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1.
T. J. Falloon R. F. Berry P. Robinson A. J. Stolz 《Australian Journal of Earth Sciences》2013,60(4):637-649
The Hili Manu peridotite occupies a key position at the outer limit of continental crust on the north coast of East Timor. Most models for the tectonic evolution of the Outer Banda Arc interpret peridotite bodies on Timor, such as Hili Manu, as fragments of young oceanic lithosphere from the Banda Arc (upper plate). However, recent workers have used major-element geochemistry to argue that the peridotite bodies on Timor were derived from the Australian subcontinental lithosphere. Our major, trace and isotopic geochemical study of the Hili Manu peridotite body supports a supra-subduction origin from either a forearc or backarc position for the Hili Manu peridotite. In particular, the wide range in Nd and Sr isotopic compositions, overlapping that of arc volcanics from the Sunda – Banda Island arc, and highly fractionated Nb/Ta values indicate a supra-subduction setting. As there is no evidence for subduction beneath the rifted Australian continental margin, it is unlikely that the Hili Manu peridotite is Australian subcontinental lithosphere. This result, along with the clear supra-subduction setting of the Ocuzzi peridotite and associated volcanics in West Timor, gives support to the interpretation that the Miocene collision between the Banda Arc and the Australian continental margin has produced widespread ‘Cordilleran’-style ophiolites on Timor. 相似文献
2.
The provenance of Cretaceous sandstones in the Banda Arc islands differs from west to east. Sandstones in Sumba and West Timor contain significant amounts of feldspar (K-feldspar and plagioclase) and lithic fragments, suggesting a recycled to magmatic arc origin. In comparison, East Timor and Tanimbar sandstones are quartz rich, and suggest a recycled origin and/or continental affinity. Heavy mineral assemblages in Sumba and West Timor indicate metamorphic and minor acidic igneous sources and include a mixture of rounded and angular zircon and tourmaline grains. In East Timor, Babar and Tanimbar, an ultimate origin from a mainly acid igneous and minor metamorphic source is interpreted, containing a mixture of rounded and angular zircon and tourmaline grains.Detrital zircon ages in all sandstones range from Archean to Mesozoic, but variations in age populations indicate local differences in source areas. Sumba and West Timor are characterised by zircon age peaks at 80–100 Ma, 200–240 Ma, 550 Ma, 1.2 Ga, 1.5 Ga and 1.8 Ma. East Timor and Tanimbar contain 80–100 Ma, 160–200 Ma, 240–280 Ma, 550 Ma and 1.5 Ga zircon peaks. Most populations are also common in Triassic and Jurassic formations along the Outer Banda Arc and in many other areas of SE Asia. However, the abundance of Jurassic and Cretaceous populations was unexpected. We interpret Cretaceous sandstones from Sumba, Timor and Tanimbar to have been deposited in SE Sundaland. Syn-sedimentary Cretaceous (68–140 Ma) sources are suggested to include the Schwaner Mountains in SW Borneo and Sumba. Material derived mainly from older recycled sediments that had their main sources in the Bird's Head, Western and Central Australia, and local sources close to Timor. 相似文献
3.
M.G. Audley-Charles 《Tectonophysics》1985,119(1-4)
The anomalous updomed morphological expression of Sumba island, its enigmatic lack of strong Neogene deformation and the northward morphological indentation of southern Sumbawa and Flores require explanation.The stratigraphy of Sumba may be correlated with the Cretaceous to Miocene part of the Timor allochthon. The sedimentary and eruptive rock succession in Sumba shows remarkable similarities with the allochthonous Palelo, Wiluba and Cablac deposits of Timor. In both islands the Cretaceous parts of these sequences are regarded as characteristic of fore-arc deposits built on thin continental crust.The Timor nappe is interpreted as a 5 km thick tectonic flake of the Banda fore-arc thrust onto the Australian continental margin in the mid-Pliocene collision. The postulated Sumba nappe has not yet been thrust onto the Australian margin which, in the Sumba region, has not yet converged as close to the arc as in the Timor area. The postulated Sumba nappe is interpreted as a diapiric elongated dome of the Sunda fore-arc that is being squeezed by the converging margin of Australia against the volcanic islands of Sumbawa and Flores.The absence of indications on the seismic reflection profiles for the presence of the thrust fault of the Sumba nappe may perhaps be explained by the thrusts being nearly horizontal within flat-lying strata.The Savu thrust is correlated with the probably older (pre-Late Pliocene) Wetar Suture as a major southward dipping lithospheric rupture. East of 124°E, this suture does not seem to have moved much since the mid-Pliocene collision that emplaced the nappes on Timor. However, microearthquake data suggest some activity is continuing. 相似文献
4.
