Graben systems and geological history of Mbokomu Mons region, Parga Chasmata, Venus

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus Pub Date : 2024-08-18 DOI:10.1016/j.icarus.2024.116268

{"title":"Graben systems and geological history of Mbokomu Mons region, Parga Chasmata, Venus","authors":"","doi":"10.1016/j.icarus.2024.116268","DOIUrl":null,"url":null,"abstract":"<div><p>The relationship between chasmata (rift zones) and spatially associated volcanism (mons and coronae) on Venus has been extensively discussed but remains enigmatic. One region where these features are prominently displayed is along the 10,000 km long, WNW trending, Parga Chasmata, which connects Atla Regio with Themis Regio. The Mbokomu Mons area (located about 2200 km SE of Atla Regio) was selected for detailed study to provide insight into these relationships. More than 39,000 extensional lineaments (grabens, fissures and fractures) were mapped at 1:500,000 scale using full resolution Magellan Synthetic Aperture Radar (SAR) images and grouped into radiating, circumferential and linear systems. They are (except where noted) interpreted to represent the surface expression of underlying mafic dyke swarms, on the basis of associated volcanic features and terrestrial analogues. Radiating and/or circumferential swarms are associated with Mbokomu Mons and the four coronae in the surrounding area, Among Corona (AC), Repa Corona (RC) and two unnamed coronae (UC1 and UC2). Mbokomu Mons is unique among the tectono-magmatic features in this region of Parga Chasmata, in having both corona and mons characteristics. The initial Corona Phase consists of radiating and circumferential systems mainly preserved in an unflooded annular uplift, while the Mons Phase includes a second radiating swarm associated with a central edifice, and smaller circumferential fracture pattern near the summit that could overlie a magma reservoir. The plume or diapir that is interpreted to have been responsible for the initial Corona Phase is estimated to have had a radius of ∼150 km. Cross-cutting relationships indicate that Mbokomu Mons is younger than nearby Among, Oduduwa and Onenhtse coronae. All four centres are aligned along a WNW-trend parallel to the Parga Chasmata (rift system). Mbokomu Mons is located at, and its emplacement may be linked to, the intersection of this WNW-trending zone of weakness and the orthogonal Jokwa Linea rift system. Mbokumo Mons is also younger than the nearby parallel Penthesilia Fossa (PF) (part of the Great Dyke of Atla Regio).</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0019103524003282/pdfft?md5=412a1b6a92872bd1cc1caa9b2d4d6a91&pid=1-s2.0-S0019103524003282-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Icarus","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0019103524003282","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}

引用次数: 0

Abstract

The relationship between chasmata (rift zones) and spatially associated volcanism (mons and coronae) on Venus has been extensively discussed but remains enigmatic. One region where these features are prominently displayed is along the 10,000 km long, WNW trending, Parga Chasmata, which connects Atla Regio with Themis Regio. The Mbokomu Mons area (located about 2200 km SE of Atla Regio) was selected for detailed study to provide insight into these relationships. More than 39,000 extensional lineaments (grabens, fissures and fractures) were mapped at 1:500,000 scale using full resolution Magellan Synthetic Aperture Radar (SAR) images and grouped into radiating, circumferential and linear systems. They are (except where noted) interpreted to represent the surface expression of underlying mafic dyke swarms, on the basis of associated volcanic features and terrestrial analogues. Radiating and/or circumferential swarms are associated with Mbokomu Mons and the four coronae in the surrounding area, Among Corona (AC), Repa Corona (RC) and two unnamed coronae (UC1 and UC2). Mbokomu Mons is unique among the tectono-magmatic features in this region of Parga Chasmata, in having both corona and mons characteristics. The initial Corona Phase consists of radiating and circumferential systems mainly preserved in an unflooded annular uplift, while the Mons Phase includes a second radiating swarm associated with a central edifice, and smaller circumferential fracture pattern near the summit that could overlie a magma reservoir. The plume or diapir that is interpreted to have been responsible for the initial Corona Phase is estimated to have had a radius of ∼150 km. Cross-cutting relationships indicate that Mbokomu Mons is younger than nearby Among, Oduduwa and Onenhtse coronae. All four centres are aligned along a WNW-trend parallel to the Parga Chasmata (rift system). Mbokomu Mons is located at, and its emplacement may be linked to, the intersection of this WNW-trending zone of weakness and the orthogonal Jokwa Linea rift system. Mbokumo Mons is also younger than the nearby parallel Penthesilia Fossa (PF) (part of the Great Dyke of Atla Regio).

查看原文本刊更多论文

金星帕尔加-查斯马塔姆博科姆蒙斯地区的地块系统和地质历史

金星上的断裂带（chasmata）与空间上相关的火山活动（火山口和火山冠）之间的关系已被广泛讨论，但仍是一个谜。连接阿特拉星区（Atla Regio）和特米斯星区（Themis Regio）的帕尔加断裂带（Parga Chasmata）长达 10,000 公里，呈西偏北方向，是这些特征的突出表现区域之一。为了深入了解这些关系，我们选择了姆博科姆蒙斯地区（位于阿特拉地区东南约 2200 公里处）进行详细研究。利用全分辨率麦哲伦合成孔径雷达（SAR）图像，以 1:500,000 的比例绘制了 39,000 多条伸展线状构造（地堑、裂缝和断裂），并将其分为放射状、环状和线状系统。根据相关的火山特征和陆地类似物，这些系统（除非有说明）被解释为代表下层岩浆岩堤群的地表表现形式。放射状和/或环状岩群与姆博科姆丘以及周边地区的四个日冕、Among Corona（AC）、Repa Corona（RC）和两个未命名的日冕（UC1 和 UC2）有关。姆博克穆丘陵在帕尔嘎-查斯马塔这一地区的构造-地貌特征中是独一无二的，它同时具有日冕和丘陵的特征。最初的日冕期由放射状和环状系统组成，主要保存在未淹没的环状隆起中，而蒙斯期则包括与中央建筑物相关的第二个放射状群，以及靠近山顶的较小环状断裂模式，该断裂可能位于岩浆储层之上。据估计，造成最初日冕阶段的羽流或断裂半径为 150 公里。横切关系表明，姆博克穆蒙斯比附近的奥姆、奥杜杜瓦和奥嫩塞日冕要年轻。所有这四个中心都沿着平行于帕尔加裂谷（Parga Chasmata）的西北走向排列。姆博库莫海隆位于这一西偏北方向的薄弱地带与正交的 Jokwa Linea 裂谷系统的交汇处，它的形成可能与此有关。姆博库姆丘也比附近平行的 Penthesilia Fossa (PF)（阿特拉大堤的一部分）年轻。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Icarus 地学天文-天文与天体物理

CiteScore

6.30

自引率

18.80%

发文量

356

审稿时长

2-4 weeks

期刊介绍： Icarus is devoted to the publication of original contributions in the field of Solar System studies. Manuscripts reporting the results of new research - observational, experimental, or theoretical - concerning the astronomy, geology, meteorology, physics, chemistry, biology, and other scientific aspects of our Solar System or extrasolar systems are welcome. The journal generally does not publish papers devoted exclusively to the Sun, the Earth, celestial mechanics, meteoritics, or astrophysics. Icarus does not publish papers that provide "improved" versions of Bode''s law, or other numerical relations, without a sound physical basis. Icarus does not publish meeting announcements or general notices. Reviews, historical papers, and manuscripts describing spacecraft instrumentation may be considered, but only with prior approval of the editor. An entire issue of the journal is occasionally devoted to a single subject, usually arising from a conference on the same topic. The language of publication is English. American or British usage is accepted, but not a mixture of these.