Southern Arm Research Articles

Growth aspects of grey mullet Mugil cephalus Linnaeus, 1758 from Kilifi creek, Kenya

Mullets form a major component of pelagic fish landings in tropical areas. M. cephalus Linnaeus, 1758 were collected from Kilifi creek between October 2002 and September 2004 using gillnets and a cast net. The sampling sites were Nkoma, Mazioni, Kidundu and Kombeni sites in the southern arm while the northern arm had Sea Horse, Fumbini, Konjora and Rare sites chosen based on observed physical characteristics. The total length (mm), total weight (g) was recorded and the abdomen dissected for gonad identification. From 765 specimens obtained, length-weight relationship (Regression and test of isometry), relative condition factor (Kn), age and growth (Von Bertalanffy Growth Equation VBGE) were performed. In 537 males, length ranged between 57mm and 480mm, the weight between 3g and 1169g. The regression line fitted for length on weight was Log10 W = 1.7457 + 2.8658 Log10 L and the test of isometry (b=2.8658) was significantly different from 3 (t^ = 21.2138; P < 0.05). The length ranged between 61mm and 507mm, weight between 3.8g and 1385g in 228 females. The regression line fitted for length on weight being Log10 W = 1.7973 + 2.8955 Log10 L and the test of isometry (b=2.8955) was significantly different from 3 (t^ = 13.5536; P < 0.05). Low monthly variations in the relative condition factors between the sexes as well as during the different seasons was observed, however, the males had higher relative condition factors than females. Asymptotic length (VBGE) was calculated for M. cephalus at each site with largest fishes caught at Sea Horse, Nkoma, Fumbini and Mazioni while the smallest fishes were from Kombeni and Kidundu. In females, the asymptotic length L∞ (51.48 cm) was higher than in males (48.3 cm) and no notable difference was observed in K (growth coefficient) between females (0.83) and males (0.79) respectively. Kilifi creek needs conservation as source of juveniles for stocking in ponds for future culture

Evaluasi Kinerja APILL di Simpang Empat Bundaran Burung Kota Palangka Raya

Burung Roundabout is an important roundabout for mobilizing the activities of people entering and leaving the city of Palangka Raya, with the increase in population and the rise in community activities the density of vehicles also increases significantly every year. Traffic problems can occur if there is a lack of coordination in each arm of the roundabout. The research objective is to know the performance of Weaving Area and the performance of APILL at Burung Roundabout. The obtained data consists of quantitative data from field survey data. The data is analyzed using Indonesian Road Capacity Manual (MKJI, 1997). The research result using the calculations from (MKJI, 1997) for the Weaving Area section show that the maximum Capacity (C) obtained is 11,125 smp/h at the DA section. The average traffic delay at the roundabout is 0,77 second/smp with the highest delay index (DS) is 0,22 at the CD section. Consequently the service level during peak hours is classified as grade A. The analysis of APILL at Burung roundabout has good traffic flow result. The highest capacity on the southern arm is 1566 smp/hour and the highest delay is 21 second/smp. The highest queue length is 22 meters on the Southern with a highest saturation degree of 0,44 on the Southern with indicates level of service index C.

Delineating geological structure utilizing integration of remote sensing and gravity data: a study from Halmahera, North Molucca, Indonesia

Halmahera Island is the result of the interaction between the Indo-Australian Plate, the Molucca Sea Plate, and the Philippine Plate, which gave rise to many active geological structures that are vulnerable to seismic activity around the island. The complexity of this geological structure makes Halmahera Island very interesting to study. This study aims to identify geological structures by integrating remote sensing and gravity satellite data. Surface lineament analysis using the remote sensing method was carried out based on Sentinel-1A imagery data. The gravity method uses GGMPlus satellite data to clarify the continuity of geological structures that cannot be clearly mapped on the surface. Lineament analysis on gravity data uses techniques such as fast sigmoid edge detection (FSED) and Euler deconvolution. The results of lineament interpretation based on integrating remote sensing and gravity satellite data show that the NE-SW structure controls the northern and northeastern arms of Halmahera.
 In contrast, the southern arm is dominated by the NW-SE structure. The Euler depth estimation shows that the Halmahera area contributes to having geological structures at various depths. Deep structures reach 4 km, while shallow structures are found at depths of up to 2 km. Earthquake hypocenter data strengthen the interpretation of this geological structure. This comprehensive study yields an excellent correlation between gravity and remote sensing techniques in describing the general structural framework of the area. The new finding is an NE-SW trending geological structure on the northern Halmahera arm, which may be caused by two different tectonics first, the subduction of the Molucca Sea Plate with the Halmahera Plate in the west. Second, the strike-slip movement is trending NE-SW, which cuts the northern and northeastern arms due to the rotational movement of the thrust fault with the Philippine Plate to the west.