This paper examines the role of custom and tradition in the process of nation building and resource management in post-independence Timor Leste (East Timor). While customary land tenure is alluded to but not explicitly recognized under the Timorese Constitution, it is clearly stated that all natural resources are owned by the State. However, this paper argues that rather than waiting for the government to create land and resource management related laws, local people in Timor Leste are making and remaking their own laws, mobilizing their customary practices and, increasingly, ‘performing’ their traditions in public demonstrations of their extant capacities. In part, this process can be read as a way of enticing in outsiders, making them a party to the law making process, a witness to its legitimacy. Often critical to such processes, is the ability of local level leaders to draw in outsiders through their engagements with the idea of ‘nature’ – a concept which allows diverse interests to come together in conversation and build relationships despite what is often a dissonance in the meanings and priorities attributed to the concept (see Tsing, A.L., 2005. Friction: An Ethnography of Global Connection. Princeton University Press, Princeton and Oxford). The paper focuses on a view from the margins – Tutuala in the far east of the country – and ways in which this community is attempting to both resist and embrace the developmental hegemony of a centrist state. This, it is argued, is a case which demonstrates the power of the local (both ritually and politically) to shape and intervene in the national development process and the associated discourses of nature preservation. 相似文献
5.
The large block of metamorphic rocks along the north coast of East Timor is of special interest as it occurs at the boundary between continental and oceanic crust in an island arc-continent collision zone. A detailed study of the structure and metamorphic history of 400 km2 of this formation showed it has a complex history of penetrative deformation but the structure is coherent.Pelites, psammites and limestones interlayered with dolerites and amphibolites have been metamorphosed in a medium pressure environment. They now form a metamorphic province zoned from low greenschist facies in the southwest to upper amphibolite facies in the east. The earliest recognised deformation phase predated the metamorphism and produced a widespread layer—parallel schistosity but no recognisable folds. The second deformation phase post-dated the metamorphic maximum and micropetrological evidence indicates a gradual cooling during this event. This deformation produced tight folds with an axial plane schistosity and transposed the earlier structures. The progressively weaker third and fourth phases developed crenulation cleavages and related folds, under greenschist facies conditions. Open, fifth phase, macroscopic folds were probably synchronous with strike slip faulting parallel to the north coast. Later dip slip faulting juxtaposed the Aileu Formation with Permian and Mesozoic sediments of very low metamorphic grade.Reconnaissance K/Ar radiometric dating using hornblende and biotite showed the prograde metamorphic maximum occurred before 11 Ma ago and implies that the second, and strongest, deformation phase occurred in the late Miocene. This young age establishes the relationship of the deformation events to the collision between Australia and the Inner Banda Arc.The proposed models for the structure of Timor must be modified to fit the deformation history of the Aileu Formation. If Timor is essentially autochthonous, the Aileu Formation was probably deposited in a Palaeozoic graben and the metamorphic maximum may have occurred in the Jurassic. The overthrusting models must be modified in the light of the close correlation in time between penetrative deformation and emplacement of the proposed thrust sheets. The analogy proposed between Timor and ‘normal’ convergent margins is not supported but it may be possible to draw analogies with the Molucca Sea. 相似文献
6.
