Showing papers in "Precambrian Research in 2000"

TL;DR: The Central Zone of the North China Craton is divisible into low-to medium-grade granite-greenstone belts and high-grade metamorphic terrains containing reworked Archean material and late Archean to Paleoproterozoic juvenile igneous and sedimentary rocks which developed in intra-continental magmatic arc and intra-arc basin environments as discussed by the authors.

TL;DR: In this article, the results of field, geochronologic, geochemical and isotopic studies are presented for the granitoids that occur east of the Closepet batholith up to the Kolar schist belt (KSB).

TL;DR: In this article, the authors show that the last major Neoproterozoic rift phase associated with the Sturtian glaciation at ∼700 ǫ million years ago can be interpreted as the initiation of continental separation.

TL;DR: The Dharwar craton comprises two distinct parts separated by a steep N−S sinistral shear zone as discussed by the authors, which is characterised by NE−SW crustal shortening and steep N-S or NW−SE linear belts of calcalkaline, anatectic and juvenile granites and granodiorites.

TL;DR: In this article, the authors analyzed the Lakhanda Group of Late Mezoproterozoic age (1050-1000 Ma) from the southeastern Siberian craton in Russia for major elements and a number of trace elements, including the REE's.

TL;DR: In this paper, a time scale for the Neoproterozoic interval from isotopic variation of δ13C and δ34Ssulfate in seawater measured from reference columns in Canada and Australia was constructed.

TL;DR: In this article, the authors employed integrated U-Pb geochronology and palaeomagnetic studies of the Mundine Well dyke swarm (MDS) of the Pilbara Craton, Western Australia, to test the hypothesis that Australia and Laurentia were joined as part of the Rodinia supercontinent.

TL;DR: In this paper, a high resolution δ13C-chemostratigraphic framework for the type Ediacarian (terminal Proterozoic) section in the Adelaide Rift Complex, a framework that contributes to the emerging global chronostrigraphic synthesis of a period that saw momentous changes in the Earth's surface environment.

TL;DR: The existence of a two-stage history is confirmed by the discovery of 1321±24 Ma detrital zircons and 1154±15 Ma metamorphic rutiles in metasedimentary rocks from Mount Ragged.

TL;DR: Nine years of intensive, multidisciplinary research by scientists from some two dozen countries have markedly improved the framework for the correlation and calibration of latest Proterozoic events, providing a rational basis for choosing the Global Stratotype Section and Point (GSSP) that will define the beginning of this period.

TL;DR: In this paper, the authors divided density currents fed directly from subaqueous eruptions into three groups based on modes of fragmentation and transport: (i) explosive fragmentation, with deposition from a gas-supported current; (ii) explosive fragmentation, and (iii) fragmentation of flowing lava.

TL;DR: The Dabieshan area between the Sino-Korean and Yangtze cratons in east-central China has become the focus of much recent attention because of the discovery of abundant coesite and rare micro-diamond inclusions in both eclogites and their enclosing country rocks as mentioned in this paper.

TL;DR: In this article, detrital zircon ages were obtained from six samples of Neoproterozoic and Lower Palaeozoic sedimentary and volcanosedimentary rocks from NW Iberia using the LAM-ICP-MS method.

TL;DR: Ion microprobe dating of structurally constrained felsic intrusives indicate that the rocks of the northern Prince Charles Mountains (nPCMs) were deformed during a single, long-lived Neoproterozoic tectonic event as mentioned in this paper.

TL;DR: U-Pb monazite and zircon ages reveal that the high pressure granulites from eastern Tanzania were metamorphosed during a Pan-African tectonothermal episode, and indicate that peak metamorphic conditions were diachronous in different granulite domains.

TL;DR: In this paper, single zircon dating of the Rampur metabasalts of the Larji-Kullu-Rampur window in the Lesser Himalayas yielded an evaporation age of 1800±13 Ma.

TL;DR: Fossils of the Ediacara biota are confined to preservational windows in the Rawnsley Quartzite (Pound Subgroup) from the Flinders Ranges, South Australia as mentioned in this paper.

TL;DR: Zhang et al. as discussed by the authors reported new paleomagnetic results, obtained independently by two separate laboratories, from a total of 157 samples of the 748±12 Ma, basal Sinian Liantuo Formation at its type locality.

TL;DR: In this paper, the authors examined the thermo-mechanical evolution of the lower crust, in Precambrian times, with an example from southern Madagascar, derived from the study of satellite images complemented by field structural analysis.

TL;DR: The Aravalli Delhi Mobile Belt (ADMB) as mentioned in this paper is a Proterozoic region with several dipping reflections and suggests a thick crust (45-46 km) and a high density (3.04 g cm−3) dome-shaped body in lower crust.

TL;DR: The anti-Atlas suture zone of southern Morocco has presented an enigma in this reconstruction as the inferred subduction zone polarity and age of suturing appear to be incongruous with better known West African orogens to the west (Mauretanian, Bassaride and Rokelide) and Transaharan orogenic belts to the east (Ougarta, Tuareg, Gourma and Dahomeyan) as mentioned in this paper.

TL;DR: In this article, the Sturtian glaciation was followed by a rise in δ34Ssulfide to an average of +30‰ (see also in China, Namibia and Canada).

TL;DR: In this article, geochemical and isotopic results are reported for late Paleoproterozoic mafic amphibolites from SW Zhejiang and NW Fujian, parts of the Cathaysia Block of SE China.

TL;DR: In this paper, four basin evolution stages are recognized (prerift, rift, transitional and flexural), represented by six unconformity-bounded tectonosequences.

TL;DR: In this paper, a study of the Neoproterozoic Borborema Province (BP) in northeastern Brazil is presented, which is characterized by a regional flat-lying foliation and by abundant magmatic rocks commonly spatially associated with large transcurrent shear zones.

TL;DR: In this paper, a correlation was made between the mid-Neoproterozoic δ 13 C carb values of 7.2 and 8.5 in Australia, Canada, Namibia and Spitsbergen.

TL;DR: The Loraboue Birimian ultramafic-mafic assemblage, located in the Boromo greenstone belt (Burkina Faso), is interpreted as the remains of a magma chamber that crystallized at the base of an island arc.

TL;DR: Palaeoproterozoic high-K I-type granites, high-level porphyry intrusions, and felsic volcanic rocks of the Whitewater Volcanics dominate the Hooper and Lamboo Complexes in the Kimberley region of northwestern Australia as mentioned in this paper.

TL;DR: The granitoids of Marajoara in the Rio Maria terrain (Carajas Mineral Province, Brazil) consist of: (i) a broad unit of 2.96 Ga syntectonic tonalites (Arco Verde Tonalites) displaying a trondhjemitic differentiation trend; (ii) 2.93 Ga post-tectonic monzogranites (Guaranta) and granodiorites (Rio Maria), displaying a calc-alkaline differentiation trend.

TL;DR: In this paper, carbon and oxygen isotope data on carbonates along three profiles of the Neoproterozoic Bambui group in central Brazil were presented, showing that the high carbon isotope values observed in limestones and marlstones from the Bama group are correlated to worldwide high carbon values reported for the Neo-terrestrial.