Sandstone Provenance of Walanae Formation as a Parent Rock in Bulukumpa area, Bulukumba Regency, South Sulawesi

The Walanae Formation has a wide distribution in the southern arm of Sulawesi, this rock formation was deposited during the formation of the basin due to the Walanae strike-slip fault. The Walanae Formation in the study area comprises sedimentary rocks and pyroclastic rocks, which give different soil characteristics. This study aims to determine the types of sandstones, rocks of origin, and provenance of sandstones in the study area by using spot sampling at representative stations and petrographic analysis. The sandstones of the study area are divided into two groups based on Folk (1974), namely arkose lithic and feldspathic litharenite. Based on the type of quartz, rock fragments, and associated minerals, the origin of the sandstones in the study area are plutonic igneous rocks, volcanic rocks, sedimentary rocks, and metamorphic rocks. The results show that the types of provenance sandstones in the study area are magmatic arc and recycled orogenic.

Ore-Forming Fluids of Orogenic Gold Deposit In Tamilouw-Haya, Seram Island, Indonesia

The Tamilouw-Haya orogenic gold deposit is located in the southern arm of Seram Island, Indonesia, occupying Tehoru Metamorphic Complex. Gold mineralization is predominantly in the form of veins, stockwork, and breccia, although minor dissemination is slightly appeared in the rock float samples. Ore-mineral assemblages are dominated by native gold, pyrite, chalcopyrite, sphalerite, tetrahedrite-tennantite (sulfosalt), galena, pyrrhotite, marcasite, realgar, kalininite, and arsenopyrite. Covellite, hematite, goethite, and malachite appear as supergene minerals. High-grade gold ores in this area are generally found in quartz-carbonate veins with the main alteration processes involving silicification, carbonatization, and sericitic. The P-T history of the mineralization was revealed by fluid inclusions, and this study implies the depth of ore deposit and its evolution during mineralization. The primary fluid inclusions from three different types of quartz/quartz-carbonate veins in Tamilouw-Haya crystallized at the homogenization temperature (Th) of 240 °C to 340 °C, with a fluid salinity from 3.87 to 0.70 wt. % NaCl equivalent, and melting temperature (Tm) of -0.4 to -2.3 oC. The ore-forming fluids consist mainly of two-phase (VCO2+LH2O) liquid-rich aqueous inclusions, characterized by low to rich CO2, low salinity, and moderate temperature. There are three vein types as the ore-bearing fluids with precious metals and anomalous high basemetal contents. Quartz type 1- veins (V1); concordant veins, formed at a temperature of 240-307 oC with an average salinity of 1.8 wt. % NaCl equivalent. Quartz type 2- veins (V2) tend to cut the rock foliation which are formed at temperature range from 293-336 oC with the average salinity that shows a value of 2.4 wt. % NaCl equivalent. Meanwhile, type 3 quartz-carbonate veins (V3) are formed at the temperature range of 240-340 oC and the average salinity of 2.72 wt. % NaCl equivalent. These quartz-carbonate veins cut the wall-rock foliation, which is identified as the late stage and associated with ore deposition in Tamilouw-Haya. The gold deposit in Tamilouw-Haya is formed at a depth of about 5.5-9 km of paleosurface, and the pressure between 1.7-2.4 Kbar in epizonal to mesozonal zones. Keywords: Tamilouw-Haya, orogenic gold, fluid inclusion, microthermometry, ore-forming fluids

Some new knowledge brought by 3D digitizations of the chapel of Kerfons (Brittany)

A few kilometers upstream from Lannion in Brittany, we can find the chapel of Kerfons. It was built on the lands of the ancient fief of Coatfrec, and the ruins of the castle are located further north on the western bank of the Léguer river. The chapel’s architecture is a mix of two styles: the flamboyant Gothic in the nave and northern chapel, and the first Breton Renaissance in the southern arm. Recognized as a Historic Monument since 1910, it boasts a remarkable flamboyant Gothic rood screen made of polychrome wood. Recently, a company conducted a voluntary 3D scanning campaign using two laser scanners to capture the chapel’s exterior and interior. From this data, we extracted unpublished plans and orthophotographs, and conducted initial investigations to answer archaeological questions about the positioning of the rood screen and the edges of the Kerfon chapel’s roof, which were previously unexplained. To address other questions about the higher exterior parts, we also conducted an UAV survey around the sculpted statues of the bell tower, the elements above the Renaissance stained glass window, and the stone under Christ’s feet of the calvary. Despite the lack of dedicated funding, these new archaeological findings contribute to the preservation and enhancement of the chapel, as well as encouraging the application of this approach to other buildings that may not have a dedicated budget for their digitization.

