Emptiness (śūnyatā) is one of the most important topics in Buddhist thought and also is one of the most perplexing. Buddhists in Tibet have developed a sophisticated tradition of philosophical discourse on emptiness and ineffability. This paper discusses the meaning(s) of emptiness within three prominent traditions in Tibet: the Geluk (dge lugs), Jonang (jo nang), and Nyingma (rnying ma). I give a concise presentation of each tradition's interpretation of emptiness and show how each interpretation represents a distinctive aspect of its meaning. Given that Buddhist traditions (1) accept an extra-linguistic reality and (2) maintain a strong tradition of suspicion of language with the belief that language both constructs and distorts reality, this paper responds to an issue that is not so much whether or not an inexpressible reality can be expressed, but rather how it is best articulated.

No description available.

published_or_final_version / abstract / Earth Sciences / Doctoral / Doctor of Philosophy

published_or_final_version / Earth Sciences / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Earth Sciences / Master / Master of Philosophy

This dissertation consists of three manuscripts that will be submitted for publication. All three of these examine various aspects of the evolution of the India-Asia suture zone in southern Tibet after the India-Asia collision. Continent-continent collision is one of the basic tectonic plate boundary types, has occurred repeatedly throughout geologic history, and represents one of the principle mechanisms responsible for the formation of high elevation plateaus and orogens. Uplift within these zones has also drastically changed the earth's climate and atmospheric circulation, and erosion from continental collision has resulted in some of the thickest accumulations of sediment in the world (Curray, 1991; Einsele et al., 1996). However, despite the global significance of continental collision, much of the fundamental geodynamic and geologic processes governing these events remain enigmatic. This is the result of several factors. First and foremost, intense deformation and uplift of rocks, often from mid crustal levels, over very short periods of time (Hodges and Silverberg, 1988; Seward and Burg, 2008; Zeitler et al., 2014) results in the erosive removal of much of the geologic record of a collision zone. Second, because the best modern example of continental collision is the Tibet-Himalayan system, the study of continental collision in general has been hampered by high elevations, remoteness, difficult working conditions, and political unrest. The work presented here represents a step toward better understanding the geology, geologic history, and geodynamic evolution of the Tibetan Plateau, the Himalaya, and the India-Asia collision. This has been accomplished through study of two of the post-collisional sedimentary basins which formed near or within the India-Asia suture zone. Appendix A addresses the structure, sedimentology, age, and provenance of the Liuqu Conglomerate. The key conclusions of this section are: 1) The Liuqu Conglomerate was deposited in north flowing, stream dominated alluvial fans. These were located situated in a wedge-top position within a system of north verging thrust faults likely associated with the Great Counter Thrust, and sediment was accommodated via burial beneath thrust structures. 2) The age of the Liuqu Conglomerate has been refined to ~20 Ma based on detrital zircon U-Pb and fission track dating, ⁴⁰Ar/³⁹Ar dating of biotite from a cross-cutting dike, re-analysis of previously published pollen data, regional structural considerations, and oxygen isotope composition of paleosol carbonates. 3) Sand-sized and finer-grained sediment eroded from the southern margin of Asia prior to collision was transported southwards across the Xigaze forearc basin, deposited within the subduction trench, and then accreted within the subduction complex mélange. After collision, this sediment was eroded from the mélange and shed northward into the India-Asia suture zone. Appendix B focuses on the abundant paleosols preserved within the Liuqu Conglomerate. This study uses major element geochemistry of these paleosols and stable isotope analyses of paleosol carbonates to constrain the degree and type of chemical weathering, and thus the paleoclimate and paleoelevation, of the Liuqu Conglomerate. The key conclusions of this paper are: 1) at ~20 Ma, the India-Asia suture zone experienced warm and wet conditions that promoted intense chemical weathering of soils exposed in the inactive portions of alluvial fans. Paleorainfall is estimated at ~1500 mm/yr, and weathering intensity was similar to soils formed in the Neogene Siwalik Group of India, Nepal, and Pakistan, which formed under wet, semitropical, and low elevation conditions. 2) The India-Asia suture zone experienced these conditions at ~20 Ma despite extensive deformation and crustal thickening which has been documented within the Tethyan Himalayan and Himalayan thrust belts. This crustal thickening should have resulted in the (surface) uplift of the entire India-Asia collision zone, and there is evidence that at least some portion of the Himalayan crest was at or near modern elevations by ~17 Ma. Our results require either that the Tethyan Himalaya and India-Asia suture zone were not uplifted despite as much as 40 million years of intense crustal shortening or that these regions attained high elevation prior to ~20 Ma, and then lost elevation around this time before being immediately re-uplifted. The viability of these two scenarios cannot be explicitly tested with the data presented in this chapter; however, based on the data presented in Appendix C, I strongly favor the second scenario. Appendix C focuses on the Kailas Formation, exposed ~20 km north of the Liuqu Conglomerate within the India-Asia suture zone. The Kailas Formation is exposed along ~1300 km of the India-Asia suture zone. For this study, I present new sedimentologic, provenance, and geochronologic data for the Kailas Formation. Key findings of this study are that 1) the Kailas Formation is younger in the center of the suture zone, near 90°E, and becomes progressively older to the west; preliminary data suggest that these rocks are older to the east as well, but additional age constraints are required. 2) The pattern of sedimentation documented for the Kailas Formation is nearly identical to the spatio-temporal pattern of adakitic and ultrapotassic rocks in southern Tibet. These rocks have been attributed to rollback and breakoff of the Indian continental slab. Sedimentation within the Kailas basin has also been attributed to rollback of the Indian slab (DeCelles et al. 2011), and this idea is corroborated by the agreement of the sedimentary and magmatic records. 3) This presents an interesting possibility for explaining the existence of low elevations within the India-Asia suture zone at ~20 Ma, as documented in Appendix B. High elevation topography produced by crustal shortening and thickening likely remained intact until slab rollback and breakoff started around 30 Ma and caused the India-Asia suture zone to experience large scale extension and subsidence. The Kailas Formation was deposited in the resulting basin, which opened first in the west, and propagated eastward. After slab breakoff occurred, contractional deformation would have resumed, and the area would have been quickly uplifted to its modern elevations.

