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Jurassic - Early Cretaceous paleogeography and paleoenvironments of the north-eastern margin of Gondwana: insights from the Carpentaria Basin, Australia
Gondwana Research ( IF 6.1 ) Pub Date : 2020-12-01 , DOI: 10.1016/j.gr.2020.07.003
Elliot K. Foley , Mason Baty , Espen M. Knutsen , John S. Lignum , Eric M. Roberts

Abstract Although Jurassic-Early Cretaceous sedimentary systems were extensively developed on northeastern Gondwana, deciphering their paleogeography has been complicated by poor exposure and the lack of a robust chronostratigraphic framework. The southeastern margin of the Carpentaria Basin, northeastern Australia is one of the few regions where these sedimentary systems are extensively exposed. Employing a combination of facies analysis and new data from paleontology and detrital zircon geochronology, we present a temporally and environmentally refined paleogeographic framework for this region. A Late Jurassic, southeasterly directed marine incursion invaded northeastern Gondwana, extending inland across the Carpentaria Basin, as demonstrated by a thin (~ 30 m), marine influenced (fluvio-estuarine) stratigraphic succession capped by a sequence bounding ~30 myr paraconformity. The depositional hiatus marked the Late Jurassic-Early Cretaceous uplift of the Euroka Arch, with loss of sedimentary and fluvial connectivity between the Carpentaria Basin and adjoining Eromanga Basin. Subsequent deposition by low-accommodation fluvial systems resulted in a thin, fluviatile depositional package developing during the Early Cretaceous. Paleocurrent and provenance data indicate that the Middle to Late Jurassic (c. 170-160 Ma) fluvial systems predating the paraconformity extended from the Eromanga Basin to the south across the southeastern Carpentaria Basin, transporting sediment from distal sources in the Lachlan Orogen of southeastern Australia. Fluvial systems of the southeastern Carpentaria Basin post-dating the paraconformity and Euroka Arch uplift show a provenance shift to easterly sources in the Mossman Orogen and Kennedy Igneous Association. Previously unrecognized Jurassic-Early Cretaceous igneous activity provided a persistent source of sediment to the southeastern Carpentaria Basin succession due to reworking of air fall tuff from an active magmatic arc located on the continental margin of northeastern Gondwana.

中文翻译:

侏罗纪 - 冈瓦纳大陆东北缘早白垩世古地理和古环境:来自澳大利亚卡奔塔利亚盆地的见解

摘要 虽然侏罗纪-早白垩世沉积系统在冈瓦纳大陆东北部广泛发育,但由于暴露不良和缺乏可靠的年代地层框架,破译其古地理变得复杂。澳大利亚东北部卡奔塔利亚盆地的东南边缘是为数不多的这些沉积系统广泛暴露的地区之一。结合相分析和古生物学和碎屑锆石年代学的新数据,我们为该地区提供了一个时间和环境完善的古地理框架。侏罗纪晚期,东南方向的海洋入侵侵入冈瓦纳大陆东北部,向内陆延伸穿过卡奔塔利亚盆地,如薄(~30 m),受海洋影响的(河流-河口)地层序列被一个约 30 米的准整合性层序覆盖。沉积间断标志着 Euroka 拱门的晚侏罗世-早白垩世隆起,失去了 Carpentaria 盆地和毗邻的 Eromanga 盆地之间的沉积和河流连通性。随后低调节河流系统的沉积导致在早白垩世期间形成薄的、河流沉积的沉积包。古流和物源数据表明,早于准整合性的中至晚侏罗世(约 170-160 Ma)河流系统从 Eromanga 盆地向南延伸穿过 Carpentaria 盆地东南部,从澳大利亚东南部的 Lachlan 造山带的远端来源输送沉积物. Carpentaria 盆地东南部的河流系统在次整合和 Euroka Arch 隆起之后显示了 Mossman Orogen 和 Kennedy Igneous Association 向东源的物源转移。由于来自冈瓦纳东北部大陆边缘的活动岩浆弧的空气坠落凝灰岩的再加工,以前未被认识的侏罗纪-早白垩世火成岩活动为卡奔塔利亚盆地东南部序列提供了持续的沉积物来源。
更新日期:2020-12-01
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