Redefinition of the Quetico Fault near Atikokan, Ontario

1982 ◽  
Vol 19 (1) ◽  
pp. 222-224
Author(s):  
S. L. Fumerton
Keyword(s):  
The Other ◽  
Fault System ◽  
Seine River ◽  
Single Fault ◽  
New Name ◽  
Fault Systems ◽  
Little Turtle

Recent mapping has shown that west of Atikokan the Quetico Fault, which is generally considered to represent part of the boundary between the northern Wabigoon and the southern Quetico Subprovinces in this region, is composed of two separate fault systems and should not have one name. The single fault system that defines the boundary between the Quetico and Wabigoon Subprovinces in this area, and includes the Seine River Fault, should all be termed the Quetico Fault as this name has precedence. To avoid confusion, the other fault system that is entirely in the Wabigoon Subprovince should have a new name, and the term Little Turtle Fault is suggested.

scholarly journals The Role of Faults in Groundwater Circulation before and after Seismic Events: Insights from Tracers, Water Isotopes and Geochemistry

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1499
Author(s):  
Davide Fronzi ◽  
Francesco Mirabella ◽  
Carlo Cardellini ◽  
Stefano Caliro ◽  
Stefano Palpacelli ◽  
...  
Keyword(s):  
Preferential Flow ◽  
Central Italy ◽  
Tracer Tests ◽  
Integrated Approach ◽  
Fault System ◽  
Tectonic Structures ◽  
Fault Systems ◽  
Isotopic Analyses ◽  
Before And After

The interaction between fluids and tectonic structures such as fault systems is a much-discussed issue. Many scientific works are aimed at understanding what the role of fault systems in the displacement of deep fluids is, by investigating the interaction between the upper mantle, the lower crustal portion and the upraising of gasses carried by liquids. Many other scientific works try to explore the interaction between the recharge processes, i.e., precipitation, and the fault zones, aiming to recognize the function of the abovementioned structures and their capability to direct groundwater flow towards preferential drainage areas. Understanding the role of faults in the recharge processes of punctual and linear springs, meant as gaining streams, is a key point in hydrogeology, as it is known that faults can act either as flow barriers or as preferential flow paths. In this work an investigation of a fault system located in the Nera River catchment (Italy), based on geo-structural investigations, tracer tests, geochemical and isotopic recharge modelling, allows to identify the role of the normal fault system before and after the 2016–2017 central Italy seismic sequence (Mmax = 6.5). The outcome was achieved by an integrated approach consisting of a structural geology field work, combined with GIS-based analysis, and of a hydrogeological investigation based on artificial tracer tests and geochemical and isotopic analyses.

scholarly journals Seismic characteristics of polygonal fault systems in the Great South Basin, New Zealand

2020 ◽  
Vol 12 (1) ◽  
pp. 851-865
Author(s):  
Sukonmeth Jitmahantakul ◽  
Piyaphong Chenrai ◽  
Pitsanupong Kanjanapayont ◽  
Waruntorn Kanitpanyacharoen
Keyword(s):  
Three Dimensional ◽  
Late Eocene ◽  
Seismic Survey ◽  
Fault System ◽  
Normal Faults ◽  
Tier 2 ◽  
South Basin ◽  
Fault Systems ◽  
Tier 1 ◽  
Polygonal Fault

AbstractA well-developed multi-tier polygonal fault system is located in the Great South Basin offshore New Zealand’s South Island. The system has been characterised using a high-quality three-dimensional seismic survey tied to available exploration boreholes using regional two-dimensional seismic data. In this study area, two polygonal fault intervals are identified and analysed, Tier 1 and Tier 2. Tier 1 coincides with the Tucker Cove Formation (Late Eocene) with small polygonal faults. Tier 2 is restricted to the Paleocene-to-Late Eocene interval with a great number of large faults. In map view, polygonal fault cells are outlined by a series of conjugate pairs of normal faults. The polygonal faults are demonstrated to be controlled by depositional facies, specifically offshore bathyal deposits characterised by fine-grained clays, marls and muds. Fault throw analysis is used to understand the propagation history of the polygonal faults in this area. Tier 1 and Tier 2 initiate at about Late Eocene and Early Eocene, respectively, based on their maximum fault throws. A set of three-dimensional fault throw images within Tier 2 shows that maximum fault throws of the inner polygonal fault cell occurs at the same age, while the outer polygonal fault cell exhibits maximum fault throws at shallower levels of different ages. The polygonal fault systems are believed to be related to the dewatering of sedimentary formation during the diagenesis process. Interpretation of the polygonal fault in this area is useful in assessing the migration pathway and seal ability of the Eocene mudstone sequence in the Great South Basin.

