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Tjornes Zone

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Journal Article
Published: 06 April 2018
Petroleum Geoscience (2018) 24 (4): 414–424.
... of Tjörnes (the Tjörnes Fracture Zone) and the Theistareykir Fissure Swarm of the Northern Rift Zone. This fissure swarm contains two north-trending central graben that are apparently shifted in a sinistral motion across a WNW-trending fault of the transform zone (the Stórihver Fault). The present analysis...
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(a) Map of the Tjörnes fracture zone (TFZ) in north Iceland, with the thick red line showing the main fault traces of the Húsavík‐Flatey fault (HFF), the thin red lines secondary fault traces of the HFF, and the dashed red lines inferred faults. The TFZ connects the Northern volcanic zone (NVZ) to the Kolbeinsey ridge (KR). Black circles show the instrumental seismicity from the Icelandic Meteorological Office (IMO) catalog, red circles show the Mw >4 earthquakes for the period 1900–2019, from the Iceland and the Northern Mid‐Atlantic Ridge (ICEL‐NMAR) catalog (Jónasson et al., 2021), and white stars show the historical earthquakes. The dashed black frame shows the location of panel (b). The black arrow in the inset shows the spreading direction and spreading rate of Eurasia at this location with respect to North America. (b) Enlargement of the HFF indicating the locations of the Traðargerði and Vestari‐Krubbsskál study sites. Red lines are fault traces. Yellow and black lines are offshore and onshore volcanic fissures, respectively. EB, Eyjafjarðaráll basin; EVZ, Eastern Volcanic Zone; EU, Eurasia plate; GOR, Grímsey oblique rift; NA, North America plate; RR, Reykjanes ridge; SISZ, South Iceland Seismic Zone; and WVZ, Western Volcanic Zone. The offshore faults have been mapped from multibeam bathymetry data, courtesy of Bryndís Brandsdóttir from the University of Iceland. The color version of this figure is available only in the electronic edition.
Published: 28 March 2024
Figure 1. (a) Map of the Tjörnes fracture zone (TFZ) in north Iceland, with the thick red line showing the main fault traces of the Húsavík‐Flatey fault (HFF), the thin red lines secondary fault traces of the HFF, and the dashed red lines inferred faults. The TFZ connects the Northern volcanic
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Transform zones in north and south Iceland. (a) Tjörnes Fracture Zone (TFZ) with overall dextral slip is composed of three seismically active strands (Dalvik Lineament, Húsavík-Flatey Fault Zone, and Grímsey Oblique Rift (GOR)) and links spreading segments of the northern rift zone (NRZ) with the Kolbeinsey Ridge (KR). The Eyjafjarðaráll Basin is a retreating segment of the KR. Volcanic centers (Mánáreyjar, Nafir, Hollinn, and Stóragrunn) and basins (e.g., Skjálfandadjúp) along the GOR are linked by seismically defined fault zones. (b) Oblique spreading on the Reykjanes Peninsula (RP) is linked to the eastern rift zone (ERZ) by the overall sinistral-slipping South Iceland seismic zone (SISZ). Very similar trends of volcanic centers and fault orientations occur along strike to the east–northeast in the Hreppar Block. North–south-trending, dextral strike-slip faults (black lines) of the SISZ overprint older oblique rifting structures. The western rift zone (WRZ) is in the process of being abandoned as the ERZ propagates to the south. Fissure swarms (yellow) related to active volcanic systems (or spreading segments) (after Hjartardóttir et al. 2015a, 2016). Inset shows locations of transform zones and regional spreading direction (bold arrows). RR, Reykjanes Ridge. [Color online.]
Published: 15 February 2019
Fig. 3. Transform zones in north and south Iceland. ( a ) Tjörnes Fracture Zone (TFZ) with overall dextral slip is composed of three seismically active strands (Dalvik Lineament, Húsavík-Flatey Fault Zone, and Grímsey Oblique Rift (GOR)) and links spreading segments of the northern rift zone (NRZ
Journal Article
Journal: Palynology
Published: 01 June 2012
Palynology (2012) 36 (1): 10–25.
...Koen Verhoeven; Stephen Louwye Abstract A new protoperidiniacean dinoflagellate cyst species recorded from the Lower Pliocene Serripes Zone of the Tjörnes beds in northern Iceland is formally described and its palaeoecological preferences are evaluated. Selenopemphix islandensis sp. nov. is a thin...
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Geological map of the Tjörnes Peninsula, northern Iceland. Modified after Eiríksson (1981). The surface circulation patterns around Iceland are adapted from Marret and Zonneveld (2003). EGC: East Greenland Current; EIC: East Icelandic Current; IC: Iceland Current; NAC: Norwegian Atlantic Current. The location of the Mid Atlantic Rift zone through Iceland is indicated, modified after Thordarson and Höskuldsson (2006). TFZ: Tjörnes Fracture Zone; RR: Reykjanes Ridge; KR: Kolbeinsey Ridge.