东帝汶国的成矿地质条件较优越,矿产资源较丰富。铬铁矿化在马纳图托省、马努法伊省和包考省有明显的找矿信息,成矿环境受环太平洋成矿带超镁铁质岩带控制。其中位于马纳托图省HiliManu地区的蛇纹石化超基性岩中呈豆荚状产出铬铁矿,Cr2O3含量在36％～51％之间,显示出较好的资源潜力。锰矿化主要分布于包考省、维克克省和马纳图托省,为海相层控型,其中位于马纳托图省Vemasse地区的锰矿床规模较大,品位较高,具有成为中-大型锰矿床的潜力。铜矿化出露于包考省、维克克省、科瓦利马省、马努法伊省、马纳图托省和劳滕省,矿化作用与蛇绿岩套有关,其中位于维克克省Ossu地区的蛇纹岩体,存在与蛇纹石化基性-超基性岩石组合有关的铜／金／银矿化露头,暗示其下可能隐伏着更大的硫化物矿化体。金矿化既有热液脉型,又有浅成低温热液蚀变浸染型,更有河流砂矿型,分布范围广,品位中等到较富,其中马努法伊省Turiscai地区Sue河、Laclo河及Cler河沿岸砂砾层中存在找寻砂金矿的前景,河流上游存在原生金矿的可能。综上所述,东帝汶国具有明显的找矿前景、矿产资源开发潜力和较好的矿业投资环境,建议加大工作力度,把握机会,适时介入。 相似文献
7.
8.
《Quaternary Science Reviews》1999,18(4-5):697-709
Since 1990 archaeological research by the Catholic University of Leuven (Belgium) has been carried out at the ancient site of Sagalassos (Aǧlasun, Burdur province, Southwestern Turkey). At first, research focused on the excavation of the city and the study of the immediate vicinity which provided it with raw materials. The main objective was to obtain a clear picture of the history and development of the city. Since 1993 research has also incorporated a study of the territory of the Roman city, from prehistoric to modern times, in order to understand why the site was selected for settlement, why it developed into a middle-sized town, its economy and subsistence, how it affected and exploited the environment, its decline, and what changes have taken place in the district subsequently. The focus has now shifted towards obtaining a better understanding of the linkages between human and environment systems so that inter-relations between the two can be more readily understood. As a result, a number of environmental topics concerning the territory of the Roman city are presently being studied. This territory extended from Lake Burdur in the West to the Aksu canyon in the East, from the Aǧlasun Daǧlari in the North to Mt. Kestel in the South. Interdisciplinary research revealed that for the early Neolithic and the Roman period there was a slightly warmer climate, a richer vegetation and more fertile soils for agricultural practice. 相似文献
9.
In the north-western Bonaparte Basin (North West Shelf of Australia) Neogene to Recent flexure-induced extension superimposed obliquely over the Mesozoic rift structures. Thus, the area offers a good opportunity to investigate the dynamics and architecture of oblique extension fault systems. Analysis of basin-scale 2D and 3D seismic data along the Vulcan sub-basin shows that Neogene deformation produced a new set of extensional, en échelon faults, at places accompanied by the reactivation of the Mesozoic faults. The pre-existing Mesozoic structures strongly control the distribution of the Neogene-Recent deformation, both at regional and local scales. Main controls on the Neogene-Recent fault style, density and segmentation/linkage include: (1) the orientation of the underlying Mesozoic structures, (2) the obliqueness of the younger extension relative to the rift-inherited faults, and (3) the proximity to the Timor Trough. Three types of vertical relationships have been observed between Mesozoic and Neogene-Recent faults. Hard linkages seems to develop when both fault systems trend parallel, therefore increasing risks for trap integrity. It is suggested that the orientation of maximum horizontal stress (SHmax) relative to the Mesozoic faults, forming hydrocarbon traps, is critical for their potential seal/leak behaviour. Stratigraphic growth across the faults indicates that main fault activity occurred during the Plio-Pleistocene, which corresponds to the timing of tectonic loading on Timor Island and the development of lithospheric flexure. Synchronism of normal faulting with flexural bending suggests that extensional deformation on the descending Australian margin accompanied the formation of the Timor Trough. 相似文献
10.