scholarly journals IV.—On a New Large Terebratula occurring in East Anglia

1870 ◽  
Vol 7 (75) ◽  
pp. 410-413 ◽  
Author(s):  
E. Ray Lankester
Keyword(s):  
Simple Form ◽  
The Other ◽  
East Anglia ◽  
Mesial Line ◽  
New Name ◽  
Gravel Pit ◽  
Great Size

The forms which Mr. Davidson in his invaluable Monograph has included under T. ovoides, are so various that it would be possible to refer the shells figured in the plate to that species, but since T. trilineata, from the Inferior Oolite, and T. lata and T. ovoides, from drift-blocks—which I shall endeavour to show are of the very latest Jurassic horizon—are very different in many respects, I prefer to give a new name to this form, which may find its place near T. ovoides and T. simplex. The specimen drawn, Fig. 1 and la, is from the collection of Mr. Roper of Lowestoft, who obtained it, with another specimen, from a gravel-pit at Thorpe in Suffolk. It has the general simple form of T. ovoides, but is remarkable for its great size. The imperforate valve is flattened in the mesial line, whilst the perforate valve is deep and raised into a well-pronounced keel in the mesial line extending from the beak; the foramen is small. The specimen figured is longer than the other in Mr. Roper's collection, which has the shorter, squarer form of Fig. 2, resembling T. simplex. This fine Terebratula may be known as T. rex.

Mapping the regional tectonic asset of the Discovery quadrangle of Mercury

2021 ◽  
Author(s):  
Valentina Galluzzi ◽  
Luigi Ferranti ◽  
Lorenza Giacomini ◽  
Pasquale Palumbo
Keyword(s):  
Imaging System ◽  
Space Environment ◽  
Fault System ◽  
Geophysical Research ◽  
Fault Systems ◽  
Space Agency ◽  
Regional Tectonic ◽  
Italian Space Agency ◽  
Dual Imaging ◽  
Map Series

<p>The Discovery quadrangle of Mercury (H-11) located in the area between 22.5°S–65°S and 270°E–360°E encompasses structures of paramount importance for understanding Mercury’s tectonics. The quadrangle is named after Discovery Rupes, a NE-SW trending lobate scarp, which is one of the longest and highest on Mercury (600 km in length and 2 km high). By examining the existing maps of this area (Trask and Dzurisin, 1984; Byrne et al., 2014), several other oblique trending structures are visible. More mapping detail could be achieved by using the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Mercury Dual Imaging System (MDIS) imagery.</p> <p>We aim at mapping the structures of H-11 at high-resolution by using MESSENGER/MDIS basemaps, in order to understand its regional tectonic history by following the work done in the Victoria quadrangle (H-2) (Galluzzi et al., 2019). Differently from H-2, located in the same longitudinal range but at opposite latitudes, this area lacks in N-S trending scarps, such as the Victoria-Endeavour-Antoniadi fault system, which dominates the northern hemisphere structural framework. The existing tectonic theories predict either an isotropic pattern of faults (global contraction) or an ordered distribution and orientation of faults (tidal despinning) for Mercury. If we expect that the existing tectonic patterns were governed by only one of the two processes or both together, it is difficult to understand how such different trends formed within these two complementary areas. The structural study done for H-2 reveals that the geochemical discontinuities present in Mercury’s crust may have guided and influenced the trend and kinematics of faults in that area (Galluzzi et al., 2019). In particular, the high-magnesium region seems to be associated with fault systems that either follow its boundary or are located within it. These fault systems show distinct kinematics and trends. The south-eastern border of the HMR is located within H-11. Hence, with this study, we aim at complementing the previous one to better describe the tectonics linked to the presence of the HMR. Furthermore, this geostructural map will complement the future geomorphological map of the area and will be part of the 1:3M quadrangle geological map series which are being prepared in view of the BepiColombo mission (Galluzzi, 2019). <em>Acknowledgments: We gratefully acknowledge funding from the Italian Space Agency (ASI) under ASI-INAF agreement 2017-47-H.0.</em></p> <p>Byrne et al. (2014). Nature Geoscience, 7(4), 301-307.<br />Galluzzi, V. (2019). In: Planetary Cartography and GIS, Springer, Cham, 207-218.<br />Galluzzi et al. (2019). Journal of Geophysical Research: Planets, 124(10), 2543-2562.<br />Trask and Dzurisin (1984). USGS, IMAP 1658.</p>