Published: 01 June 2012
Atlantic Current. The location of the Mid Atlantic Rift zone through Iceland is indicated, modified after Thordarson and Höskuldsson (2006) . TFZ: Tjörnes Fracture Zone; RR: Reykjanes Ridge; KR: Kolbeinsey Ridge.
Journal Article
Published: 01 November 1995
Journal of the Geological Society (1995) 152 (6): 1011–1015.
...Agust Gudmundsson Abstract The Tjörnes fracture zone in North Iceland and the South Iceland seismic zone are ocean-ridge discontinuities that are partly exposed on land. These are zones of high seismicity, but contrasting style of crustal deformation. Detailed field studies and numerical modelling...
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Photomicrographs of Selenopemphix species with a comparable morphology to Selenopemphix islandensis sp. nov. Scale bars indicate 20 μm and arrows show the archeopyle. EF: England Finder coordinates. Figures 1, 2. Selenopemphix dionaeocysta, Tjörnes beds, Tapes Zone, slide WP 98, EF: H52/4, apical view. Figure 3. Selenopemphix? sp. 3 Head and Norris (1989); Kallo −92.6m, slide 2, EF: Q58/1, antapical view, De Coninck (1999). Figure 4. Selenopemphix? sp. 3 Head and Norris (1989); Kallo, −92.6m, slide 2, EF: O39/3, De Coninck, (1999). Figures 5–7. ?Selenopemphix brevispinosa, Tjörnes beds, Serripes Zone, slide WP 10, EF: E42/3, equatorial view. Figure 8. Selenopemphix brevispinosa, Tjörnes beds, Serripes Zone, slide WP 9, EF: Z41/0, antapical view. Figures 9, 10. Selenopemphix coronata, Kallo, −115 m, slide 5, R46/0, antapical view, De Coninck (1995). Figure 11. Selenopemphix selenoides, Kallo, −106 m, slide 1, EF: U41/3; antapical view, De Coninck (1999). Figure 12. Selenopemphix selenoides, Kallo, −96 m, slide 1, EF: D46/2, antapical view, De Coninck (1999).
Published: 01 June 2012
Plate 3 Photomicrographs of Selenopemphix species with a comparable morphology to Selenopemphix islandensis sp. nov. Scale bars indicate 20 μ m and arrows show the archeopyle. EF: England Finder coordinates. Figures 1, 2. Selenopemphix dionaeocysta , Tjörnes beds, Tapes Zone, slide WP 98
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Map of Iceland showing variation in age of lava flows (including coeval volcaniclastic deposits) and distribution of volcanic systems. The neovolcanic zone is characterized by young Holocene lavas. Volcanic systems are concentrated within the Central Rift Zone of Iceland, which is a part of the neovolcanic zone. Also shown are the main ocean ridge discontinuities: Tjörnes Fracture Zone, Kolbeinsey Ridge, and Reykjanes Ridge.
Published: 01 July 2006
is a part of the neovolcanic zone. Also shown are the main ocean ridge discontinuities: Tjörnes Fracture Zone, Kolbeinsey Ridge, and Reykjanes Ridge.
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Schematic geologic map of Iceland (after Thordarson and Hoskuldsson 2002) with sample locations. Major tectonic features: Western Volcanic Zone (WVZ), Eastern Volcanic Zone (EVZ), Northern Volcanic Zone (NVZ), Reykjanes Volcanic Belt (RVB), Kolbeinsey Ridge (KR), Snæfellsnes Volcanic Belt (SVB), Öræfi Volcanic Belt (ÖVB), South Iceland Seismic Zone (SISZ), Mid-Icelandic Seismic Belt (MIB), and Tjörnes Fracture Zone (TFZ). Extrusive volcanic samples (triangles): (1) Hrafnfjörður, (2) Árnes, (3) Króksfjörður, (4) Hafnarfjall-Skarðsheiði, (5) Kerlingarfjoll, (6) Stóra-Laxá, (7) Hekla, (8) Torfajökull, (9) Krafla, (10) Öræfajökull. Intrusive samples (diamonds): (11) Snæfellsnes-Knörr, (12) Viðidalsfjall, (13) Laxardálsfjöll, (14) Vesturhorn, (15) Slaufrudalur, (16) Austurhorn, (17) Sandfell. Detrital samples (circles: modern river sediments; squares: ancient sedimentary rocks): (18) Miðá, (19) Markarfljót, (20) Lagarfljót, (21) Jökulsá í Lóni, (22) Fjardarsá, (23) Breiðavík-Kækjuskörđ (note: this sample includes detrital zircon and volcanic whole-rock material from an ignimbrite eroding to form the stream sediments), (24) Selardalur, (25) Húsavíkurkleif, (26) Tjörnes. The colors used in this figure to highlight specific tectonic settings and samples are consistent with the colors used in subsequent figures (e.g., figs. 2, 3, 5–9, 11, and 12).
