The Ochil Fault and the Kincardine basin: key structures in the tectonic evolution of the Midland Valley of Scotland

Abstract

The Ochil Fault, one of the most prominent tectonic features in the Midland Valley of Scotland, juxtaposes Lower Devonian volcanic rocks against late Westphalian strata, implying a possible vertical displacement of up to 4 km. The Kincardine Basin in its hanging-wall, although actively subsiding during the greater part of the Silesian, trends generally N–S, perpendicular to the Ochil Fault, and its Silesian sedimentary record shows little sign of tectonic control by that fault. It is proposed that the Ochil Fault was initiated, possibly as a sinistral strike-slip feature, in the Devonian, but acted as a sidewall fault during the early evolution of the Kincardine Basin, attributed to extension on a hypothetical pre-Brigantian fault along the Bo'ness Line on the east side of the basin until late Namurian times, when active extension ceased. Both faults were probably buried during late Namurian and Westphalian times. Reactivation of the Ochil Fault during end-Carboniferous N–S extension, dated by quartz-dolerite emplacement, was responsible for probably at least 2 km displacement. including the presently visible footwall uplift. It is suggested that the hanging wall may have contained a Permian basin, now removed.

A depositional model for spherulitic carbonates associated with alkaline, volcanic lakes

“…Half-grabens and intervening highs in the Midland Valley of Scotland were generated during the Early Carboniferous by N-S oriented fault systems, with a right lateral strike-slip component (Rippon et al, 1996). The Carboniferous strata are divided into the Inverclyde (Tournasian) and Strathclyde (Viséan) Groups (Whyte, 1993 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 6 climate and collectively referred to as Lake Cadell (Greensmith, 1968) (Fig.…”

New insights from 3D geological models at analogue CO 2 storage sites in Lincolnshire and eastern Scotland, UK

“…Clearly, the East Ochil Fault existed as an active feature during Visean and Namurian development of the Midlothian-Leven Syncline and associated growth folds. Rippon et al (1996) described an active West Ochil Fault from Lower Devonian to Namurian times. In the light of recent work documenting less than 30 km of post-Early Devonian lateral movement on the Highland Boundary Fault (Tanner 2008), the East and West Ochil faults possibly played a more significant role in the Carboniferous dextral strike-slip evolution of the eastern Midland…”

Thermal and burial history modelling in the Midlothian-Leven syncline in the Midland Valley of Scotland using BasinMod and HotPot

“…The MVS is bounded by the Caledonide Highland Boundary Fault to the north and the Southern et al 1996;Rippon et al 1996).…”

“…The thermal and burial history modelling indicates up to 1.9 km of additional burial of Carboniferous strata compared to present day levels: up to 660 m deposited by the end of the Carboniferous period subsequently removed by Variscan uplift and erosion, followed by up to 1.9 km of burial Smith 1995;Rippon et al 1996). The post-Palaeozoic history is difficult to define due to erosion and overprinting by younger tectonic events.…”

“…The post-Palaeozoic history is difficult to define due to erosion and overprinting by younger tectonic events. Carboniferous sedimentary basins exhibit faultbounded and synclinal/anticlinal structural styles typical of extensional to strike-slip settings (Read et al 2002;Rippon et al 1996;Ritchie et al 2003;Underhill et al, 2008). One such Carboniferous basin, the Midlothian-Leven syncline (Figure 1), in the eastern Midland Valley of Scotland, has been extensively studied due to a high quality seismic dataset and coastal exposures.…”