《Geoforum》2015
The Reduction of Deforestation and Forest Degradation initiative (REDD+) was initially hailed widely as a smart and cost-effective way to mitigate climate change and has moved quickly compared to other strands of the United Nations Framework Convention on Climate Change (UNFCCC) negotiations. Much of the initiative’s original appeal – and a good deal of subsequent controversy around it – relates to framing the world’s tropical forests as carbon sinks and compensating developing countries that manage to reverse or avoid deforestation. REDD+ negotiations can thus be seen a site where the standard divisions between Annex 1 and non-Annex 1 (‘developed’ and ‘developing’) were being challenged and interrogated by the negotiating parties and the broader network of actors around the climate regime. This article suggests that such complex and changing global governance policy fields need to be analysed as ‘places’ in their own right, populated by actors engaged in field-specific power relations that may not reflect international hierarchies or power relations manifested in other international settings. Based in a unique set of interviews supplemented by primary data analysis, this article unpacks the power relations of REDD+ negotiations by examining how those involved seek to assume competence, designate and recognize leadership, and shape outcomes. In tracing the dynamics of claiming competence, the ‘competition’ between two disciplinary milieus around forests as an international policy object and also delegates’ shifting between reliance on expert knowledge and political ‘know-how’ in the negotiations themselves are identified. To understand the politics of recognition – that is to have a claim to competence or position acknowledged by others – the perceived qualities and resources of recognized leadership are examined and the absence of global superpowers amongst REDD+ leadership is problematized and discussed. Finally, in terms of wielding influence over outcomes, the fate of two quite similar ideas – one that has become incorporated into REDD+ methodology and another that is failing to be – further illustrate how the field is marked by internal power practices and that not all actors are equally well-positioned to achieve desired outcomes. 相似文献
11.
An ‘autochthon’ model for the tectonic development of Timor is suggested, based on observations of Palaeozoic‐Mesozoic relationships from a broad area of central East Timor, including:
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(a) ‘allochthonous’ Permian rocks unconformable on metamorphic rocks
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(b) ‘allochthonous’ Permian units interbedded with ‘autochthonous’ Permian units, and
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(c) ‘autochthonous’ Triassic sediments stratigraphically overlying ‘allochthonous’ Permian rocks.
12.
The bathymetry and abrupt changes in earthquake seismicity around the eastern end of the Java Trench suggest it is now blocked south–east of Sumba by the Australian, Jurassic-rifted, continental margin forming the largely submarine Roti–Savu Ridge. Plate reconstructions have demonstrated that from at least 45 Ma the Java Trench continued far to the east of Sumba. From about 12 Ma the eastern part of the Java Trench (called Banda Trench) continued as the active plate boundary, located between what was to become Timor Island, then part of the Australian proximal continental slope, and the Banda Volcanic Arc. This Banda Trench began to be obliterated by continental margin-arc collision between about 3.5 and 2 Ma.The present position of the defunct Banda Trench can be located by use of plate reconstructions, earthquake seismology, deep reflection seismology, DSDP 262 results and geological mapping as being buried under the para-autochthon below the foothills of southern Timor. Locating the former trench guides the location of the apparently missing large southern part of the Banda forearc that was carried over the Australian continental margin during the final stage of the period of subduction of that continental margin that lasted from about 12 Ma to about 3.5 Ma.Tectonic collision is defined and distinguished from subduction and rollback. Collision in the southern part of the Banda Arc was initiated when the overriding forearc basement of the upper plate reached the proximal part of the Australian continental slope of the lower plate, and subduction stopped. Collision is characterised by fold and thrust deformation associated with the development of structurally high decollements. This collision deformed the basement and cover of the forearc accretionary prism of the upper plate with part of the unsubducted Australian cover rock sequences from the lower plate. Together with parts of the forearc basement they now form the exposed Banda orogen. The conversion of the northern flank of the Timor Trough from being the distal part of the Banda forearc accretionary prism, carried over the Australian continental margin, into a foreland basin was initiated by the cessation of subduction and simultaneous onset of collisional tectonics.This reinterpretation of the locked eastern end of the Java Trench proposes that, from its termination south of Sumba to at least as far east as Timor, and probably far beyond, the Java-Banda Trench and forearc overrode the subducting Australian proximal continental slope, locally to within 60 km of the shelf break. Part of the proximal forearc's accretionary prism together with part of the proximal continental slope cover sequence were detached and thrust northwards over the Java-Banda Trench and forearc by up to 80 km along the southwards dipping Savu Thrust and Wetar Suture. These reinterpretations explain the present absence of any discernible subduction ocean trench in the southern Banda Arc and the narrowness of the forearc, reduced to 30 km at Atauro, north of East Timor. 相似文献
13.