Published: 01 January 2020
Belt (SVB), Öræfi Volcanic Belt (ÖVB), South Iceland Seismic Zone (SISZ), Mid-Icelandic Seismic Belt (MIB), and Tjörnes Fracture Zone (TFZ). Extrusive volcanic samples (triangles): (1) Hrafnfjörður, (2) Árnes, (3) Króksfjörður, (4) Hafnarfjall-Skarðsheiði, (5) Kerlingarfjoll, (6) Stóra-Laxá, (7) Hekla
Image
Asymmetrical migration of transform deformation related to rift propagation. (a) Oblique rift zone with right-stepping, pull-apart basins and volcanic centers (white ovals) linked by dextral fault zones changes to an orthogonal trend (parallel to plate motion) by rift propagation abandoning older structures in its wake across the gray area (similar to the Tjörnes Fracture Zone). (b) Same for left-stepping oblique rift zone, similar to south Iceland. [Color online.]
Published: 15 February 2019
abandoning older structures in its wake across the gray area (similar to the Tjörnes Fracture Zone). ( b ) Same for left-stepping oblique rift zone, similar to south Iceland. [Color online.]
Journal Article
Journal: Palynology
Published: 01 June 2014
Palynology (2014) 38 (1): 38–50.
... of new acritarch species. Halodinium eirikssonii n. sp. is recovered from the lower Pliocene Serripes Zone of the Tjörnes beds in northern Iceland, where its range is well constrained through magnetostratigraphy and biostratigraphy using dinoflagellate cysts. Leiosphaeridia spongiosa n. sp. is recovered...
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Figure 1. Shortening axes derived from calcite-twin analysis. A: Ridge-normal positive expected value (PEV) data (bold lines). B: Ridge-parallel negative expected value (NEV) data; plunge angles are indicated by bold arrows. See data in Table 1 and Figure DR-1 (stereonets; see footnote 1). TFZ—Tjornes fracture zone; SISZ—South Iceland shear zone; NVZ—northern volcanic zone; WVZ—western volcanic zone; EVZ—eastern volcanic zone
Published: 01 January 2004
Tjornes fracture zone; SISZ—South Iceland shear zone; NVZ—northern volcanic zone; WVZ—western volcanic zone; EVZ—eastern volcanic zone
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Geological setting of Iceland based on the geological map of Iceland (Johannesson & Saemundsson 1988). Iceland is located both on the Mid-Atlantic Ridge and on a mantle plume. Three main rift zones link the Reykjanes Ridge in the SW and the Kolbeinsey Ridge in the north: the East Volcanic Zone (EVZ), the West Volcanic Zone (WVZ) and the North Volcanic Zone (NVZ). These rift zones are connected to each other by transform fault systems such as the South Iceland Seismic Zone (SISZ), the Mid Iceland Belt (MIB) and the Tjörnes Fracture Zone (TFZ). SnVZ, Snaefellsnes Volcanic Zone.
Published: 01 March 2010
Volcanic Zone (EVZ), the West Volcanic Zone (WVZ) and the North Volcanic Zone (NVZ). These rift zones are connected to each other by transform fault systems such as the South Iceland Seismic Zone (SISZ), the Mid Iceland Belt (MIB) and the Tjörnes Fracture Zone (TFZ). SnVZ, Snaefellsnes Volcanic Zone.
Series: Geological Society, London, Special Publications
Published: 01 January 2016
DOI: 10.1144/SP420.1
EISBN: 9781862391345
..., and at the junction of the NVZ and the Tjörnes Fracture Zone, where high fracture densities also occur. WNW-orientated fractures at the southern end of the Krafla Fissure Swarm, and the northern end of the Kverkfjöll Fissure Swarm, exhibit surface expressions of a transform zone. The fissure swarms within the rift...
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Journal Article
Published: 15 February 2019
Canadian Journal of Earth Sciences (2019) 56 (12): 1297–1308.
...Fig. 3. Transform zones in north and south Iceland. ( a ) Tjörnes Fracture Zone (TFZ) with overall dextral slip is composed of three seismically active strands (Dalvik Lineament, Húsavík-Flatey Fault Zone, and Grímsey Oblique Rift (GOR)) and links spreading segments of the northern rift zone (NRZ...
