurs de la croûte inférieure et des péridotites mantelliques a été entreprise afin de mieux caractériser les mécanismes d’incorporation et les teneurs en eau de ces minéraux nominalement anhydres, et de déterminer leurs compostions isotopiques en H, O, et Li pour retracer les échanges latéraux et horizontaux de l’eau dans la lithosphère continentale profonde. Les résultats montrent que: (1) Les minéraux nominalement anhydres, comme les pyroxènes et plagioclase, dans les granulites de la croûte inférieure contiennent de l’eau en trace essentiellement sous forme hydroxyles et accessoirement sous forme moléculaire, avec des concentrations (exprimées en poids H2O) allant de 200 à 2330 ppm pour les clinopyroxènes, de 60 à 1875 ppm pour les orthopyroxènes, de 65 à 900 ppm pour les plagioclases. Les teneurs calculées pour chaque roche totale d’après sa composition minéralogique et la teneur en eau des minéraux varient de 155 à 1100 ppm. (2) Les teneurs en H2O des minéraux majeurs et en roche totale de la croûte continentale inférieure sont manifestement plus élevées que celles du manteau lithosphérique sous-jacent, suggérant des variations verticales de la quantité d’H2O dans la lithosphère continentale profonde. Un tel contraste peut affecter de façon notable le comportement rhéologique de la lithosphère continentale. (3) Les rapports isotopiques de l’oxygène des pyroxènes étudiés, et probablement les roches totales, exprimés en [delta]18OSMOW , vont de ~ 4,5 à 12,5‰. Ceci indique la contribution de matériaux recyclés de la croûte continentale durant la pétrogenèse des échantillons ayant un TM18O élevé. (4) Les minéraux de la granulites sont caractérisés par des valeurs de élevées TMD, avec des valeurs de -80~-10‰ exprimées en [delta]DSMOW; les minéraux sont le plus souvent en équilibre les uns avec les autres lorsque l’on considère leurs compositions isotopiques moyennes. (5) Les compositions isotopiques du Lithium mesurée dans les minéraux de nos échantillons de granulites, exprimées en [delta]7Li par rapport à Lsvec, varient de -13 à +4.7 ‰. Ces valeurs sont donc pour la plus part inférieures à celles mesurées sur les MORB (2 – 6‰). La dispersion des valeurs reflètent l’hétérogénéité de la source des granulites, et les valeurs bassent resultent probablement de la perte par diffusion de Li pendant la mise en place des liquides silicatées provenant du manteau dans la croûte inférieure. (6) La grande hétérogénéité des teneurs en eau et en Lithium, et des compositions isotopiques de H-O-Li indique l’absence de circulation de fluide pervasive au travers de la croûte inférieure, qui aurait pour effet de supprimer les hétérogénéités à petite échelle et de les diminuer fortement à grande échelle / For the first time, systematic investigations of water content and H-O-Li isotopic compositions of minerals in lower crustal granulites, as well as water content of minerals in mantle peridotites, from eastern China have been carried out by Fourier transform infrared spectrometer and ion microprobe. The results show that: (1) Nominally anhydrous minerals, such as pyroxenes and plagioclase, in the lower crust generally contain trace amounts of structural water, with their content (H2O by wt.) varying from 200 to 2330 ppm for clinopyroxene, 60 to 1875 ppm for orthopyroxene, 65 to 900 ppm for plagioclase and 155 to 1100 ppm for the estimated bulk compositions. (2) Water contents of minerals in lower crustal granulites from eastern China, and their bulk values, are significantly higher than those in the underlying upper mantle, implying vertical heterogeneities of water distribution in the deep continental lithosphere; the contrast in water content even affect the rheological strength of the lithosphere. (3) The O-isotopic compositions of pyroxenes in the lower crustal granulites from eastern China are highly variable between different localities (~ 4.5 to 12.5‰, expressed in [delta]18OSMOW values), indicating variable influences from recycled crustal materials on their protoliths. (4) The H-isotopic compositions of granulite minerals from eastern China, are mostly in the range of -80 to -10‰ expressed in [delta]DSMOW values, and these minerals are usually in equilibrium with their [delta]D values. The relatively high [delta]D of granulite minerals may be related with degassing loss of H during the genesis of granulites. (5) The Li-isotopic compositions of granulite minerals from eastern China are usually in the range of -13 to 4.7‰, mostly lower than those of MORB (2-6‰). They reflect the source heterogeneity and are probably results of high-T Li diffusion during the intrusion of their original melts into the preexisting lower crust. (6) The large dispersion of Li and water contents and of H-O-Li isotopic results indicate the absence of any pervasive fluids in the lower crust