Earth Sciences

2005 ◽  
Author(s):  
Glennda Chui
Keyword(s):  
Natural Hazards ◽  
Plate Tectonics ◽  
Earth Science ◽  
North Anatolian Fault ◽  
The Other ◽  
Fault System ◽  
Military Officers ◽  
Apartment Building ◽  
The North ◽  
Scientists And Engineers

In August 1999, I stood in the ruins of a collapsed apartment building near Izmit, Turkey—one of 60,000 buildings destroyed in 40 seconds by the most powerful earthquake to strike a major city in nearly a century. It was a modern building surrounded by trees and greenery. A couch and a table stood intact in a room bright with potted flowers, now open to the air. A woman's coat had been carefully draped over the remains of a wall. As the stench of death rose around us, I wondered if the coat's owner was buried in the rubble beneath my feet. I was sent to Turkey to chase the science—to bring home lessons for readers who live near a strikingly similar fault system in California. But as I surveyed the damage with a team of scientists and engineers, there was no separating the science from the politics. Covered with a fine film of sweat mixed with dust from crumbled buildings and lime that had been scattered to prevent the spread of disease, we saw firsthand how corruption and greed had conspired with the forces of nature to kill more than 17,000 people. Some buildings were constructed right on the North Anatolian Fault. Its mole-like tracks plowed through barracks that had collapsed on 120 military officers, a highway overpass that fell on a bus, a bridge whose failure cut off access and aid to four villages. Researchers found concrete that was crumbly with seashells, chunks of Styrofoam where reinforcing metal bars should have been. Yet some well-reinforced buildings nicked or even pierced by the fault came through just fine, including an apartment building that moved 10 feet and had its front steps sliced off. Another home was cut in two; half collapsed, the other survived with windows intact. “How the hell?” marveled one engineer. “There's no way that building should stand in an earthquake.” That blend of science, politics, and human nature is just part of what makes earth science so compelling. It goes far beyond the academics of geology and plate tectonics to embrace earthquakes, floods, hurricanes, volcanoes, landslides—natural hazards that affect thousands of people and change the course of civilization.

scholarly journals Balanced reconnection intervals: four case studies

2008 ◽  
Vol 26 (12) ◽  
pp. 3897-3912 ◽  
Author(s):  
A. D. DeJong ◽  
A. J. Ridley ◽  
C. R. Clauer
Keyword(s):  
Case Studies ◽  
Large Scale ◽  
The Other ◽  
Small Scale ◽  
Polar Cap ◽  
Reconnection Rate ◽  
Magnetospheric Convection ◽  
The Third ◽  
New Name ◽  
Definition Of

Abstract. During steady magnetospheric convection (SMC) events the magnetosphere is active, yet there are no data signatures of a large scale reconfiguration, such as a substorm. While this definition has been used for years it fails to elucidate the true physics that is occurring within the magnetosphere, which is that the dayside merging rate and the nightside reconnection rate balance. Thus, it is suggested that these events be renamed Balanced Reconnection Intervals (BRIs). This paper investigates four diverse BRI events that support the idea that new name for these events is needed. The 3–4 February 1998 event falls well into the classic definition of an SMC set forth by Sergeev et al. (1996), while the other challenge some previous notions about SMCs. The 15 February 1998 event fails to end with a substorm expansion and concludes as the magnetospheric activity slowly quiets. The third event, 22–23 December 2000, begins with a slow build up of magnetospheric activity, thus there is no initiating substorm expansion. The last event, 17 February 1998, is more active (larger AE, AL and cross polar cap potential) than previously studied SMCs. It also has more small scale activity than the other events studied here.

