Terrane

About: Terrane is a research topic. Over the lifetime, 11025 publications have been published within this topic receiving 442596 citations. The topic is also known as: tectonostratigraphic terrane.

Provenance comparisons of Permian to Jurassic tectonostratigraphic terranes in New Zealand: perspectives from detrital zircon age patterns

Abstract: U–Pb detrital zircon ages (LAM-ICPMS) are reported for 20 greywackes and sandstones from seven major tectono-stratigraphic terranes of the Eastern Province of New Zealand (Cretaceous to Carboniferous) to constrain sediment provenances Samples are mainly from three time horizons: Late Permian, Late Triassic and Late Jurassic Age datasets are analysed as percentages in geological intervals, and in histogram and cumulative probability diagrams The latter discriminate significant zircon age components in terms of terrane, sample stratigraphic age, component age, precision and percentage (of total set) Zircon age distributions from all samples have persistent, large Triassic–Permian, and very few Devonian–Silurian, populations, features which exclude a sediment provenance from the early Palaeozoic, Lachlan Fold Belt of southeast Australia or continuations in New Zealand and Antarctica In the accretionary terranes, significant Palaeozoic (and Precambrian) zircon age populations are present in Torlesse and Waipapa terranes, and variably in Caples terrane In the fore-arc and back-arc terranes, a unimodal character persists in Murihiku and Brook Street terranes, while Dun Mountain–Maitai terrane is more variable, and with Caples terrane, displays a hybrid character Required extensive Triassic–Permian zircon sources can only be found within the New England Fold Belt and Hodgkinson Province of northeast Australia, and southward continuations to Dampier Ridge, Lord Howe Rise and West Norfolk Ridge (Tasman Sea) Small but significant Palaeozoic (and Precambrian) age components in the accretionary terranes (plus Dun Mountain–Maitai terrane), have sources in hinterlands of the New England Fold Belt, in particular to mid-Palaeozoic granite complexes in NE Queensland, and Carboniferous granite complexes in NE New South Wales Major and minor components place sources (1) for the older Torlesse (Rakaia) terrane, in NE Queensland, and (2) for Waipapa terrane, in NE New South Wales, with Dun Mountain–Maitai and Caples terrane sources more inshore and offshore, respectively In Early Jurassic–Late Cretaceous, Torlesse (Pahau) and Waipapa terranes, there is less continental influence, and more isolated, offshore volcanic arc sources are suggested There is local input of plutonic rock detritus into Pahau depocentres from the Median Batholith in New Zealand, or its northward continuation on Lord Howe Rise Excepting Murihiku and Brook Street terranes, all others are suspect terranes, with depocentres close to the contemporary Gondwanaland margin in NE Australia, and subsequent margin-parallel, tectonic transport to their present New Zealand position This is highlighted by a slight southeastward migration of terrane depocentres with time Murihiku and Brook Street terrane sources are more remote from continental influences and represent isolated offshore volcanic depocentres, perhaps in their present New Zealand position

Palaeozoic pre- and post-collision calc-alkaline magmatism in the Qinling orogenic belt, central China, as documented by zircon ages on granitoid rocks

Abstract: Based on large-scale reconnaissance mapping, we identified two calc-alkaline plutonic assemblages from the northern Qinling orogenic belt. central China. The older assemblage of intrusions. closely associated and deformed coevally with their host volcanic arc sequences, seems to represent the fractionation product of basaltic arc magma. It therefore predates the collision of the North China Block with the Central Qinling island-arc system that developed in a SW Pacific-type oceanic domain south of the North China Block. Single-zircon 207Pb/206Pb evaporation dating yielded early to middle Ordovician ages for this assemblage. with a relatively small range from 487.2 ± 1.1 to 470.2 ± 1.3 Ma. Intrusions of the younger assemblage are largely undeformed and truncate structures shown in rocks of the older assemblage. They are interpreted as post-collisional calc-alkaline granitoids. Single zircon dating provided an age of 401.8 ± 0.8 Ma for the younger assemblage. consistent with earlier work that defines an age range from c. 420 to 395 Ma. Our data favour a tectonic model involving formation and amalgamation of island arc and microcontinent terranes between ca. 490 and 470 Ma ago to create the Central Qinling Zone which subsequently collided with the North China Block prior to c. 400 Ma ago. A late Precambrian age of 762.0 ± 0.7 Ma for a granitoid gneiss at the northern margin of the Yangtze Block supports a Gondwana affinity for this large continental block.

Growth, stabilization, and reactivation of Proterozoic lithosphere in the southwestern United States

Abstract: Growth of Proterozoic continental lithosphere in the southwestern United States involved assembly of tectonostratigraphic terranes during several pulses of convergent tectonism ca. 1.74, 1.70, and 1.65-1.60 Ga. Prograde metamorphism accompanied orogenic assembly, and peak metamorphic conditions outlasted deformation. Regions now characterized by the highest metamorphic grades underwent slow isobaric cooling and were not uplifted until more than 200 m.y. after assembly. Regions of low metamorphic grade were not uplifted substantially after assembly. We suggest that (1) relatively thin lithospheric fragments were assembled into isostatically stable, "normal" thickness continental lithosphere; (2) assembly did not erase lithospheric-scale heterogeneities; (3) the present juxtaposition of different crustal levels reflects differential uplift related to 1.4-1.1 Ga tectonomagmatic activity; and (4) the boundaries between different lithospheric blocks were repeatedly reactivated from Precambrian through Tertiary time.