Neoproterozoic stratigraphy of the Southwestern Basement Province, Svalbard (Norway): Constraints on the Proterozoic-Paleozoic evolution of the North Atlantic-Arctic Caledonides
Neoproterozoic stratigraphy of the Southwestern Basement Province, Svalbard (Norway): Constraints on the Proterozoic-Paleozoic evolution of the North Atlantic-Arctic Caledonides
复制标题
DOI：
10.1016/j.precamres.2021.106138
复制
发表时间：
2021-06
影响因子：
3.8
通讯作者：
V. T. Wala;G. Ziemniak;J. Majka;K. Faehnrich;W. McClelland;E. E. Meyer-E.;M. Manecki;J. Bazarnik;J. Strauss
中科院分区：
文献类型：
--
作者：
V. T. Wala;G. Ziemniak;J. Majka;K. Faehnrich;W. McClelland;E. E. Meyer-E.;M. Manecki;J. Bazarnik;J. Strauss
挪威斯瓦尔巴群岛北极群岛在北大西洋和环北极地区寒武纪-泥盆纪加里东造山带的构造重建中发挥着重要作用。为了阐明斯瓦尔巴西南基底省的元古宙地质历史，并将其起源和位移历史置于区域构造-地层事件的背景下，我们提出了新的地质填图，地层分配，碳酸盐碳（δ 13 Ccarb）和锶（87 Sr/86 Sr）同位素化学地层学，和碎屑/火成岩锆石U-Pb年代学与Hf同位素地球化学耦合的新元古代岩石在西南斯匹次卑尔根。所研究的变质沉积岩系列包括托尼奥期混合碳酸盐-硅质岩系列（Nordbukta/Deilegga群），该系列在区域上被低温期（<650 Ma）角度不整合面（Torellian不整合面）截断，其年龄在此通过野外关系和对先前报道的碎屑独居石数据的重新分析得到证实。新的碎屑锆石U-Pb数据从Nordbukta群产量约。1030-1170、1280-1400、1430-1510和1580-1680 Ma年龄的人口是北大西洋的典型人口（例如，格陵兰岛北部和东部、苏格兰和斯堪的纳维亚加里东期）中元古代-新元古代沉积序列。上覆的Sofiebogen，Dunderbukta和Kapp Lyell（Bellsund）组的Cryogenian-Ediacaran地层记录了裂谷相关的沉积和宿主化学地层学数据，这些数据提供了与ca. 640（？）-635 Ma Marinoan snowball地球冰川。Cryogenian Slyngfjellet、Jens Erikfjellet和Konglomeratfjellet地层的碎屑锆石U-Pb数据产生了与下伏Nordbukta群和Deilegga群相似的年龄谱，而Höferpynten和Gåshamna地层的Ediacaran较年轻的地层记录了向双峰约的显著转变。1850和2850 Ma U-Pb年龄群体。将这些数据与先前发表的来自斯瓦尔巴特群岛和其他环北极中-新元古代序列的地球化学和年代学数据集相结合，我们提出西南基底省代表了由多个波罗的海周边地区组成的复合盆地。（韦德尔·雅尔斯贝格-奥斯卡二世，贝采利乌塞格涅-艾姆菲耶莱，和Prins Karls Forland Schools）和佩里-劳伦（Hornsund e）在加里东造山运动期间可能最初并置和/或合并的地壳碎片。这些岩石随后复杂的变形和修改在年轻的泥盆纪石炭纪Ellesmerian和古近纪始新世尤里卡造山事件，影响斯瓦尔巴群岛西部。
The Arctic archipelago of Svalbard, Norway, plays an important role in tectonic reconstructions of the Cambrian–Devonian Caledonian orogen in the North Atlantic and circum-Arctic regions. To elucidate the Proterozoic geological history of the Southwestern Basement Province of Svalbard and place its origin and displacement history in the context of regional tectono-stratigraphic events, we present new geological mapping, stratigraphic assignments, carbonate carbon (δ13Ccarb) and strontium (87Sr/86Sr) isotope chemostratigraphy, and detrital/igneous zircon U-Pb geochronology coupled with Hf isotope geochemistry from Neoproterozoic rocks exposed in southwestern Spitsbergen. The examined metasedimentary successions include a Tonian mixed carbonate-siliciclastic succession (the Nordbukta/Deilegga groups) that is regionally truncated by a Cryogenian (<650 Ma) angular unconformity (the Torellian unconformity), the age of which is confirmed herein by field relationships and re-analysis of previously reported detrital monazite data. New detrital zircon U-Pb data from the Nordbukta Group yield ca. 1030–1170, 1280–1400, 1430–1510, and 1580–1680 Ma age populations that are typical of North Atlantic (e.g., North and East Greenland, Scotland, and the Scandinavian Caledonides) Mesoproterozoic-Neoproterozoic sedimentary successions. Overlying Cryogenian–Ediacaran strata of the Sofiebogen, Dunderbukta, and Kapp Lyell (Bellsund) groups record rift-related sedimentation and host chemostratigraphic data that provide ties to the ca. 640(?)–635 Ma Marinoan snowball Earth glaciation. Detrital zircon U-Pb data from the Cryogenian Slyngfjellet, Jens Erikfjellet, and Konglomeratfjellet formations yield similar age spectra to the underlying Nordbukta and Deilegga groups, while younger Ediacaran strata of the Höferpynten and Gåshamna formations record a prominent shift to bimodal ca. 1850 and 2850 Ma U-Pb age populations. Integrating these data with previously published geochemical and geochronological datasets from Svalbard and other circum-Arctic Mesoproterozoic–Neoproterozoic successions, we propose that the Southwestern Basement Province represents a composite terrane composed of multiple peri-Baltican (Wedel Jarlsberg-Oscar II, Berzeliuseggene-Eimfjellet, and Prins Karls Forland terranes) and peri-Laurentian (Hornsund terrane) crustal fragments that were likely initially juxtaposed and/or amalgamated during the Caledonian orogeny. These terranes were subsequently complexly deformed and modified during the younger Devonian-Carboniferous Ellesmerian and Paleogene-Eocene Eurekan orogenic events that affected western Svalbard.