Abstract Geological mapping principles have been applied across planet Earth since William Smith's initial 1815 map. During the Space Age, these principles were applied to smaller moons and planets, appropriately adjusted for remote conditions and data, and revealing ‘one plate planets’ recording Earth's missing chapters. Yet what of Venus, Earth's ‘twin’, shrouded in opaque clouds? How can these geological mapping principles be applied to address fundamental questions of planetary history? We outline how Venus's geological mapping over the last 35 years has proceeded towards a successively integrated more global picture that has revealed a surface and history unlike Earth or the smaller planetary bodies! The current 1 : 10 M global geological map documents geological units that all formed in the last c. 20% of Venus's history. The oldest, Fortunian, involved intense deformation and building of thicker crust (tessera). The Guineverian featured near-global emplacement of vast volcanic plains. The Atlian saw prominent rift zones and large shield volcanoes. The three major phases of activity provide a basis for assessing the geological, atmospheric and geodynamical processes operating earlier in Venus's history that led to the preserved record, raising a series of questions to be investigated in the coming decade by an international armada of Venus missions.

Abstract The Changbaishan volcanic field located on the Gaima (Gaema, Gaiman) Plateau has witnessed plateau-forming eruptions along with the uplift of the Gaima Plateau. The Tianchi basaltic lava shield volcano was formed at the main peak of Changbaishan, with cone construction eruptions that formed a huge and steep trachytic composite cone on the gentle lava shield. At the peak of the Millennium Eruption (ME), the height of the eruption column reached 25 km and the bulk volume of tephra was about 120 km 3 . The ME eventually formed Tianchi caldera, after which several eruptions occurred, albeit of a much smaller scale. The magmas involved in the shield-forming eruptions are characterized by both alkalic series trachybasalt and basaltic trachyandesite and subalkalic tholeiite and basaltic andesite. In the cone-construction and ignimbrite-forming eruption stages, the magma is completely composed of alkalic series trachyte and comendite. The largest negative Eu anomalies observed in ME magmas indicate that plagioclase was strongly crystallized and differentiated.

Abstract Ashikule volcanic field, developed in the western Kunlun mountain of north Tibet, is composed of approximately 10 volcanoes, and covers a total area of about 200 km 2 at an average altitude of approximately 5000 m, one of the highest volcanic fields in the world. In this study, we conducted detailed field investigations of the geological and geomorphological features of volcanic rocks and volcanic edifices in Ashikule basin, and compiled a large-scale geological map of the study area for the first time. We also collected a series of samples for petrochemistry analysis, as well as a high-precision 40 Ar/ 39 Ar geochronology study of selected lavas from Ashikule volcanic field. Finally, we refined the eruption history for the volcanic activity in the basin, which provides some new volcanological evidence for the study of the tectonic evolution of the Northern Tibetan Plateau.

Abstract The Jurassic igneous rocks of Dronning Maud Land represent Karoo flood basalt magmatism in Antarctica. Fifty years of research has documented systematic differences between magmas associated with the Karoo rift-zone (Vestfjella and Ahlmannryggen) and the rift-shoulder (Sembberget, Kirwanveggen) settings. The 189–182 Ma rift-zone tholeiites were chemically diverse and mainly formed compound-braided flow fields which record several magnetic polarity reversals. In contrast, the c. 181 Ma rift-shoulder tholeiites were chemically uniform and formed thick tabular sheet lavas within a single normal polarity period. The volcanic architecture records a long initial phase of slow eruptions from shield volcanoes in the initial rift and a brief phase of voluminous fissure eruptions flooding the rift shoulder. All of the major magma types in the rift-zone and rift-shoulder settings belong to a Nb-depleted category of Karoo flood basalts and were mainly derived from depleted convective upper mantle by magmatic differentiation. Pyroxenite-rich mantle components may have been significant sources for the most enriched magma types. Geochemical fingerprints of recycled crustal material imply that the Nb-depleted Karoo tholeiites may have been derived from mildly subduction-modified parts of the same overall upper-mantle reservoir which has been associated with the Ferrar tholeiites.

Abstract Following more than 25 years of exploration and research since the last regional appraisal, the number of known subaerially exposed volcanoes in the northern Antarctic Peninsula region has more than trebled, from less than 15 to more than 50, and that total must be increased at least three-fold if seamounts in Bransfield Strait are included. Several volcanoes remain unvisited and there are relatively few detailed studies. The region includes Deception Island, the most prolific active volcano in Antarctica, and Mount Haddington, the largest volcano in Antarctica. The tectonic environment of the volcanism is more variable than elsewhere in Antarctica. Most of the volcanism is related to subduction. It includes very young ensialic marginal basin volcanism (Bransfield Strait), back-arc alkaline volcanism (James Ross Island Volcanic Group) and slab-window-related volcanism (seamount offshore of Anvers Island), as well as volcanism of uncertain origin (Anvers and Brabant islands; small volcanic centres on Livingston and Greenwich islands). Only ‘normal’ arc volcanism is not clearly represented, possibly because active subduction virtually ceased at c. 4 Ma. The eruptive environment for the volcanism varied between subglacial, marine and subaerial but a subglacial setting is prominent, particularly in the James Ross Island Volcanic Group.

Abstract Neogene volcanism is widespread in northern Victoria Land, and is part of the McMurdo Volcanic Group. It is characterized by multiple coalesced shield volcanoes but includes a few relatively small stratovolcanoes. Two volcanic provinces are defined (Hallett and Melbourne), with nine constituent volcanic fields. Multitudes of tiny monogenetic volcanic centres (mainly scoria cones) are also scattered across the region and are called the Northern Local Suite. The volcanism extends in age between middle Miocene ( c. 15 Ma) and present but most is <10 Ma. Two centres may still be active (Mount Melbourne and Mount Rittmann). It is alkaline, varying between basalt (basanite) and trachyte/rhyolite. There are also associated, geographically restricted, alkaline gabbro to granite plutons and dykes (Meander Intrusive Group) with mainly Eocene–Oligocene ages (52–18 Ma). The isotopic compositions of the plutons have been used to infer overall cooling of climate during the Eocene–Oligocene. The volcanic sequences are overwhelmingly glaciovolcanic and are dominated by ‘a‘ā lava-fed deltas, the first to be described anywhere. They have been a major source of information on Mio-Pliocene glacial conditions and were used to establish that the thermal regime during glacial periods was polythermal, thus necessitating a change in the prevailing paradigm for ice-sheet evolution.