The Volgian–Ryazanian shale interval in the Norwegian Central Graben, North Sea, is assigned to the Mandal Formation. Despite shales with similar lithological and log characteristics are being present in the Danish Central Graben, the formation is not defined for this part of the Central Graben. This paper presents a new lithostratigraphic subdivision of the Upper Volgian–Upper Ryazanian interval in the Danish Central Graben, where the Mandal Formation is defined and replaces the uppermost part of the Farsund Formation in the ‘old’ lithostratigraphy. The Mandal Formation is recognized from its log character and is correlatable across the Danish Central Graben. The formation typically has high gamma-ray (GR) and resistivity readings accompanied by low velocity and density values. In basin centres it normally consists of a lower part showing an upward increase in GR readings (‘warming-up’ interval), an overlying interval with conspicuous high GR readings (Bo Member), and an upper heterogeneous shale interval. The base of the Mandal Formation can be seismically mapped in most of the Danish Central Graben. The upper boundary of the formation, corresponding to the Base Cretaceous Unconformity (BCU) at the transition to the Lower Cretaceous, can likewise be seismically mapped throughout the basin. The Mandal Formation is developed with thick successions in basin depocentres, while it is thin or absent along inversion structures and on structural highs. The organic-rich shales of the Mandal Formation were deposited in a restricted, low-energy, oxygen-deficient/anoxic marine environment distal from any significant terrestrial influence. Along the eastern Coffee Soil Fault in the Danish Central Graben, siliciclastic deposits constituting the gravity-flow sandstones of the Poul Member interfinger with the Mandal Formation. Gravity-flow deposits formed by turbidite currents are also common throughout the Mandal Formation in basin centres. The Mandal Formation and particularly the Bo Member are highly oil-prone and contain the best source rock quality of the entire Upper Jurassic – lowermost Cretaceous shale succession in the Danish Central Graben. Interbedded potential reservoir sandstones suggest the Mandal Formation may in places be considered as an interval with hydrocarbon prospectivity, especially along the Coffee Soil Fault.

挪威中北部格拉本中部的Volgian-Ryazanian页岩层段属于Mandal组。尽管丹麦中部Graben中存在具有相似岩性和测井特征的页岩，但中部Graben的这一部分地层没有定义。本文介绍了丹麦中格拉本中上伏尔冈－上梁赞地区段的一个新的岩石地层学细分，其中定义了曼达尔组，并取代了“旧”岩石地层中法尔松德组的最上部。曼达尔地层从对数特征中可以识别，并且在丹麦中部格拉本地区具有相关性。地层通常具有较高的伽马射线（GR）和电阻率读数，同时具有较低的速度和密度值。在盆地中心，它通常由一个下部组成，该下部显示出了GR读数的向上增加（“升温”间隔），一个具有显着高GR读数的上覆层（Bo成员）和一个上部非均质页岩间隔。曼达尔地层的基础可以在丹麦中部格拉本大部分地区进行地震测绘。地层的上边界对应于过渡到下白垩统的基底白垩纪不整合面（BCU），同样可以在整个盆地上进行地震测绘。曼达尔地层在盆地深处发育，并具有较厚的连续序列，而在反演结构和构造高处则较薄或不存在。曼达组富含有机质的页岩以受限的低能量沉积，远离任何重大陆地影响的缺氧/缺氧海洋环境。沿着丹麦中部Graben中部的东部咖啡土壤断层，硅质碎屑沉积物构成了Poul成员与Mandal组互指的重力流砂岩。在盆地中心的整个曼达尔组中，由浊流形成的重力流沉积物也很普遍。曼达尔组，尤其是Bo成员，极容易发生石油，并且在整个上侏罗统（丹麦中部Graben中最低的白垩纪页岩层序）中拥有最好的烃源岩质量。层间潜在的储层砂岩表明，在某些地方，Mandal组可能被认为是具有油气远景的层段，尤其是沿咖啡土壤断层。沿丹麦中部格拉本中部的东部咖啡土壤断层，硅质碎屑沉积物构成了波尔成员与曼达尔组之间的重力流砂岩。在盆地中心的整个曼达尔组中，由浊流形成的重力流沉积物也很普遍。曼达尔组，尤其是Bo成员，极容易发生石油，并且在整个上侏罗统（丹麦中部Graben中最低的白垩纪页岩层序）中拥有最好的烃源岩质量。层间潜在的储层砂岩表明，在某些地方，Mandal组可能被认为是具有油气远景的层段，尤其是沿咖啡土壤断层。沿着丹麦中部Graben中部的东部咖啡土壤断层，硅质碎屑沉积物构成了Poul成员与Mandal组互指的重力流砂岩。在盆地中心的整个曼达尔组中，由浊流形成的重力流沉积物也很普遍。曼达尔组，尤其是Bo成员，极容易发生石油，并且在整个上侏罗统（丹麦中部Graben中最低的白垩纪页岩层序）中拥有最好的烃源岩质量。层间潜在的储层砂岩表明，在某些地方，Mandal组可能被认为是具有油气远景的层段，尤其是沿咖啡土壤断层。在盆地中心的整个曼达尔组中，由浊流形成的重力流沉积物也很普遍。曼达尔组，尤其是Bo成员，极容易发生石油，并且在整个上侏罗统（丹麦中部Graben中最低的白垩纪页岩层序）中拥有最好的烃源岩质量。层间潜在的储层砂岩表明，在某些地方，Mandal组可能被认为是具有油气远景的层段，尤其是沿咖啡土壤断层。在盆地中心的整个曼达尔组中，由浊流形成的重力流沉积物也很普遍。曼达尔组，尤其是Bo成员，极容易发生石油，并且在整个上侏罗统（丹麦中部Graben中最低的白垩纪页岩层序）中拥有最好的烃源岩质量。层间潜在的储层砂岩表明，在某些地方，Mandal组可能被认为是具有油气远景的层段，尤其是沿咖啡土壤断层。