Surface and subsurface fault mapping in the Yorkshire Wolds, UK

2020 ◽  
Author(s):  
Rowan Vernon ◽  
Jon Ford ◽  
Katie Watkinson ◽  
Richard Haslam ◽  
Mark Woods ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Geological Mapping ◽  
Fault System ◽  
British Geological Survey ◽  
Field Mapping ◽  
Northern Margin ◽  
The North ◽  
Passive Seismic ◽  
History Of ◽  
Environment Agency

<p>The Flamborough Head Fault Zone (FHFZ) marks the southern extent of the Cleveland Basin and the northern margin of the Market Weighton Block, England. It is a regionally-significant structural zone which has undergone a complex history of Mesozoic-Cenozoic extension and compression. It is predominantly comprised of east-west trending faults which form a graben that is dissected by north-south trending faults, including the southern extension to the Peak Trough, the Hunmanby Fault. To the west, FHFZ links with the Howardian Fault System and offshore, in the east, it is truncated by the north-south trending Dowsing Fault. The FHFZ is well exposed and described from coastal cliff sections at Flamborough Head but the inland development of the faults have hitherto been poorly explored predominantly due to limited inland-exposure.</p><p>The region around the FHFZ is underlain by the Chalk Group, a 500 m thick limestone succession. The Chalk Group is a principal aquifer that is the main source of water supply in East Yorkshire. The geometry and physical characteristics of the Chalk succession, including the effects of faulting, influence groundwater flow across the region. A range of modern data and recent geological research highlight that considerable changes can be made to the region’s current geological maps and subsurface understanding. Ensuring these features are better-documented is key for up-dating groundwater models to enable more confident decisions about land-use, water management and environmental regulation.</p><p>A multi-faceted approach to geological mapping has been undertaken in the region by the British Geological Survey (BGS), in collaboration with the Environment Agency. Remote sensing and field mapping of the superficial deposits has better characterised the extent and nature of these deposits and identified potential recharge ‘windows’ into the bedrock. Remote sensing, targeted field mapping, palaeontological analysis, passive seismic and 2D onshore seismic interpretation have been integrated to produce a new map of the Chalk succession, which reveals the inland extension of the FHFZ in unprecedented detail. Combining these techniques has enabled us to bridge the gap between the surface geology and deeper subsurface structure, increase our understanding of the geology of the region and produce an improved conceptual model at a range of depths which will be used to better manage water resources.</p>

scholarly journals EVOLUTION OF KARAKORAM SEQUENCE, HUNZA VALLEY NE PAKISTAN: EVIDENCES FROM FIELD MAPPING AND MICRO-ANALYTICAL WORK

2020 ◽  
Vol 5 ◽  
pp. 19
Author(s):  
S. S. Baig ◽  
C. Xue ◽  
Masroor Alam ◽  
Naeem Ullah ◽  
M. Alam ◽  
...  
Keyword(s):  
Geological Mapping ◽  
Central Portion ◽  
High Grade ◽  
Metamorphic Complex ◽  
Field Mapping ◽  
The North ◽  
Analytical Work ◽  
History Of ◽  
Micro Analysis ◽  
East West

The Karakoram metamorphic Complex (KMC) in the southern Karakoram block is one of the best examples of Barrovian type metamorphism that comprises numerous exhumed metapelite units where a series of low to high grade (green schist to sillimanite facie) rocks are exposed. This sequence shows a complex polyphase history of metamorphism and deformation which offer deeper understanding of collision orogeny. Karakoram metamorphic Complex contains metapelites, meta-carbonates, meta-igneous and amphibolite layers, cross-cut by granite sheets in the northern part. This complex is bounded to the north by the Hunza plutonic unit which is the central portion of the massive east-west trending Karakoram axial batholith and to the southwest by the Main Karakoram thrust (MKT). In this contribution, we provide detail geological mapping, petrography, geochemistry and micro-analytical work using Electron Prob-micro analysis in the central Hunza Valley.