《Journal of Asian Earth Sciences》2009,34(5-6):366-378
The Cablac Limestone, widely recorded in Timor, has its type area on Cablac Mountain where it was regarded as a Lower Miocene shallow-marine carbonate-platform succession. The Bahaman-like facies placed in the Cablac Limestone are now known to belong to the Upper Triassic–Lower Jurassic rather than the Lower Miocene. On the northern slopes of Cablac Mountain, a crush breccia, formerly regarded as the basal conglomerate of the formation, is now considered to have developed along a high-angle fault separating Banda Terrane units of Asian affinity from an overthrust limestone stack containing units belonging to the Gondwana and Australian-Margin Megasequences. The Cablac breccia includes rock fragments that were probably derived locally from these tectonostratigraphic units after terrane emplacement and overthrusting. Clasts include peloid and oolitic limestones of the Upper Triassic–Lower Jurassic derived from the Gondwana Megasequence, deep-water carbonate pelagites of the Cretaceous and Paleogene derived from the Australian-Margin Megasequence, Upper Oligocene–Lower Miocene (Te Letter Stage) shallow-water limestone derived from the Banda Terrane, and a younger Neogene calcarenite containing clasts of mixed tectonostratigraphic affinity. There is no evidence for significant sedimentary or tectonic transport of clasts that form the breccia. The clast types and the present understanding of the geological history of Timor suggest that the crush breccia formed late in the Plio-Pleistocene uplift history of Timor. It is not the basal conglomerate of the Cablac Limestone. However, the clasts of an Upper Oligocene–Lower Miocene limestone found in the breccia suggest that a shallow-marine limestone unit of this age either outcrops in the region and has not been detected in the field, or has been eroded completely during late Neogene uplift. The clasts are similar in age and lithology to an Upper Oligocene–Lower Miocene formation that unconformably overlies a metamorphic complex in the Booi region of West Timor, similar to the Lolotoi Metamorphic Complex (Banda Terrane) that is juxtaposed against the crush breccia of Cablac Mountain. The Cablac Limestone at its type area includes a mixed assemblage of carbonate rock units ranging in age from Triassic to Plio-Pleistocene and representing diverse facies. As a formation, the name “Cablac Limestone” should be discarded for a Cenozoic unit. The Upper Oligocene–Lower Miocene shallow-water limestone unit that is typified by outcrops in the Booi region of West Timor, and that has contributed to clasts in the Cablac breccia, is informally named the Booi limestone. It is considered part of the allochthonous Banda Terrane of Asian affinity and represents the only shallow-marine Lower Miocene unit known from Timor. The only other Miocene sedimentary unit known from Timor includes carbonate pelagites – designated the Kolbano beds – probably deposited on an Australian continental terrace at water depths between 1000 and 3000 m. On the northeastern edge of Cablac Mountain, oolitic limestone and associated units of the Gondwana Megasequence, the Kolbano beds of the Australian-Margin Megasequence, and the Booi limestone and associated metasediments of the Banda Terrane were juxtaposed by a Plio-Pleistocene high-angle fault along which the Cablac crush breccia formed. 相似文献
14.
