Wave‐dominated deltas and strandplains make up the majority of the world’s depositional coastlines, provide an important record of sea‐level change and serve as hydrocarbon reservoirs worldwide. Satellite imagery forms a great source of data on the recent depositional history of modern deltaic systems. In the subsurface, three‐dimensional seismic and well data make the three‐dimensional assessment of large‐scale deltaic reservoir bodies possible but struggle to resolve internal heterogeneities away from wells. To bridge this gap in characterizing deltaic sedimentation, this study combines measurements from both the shallow, high‐resolution section of three‐dimensional seismic data of the Eocene Halibut Delta in the Outer Moray Firth, offshore Scotland, with information from Google Earth’s satellite imagery and digital elevation model on south‐east Brazilian river deltas (São Francisco, Jequitinhonha, Doce and Paraíba do Sul) to present a means of predicting the location of fluvial sediment input points with respect to clinoform geometry. The key measurement for this study is the delta front and clinoform dip which has been measured at multiple locations along strike of the coastline of the examined deltas. Dip decreases away from the inferred river mouth for all deltas by 50% within 7.2 km. The river mouth location was inferred from the position of palaeo‐channels visible on the delta top and coarse sediment recorded in grab samples offshore for the south‐east Brazilian deltas, and from imprints of palaeo‐channels on attribute maps for the Eocene Halibut Delta. In summary, this study found that delta front dip is steepest at the location of the river mouth and decreases, along with grain size, away from it. This suggests that high dip values correlate with the proximity to the channel mouth and can be used to predict fluvial channel facies in modern deltaic systems and subsurface reservoirs.

中文翻译：

---

在现代和古代波浪主导的三角洲中，从三角洲前倾角和斜面形倾角预测河口位置

波浪主导的三角洲和链状平原构成了世界上大部分的沉积海岸线，是海平面变化的重要记录，并且是全世界的油气储集层。卫星图像构成了有关现代三角洲系统近期沉积史的重要数据来源。在地下，三维地震和井数据使对大型三角洲储层体的三维评估成为可能，但很难解决井外的内部非均质性问题。为了弥补表征三角洲沉积的空白，本研究结合了苏格兰近海莫里峡湾始新世大比目鱼三角洲三维地震数据的高分辨率高分辨率浅层剖面测量结果 结合Google Earth的卫星图像和巴西东南部三角洲（圣弗朗西斯科，Jequitinhonha，Doce和Paraíbado Sul）的数字高程模型提供的信息，提出了一种预测河流沉积物输入点相对于斜形几何形状位置的方法。这项研究的关键指标是三角洲前缘和斜形倾角，这是在沿所考察的三角洲海岸线走向的多个位置进行测量的。在7.2公里范围内，所有三角洲的倾角都将从推断的河口处减少50％。河口的位置是根据三角洲顶部可见的古河道的位置和巴西东南部三角洲的近海抓斗样品中记录的粗沉积物以及始新世大比目鱼三角洲的属性图上的古河道的印记推断的。综上所述，这项研究发现，三角洲前倾角在河口位置最陡，并且随着晶粒尺寸的减小而减小。这表明高倾角值与通道口的接近程度有关，可用于预测现代三角洲系统和地下储层中的河流通道相。