Kinematic analysis of the super-extended H I disk of the nearby spiral galaxy M 83

We present new H I observations of the nearby massive spiral galaxy M 83 taken with the JVLA at 21″ angular resolution (≈500 pc) of an extended (∼1.5 deg2) ten-point mosaic combined with GBT single-dish data. We study the super-extended H I disk of M 83 (∼50 kpc in radius), in particular disk kinematics, rotation, and the turbulent nature of the atomic interstellar medium. We define distinct regions in the outer disk (rgal> central optical disk), including a ring, a southern area, a southern arm and a northern arm. We examine H I gas surface density, velocity dispersion, and noncircular motions in the outskirts, which we compare to the inner optical disk. We find an increase of velocity dispersion (σv) toward the pronounced H I ring, indicative of more turbulent H I gas. Additionally, we report over a large galactocentric radius range (until rgal ∼ 50 kpc) where σv is slightly larger than thermal component (i.e., > 8 km s−1). We find that a higher star-formation rate (as traced by far UV emission) is not necessarily always associated with a higher H I velocity dispersion, suggesting that radial transport could be a dominant driver for the enhanced velocity dispersion. Furthermore, we find a possible branch that connects the extended H I disk to the dwarf irregular galaxy UGCA 365 and that deviates from the general direction of the northern arm. Lastly, we compare mass flow rate profiles (based on 2D and 3D tilted ring models) and find evidence for outflowing gas at rgal ∼ 2 kpc, inflowing gas at rgal ∼ 5.5 kpc, and outflowing gas at rgal ∼ 14 kpc. We caution that mass flow rates are highly sensitive to the assumed kinematic disk parameters, in particular to inclination.

Imaging of HH80-81 Jet in the Near-infrared Shock Tracers H2 and [Fe ii

The HH80-81 system is one of the most powerful jets driven by a massive protostar. We present new near-infrared (NIR) line imaging observations of the HH80-81 jet in the H2 (2.122 μm) and [Fe ii] (1.644 μm) lines. These lines trace not only the jet close to the exciting source but also the knots located farther away. We have detected nine groups of knot-like structures in the jet including HH80 and HH81 spaced 0.2–0.9 pc apart. The knots in the northern arm of the jet show only [Fe ii] emission closer to the exciting source, a combination of [Fe ii] and H2 at intermediate distances, and solely H2 emission farther outwards. Toward the southern arm, all the knots exhibit both H2 and [Fe ii] emission. The nature of the shocks is inferred by combining the NIR observations with radio and X-ray observations from the literature. In the northern arm, we infer the presence of strong dissociative shocks, in the knots located close to the exciting source. The knots in the southern arm that include HH80 and HH81 are explicable as a combination of strong and weak shocks. The mass-loss rates of the knots determined from [Fe ii] luminosities are in the range ∼3.0 × 10−7–5.2 × 10−5 M ⊙ yr−1, consistent with those from massive protostars. Toward the central region, close to the driving source of the jet, we have observed various arcs in H2 emission that resemble bow shocks, and strings of H2 knots that reveal traces of multiple outflows.

Diversity of Fishery Organisms and Their Contribution to The Community Sustainability of Kilifi Creek, Kenya

Fishery organisms are a source of food and income in local societies surrounding any water body. Investigations were carried out to study the diversity and distribution of fishery organisms of the Kilifi estuarine creek and their contribution to community sustainability. Sampling took place at Sea horse, Fumbini, Konjora, and Rare on the northern arm and at Nkoma, Mazioni, Fumbini, and Kombeni on the southern arm of the creek. All fishery organisms obtained were identified, counted and length dimensions taken. The 1444 prawns obtained were Fenneropenaeus indicus and Penaeus monodon while the 207 were four crab species Portunus armatus, Portunus sanguinolentus, Scylla serrata, and Thalamita crenata. F. indicus was the most abundant of the prawn species whereas P. armatus and S. serrata were caught at all study sites in smaller class sizes. 7,258 finfishes identified were 85 species belonging to 14 orders, 46 families. Biodiversity indices analysed showed that Margalef’s species richness index was highest (8.293) at Sea horse and lowest (3.874) at Rare. Pielou’s evenness was highest (0.7286) at Nkoma and lowest (0.5319) at Rare. Simpson’s diversity index was highest at Nkoma (0.8917) and lowest at Rare (0.6672). Bray-Curtis similarity grouped all fishes into three ecosystems, open sea waters, the mudflats, and river channels. The most abundant finfish species were Leiognathus equula (20.17 %) followed by Mugil cephalus (17.64%), Gerres filamentosus (10.25%), and Pomadasys multimaculatum (7.37%). Most abundant finfish species and crustaceans were in small class sizes hence for local consumption by communities around the creek

Survey, Traffic Analysis & Design of Four-lane elevated road (Flyover) in the city of Hubli, Karnataka.