This thesis examines how Tibetan residents of different social backgrounds use and experience the space of the city of Lhasa. I mainly concentrate on young Tibetan rural migrants and document a number of similarities and differences between their spatial practices and those of young Tibetans from urban backgrounds. This thesis shows that my rural migrant informants generally gravitate towards the old quarter of the city, where they practise at religious sites, attend informal private schools, and reside in heavily religious and traditionalist domestic spaces. These spatial practices largely distinguish them from young Tibetans from wealthier families (particularly those of government workers) and who have previously lived in inland China: most often these youths frequent sinicised parts of the city, inhabit domestic spaces lacking religious objects, and are either less interested in or banned from engaging in religious practice. Despite these different orientations, however, the ethnography ultimately shows that a clear-cut distinction between villagers and urbanites cannot be drawn. By looking at both the city of Lhasa and nearby rural villages, the thesis shows that neither the former nor the latter are univocally traditionalist or modernising. Furthermore, informants’ practices both persist and change over time and while throughout the fieldwork some young migrant informants continued in their largely traditionalist engagements within Lhasa’s space, others changed their attitudes and started paying less attention to religion and traditionalist pursuits. To do justice to the changing orientations of my informants, I apply a dynamic theoretical model drawn from practice theory whereby practices and predispositions are shown to be resilient, but not fixed. Ultimately, this thesis proposes that, despite the presence of often-distinct orientations between villagers and urbanites in contemporary Lhasa, all young Tibetans in the city share a common socio-political terrain. In Lhasa, traditionalist predispositions persist, but social mobility, government control, and urbanisation also often lead to the development of more practical, secular, and sinicised attitudes.

