The Variscan Orogeny: the development and deformation of Devonian/Carboniferous basins in SW England and South Wales
The Variscan Orogeny: the development and deformation of Devonian/Carboniferous basins in SW England and South Wales
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瓦里坎造山运动：英格兰西南部和南威尔士泥盆纪/石炭纪盆地的发育和变形
DOI：
10.1144/goewp.10
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
A. Hartley
中科院分区：
文献类型：
--
作者：
B. Leveridge;A. Hartley
位于其以东约800公里处的德国的希费尔山（例如Franke & Engel 1982;保持器& Leveridge 1986 a），它们共同构成了莱茵海西带的主要部分。这是科斯马特（1927）提出的古地理和构造带的最北端，它与萨克苏林阶和摩尔达努阶带一起构成了德国和中欧的造山带（图10.2）。Bard等人（1980）和Matte（1986）提出了从板块构造学的角度来解释Kossmat带。当时对英格兰西南部的假设背景多种多样：一个硅质弧后盆地（弗洛伊德，1982），一个跨欧洲斜向剪切带的一部分（巴德姆，1982），以及一个陆内褶皱带（马修斯，1984）。巴恩斯和安德鲁斯（1986）认为，康沃尔南部的格拉姆斯卡托复理石（Hendriks 1949）和相关的绿帘蛇绿岩（Strong et al. 1975; Styles & Kirby 1980）代表了横跨北方欧洲的东西向走滑带中产生的一个小型陆内盆地。相反，保持器和Leveridge（1986 b）将其解释为更广泛的海洋化盆地闭合的产物。英格兰西南部和中欧之间地层和构造的相关性和连续性（保持器和Leveridge，1986 a）似乎加强了欧洲东西向线性莱茵海西期大洋化带和碰撞带的概念（Franke，1989）。通过将科斯马特的带从西欧外推到伊比利亚（图10.2），Franke（1989，1992）和Matte等人（1990）定义了次线性微板块和分离碰撞带，其中南俯冲带位于莱茵海西期和萨克苏林期，北俯冲带位于摩尔达努期之下。然而，霍尔兹沃思（1989年）在英格兰西南部重新发现了右旋板间运动和小的斜向盆地。他推测，东西向的“Start- Perranporth线”可能代表了一个“老红砂岩”大陆和南部的阿莫里西微板块之间的边界，而张扭作用积极地控制着泥盆纪盆地的演化。欧洲大陆的Rhenohercynian带现在被认为位于或接近东阿瓦隆尼亚板块的南缘（Franke 2000），三个板块的南部，英格兰西南部的上古生界造山带是泥盆纪和石炭纪盆地带的一部分，从德文郡和康沃尔延伸到德国，向东约800 km。本章所述的复杂的盆地发展序列和变形阶段累积构成了该地区的华力西造山运动。与华力西造山带内的泥盆纪事件同步，华力西前缘北部阿瓦隆大陆的古红砂岩充填盆地的主要河流相（第6章）。在随后的石炭纪，大陆内的盆地主要是伸展性的，直到晚石炭纪的一个时期，许多基底断层反转（第7章），导致盆地充填物隆起，在二叠纪开始时形成了一个新的古地理。南威尔士盆地是华力西移动的带和北部大陆之间的过渡地带。在泥盆纪，这一过渡位置反映在华力西盆地北方边缘的老红砂岩相和海相沉积物的交错上（第6章）。在整个迪南纪和纳穆里纪，南威尔士盆地内的层序与北部大陆内盆地的层序有许多共同之处（第7章）。直到西里西亚，华力西变形才影响盆地的发展并导致盆地变形（见本章）。
Shiefergebirge of Germany, some 800 km to the east, is established (e.g. Franke & Engel 1982; Holder & Leveridge 1986a) and together they make up a major part of the Rhenohercynian Zone. That is the northernmost of the palaeogeographical and tectonic zones proposed by Kossmat (1927), which, with the Saxothuringian and Moldanubian zones, constitute the orogenic belt in Germany and central Europe (Fig. 10.2). Bard et al. (1980) and Matte (1986) proposed interpretation of Kossmat’s zones in terms of plate tectonics. At that time postulated settings for SW England were diverse; an ensialic back arc basin (Floyd 1982), part of a trans-Europe oblique shear zone (Badham 1982), and an intracontinental fold belt (Matthews 1984). The Gramscatho flysch (Hendriks 1949) and associated Lizard ophiolite (Strong et al. 1975; Styles & Kirby 1980) in southern Cornwall were seen by Barnes & Andrews (1986) as representing a small intracontinental basin generated in an E–W strike–slip zone across northern Europe. In contrast Holder & Leveridge (1986b) interpreted those as products of the closure of a more extensive oceanized basin. Correlation and continuity of stratigraphies and structures between SW England and central Europe (Holder & Leveridge 1986a) appeared to enhance the concept of an E–W linear Europe-wide Rhenohercynian oceanized zone and collision belt (Franke 1989). By extrapolation of Kossmat’s zones through western Europe into Iberia (Fig. 10.2), Franke (1989, 1992) and Matte et al. (1990) defined sublinear microplates and separating collision belts, with southerly subduction zones in the Rhenohercynian and Saxothuringian and northerly subduction beneath the Moldanubian. Dextral interplate movements and small oblique basins were reinvoked, however, for SW England by Holdsworth (1989). He speculated that the E–W ‘Start– Perranporth Line’ might represent a terrane boundary, between the ‘Old Red Sandstone’ continent to the north and an Armorican microplate to the south, with transtension actively controlling intervening Devonian basin evolution. The Rhenohercynian Zone in continental Europe is now considered to lie at or near the southern margin of the Eastern Avalonia plate (Franke 2000), the southerly of the three plates, The upper Palaeozoic Orogenic Province of SW England is a part of a belt of Devonian and Carboniferous basins that extended from Devon and Cornwall through to Germany, some 800 km to the east. Their complex sequence of basin development and phases of deformation, described in this chapter cumulatively comprise the Variscan Orogeny in this region. Synchronously with the Devonian events within the Variscan Orogen, the mainly fluvial facies of the Old Red Sandstone filled basins in the Avalonian continent north of the Variscan front (Chapter 6). During the succeeding Carboniferous, basins within the continent were mainly extensional in origin, until a period in the late Carboniferous when many basement faults were inverted (Chapter 7) resulting in uplift of the basin fill, that initiated a new palaeogeography at the start of the Permian. The South Wales Basin represents a transitional zone between the mobile Variscan belt and the continent to the north. This transitional position is reflected in the Devonian by the interdigitationof the Old Red Sandstone facies and marine sediments at the northern margins of the Variscan basins (Chapter 6). Throughout the Dinantian and Namurian the succession within the South Wales basin had much in common with successions in basins within the continent to the north (Chapter 7). It was not until the Silesian that Variscan deformation affected basin development and caused its deformation (see this chapter).