Detailed mapping of major-scale volcanic centres on Venus provides a complementary view to terrestrial large igneous provinces (LIPs). On Venus, the surface flood basalt relationships are preserved owing to the absence of erosion, but the plumbing system is only indirectly revealed. In contrast, erosion on Earth dissects flood basalt packages and can directly reveal the plumbing system of mafic dykes, sills and larger intrusions. Herein we report on detailed mapping at 1:500,000 scale of the Derceto Corona (DC) volcanic event located in southern Astkhik Planum (our map area: 1,920,000 km²) using full resolution (100–200 m/pixel) Magellan synthetic aperture radar (SAR images). Our map builds on earlier reconnaissance scale mapping (1:5,000,000 scale) in parts of quadrangles V-44, V-45, and V-56.

Thirty-seven distinct lava flow units were mapped and grouped into eight main and multiple minor volcanic stages, along with six regional graben systems (marking underlying dyke swarms). On the east side of DC, the Eastern Stage flows (fES) which extend for 750 km, are fed from NNW-NW-trending grabens (overlying dykes) and from more local (small shield) sources. The Kallistos-Ubastet Stage (fKUS) consists of the 1200 km long Kallistos Vallis and its overflow Ubastet Fluctus, all fed from an irregular 30 × 10 km depression (interpreted to represent roof collapse above a magma chamber) on the south side of DC. Lavas of both the Eastern Stage and the Kallistos-Ubastet Stage flowed over a section of Vaidilute Rupes and spread out on its eastern side. A Western Stage flow field (fWS-3) (>1000 km long) was sourced from the elliptical graben system (overlying dykes) of DC; after flowing downslope to the north it swings almost 180 degrees to follow a preexisting rift, Hanghepiwi Chasma. At its distal end, fWS-3 is locally superimposed with radar-bright flows interpreted to be derived from east-trending grabens (overlying dykes) belonging to Sarpanitum Corona. On the north side of DC, a laterally propagating NE-trending graben system (overlying dykes) produces a 90 km long “Great Dyke” that itself feeds a flow field; additional grabens of this swarm also spawned smaller flows.

All the above-mentioned flows have sources within 250 km from the centre of DC, within the area of interpreted original regional uplift, and possible magmatic underplate. Two flow stages (Western Stage-3 and the Great Dyke/NE-trending dyke swarms) are inferred to be fed via dykes from elliptical-shaped down-sag caldera collapse of DC. The Eastern Stage flows are fed mostly from a region to the east of the corona, and the rest of the flows are fed via an older (pre-Derceto) regional NW-trending graben system that was reused for magma transport from underlying chambers fed from the magmatic underplate or laterally from the collapse of the central chamber of DC. The total areal extent of flows is 534,650 km² with an inferred volume of 26,730 km³ (assuming a flow thickness of 50 m), corresponding to LIP-scale in terms of area, and likely LIP-scale volume if the expected underlying plumbing system were catalogued.

金星上大型火山中心的详细地图为陆地大型火成岩省 (LIP) 提供了补充视图。在金星上，由于没有侵蚀，地表洪水玄武岩的关系得以保留，但管道系统只是间接暴露出来。相比之下，地球上的侵蚀解剖了泛滥玄武岩包，可以直接揭示基性岩脉、窗台和更大侵入体的管道系统。在此，我们使用全分辨率（100-200 m/像素）麦哲伦合成孔径雷达（1:500,000 比例尺）报告了位于 Astkhik Planum 南部（我们的地图区域：1,920,000 km ²）的 Derceto Corona (DC) 火山事件的详细绘图（ SAR 图像）。我们的地图建立在早期侦察比例尺映射（1:5,000,000 比例尺）的基础上，位于四边形 V-44、V-45 和 V-56 的部分区域。

绘制了 37 个不同的熔岩流单元并将其分为八个主要和多个次要火山阶段，以及六个区域地堑系统（标记下伏堤群）。在 DC 的东侧，东段流 (fES) 延伸 750 公里，来自 NNW-NW 向地堑（上覆岩脉）和更多局部（小盾构）源。Kallistos-Ubastet 阶段 (fKUS) 由 1200 公里长的 Kallistos Vallis 及其溢流 Ubastet Fluctus 组成，全部来自 DC 南侧的一个不规则的 30 × 10 公里凹陷（解释为代表岩浆房上方的顶板坍塌）。东段和卡利斯托斯-乌巴斯特段的熔岩都流过一段瓦迪鲁特鲁佩斯，并在其东侧展开。西级流场 (fWS-3) (> 1000 公里长）来源于 DC 的椭圆地堑系统（上覆岩脉）；在顺坡向北流动后，它摆动了近 180 度，沿着先前存在的裂缝，Hanghepiwi Chasma。在其远端，fWS-3 局部叠加有雷达明亮的流动，被解释为来自属于 Sarpanitum Corona 的东向地堑（上覆岩脉）。在 DC 的北侧，一个横向传播的 NE 向地堑系统（上覆堤坝）产生了一条 90 公里长的“大堤坝”，它本身供给了一个流场；这个群体的额外地堑也产生了较小的流。fWS-3 局部叠加有雷达明亮的流动，被解释为来自属于 Sarpanitum Corona 的东向地堑（上覆岩脉）。在 DC 的北侧，一个横向传播的 NE 向地堑系统（上覆堤坝）产生了一条 90 公里长的“大堤坝”，它本身供给了一个流场；这个群体的额外地堑也产生了较小的流。fWS-3 局部叠加有雷达明亮的流动，被解释为来自属于 Sarpanitum Corona 的东向地堑（上覆岩脉）。在 DC 的北侧，一个横向传播的 NE 向地堑系统（上覆堤坝）产生了一条 90 公里长的“大堤坝”，它本身供给了一个流场；这个群体的额外地堑也产生了较小的流。

上述流源均在距DC中心250km以内，在解释的原始区域隆起区域内，可能有岩浆底板。从 DC 的椭圆形下凹火山口坍塌推断出两个流动阶段（西部第 3 阶段和大堤 / NE 向堤群）通过堤坝进料。东段的气流主要来自日冕以东的一个区域，其余的气流通过较旧的（前德塞托）区域西北向地堑系统馈送，该系统被重新用于从下层室馈送的岩浆输送岩浆底板或横向来自DC中央室的坍塌。总面积流量为 534,650 km ²，推断体积为 26,730 km ³ （假设流动厚度为 50 m），对应于面积的 LIP 尺度，如果预期的底层管道系统被编目，则可能对应于 LIP 尺度的体积。