geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Early Proterozoic collisional granites and shear zones as markers of the Siberian Craton reconstruction


, : Early Proterozoic collisional granites and shear zones as markers of the Siberian Craton reconstruction. Abstracts with Programs - Geological Society of America 31(7): 205

Paleoproterozoic granites, monzogranites and syenites are localized along shear zones and formed by partial melting of tectonites (blasto-mylonites, biotite-hornblende gneisses) in those zones. This granite system is important for understanding the Laurentia-Siberia connection. Sm-Nd isotopic studies and U-Pb zircon dating, including SHRIMP, were used for basement rocks cropping out in the Anabar Shield and the Olenek Uplift. Investigations of drill cores and crustal xenoliths in kimberlites, together with interpretation of potential field data, were also used where sedimentary basins cover basement. The NE Siberian craton formed in the Late Paleoproterozoic (2.0-1.8 Ga) by amalgamation of Archean microcontinents along collisional shear zones. Juvenile crust of the Magan and Daldyn granulite terranes in the Anabar shield separated from depleted mantle at 3.0 Ga (TDM); that of the Birekte and Markha granite-greenstone terranes at 2.5-2.4 Ga (TDM). Volcanic-sedimentary sequences formed at 2.4 Ga upon the Magan terrane (U-Pb zircon) and 2.1 Ga upon the Birekte terrane (U-Pb zircon and TDM). The Kotuykan and Billyakh collisional shear zones of the Anabar shield evolved through at least two stages, like Phanerozoic systems (Himalaya, Caucasus, etc.); the first stage at 1.9 Ga and the second at 1.8 Ga. Granite melting and metamorphism inside shear zones (U-Pb zircon) was accompanied by coeval granulite metamorphism (Sm-Nd mineral isochrons) in nearby terranes. A homogeneous field of high temperatures and pressures was evidently widespread inside thickened crust that was under the terranes. As a whole, such an association of granite melting, shear zones, and ancient terranes is indicative of the deep roots of a continental-collision orogen. Invasion of juvenile material into the crust during Late Paleoproterozoic collision is absent except in rare cases (TDM data).

US$29.90


Other references

Vergnes, H.; Grozdea, J.; Denier, C.; Bourrouillou, G.; Calvas, P.; D.L.F.rge, F.; Valdiguie, P.; Calot, M., 2000: Lower alkaline phosphatase activity and occurrence of an abnormal hybrid intestinal/tissue non-specific isoform in Down's syndrome amniotic fluids. Quantitative and qualitative analysis of alkaline phosphatases (AP) was performed on amniotic fluid in 59 normal pregnancies and 14 Down's syndrome (DS) pregnancies at 16, 18 and 19 weeks of gestation. In DS cases, intestinal and placental is...

Krivisky, K.; Einat, H.; Kronfeld-Schor, N., 2013: Effects of morning compared with evening bright light administration to ameliorate short-photoperiod induced depression- and anxiety-like behaviors in a diurnal rodent model. The lack of appropriate animal models for affective disorders is a major factor hindering better understanding of the underlying pathologies and the development of more efficacious treatments. Because circadian rhythms play an important role in af...

Neumann, P.; Hepburn, H.R.; Radloff, S.E., 2000: Modes of worker reproduction, reproductive dominance and brood cell construction in queenless honeybee (Apis mellifera L.) colonies. Colonies of A. m. capensis, A. m. scutellata and their natural hybrids were dequeened and debrooded. The ratio of worker/drone cell construction and the sex of laying worker offspring were determined for 26 colonies. All A. m. capensis laying work...

Ishii, H.; Harada, K.I.; Ishida, T.; Deushi, T.; Masuda, T.; Sakamoto, M.; Ichikawa, Y.I.; Takahashi, T.; Ishikawa, M.; Ishikawa, T., 1984: Studies on the chemical constituents of rutaceous plants 54. the development of a versatile method for the synthesis of antitumor active benzo c phenanthridine alkaloids 4. limitation of bischler napieralski cyclization and detailed examination of the dehydrogenation of the bischler napieralski products in the robinson synthetic pathway for benzo c phenanthridine alkaloids. In order to establish a versatile method for the preparation of antitumor benzo[c]phenanthridine alkaloids, the reaction steps from the 2-aryl-1-formamido-1,2,3,4-tetrahydronaphthalene (2) to the fully aromatized benzo[c]phenanthridine derivatives...

Kleinfeld M.; Stein E., 1968: Effects of di phenyl hydantoin cardio vasc on action potentials of canine purkinje and ventricular fibers abstract. Circulation 38(4 SUPPL 6): VI-116

Livingston, M.G., 1990: Rehabilitation in neuropsychiatry. Patients with neuropsychiatric disorders may present with multiple functional deficits. A rehabilitation approach tends to focus on problems presented and involve multidisciplinary assessment and therapeutic programmes. Ideally the programme shoul...

Warner, K.J.; Cuschieri, J.; Copass, M.K.; Jurkovich, G.J.; Bulger, E.M., 2007: The impact of prehospital ventilation on outcome after severe traumatic brain injury. Background: Prehospital intubation has been challenged on the grounds that it predisposes to hyperventilation, which is detrimental after traumatic brain injury (TBI), and impairs venous return in patients with hypovolemia. We sought to determine...

Oxley, D.; Wilkinson, S.G., 1988: Structural studies of an acidic galactomannan from the reference strain for Serratia marcescens serogroup O4. An acidic, partially acetylated galactomannan has been isolated from the lipopolysaccharide of the reference strain (C.D.C. 864-57) for Serratia marcescens serogroup O4. From the results of methylation analysis, Smith degradations, and n.m.r. spec...

Mathew, N.T., 2005: Efficacy and tolerability of almotriptan in controlled clinical trials. Seven triptans are now available for the acute treatment of migraine. While all of these agents have been shown to be safe and more or less well tolerated, they differ in ways that are clinically relevant to individual patients. Almotriptan has be...

Posselt, Adolf., 1906: Die Stellung des Alveolarechinokokkus. Muenchener Medizinische Wochenschrift, 53 537-541, 605-609