Xigaze forearc basin revisited (South Tibet): Provenance changes and origin of the Xigaze Ophiolite
Xigaze forearc basin revisited (South Tibet): Provenance changes and origin of the Xigaze Ophiolite
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再访日喀则弧前盆地（藏南）：日喀则蛇绿岩的物源变化与成因
DOI：
10.1130/b31020.1
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发表时间：
2014-11
影响因子：
4.9
通讯作者：
Sun, Gaoyuan
中科院分区：
文献类型：
--
作者：
Garzanti, Eduardo;BouDagher-Fadel, Marcelle K.;Wang, Jiangang;Sun, Gaoyuan
我们新的地层学，沉积学和微体古生物学分析，结合玄武岩地球化学，砂岩岩相学，和碎屑锆石U-Pb和Hf同位素数据，建议修改目前的亚洲活动边缘在白垩纪的地质演化模型。日喀则弧前盆地形成于冈底斯弧以南的早白垩世晚期，是新特提斯洋岩石圈向拉萨造山带俯冲的初始阶段。保存完好的地层序列记录了典型的弧前盆地地层向上变浅的模式，并阐明了相关的大洋岩浆岩的起源。正常地幔脊玄武岩（N-MORB）地球化学特征及与上覆深海硅质岩（冲堆组）的地层接触关系表明，日喀则蛇绿岩是弧前扩张形成的，代表了弧前沉积序列的基底。火山岩沉积开始于阿尔比安-桑顿晚期（Ngamring组）的厚浊积砂岩和互层页岩，随后是陆棚、三角洲和冲积层（Padana组），最后在坎帕尼亚期填充盆地。弧前砂岩没有表现出典型的从闪长石质火山岩到石英-闪长石质深成岩成分的变化趋势，表明冈底斯弧在碰撞前的去顶作用有限。碎屑锆石U-Pb年龄谱为单峰型（104-99 Ma），在昂坪组下部（107 Ma）有一个峰值;双峰型（99 ~ 88 Ma），在昂坪组中部（157 Ma）有一个次级峰值;这三种具有不同物源的岩相记录了冈底斯弧的渐进侵蚀演化，其中拉萨地体中部在晚白垩世期间隆升，河流集水区扩大到包括拉萨地体中部。
Our new stratigraphic, sedimentological, and micropaleontological analysis, integrated with basalt geochemistry, sandstone petrography, and detrital-zircon U-Pb and Hf isotope data, suggests the revision of current models for the geological evolution of the Asian active margin during the Cretaceous. The Xigaze forearc basin began to form in the late Early Cretaceous, south of the Gangdese arc, during the initial subduction of the Neotethyan oceanic lithosphere under the Lhasa terrane. Well-preserved stratigraphic successions document the classical upwardshallowing pattern of the forearc-basin strata and elucidate the origin of the associated oceanic magmatic rocks. The normal midocean-ridge basalt (N-MORB) geochemical signature and stratigraphic contact with the overlying abyssal cherts (Chongdui Formation) indicate that the Xigaze Ophiolite formed by forearc spreading and represents the basement of the forearc sedimentary sequence. Volcaniclastic sedimentation began with thick turbiditic sandstones and interbedded shales in the late Albian–Santonian (Ngamring Formation) followed by shelfal, deltaic, and fl uvial strata (Padana Formation), with fi nal fi lling of the basin by the Campanian age. Forearc sandstones do not show the classical trend from feldspatholithic volcaniclastic to quartzo-feldspathic plutoniclastic compositions, indicating limited unroofi ng of the Gangdese arc prior to collision. U-Pb age spectra of detrital zircons are unimodal with a 107 Ma peak in the lower Ngamring Formation (104–99 Ma), bimodal with a subordinate additional peak at 157 Ma in the middle Ngamring Formation (99– 88 Ma), and multimodal with more abundant pre-Mesozoic ages in the upper Ngamring and Padana Formations (88–76 Ma). These three petrofacies with distinct provenances document the progressive erosional evolution of the Gangdese arc, with uplift of the central Lhasa terrane and expanding river catchments to include the central Lhasa terrane during the Late Cretaceous.
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影响因子：
2.9
作者：
J. Girardeau;J. Mercier;Z. Yougong
通讯作者：
J. Girardeau;J. Mercier;Z. Yougong
DOI：
10.1007/978-3-662-03237-4
发表时间：
2006
期刊：
--
影响因子：
--
作者：
A. Miall
通讯作者：
A. Miall
影响因子：
2.7
作者：
S. Ziabrev;J. Aitchison;A. Abrajevitch;Badengzhu;Aileen M. Davis;Hui Luo
通讯作者：
S. Ziabrev;J. Aitchison;A. Abrajevitch;Badengzhu;Aileen M. Davis;Hui Luo
影响因子：
2.7
作者：
S. Ziabrev;J. Aitchison;A. Abrajevitch;Badengzhu;Aileen M. Davis;Hui Luo
通讯作者：
S. Ziabrev;J. Aitchison;A. Abrajevitch;Badengzhu;Aileen M. Davis;Hui Luo
影响因子：
3.5
作者：
S. Whattam;R. Stern
通讯作者：
S. Whattam;R. Stern