The following chemostratigraphy study was conducted on Paleozoic sediments encountered in 14 wells in eastern Saudi Arabia. A total of 1500 samples were analysed by inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS), with data acquired for 48 elements, ranging from Na to U in the periodic table. The aim was to utilize chemostratigraphy, in conjunction with existing biostratigraphic, lithostratigraphic and sedimentological data, to define the Hercynian Unconformity in each well and to recognize stratigraphic boundaries occurring above and below it. This was necessary as the unconformity eroded to different stratigraphic levels in each well, with Devonian, Silurian and Ordovician sediments found immediately below it in adjacent locations. In the absence of chemostratigraphic, biostratigraphic and sedimentological data, it is often very difficult to define this boundary and others using lithostratigraphy alone as many stratigraphic intervals yield similar gamma-ray (GR) log trends. For example, a low ‘blocky’ GR response is typical of both the Carboniferous Ghazal Member and the Ordovician Sarah Formation. Similarly, both the Silurian Sharawra Member and the Silurian–Devonian Tawil Formation produce a ‘ratty’ GR trend. Each stratigraphic member and formation was found to have distinctive chemostratigraphic, biostratigraphic, sedimentological and/or wireline log signatures.

中文翻译：

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使用化学地层学结合生物地层学、沉积学和岩石地层学定义沙特阿拉伯东部的海西不整合面

以下化学地层学研究是对沙特阿拉伯东部 14 口井中遇到的古生代沉积物进行的。通过电感耦合等离子体发射光谱法 (ICP-OES) 和电感耦合等离子体质谱法 (ICP-MS) 分析了总共 1500 个样品，获得了元素周期表中从 Na 到 U 的 48 种元素的数据。目的是利用化学地层学，结合现有的生物地层学、岩石地层学和沉积学数据，确定每口井中的海西不整合面，并识别其上方和下方的地层边界。这是必要的，因为不整合面在每口井中被侵蚀到不同的地层水平，在其下方的相邻位置发现了泥盆纪、志留纪和奥陶纪沉积物。在没有化学地层学的情况下，生物地层学和沉积学数据，通常很难单独使用岩石地层学来定义这个边界和其他边界，因为许多地层间隔产生类似的伽马射线 (GR) 测井趋势。例如，低“块状”GR 响应是石炭纪 Ghazal 段和奥陶纪 Sarah 地层的典型特征。类似地，志留系 Sharawra 段和志留系-泥盆系 Tawil 组都产生了 'ratty' GR 趋势。发现每个地层成员和地层都具有独特的化学地层学、生物地层学、沉积学和/或电缆测井特征。低“块状”GR 响应是石炭纪 Ghazal 段和奥陶纪 Sarah 地层的典型特征。类似地，志留系 Sharawra 段和志留系-泥盆系 Tawil 组都产生了 'ratty' GR 趋势。发现每个地层成员和地层都具有独特的化学地层学、生物地层学、沉积学和/或电缆测井特征。低“块状”GR 响应是石炭纪 Ghazal 段和奥陶纪 Sarah 地层的典型特征。类似地，志留系 Sharawra 段和志留系-泥盆系 Tawil 组都产生了 'ratty' GR 趋势。发现每个地层成员和地层都具有独特的化学地层学、生物地层学、沉积学和/或电缆测井特征。