published_or_final_version / Chinese / Master / Master of Arts

The Yarlung (India-Asia) suture zone in southern Tibet records Middle Jurassic—Late Cretaceous development of the Lhasa terrane (Eurasian) convergent margin and subsequent India-Asia collision beginning in Paleocene time. This dissertation reports data from field-based geologic investigation of the Yarlung suture zone in the Lopu Range and Lazi Regions, ~600 and ~300 km west of the city of Lhasa, respectively. Field data were combined with new geochronology (detrital and igneous zircon U-Pb, garnet Lu-Hf), thermochronology (white mica Ar-Ar and zircon U-Th/He), and metamorphic petrology data to develop a tectonic model involving multiple episodes of shallow underthrusting, rollback, and breakoff of both oceanic and continental lithosphere. Switches between extensional and contractional deformation along the Yarlung suture zone appear to be controlled by changes in subduction dynamics. If this tectonic model is representative, then the tectonic process of inter-continental collision is responsible for much larger magnitudes of crustal recycling that previously thought. A hornblende-plagioclase-epidote paragneiss block in ophiolitic mélange, deposited during Middle Jurassic time, records Late Jurassic or Early Cretaceous subduction initiation along the Eurasian margin followed by Early Cretaceous forearc extension. Detrital zircons from Xigaze forearc basin strata deposited unconformably atop ophiolitic mélange produced a maximum depositional age of 97 ± 1 Ma, providing a minimum age for establishment of an arc-forearc-trench convergent margin along the southern Lhasa terrane. Metasedimentary rocks that were originally deposited along the Indian passive margin were subducted beneath the Lhasa terrane to upper-mantle depths, reaching high-pressure (HP), low-temperature conditions (≥1.4 GPa at T≤600 °C). Garnet Lu-Hf geochronology indicates that prograde metamorphism of the Indian metasedimentary rocks was ongoing at 40.4 ± 1.4 Ma while white mica Ar-Ar thermochronology indicates exhumation to mid-crustal depths between 39-34 Ma. Gangdese arc magmatism persisted after the onset of India-Asia collision, producing plutons that intruded sedimentary-matrix mélange of the southern Lhasa terrane subduction-accretion complex between 49-37 Ma. These data suggest steep subduction or southward trench retreat immediately prior to shutdown of arc magmatism along the Yarlung suture zone (37 Ma), shortly after the onset of high-pressure rock exhumation. We interpret that these data record a Paleocene—Eocene episode of southward rollback, breakoff, and underthrusting. During Oligocene—Miocene time, nonmarine strata were deposited along the Yarlung suture zone immediately prior to shortening across a system of out-of-sequence, top-north reverse faults. Based on our data and previous work, we interpret that sedimentation was driven by a second episode of rollback and breakoff of Indian continental lithosphere, whereas subsequent contractional deformation was driven by renewed shallow subduction. Compilation of regional thermochronological data and interpretation of seismic reflection data from previous investigations suggests that the top-north reverse faults comprise a foreland-dipping passive roof duplex above the leading edge of a structurally deeper, hinterland-dipping duplex beneath the southern Lhasa terrane. The Yarlung suture zone switched from north-south contraction to east-west extension by ~16 Ma based on a crosscutting relationship between a leucogranitic dike and a normal fault related to a larger horst structure in the Lopu Range region. Tectonic exhumation in the footwall block of the horst drove cooling through zircon (U-Th)/He closure temperature (~180 °C) between 12-6 Ma.

Cette thèse est consacrée à l’étude de la question tibétaine et des différents aspects sous lesquels elle est traitée : géographique, économiques, stratégiques et politiques. Nous étudions l’évolution des attitudes et les divergences d’opinion selon une polarisation allant du conservatisme au progressisme. Nous en mesurons les influences dans l’histoire récente et nous projetons les développements probables à court et moyen termes.- Cette thèse s’attache à démontrer que le Tibet reste un enjeu important pour la Chine et qu’à ce titre, la ligne de chemin de fer reliant le Qinghai au Tibet symbolise la politique et la solution chinoise vis-à-vis du Tibet. - Cette thèse s’attache à démontrer que le dalaï-lama est toujours considéré par les tibétains comme la seule instance à même de pouvoir résoudre les problèmes tibétains, et ceci en dépit des nombreuses crises auxquelles le chef spirituel a pu être confronté.- Enfin, cette thèse s’attache à démontrer que la société chinoise est en train d’évoluer vers une attitude plus progressiste. Sur cette question notamment, les intellectuels chinois ont acquis davantage d’influence que par le passé, influence qui pourrait, à l’avenir, se développer davantage. Ce travail, relevant d’un champ d’analyse pluridisciplinaire, couvre l’essentiel du XXème siècle et de l’époque actuelle. Il se focalise particulièrement sur la période postérieure aux années 1980, qui a été le témoin d’une internalisation plus poussée de la question tibétaine. / This thesis focuses on the Tibetan issue in its various aspects: geographic, economic, strategic and political. We examine the evolution of attitudes and differences of opinion according to their polarization ranging from conservatism to progressivism. We assess their influences in recent history and we project the likely developments in the near future.- This thesis aims at showing that Tibet remains an important matter at stake for China. Hence the Qinghai-Tibet rail link embodies the Chinese national policy as well as the Chinese solution vis-à-vis Tibet.- This thesis aims at demonstrating that the Dalai Lama is still regarded by Tibetans as the key to the resolution of Tibetan problems despite the many crises the spiritual leader has had to face.- Finally this thesis aims at pointing out that the Chinese society is evolving towards a more progressive attitude. On this issue Chinese intellectuals have acquired more influence than before and this influence could develop even further in the future. This work belongs to an inter-disciplinary field of study and covers most of the 20th century and present times. It focuses especially on the post 1980’s period when the Tibetan issue became more international.