III.—The Pre-Cambrian Rocks of Wales

1893 ◽  
Vol 10 (9) ◽  
pp. 396-401
Author(s):  
Henry Hicks
Keyword(s):  
Recent Article ◽  
British Isles ◽  
The West ◽  
British Geological Survey ◽  
England And Wales ◽  
North West ◽  
The Past ◽  
The North ◽  
History Of ◽  
Lithological Character

In a recent article on the Pre-Cambrian Rocks of the British Isles in the Journal of Geology, vol. i., No. 1, Sir Archibald Geikie makes the following statement: “There cannot, I think, be now any doubt that small tracts of gneiss, quite comparable in lithological character to portions of the Lewisian rocks of the North-West of Scotland, rise to the surface in a few places in England and Wales. In the heart of Anglesey, for example, a tract of such rocks presents some striking external or scenic resemblance to the characteristic types of ground where the oldest gneiss forms the surface in Scotland and the West of Ireland.” To those who have followed the controversy which has been going on for nearly thirty years between the chiefs of the British Geological Survey and some geologists who have been working amongst the rocks in Wales, the importance of the above admission will be readily apparent; but as it is possible that some may be unable to realize what such an admission means in showing geological progress in unravelling the history of the older rocks in Wales during the past thirty years, a brief summary of the results obtained may possibly be considered useful.

scholarly journals Seismological Investigations in the Olduvai Basin and Ngorongoro Volcanic Highlands (Western Flank of the North Tanzanian Divergence)

2020 ◽  
Vol 91 (6) ◽  
pp. 3286-3303 ◽  
Author(s):  
Laura Parisi ◽  
Ian Stanistreet ◽  
Jackson Njau ◽  
Kathy Schick ◽  
Nicholas Toth ◽  
...  
Keyword(s):  
Sedimentary Basins ◽  
Quality Analysis ◽  
Fault System ◽  
Conservation Area ◽  
Data Set ◽  
The North ◽  
Western Flank ◽  
Passive Seismic ◽  
African Rift ◽  
Western Side

Abstract We present data and results of a passive seismic experiment that we operated between June 2016 and May 2018 in the Ngorongoro Conservation Area (northern Tanzania), located on the western side of the eastern branch of the Eastern African Rift (EAR) system. The motivation for this experiment is twofold: (1) investigating the extension of the Olduvai basin, referred to also as the “Cradle of Human Mankind,” as it hosted a variety of paleoenvironments exploited by hominins during their evolution; and (2) studying the link between the fault system in the main EAR and in its western flank. We conduct detailed data-quality analysis of the seismic recordings based upon ambient noise characterization and numerical waveform simulations. Our data set is of good quality, and we observe that local magnitude can be overestimated up to at least 0.23, due to wave-amplifications effects occurring at sites with loose sedimentary material. Based on a new but simple approach using power spectral density measurements, we calculate the thickness of sedimentary basins. This allows us to map the bottom of the Olduvai paleolake confirming that its sedimentary record may be at least 200 m deeper than previously inferred from core drilling. We also map the bottom of the Olbalbal depression for the first time. In addition, we present a seismicity map of the Ngorongoro Conservation Area with unprecedented detail. The seismicity depicts the suture zone between the Tanzanian craton and the Mozambique belt and reveals that the fault system in the western flank of the rift merges at depth into a single detachment that joins the Manyara fault on the western side of the main rift valley.

Geological mapping of the 1985 Chinese—British Tibetan (Xizang—Qinghai) Plateau Geotraverse route

1988 ◽  
Vol 327 (1594) ◽  
pp. 287-305 ◽  
Keyword(s):  
Strike Slip ◽  
Geological Mapping ◽  
Strike Slip Fault ◽  
Fault System ◽  
Late Triassic ◽  
Clastic Rocks ◽  
The North ◽  
Opposite Sequence ◽  
Geological Map ◽  
Qiangtang Terrane

The 1:500,000 coloured geological map of the traverse route combines observations from the Geotraverse, previous mapping, and interpretation of orbital images. The position of all localities visited by Geotraverse participants and basic geological data collected by them along the traverse route are shown on a set of maps originally drawn at 1:100,000 scale, reproduced on microfiche for this publication. More detailed mapping, beyond a single line of section, was achieved in five separate areas. The relationships between major rock units in these areas, and their significance, are outlined in this paper. Near Gyanco, (Lhasa Terrane) an ophiolite nappe, apparently connected with outcrops of ophiolites in the Banggong Suture about 100 km to the north, was under thrust by a discontinuous slice of Carboniferous—Permian clastic rocks and limestone, contrary to a previous report of the opposite sequence. At Amdo, a compressional left-lateral strike-slip fault zone has modified relationships along the Banggong Suture. Near Wuli, (northern Qiangtang Terrane) limited truncation of Triassic strata at the angular unconformity below Eocene redbeds demonstrates that most of the folding here is of Tertiary age. The map of the nearby Erdaogou region displays strong fold and thrust-shortening of the Eocene redbeds, evidence of significant crustal shortening after the India- Asia collision began. In the Xidatan-Kunlun Pass area, blocks of contrasting Permo—Triassic rocks are separated by east-trending faults. Some of these faults are ductile and of late Triassic — early Jurassic age, others are brittle and part of the Neogene—Quaternary Kunlun leftlateral strike-slip fault system. Some more significant remaining problems that geological mapping might help to solve are discussed briefly, including evidence for a possible additional ophiolitic suture within the Qiangtang Terrane.

