Lower Pleistocene deltaic and marine sediments in boreholes from the central North Sea
Lower Pleistocene deltaic and marine sediments in boreholes from the central North Sea
复制标题
北海中部钻孔中的下更新世三角洲和海洋沉积物
DOI：
10.1002/jqs.3390020202
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发表时间：
1987
影响因子：
2.3
通讯作者：
A. Bent
中科院分区：
文献类型：
--
作者：
M. Stoker;A. Bent
在北海中部阿伯丁地层钻孔中发现的下更新世沉积物表明，该单元沉积于三角洲前缘至前三角洲/浅层、开放陆架海相环境。在盆地西缘发现了可能的河口和碎屑近岸海相沉积。三角洲前缘沉积物为互层状、无构造至层状砂泥，含有机碎屑、含铁结核和常见的软沉积变形构造。零星的波纹层和渐变层，基底冲刷层和饥饿的波纹表明周期性的波流改造。前三角洲/陆架海相沉积物以泥质为主，偶有薄砂层和罕见的磷带。一个特别厚的砂体或海底河道填充物，尽管这仍不确定。河口/碎屑近岸海相沉积物包括粗质河道滞后沉积物和波纹层状潮下砂。从前三角洲/陆架海相层序中恢复的丰富微化石组合表明沉积发生在波动的气候条件下。
Lower Pleistocene sediments recovered in boreholes from the Aberdeen Ground Formation in the central North Sea indicate that the unit was deposited in a delta front to prodelta/shallow, open shelf marine setting. Possible estuarine and clastic nearshore marine deposits have been identified on the western margin of the basin. The delta front sediments consist of interbedded, structureless to laminated sands and muds with organic debris, ferruginous nodules and common soft sediment deformation structures. Sporadic rippled and graded beds, basal scours to beds and starved ripples suggest periodic wave–current reworking. Prodelta/shelf marine sediments are predominantly argillaceous with only occasional thin sand beds and rare phosphatic bands. One exceptionally thick sand body or submarine channel-fill although this remains uncertain. The estuarine/clastic nearshore marine sediments include coarse channel-lag deposits and rippled and laminated subtidal sands. A rich microfossil assemblage recovered from the prodelta/shelf marine sequence indicates that deposition occurred under fluctuating climatic conditions.