Fault slip envelope: A new parametric investigation tool for fault system strength and slip

2020 ◽  
Author(s):  
Roger Soliva ◽  
Frantz Maerten ◽  
Laurent Maerten ◽  
Jussi Mattila
Keyword(s):  
Mechanical Properties ◽  
Fault Slip ◽  
Fault System ◽  
Nuclear Waste Repository ◽  
Computation Method ◽  
Strength Anisotropy ◽  
Stress Regime ◽  
Fault Systems ◽  
Geological Conditions ◽  
Wide Range

<p>The fact that inherited fault systems show strong variability in their 3D shape provides good reasons to consider the strength of the Earth’s brittle crust as variably anisotropic. In this work we quantify this strength anisotropy as a function of fault system complexity by combining 3D boundary element model, frictional slip theory and fast iterative computation method. This method allows to analyze together a very large number of scenarios of stress and fault mechanical properties variations through space and time. Using both synthetic and real fault system geometries we analyze a very large number of numerical simulations (125,000) to define for the first time macroscopic rupture envelopes for fault systems, referred to as “fault slip envelopes”. Fault slip envelopes are defined using variable friction, cohesion and stress state, and their shape is directly related to the fault system 3D geometry and the friction coefficient on fault surfaces. The obtained fault slip envelopes shows that very complex fault geometry implies low and isotropic strength of the fault system compared to geometry having limited fault orientations relative to the remote stresses, providing strong strength anisotropy. This technique is applied to the realistic geological conditions of the Olkiluoto high-level nuclear waste repository (Finland). The model results suggests that Olkiluoto fault system has a better probability to slip under the present day Andersonian thrust stress regime, than for the strike-slip and normal stress regimes expected in the future due to the probable presence of an ice sheet. This new tool allows to quantify the anisotropy of strength and probability of slip of 3D real fault networks as a function of a wide range of possible geological conditions an mechanical properties. This significantly helps to define the most conservative fault slip hazard case or to account for potential uncertainties in the input data for slip. This technique therefore applies to earthquakes hazard studies, geological storage, geothermal resources along faults and fault leaks/seals in geological reservoirs.</p>

Tardigrades from Portugal: four new records and description of two new species

Zootaxa ◽  
2009 ◽  
Vol 2030 (1) ◽  
pp. 21-38 ◽  
Author(s):  
PAULO FONTOURA ◽  
GIOVANNI PILATO ◽  
OSCAR LISI ◽  
PAULO MORAIS
Keyword(s):  
New Species ◽  
Iberian Peninsula ◽  
New Records ◽  
First Record ◽  
The Other ◽  
New Name ◽  
Two New Species ◽  
First Time

Six species of Eutardigrada are recorded from Portugal; four of them, Macrobiotus crenulatus Richters, 1904, Hypsibius seychellensis Pilato, Binda & Lisi, 2006, Diphascon (Diphascon) pingue (Marcus, 1936) and D. (Diphascon) patanei Binda & Pilato, 1971 are recorded for the first time in Portugal. Two species, Minibiotus orthofasciatus sp. nov. and Bertolanius (new name of Amphibolus) portucalensis sp. nov. are new to science. Minibiotus orthofasciatus sp. nov. is one of the species of the genus with three macroplacoids, microplacoid and cuticular pores forming transverse bands. The new species differs from all existing species by one or more of the following characters: distribution of the pores, shape of the pores, absence of dots on the legs, level of insertion of the stylet supports on the buccal tube. To the new species is attributed an unembryonated egg similar to those of Minibiotus intermedius (Plate, 1888), M. poricinctus Claxton, 1998, M. floriparus Claxton, 1998, and M. weglarskae Michalczyk, Kaczmarek & Claxton, 2005 but different from them in some details. Bertolanius portucalensis sp. nov. is very similar to the other species of the genus, but it differs from them in having very small cuticular tubercles. From some of them it differs by characters of the buccopharyngeal apparatus and/or of the eggs. This is the first record of the genus and of the Eohypsibiidae family in the Iberian Peninsula.