scholarly journals Chapter 4. Paleozoic granitoid magmatism of South and Middle Tien Shan in Uzbekistan

2020 ◽  
pp. 102-163
Author(s):  
Dmitry L. Konopelko ◽  
Keyword(s):  
Early Carboniferous ◽  
Tien Shan ◽  
Passive Margin ◽  
Granitoid Magmatism ◽  
Northern Margin ◽  
The North ◽  
History Of ◽  
Different Depths ◽  
Andean Type ◽  
Tectonic Settings

The Paleozoic evolution of the Southern and Middle Tien Shan terranes is generally associated with the history of two ocean basins - the Turkestan and Paleotethys. Ages of ophiolites indicate the opening of the oceans in Cambrian – Ordovician, and partial closure with formation of an island arc in the northern part of the basin in Ordovician - Silurian. At the northern margin of the Turkestan ocean, the northward subduction under the Middle Tien Shan continued until Devonian, which led to formation of an active margin with granitoids emplaced between 429 and 416 Ma. In the late Devonian, subduction-related magmatism terminated and the whole region developed as passive margin. Northward subduction resumed in the early Carboniferous and formed magmatic Andean-type belt exposed in the Chatkal-Kurama terrane. Late Carboniferous collision resulted in crust thickening and emplacement of postcollisional granitoids. Formation of postcollisional intrusions in different terranes took place in various tectonic settings. Shoshonitic granitoids of the Chatkal-Kurama terrane formed as a result of slab break off at postcollisional stage. Voluminous postcollisional magmatism of Kyzylkum can be explained by delamination of lower crust and its replacement by the material of astenospheric mantle. Coeval emplacement of geochemically contrasting granitoids in the North Nuratau fault zone could result from contemporaneous melting of different protoliths at different depths in a translithospheric shear zone.

scholarly journals Volkanostratigrafi Inderaan Jauh Kompleks Gunungapi Gede dan Sekitarnya, Jawa Barat, Indonesia

2019 ◽  
Vol 20 (1) ◽  
pp. 9
Author(s):  
Fitriani Agustin ◽  
Sutikno Bronto
Keyword(s):  
Remote Sensing ◽  
Geological Mapping ◽  
Lava Flows ◽  
Energy Resources ◽  
Visual Interpretation ◽  
Remote Sensing Technology ◽  
Sensing Technology ◽  
Digital Elevation ◽  
History Of ◽  
Elevation Model

Remote sensing technology greatly helps to identify the various of volcano features, including active, old and ancient volcanoes. The aim of this  paper is intended to introduce various volcanic features in the Gede Volcano Complexs (GVC) and souronding area; compose volcanostratigraphy; and estimate the history of the volcanoes. The method used is a visual interpretation 9 meters spatial resolution of Digital Elevation Model (DEM) TerraSar-x image. Indonesian Stratigraphy Nomenclature Guide 1996 was implemented in vocanostratigraphy unit classification, involving Arc, Super Brigate, Brigate, Crown and Hummockly. Based on the interpretation the DEM image, volcanostratigraphic unit the Gede Volcano Complex consists of Bregade Masigit (Br. M.), which consists of Joklok (Gm.J.) and Gegerbentang (Gm.G.) Hummocs; Crown Lingkung (Kh.L.) consisting of Pangrango (Gm.P.), Situ Gunung (Gm Sg.), Cikahuripan (Gm.Ck.), Pasir Prahu (Gm.Ph) Hummocs; Gege Crown (Kh.G.), which is located in the east of Lingkung Crown. The Gede Crown consists of Gumuruh humock (Gm.Gh.), Gunung Gede lava flows (LG 1,2,3,4,5), and giant debrise avalances (gv-G). The geological mapping based volcanostratigraphy is very useful for exploration of mineral and energy resources, as well as geological hazards.Keywords : volcanostratigraphy, DEM TerraSar-x image, Gunung Gede Complexs.

scholarly journals A review of the Pan-African evolution of the Arabian Shield

GeoArabia ◽  
2002 ◽  
Vol 7 (1) ◽  
pp. 103-124 ◽  
Author(s):  
Pierre Nehlig ◽  
Antonin Genna ◽  
Fawzia Asfirane ◽  
C. Guerrot ◽  
J.M. Eberlé ◽  
...  
Keyword(s):  
Structural Evolution ◽  
Sedimentary Basins ◽  
Fault Zones ◽  
Fault System ◽  
Arabian Shield ◽  
Geologic History ◽  
Lower Paleozoic ◽  
The North ◽  
Pan African ◽  
History Of