David W. Haig Eujay W. McCartain Myra Keep Logan Barber 《Journal of Asian Earth Sciences》2008,33(5-6):366-378
The Cablac Limestone, widely recorded in Timor, has its type area on Cablac Mountain where it was regarded as a Lower Miocene shallow-marine carbonate-platform succession. The Bahaman-like facies placed in the Cablac Limestone are now known to belong to the Upper Triassic–Lower Jurassic rather than the Lower Miocene. On the northern slopes of Cablac Mountain, a crush breccia, formerly regarded as the basal conglomerate of the formation, is now considered to have developed along a high-angle fault separating Banda Terrane units of Asian affinity from an overthrust limestone stack containing units belonging to the Gondwana and Australian-Margin Megasequences. The Cablac breccia includes rock fragments that were probably derived locally from these tectonostratigraphic units after terrane emplacement and overthrusting. Clasts include peloid and oolitic limestones of the Upper Triassic–Lower Jurassic derived from the Gondwana Megasequence, deep-water carbonate pelagites of the Cretaceous and Paleogene derived from the Australian-Margin Megasequence, Upper Oligocene–Lower Miocene (Te Letter Stage) shallow-water limestone derived from the Banda Terrane, and a younger Neogene calcarenite containing clasts of mixed tectonostratigraphic affinity. There is no evidence for significant sedimentary or tectonic transport of clasts that form the breccia. The clast types and the present understanding of the geological history of Timor suggest that the crush breccia formed late in the Plio-Pleistocene uplift history of Timor. It is not the basal conglomerate of the Cablac Limestone. However, the clasts of an Upper Oligocene–Lower Miocene limestone found in the breccia suggest that a shallow-marine limestone unit of this age either outcrops in the region and has not been detected in the field, or has been eroded completely during late Neogene uplift. The clasts are similar in age and lithology to an Upper Oligocene–Lower Miocene formation that unconformably overlies a metamorphic complex in the Booi region of West Timor, similar to the Lolotoi Metamorphic Complex (Banda Terrane) that is juxtaposed against the crush breccia of Cablac Mountain. The Cablac Limestone at its type area includes a mixed assemblage of carbonate rock units ranging in age from Triassic to Plio-Pleistocene and representing diverse facies. As a formation, the name “Cablac Limestone” should be discarded for a Cenozoic unit. The Upper Oligocene–Lower Miocene shallow-water limestone unit that is typified by outcrops in the Booi region of West Timor, and that has contributed to clasts in the Cablac breccia, is informally named the Booi limestone. It is considered part of the allochthonous Banda Terrane of Asian affinity and represents the only shallow-marine Lower Miocene unit known from Timor. The only other Miocene sedimentary unit known from Timor includes carbonate pelagites – designated the Kolbano beds – probably deposited on an Australian continental terrace at water depths between 1000 and 3000 m. On the northeastern edge of Cablac Mountain, oolitic limestone and associated units of the Gondwana Megasequence, the Kolbano beds of the Australian-Margin Megasequence, and the Booi limestone and associated metasediments of the Banda Terrane were juxtaposed by a Plio-Pleistocene high-angle fault along which the Cablac crush breccia formed. 相似文献
15.
Water resources in the history of the Palestine-Israel conflict 总被引：1，自引：0，他引：1
Basheer K. Nijim Prof. Dr. 《GeoJournal》1990,21(4):317-323
The quest for water resources by Zionist leaders started in the early years of the Zionist movement. Attempts were made to delimit Palestine according to rivers and headwaters. This quest has been independent of the political status of the territory of Palestine. The quest was intense in the early 1950s during the Johnston negotiations, and it became especially crucial after the 1967 occupation by Israel of the rest of Palestine, the West Bank. Lebanon's Litani river has been included in Israeli considerations, as well as the Jordan river's tributary the Yarmuk river. The Kingdom of Jordan's development plans for the latter may be compromised. Control of underground water resources in the West Bank is deemed essential to Israel, given their importance to the ground supply of pre-1967 Israel. Israel is unlikely to relinquish control of the water resources of the West Bank in the event of a political settlement. 相似文献
16.
The metamorphic rocks of Timor are reinterpreted in the light of reconnaissance mapping of the whole island. All metamorphic rocks that crop out in Timor are allochthonous. Several metamorphic massifs are reported for the first time, the outline of others is revised. On the basis of their grade, three distinct groups can be mapped: lustrous slate, amphibolite-serpentinite, and a granulite-amphibolite-greenschist complex. Each group has distinctive structural relations to other allochthonous elements. The granulite facies meta-anorthosite in Timor must have originated near the boundary between the continental mantle and the crust. These and related high-grade metamorphic rocks may represent slices of an ancient Asian continental basement. These rocks imply that the history of the Mesozoic-Cinozoic fold belt of the Outer Banda Arc extends into the Precambrian Era. The metamorphic rocks of Seram appear to be remarkably similar to those of Timor in grade, distribution and structural relations. The overthrust directions of the metamorphic rocks in Timor is southwards, in Seram it is northwards. As the islands are separated by the 4–5 km deep Banda Sea, these directly opposite thrusts may be explained in terms of the Banda Arc acquiring its sinuosity after the emplacement of the metamorphic rocks. 相似文献
17.
