Lithostratigraphy of the Vuurdood Subsuite, an early mafic-ultramafic phase of the Palaeoproterozoic Vioolsdrif Intrusive Suite, Richtersveld Magmatic Arc, Northern Cape Province

Mafic-ultramafic plutonic intrusions form an early phase in the emplacement of the predominantly granitic Vioolsdrif Suite, which together with its extrusive carapace, the Orange River Group, form the Richtersveld Magmatic Arc, a Palaeoproterozoic crustal segment formed between 1910 and 1865 Ma. Their lithologic character and distinctive dark weathering features in the mountain desert landscape of the Richtersveld, neighbouring regions of the Northern Cape Province and southern Namibia, make them a separate mappable unit in what is a predominantly granitic terrain. The name of the subsuite is taken from a spectacular twin peak massif near Goodhouse (Vuurdoodberg), while the type locality is one of the best preserved central-type intrusive bodies at Swartkop, situated 2 km off the N7 highway about 20 km south of the border town of Vioolsdrif, where the rock types present include gabbro, metagabbro, quartz-metagabbro, peridotite and troctolite.

Surf3DNet1.0: A deep learning model for regional-scale 3D subsurface structure mapping

This study introduces an efficient deep learning approach based on convolutional neural networks with joint autoencoder and adversarial structures for 3D subsurface mapping from surface observations. The method was applied to delineate palaeovalleys in an Australian desert landscape. The neural network was trained on a 6,400 km2 domain by using a land surface tomography as 2D input and an airborne electromagnetic (AEM)-derived probability map of palaeovalley presence as 3D output. The trained neural network has a maximum square error

Onset of permanent Taklimakan Desert linked to the mid-Pleistocene transition

The initial occurrence of desert landscape or eolian sand dunes is thought to have occurred long before the Pleistocene, and desertification was subsequently enhanced under cold, dusty glacial conditions. However, when and how the desert landscape persisted during both glacial and interglacial periods, defined as “permanent” desert here, remain elusive. Here, we present carbonate carbon isotope and grain-size records from the Tarim Basin, western China, revealing a detailed desertification history for the Taklimakan Desert. Our records demonstrate that after desiccation of episodic lakes at ca. 4.9 Ma, alternations of eolian sand dunes and fluvial and playa-like conditions persisted for a long period until 0.7 Ma in the Tarim Basin. The onset of permanent desert landscape around 0.7–0.5 Ma occurred concurrently with the climatic reorganization across the mid-Pleistocene transition. The occurrence of mountain glaciers on the Tibetan Plateau and atmospheric circulation changes may have controlled the formation and extreme aridification of the permanent desert in inland Asia since the mid-Pleistocene transition.