ABSTRACT Recent fieldwork and the synthesis and reappraisal of aeromagnetic, geologic, structural, geochemical, and geochronologic data have provided a new perspective on the structural evolution and geologic history of the Arabian Shield. Although Paleoproterozoic rocks are present in the eastern part of the Shield, its geologic evolution was mainly concentrated in the period from 900 to 550 Ma during which the formation, amalgamation, and final Pan-African cratonization of several tectonostratigraphic terranes took place. The terranes are separated by major NW-trending faults and by N-, NW- and NE-oriented suture zones lined by serpentinized ultramafic rocks (ophiolites). Terrane analysis using the lithostratigraphy and geochronology of suture zones, fault zones, overlapping basins, and stitching plutons, has helped to constrain the geologic history of the Arabian Shield. Ophiolites and volcanic-arcs have been dated at between 900 and 680 Ma, with the southern terrane of Asir being older than the Midyan terrane in the north and the Ar Rayn terrane in the east. Final cratonization of the terranes between 680 and 610 Ma induced a network of anastomosing, strike-slip faults consisting of the N-trending Nabitah belt, the major NW-striking left-lateral transpressive faults (early Najd faults), lined by gneiss domes and associated with sedimentary basins, and N- to NE-trending right-lateral transpressive faults. Following the Pan-African cratonization, widespread alkaline granitization was contemporaneous with the deposition of the Jibalah volcanic and sedimentary rocks in transtensional pull-apart basins. Crustal thinning was governed by the Najd fault system of left-lateral transform faults that controlled the formation of the Jibalah basins and was synchronous with the emplacement of major E- to NW-trending dike swarms throughout the Arabian Shield. The extensional episode ended with a marine transgression in which carbonates were deposited in the Jibalah basins. Continuation of the thinning process may explain the subsequent deposition of the marine formations of the lower Paleozoic cover. Our interpretation of the distribution and chronology of orogenic zones does not correspond entirely to those proposed in earlier studies. In particular, the N-trending Nabitah and NW-trending Najd fault zones are shown to be part of the same history of oblique transpressional accretion rather than being two distinct events related to accretion and dispersion of the terranes.

The margins of Avalonia

1997 ◽  
Vol 134 (5) ◽  
pp. 627-636 ◽  
Author(s):  
L. R. M. COCKS ◽  
W. S. MCKERROW ◽  
C. R. VAN STAAL
Keyword(s):  
Nova Scotia ◽  
Cape Cod ◽  
The South ◽  
Cape Breton Island ◽  
Northern Margin ◽  
The North ◽  
Southern Margin ◽  
Iapetus Ocean ◽  
History Of ◽  
Meguma Terrane

During Cambrian and earliest Ordovician times, Avalonia was an area forming an integral part of the huge Gondwanan continent, probably along the northern margin of Amazonia, until in early Ordovician (late Arenig or Llanvirn) time it split off from Gondwana, leaving a widening Rheic Ocean to its south. Today, its southern margin with Gondwana extends northeast from east of Cape Cod, Massachusetts, through Nova Scotia north of the Meguma terrane, and thence below sea level to the south of Newfoundland. On the eastern side of the present Atlantic, the southern margin may separate southwest Portugal from the rest of the Iberian Peninsula; it can be traced eastwards with more certainty from the south Cornwall nappes to a line separating the Northern Phyllite Belt (on the southern margin of the Rhenohercynian terrane) and the Mid-German Crystalline High. There is no certain evidence of Avalonian crust to the northeast of the Elbe Line. The northern margin of Avalonia extends westwards from south of Denmark to the British Isles, where it merges with the Iapetus Ocean suture between Scotland and England. Traced westwards, it crosses Ireland and reappears in northern Newfoundland to the east of New World Island, where it may follow the trace of the Dog Bay Line and the Cape Ray Fault. Recent work suggests that the northern margin of Avalonia may clip the northern tip of Cape Breton Island in Nova Scotia, and then enter the North American mainland at the Bay of Chaleur; it may then be traced from north and west of the Popelogan and Bronson Hill arcs to Long Island Sound near Newhaven, Connecticut. The Cambrian to Devonian faunas reflect the history of Avalonia: initially they were purely Gondwanan but, as Ordovician time proceeded, more genera crossed firstly the Tornquist Ocean as it narrowed between Avalonia and Baltica to close in latest Ordovician and early Silurian times, and secondly the Iapetus Ocean, so that by the early Silurian most of the benthic shelly faunas, apart from the ostracods, were the same round the adjacent margins of all three palaeocontinents.

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