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Seismicity along the Iceland plate boundary zones. Active rift zones are marked by fissure (and dike) swarms (yellow) and central volcanoes (black outlines) (Einarsson 2008; Einarsson and Sæmundsson 1987; Hjartardóttir et al. 2015a; Jóhannesson and Sæmundsson 1998). DL, Dalvik Lineament; ERZ, eastern rift zone; GOR, Grímsey Oblique Rift; HFF, Húsavík-Flatey Fault; KR, Kolbeinsey Ridge; NRZ, northern rift zone; RP, Reykjanes Peninsula; RR, Reykjanes Ridge; SAR, Skagi Abandoned Rift; SISZ, South Iceland seismic zone; TFZ, Tjörnes Fracture Zone; V, Vatnajökull Glacial Icecap; WRZ, western rift zone. Map and epicenters from the Icelandic Meteorological Office provided by Gunnar B. Guðmundsson. [Color online.]
Published: 15 February 2019
Lineament; ERZ, eastern rift zone; GOR, Grímsey Oblique Rift; HFF, Húsavík-Flatey Fault; KR, Kolbeinsey Ridge; NRZ, northern rift zone; RP, Reykjanes Peninsula; RR, Reykjanes Ridge; SAR, Skagi Abandoned Rift; SISZ, South Iceland seismic zone; TFZ, Tjörnes Fracture Zone; V, Vatnajökull Glacial Icecap; WRZ
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Locations of 1 month of aftershocks (blue circles) following the 15:45 UTC 29 May 2008 magnitude 6.3 earthquake (red star marks the epicenter) in the South Iceland Seismic Zone (SISZ), which ruptured two parallel faults (approximated by the black dashed lines).
Published: 01 February 2022
shows the present-day rift axis of the Mid-Atlantic Ridge (gray line) in Iceland, with the Tjörnes Fracture Zone (TFZ) in the north and the SISZ indicated by the yellow shaded areas; the red rectangle marks the area shown in the main figure. The top left inset shows the locations of the ICEARRAY strong
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Map of Iceland, including major tectonic features, volcanic systems mentioned in this study, and the general field area and sample locations for this study. Major tectonic features: WVZ—Western Volcanic Zone; EVZ—Eastern Volcanic Zone; NVZ—Northern Volcanic Zone; RVB—Reykjanes Volcanic Belt; KR—Kolbeinsey Ridge; SVB—Snæfellsness Volcanic Belt; OVB—Öræfi Volcanic Belt; SISZ—South Iceland Seismic Zone; MIB—Mid-Iceland Belt; TFZ—Tjörnes Fracture Zone. Volcanic systems: Lj—Ljósufjöll; Ker—Kerlingarfjöll; Hk—Hekla; To—Torfajökull; Or—Öræfajökull; As—Askja; Kra—Krafla; Th—Thingmuli. Field area and samples (general area is the Borgarfjörđur eystri); Hv—Hvítserkur, volcanic landform in area; ISS and ISKK—detrital samples. The base map is modified from Thordarson and Hoskuldsson (2002).
Published: 27 July 2017
Belt; KR—Kolbeinsey Ridge; SVB—Snæfellsness Volcanic Belt; OVB—Öræfi Volcanic Belt; SISZ—South Iceland Seismic Zone; MIB—Mid-Iceland Belt; TFZ—Tjörnes Fracture Zone. Volcanic systems: Lj—Ljósufjöll; Ker—Kerlingarfjöll; Hk—Hekla; To—Torfajökull; Or—Öræfajökull; As—Askja; Kra—Krafla; Th—Thingmuli. Field
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Photomicrographs of Selenopemphix islandensis sp. nov., all specimens from the Serripes zone of the Tjörnes beds. Scale bars indicate 20 μm and arrows show the archeopyle. EF: England Finder coordinates. Figures 1–3. Holotype, slide WP22, EF: K48/1, antapical view. Figures 4–5. Slide WP6, EF: X56/2, antapical view. Figures 6–8. Slide WP23, EF: X41/4, antapical view. Figures 9–10. Slide WP23, EF: R32/2, apical view. Figures 11–12. Slide WP20, EF: A64/3, apical view.
Published: 01 June 2012
Plate 1 Photomicrographs of Selenopemphix islandensis sp. nov., all specimens from the Serripes zone of the Tjörnes beds. Scale bars indicate 20 μ m and arrows show the archeopyle. EF: England Finder coordinates. Figures 1–3. Holotype, slide WP22, EF: K48/1, antapical view. Figures 4–5
Journal Article
Published: 01 April 1996
Journal of the Geological Society (1996) 153 (2): 185–189.
.... E. Pinet P. Plate boundary within Tjornes fracture zone on northen Iceland's insular margin Nature 1977 269 663 668 Mitchell N. C. An evolving ridge system around the Indian Ocean triple junction Marine Geophysical Researches 1991 13 173 201 Murton B. J...