A clarification of the name Carex hypsipedos C.B.Clarke (Cyperaceae) and a new name for the South American Carex section Acrocystis taxon

Phytotaxa ◽  
2017 ◽  
Vol 291 (4) ◽  
pp. 287 ◽  
Author(s):  
D. B. POINDEXTER ◽  
M. ESCUDERO ◽  
P. JIMÉNEZ-MEJÍAS
Keyword(s):  
South America ◽  
Original Description ◽  
The Other ◽  
South American ◽  
The South ◽  
New Name ◽  
Additional Detail ◽  
Mixed Collection

In 1906, Clarke described C. hypsipedos based on specimens of Weberbauer 2617 and placed this species in subgenus Vignea. In 1909, Kükenthal also described the name C. umbellata var. depressa on the basis of the number Weberbauer 2617, a species attributed to section Acrocystis of subgenus Carex. Wheeler in 1988 also placed C. hypsipedos in section Acrocystis while reducing Kükenthal’s name to synonymy. During a recent herbarium survey, we studied syntypes corresponding to Weberbauer 2617 at B, F, G, and MOL. The study of these materials revealed important inconsistencies between the specimens and Clarke’s protologue and Wheeler’s study, suggesting that Weberbauer 2617 is a mixed collection of two different species. One plant conforms to Carex sect. Acrocystis, while the other bears resemblance to subgenus Vignea. Several salient characters distinguish these two taxa from each other, most notably including: stigmas 3 vs. stigmas 2, achenes trigonous vs. lenticular, and perigynium pubescent to puberulent vs. glabrous. Carex hypsipedos from Peru, corresponding to Clarke’s original description, is here lectotypified. The Carex sect. Acrocystis species is assigned a new name, Carex punicola, from Argentina, Bolivia, and Peru (South America). In addition to Wheeler’s (1988) observations, we here provide additional detail and illustration of this species. It is closely related to C. geophila, another American species in section Acrocystis.

scholarly journals Unravelling the convoluted nomenclature of Marphysa simplex (Annelida, Eunicidae) with the proposal of a new name and the re-description of species

2021 ◽  
Vol 97 (1) ◽  
pp. 121-139
Author(s):  
Isabel Cristina Molina-Acevedo ◽  
Izwandy Idris
Keyword(s):  
Morphological Characteristics ◽  
Species Group ◽  
Junior Synonym ◽  
The Other ◽  
Anterior Region ◽  
Type Specimens ◽  
New Name ◽  
Other Hand ◽  
Group A ◽  
Taxonomic Confusion

Marphysa simplex is a name that three species bear within the same genus, but each has a different authority and morphological characteristics. This homonymy condition leads to taxonomic confusion and the finite designation of name-bearing is imperative. The current study focuses on two species identified as M. simplex Crossland, 1903 and M. simplex Treadwell, 1922 and a third one, recently considered a secondary homonymy, M. simplex (Langerhans, 1884), is also assessed. The available type specimens were examined and re-described in detail using updated characters and the original descriptions. Marphysa simplex (Langerhans, 1884) is herein judged as an indeterminable species. Marphysa simplex Crossland, 1903 is confirmed as a junior synonym of M. teretiuscula (Schmarda, 1861a) because the differences are minimal. Moreover, M. teretiuscula has characteristics similar to Group B2 (Sanguinea-group; only compound spinigers), instead of the Teretiuscula-group (compound spinigers in the anterior region, subacicular limbate in all chaetigers). On the other hand, M. simplex Treadwell, 1922 is a junior primary homonym of Crossland’s species replaced by M. fijiensisnom. nov. with the chaetal arrangement similar to Group A (limbate chaetae only). In conclusion, the name M. simplex is now unacceptable. The hypothesis on species group only with limbate chaetae and the redescription on M. teretiuscula is also given.

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