Abstract: Hubli-Dharwad is now increasing in importance as a Commercial, Industrial, and educational centre. Traffic congestions in the city is increasing day by day due to extensive urbanization and industrialization along the Hubli-Dharwad belt, this has led to major intersections in the cities being saturated resulting in traffic congestion and delays subsequently increasing the vehicle operating cost and pollution levels in the cities. Rani Chennamma Junction in the city of Hubli is one such junction, its seven arms serve as the arterial roads of the Hubli city. The old NH-4 connecting the NH 48 is the southern arm of the junction, NH-67 (previously NH-63) forms the two arms of the junction, NH-52 heading towards Vijayapura makes the north arm of the junction, the rest arms of the junction are Arterial roads of Hubli city. As per the Comprehensive Traffic & Transportation Plan (CTTP) report, some of the junction experiences traffic snarls and needs an immediate attention in terms of engineering interventions. It is also noted that there is lack of pedestrian’s facilities at most of the major junctions that need to be investigated to avoid pedestrian vehicular conflicts at junction. The traffic trend observed in the CTTP report requires treatment at this junction to decongest the junction in the form of grade separated structures so that the majority portion of vehicles can bypass the at-grade conflicts and greatly reduce the traffic conflict points. This Study shall provide engineering solutions to cater to the increased congestion on the seven-arm Rani Chennamma junction.

Unveiling polarized emission from interstellar dust of the Large Magellanic Cloud with Planck

ABSTRACT Polarization of interstellar dust emission is a powerful probe of dust properties and magnetic field structure. Yet studies of external galaxies are hampered by foreground dust contribution. The study aims at separating the polarized signal from the Large Magellanic Cloud (LMC) from that of the Milky Way (MW) to construct a wide-field, spatially complete map of dust polarization using the Planck 353 GHz data. To estimate the foreground polarization direction, we used velocity gradients in H i spectral line data and assessed the performance of the output by comparing to starlight extinction polarization. We estimate the foreground intensity using the dust-to-gas correlation and the average intensity around the LMC and we assume the foreground polarization to be uniform and equal to the average of the MW around the galaxy to derive foreground I, Q, and U parameters. After foreground removal, the geometry of the plane-of-the-sky magnetic field tends to follow the structure of the atomic gas. This is notably the case along the molecular ridges extending south and south-east of the 30 Doradus star-forming complex and along the more diffuse southern arm extending towards the Small Magellanic Cloud. There is also an alignment between the magnetic field and the outer arm in the western part. The median polarization fraction in the LMC is slightly lower than that observed for the MW as well as the anticorrelation between the polarization angle dispersion function and the polarization fraction. Overall, polarization fraction distribution is similar to that observed in the MW.

Early Neoproterozoic Tectonics in the Godhra–Chhota Udepur Sector: Evidence for Two-Stage Accretion in the Great Indian Proterozoic Fold Belt

Abstract The Great Indian Proterozoic Fold Belt (GIPFOB) is a curviplanar highly-tectonized zone of Precambrian crystalline rocks. In the GIPFOB, the N/NNE-striking western arm (the Aravalli Delhi Fold Belt, ADFB) and the E-striking southern arm consisting of the Chottanagpur Gneiss Complex (CGC) and the central/southern domains of the Satpura Mobile Belt (SMB) converge at the Godhra-Chhota Udepur sector. To investigate the tectonics of the sector, we combine the results of analyses of mesoscale and regional structures, U-Pb (zircon) geochronology, and monazite chemical dating to constrain the convergence. The sector is dominated by an ensemble of shallow-dipping granitoid mylonites (D2 deformation) and recumbently folded anatectic granulite-facies basement gneisses interleaved with allochthonous greenschist/epidote-amphibolite facies supracrustal rocks thrust top-to-the-south. The shallow-dipping carapace is traversed by a network of E-striking steep-dipping shear zones with sinistral and N-down kinematics (D3 deformation). The D3 shear zone hosted granitoids exhibit E-striking suprasolidus deformation fabrics and chessboard microstructures. In the shallow-dipping carapace, the partly overlapping stretching lineations associated with D2-D3 deformations share low-angle obliquities with the W/WNW plunging hinges of D2 recumbent folds and the upright/moderately-inclined D3 folds in the basement gneisses and the supracrustal rocks. The transition from thrust-dominated (D2) to wrench-dominated (D3) deformation involved flipping of Y and Z strain axes for similar orientations of orogen-parallel stretching caused by N-S shortening. U-Pb LA-ICP-MS (zircon) and monazite chemical dates suggest the D2-D3 deformation and felsic plutonism occurred at 0.95–0.90 Ga, the pre-D2 high-grade metamorphism in the anatectic gneisses at 1.7–1.6 Ga. The 0.95–0.90 Ga structures in the Godhra-Chhota Udepur are identical to those in CGC-SMB in the southern arm and terminate the N/NNE-striking structures in the ADFB. We suggest the GIPFOB comprises two Early Neoproterozoic accretion zones, e.g., the western arm (ADFB) and the younger (GC-SMB-CGC) southern arm.

