Editorial Board

We are pleased to welcome to the Editorial Board Dr Miroslaw Slowakiewicz of the University of Warsaw, Poland. Dr Slowakiewicz was awarded a PhD in Earth Science from the University of Mining and Metallurgy in 2005. He then spent several years as an adjunct at the Polish Geological Institute and three years at the University of Bristol, and moved to the University of Warsaw in 2017. His research interests include astrobiology, organic geochemistry and source rock analysis, biogeochemistry and biomineralogy.

In this issue…

Liu, Blackbourn et al. (pp 127–156) describe and assess resources of bitumen (i.e. hydrocarbons with specific gravity <10° API) in the East Siberian Basin, a relatively remote area which, in spite of geological investigations dating back to the 19th century, remains poorly-known. The outline of the basin in general corresponds to that of the Siberian Platform, a crustal block covering an area of ∼l.5 million sq.km in which uplifted Proterozoic basement rocks are exposed at the surface over large areas. Proterozoic (“Riphean”: 1650–650 Ma) marine source rocks occur in kitchen areas around the basin margins, and generated hydrocarbons which in the Late Palaeozoic migrated updip over long distances to reservoirs mainly comprising Upper Precambrian and Cambrian sandstones and carbonates. Seals for conventional hydrocarbon accumulations consist of thick Lower Cambrian evaporites. However where this seal is not present for example in the north of the basin, in situ oils were biodegraded and oxidised as the reservoirs were uplifted and partially unroofed, resulting in the formation of widespread accumulations of immobile bitumen as lighter hydrocarbon fractions were lost.

Khalifeh-Soltani et al. (pp 157–290) used 3D finite-element modelling to investigate the influence of parameters including the obliquity of the applied stress, the friction coefficient and the internal friction angle on the development of detachment folds and fault-bend folds. The model set-up consisted of five layers whose mechanical properties were based on those of stratigraphic units in the Zagros fold-and-thrust belt. The effect of variations in the geometry of the faults associated with these two classes of folds was also investigated. Thus for detachment folds, models investigated the effect of faults which in plan view were concave, convex or wavy; for fault-bend folds, models investigated the effect of variations in ramp dip angle. Results of model runs are illustrated by 3D block diagrams and cross-sections which show both the plastic strain distribution and also the fold class for the deformed layers. In a final section, the detachment fold at the Ahwaz anticline was numerically modelled, and modelled cross-sections were found to be similar to cross-sections interpreted from seismic data.

Orozova-Bekkevold et al. (pp 191–217) numerically simulated the post-Danian (Selandian to present-day) depositional process in a study area in the Danish sector of the North Sea Central Graben. They examined the build-up and magnitude of overpressures in the thick, clay-rich successions from seafloor to the top of the Chalk Group (the “overburden”) in relation to variations in water depth and sedimentation rate over the last 61 million years. Variations in sedimentation rate, especially during the Miocene, appear to influence overpressure development significantly, while changes in overpressure due to variations in water depth were not clear-cut although some transient influence was found. Thus in general overpressures were developed during periods of relatively high depositional rate (e.g. in the Paleocene, Aquitanian-Langhian, Tortonian-Messinian, Pliocene and Quaternary) but were dissipated in intervening periods (in the Oligocene, Eocene, and Serravallian) when the depositional rate was lower.

编辑委员会

我们很高兴地欢迎波兰华沙大学的 Miroslaw Slowakiewicz 博士加入编辑委员会。Slowakiewicz 博士于 2005 年获得矿业和冶金大学地球科学博士学位。随后，他在波兰地质研究所担任了几年的兼职人员，并在布里斯托尔大学担任了三年，并于 2017 年转到华沙大学. 他的研究兴趣包括天体生物学、有机地球化学和烃源岩分析、生物地球化学和生物矿物学。

在这个问题上…

刘，布莱克本等. (pp 127–156) describe and assess resources of bitumen (i.e. hydrocarbons with specific gravity <10° API) in the East Siberian Basin, a relatively remote area which, in spite of geological investigations dating back to the 19th century, remains poorly-known. The outline of the basin in general corresponds to that of the Siberian Platform, a crustal block covering an area of ∼l.5 million sq.km in which uplifted Proterozoic basement rocks are exposed at the surface over large areas. Proterozoic (“Riphean”: 1650–650 Ma) marine source rocks occur in kitchen areas around the basin margins, and generated hydrocarbons which in the Late Palaeozoic migrated updip over long distances to reservoirs mainly comprising Upper Precambrian and Cambrian sandstones and carbonates. Seals for conventional hydrocarbon accumulations consist of thick Lower Cambrian evaporites. However where this seal is not present for example in the north of the basin, 随着储层的抬升和部分顶盖的打开，原地石油被生物降解和氧化，导致随着较轻的碳氢化合物馏分的流失，形成了广泛的固定沥青堆积。

Khalifeh-Soltani等人. (pp 157–290) 使用 3D 有限元模型研究了施加应力的倾斜度、摩擦系数和内摩擦角等参数对滑脱褶皱和断层弯曲褶皱发育的影响。模型设置由五层组成，其力学特性基于扎格罗斯褶皱冲断带中的地层单元。还研究了与这两类褶皱相关的断层几何形状变化的影响。因此，对于拆离褶皱，模型研究了在平面图中呈凹形、凸形或波浪形的断层的影响；对于断层弯曲褶皱，模型研究了斜坡倾角变化的影响。模型运行的结果通过 3D 框图和横截面进行说明，其中显示了塑性应变分布以及变形层的折叠等级。在最后一部分中，对 Ahwaz 背斜处的滑脱褶皱进行了数值模拟，发现模拟的横截面与根据地震数据解释的横截面相似。

Orozova-Bekkevold等人. (pp 191–217) 数值模拟了北海中央地堑丹麦部分研究区的后达尼期（Selandian 到现在）沉积过程。他们检查了过去 6100 万年来水深和沉积速率变化与从海底到白垩岩群顶部的厚厚、富含粘土的层序（“上覆岩层”）中超压的累积和大小。沉积速率的变化，尤其是在中新世期间，似乎对超压发展有显着影响，而由于水深变化引起的超压变化并不明确，尽管发现了一些瞬态影响。因此，一般而言，超压是在沉积速率相对较高的时期（例如古新世、阿基坦期-朗吉期、托尔通期-麦西尼期、