The Timor Orogen represents one of the youngest arc–continent collisions exposed on the Earth. It has the potential to provide some of the key parameters about how this style of orogeny evolves. However, the metamorphic age of the highest-grade rocks formed in the collision remains controversial. Using U–Th–Pb dating of monazite from amphibolite-grade sillimanite and garnet-bearing schists we show the peak metamorphism occurred at 5.5–4.7 Ma. The young age of the monazite and the presence of significant amounts of common Pb required the development of a new protocol to simultaneously account for the 230Th disequilibrium and the 207Pb common Pb correction. The new estimate of metamorphic age is consistent with the estimates based on plate reconstructions for the initiation of arc–continent collision in East Timor. The metamorphic event is a result of this collision. 相似文献
18.
D.W. Ellenor 《Sedimentary Geology》1975,13(2):125-152
The microfacies assemblages and their distribution within the Middle Devonian Timor Limestone, exposed in the Timor Valley of northeastern New South Wales, Australia are described, and a depositional model for the carbonate buildup presented.Two broad lithological divisions are clearly recognizable within this thick (345 m) but lensoidal mass. Lime wackestones/packstones dominate the lower 200–215 m of the buildup while lime grainstones characterize the upper 130 m. Using cluster-sorting techniques on 697 modally analysed limestone samples, five microfacies and several subgroups each characterized by a unique combination of allochems have been recognized within this gross subdivision.The microfacies data and field observations suggest that carbonate sedimentation was initiated in an open marine shelf environment. It began simply because local conditions were favourable for calcareous organisms to become established. The benthos flourished ultimately spreading out over an area of 25 km2. Although reefal in outline, the limestone is a bedded deposit containing chiefly comminuted skeletal debris and never had the ecologic potential to form a wave-resistant mass.Lime mud sedimentation began in a sublittoral environment. Abundant calcareous algae throughout most of the lower two-thirds of the buildup suggest that deposition occurred within the photic zone. In succeeding horizons, pellet and intraclast lime grainstones gradually replace the lime mud dominated microfacies, indicating that carbonate deposition slowly outpaced basin subsidence and shoal-water conditions developed over the buildup. During the buildup's final stage, a transgression occurred resulting in quieter marine conditions and the deposition of coral lime wackestones in the former shoal area.Carbonate sedimentation was terminated by an extensive marine tuff killing the calcareous benthos. No further extensive carbonate sedimentation during the Middle Devonian is recorded in the Timor Valley. 相似文献
19.
G. Falah 《GeoJournal》1995,37(1):145-160
The purpose of this paper is to examine the future geopolitics of the Middle East against the backdrop of the Gulf War crisis and its aftermath. Special attention was given to the case of Palestinians and their search for peaceful solution to their territorial conflict with Israel. It is suggested that in an era of a new world order most Middle Eastern governments will give priority to their domestic problems, gearing toward power sharing at home and evolving a certain degree of liberalizations as an attempt to be accommodated within a worldwide sphere of social, economic and political reconciliation. Having overcome the post-Gulf political isolation, the Palestinians are now in a better position to make their claim for self-determination recognized. Ultimately, the fulfilment of such claim is desirable for achieving lasting peace and regional stability. This paper also proposes concrete suggestions for future Palestinian territorial behaviour addressed mainly to the Palestinian government to be considered while they are engaging in peaceful negotiations with Israel. 相似文献
20.
Dominic Fenech 《GeoJournal》1993,31(2):129-140
The onset of modern history in the sixteenth century coincided with the peaking of the Christian-Islamic East-West confrontation in the Mediterranean and, concurrently, a North-South struggle within Europe. The resulting ascendancy of the innovative North resulted in the subjugation of the old Mediterranean power bases and of the whole region. As the Mediterranean slid into underdevelopment, it became in due course the contesting ground of the Great Powers, whose world interests coincided or clashed with regional interests, while more and more of the region's territory fell under external domination. During the cold war era in particular, the Mediterranean returned to be a major theatre of confrontation between the powers of East and West, that contest intersecting with a widening divide between North and South. The end of the East-West contest has exposed the North-South gulf, and its potential for adversity, for what it is. Does the end of one divide promise to help heal the other, or simply to entrench it further? 相似文献