Multiwavelength and Multi-CO View of the Minor Merger Driven Star Formation in the Nearby LIRG NGC 3110

We present Atacama Large Millimeter/submillimeter Array observations of multiple 12CO, 13CO, and C18O lines and 2.9 mm and 1.3 mm continuum emission toward the nearby interacting luminous infrared galaxy NGC 3110, supplemented with similar spatial resolution Hα, 1.4 GHz continuum, and K-band data. We estimate the typical CO-to-H2 conversion factor of 1.7 M ⊙ (K km s−1 pc2)−1 within the disk using local thermal equilibrium-based and dust-based H2 column densities, and measure the 1 kpc scale surface densities of the star formation rate (ΣSFR), super star clusters (ΣSSC), molecular gas mass, and star formation efficiency (SFE) toward the entire gas disk. These parameters show a peak in the southern part of the southern spiral arm (SFE ∼ 10−8.2 yr−1, ΣSFR ∼ 10−0.6 M ⊙ kpc−2 yr−1, ΣSSC ∼ 6.0 kpc−2), which is likely attributable to the ongoing tidal interaction with the companion galaxy MCG-01-26-013, as well as toward the circumnuclear region. We also find that thermal free–free emission contributes to a significant fraction of the millimeter continuum emission at the position of the southern peak. These measurements imply that the peak of the southern arm is an active and young star-forming region, whereas the central part of NGC 3110 is a site of long-continued star formation. We suggest that during the early stage of the galaxy–galaxy interaction in which the mass ratio was high in NGC 3110, fragmentation along the main galaxy arms is an important driver of merger-induced star formation, and that massive gas inflow results in dusty nuclear starbursts.

H I mapping of the Leo Triplet

A fully sampled and hitherto highest resolution and sensitivity observation of neutral hydrogen (H I) in the Leo Triplet (NGC 3628, M 65/NGC 3623, and M 66/NGC 3627) reveals six H I structures beyond the three galaxies. We present detailed results of the morphologies and kinematics of these structures, which can be used for future simulations. In particular, we detect a two-arm structure in the plume of NGC 3628 for the first time, which can be explained by a tidal interaction model. The optical counterpart of the plume is mainly associated with the southern arm. The connecting part (base) of the plume (directed eastward) with NGC 3628 is located at the blueshifted (western) side of NGC 3628. Two bases appear to be associated with the two arms of the plume. A clump with a reversed velocity gradient (relative to the velocity gradient of M 66) and a newly detected tail, that is to say M 66SE, is found in the southeast of M 66. We suspect that M 66SE represents gas from NGC 3628, which was captured by M 66 in the recent interaction between the two galaxies. Meanwhile gas is falling toward M 66, resulting in features previously observed in the southeastern part of M 66, such as large line widths and double peaks. An upside-down “Y”-shaped H I gas component (M 65S) is detected in the south of M 65, which suggests that M 65 may also have been involved in the interaction. We strongly encourage modern hydrodynamical simulations of this interacting group of galaxies to reveal the origin of the gaseous debris surrounding all three galaxies.

Non-invasive Investigation of Segment C of the Krzemionki Exploitation Field. Initial Research Results

Non-invasive research has been undertaken in the southern arm of the archaeological area of the Krzemionki exploitation field, which is one of the least excavated of its regions. Geophysical prospection covered an area of 3.5 ha, and in addition, an area of more than 5 ha was examined by surface collection. The image of the underground structures was obtained thanks to a comprehensive comparison of the results of magnetic, earth resistance and GPR measurements, as well as the distribution of archaeological finds on the ground surface. The study was supplemented with data obtained from the analysis of archival aerial photos and Airborne Laser Scanning (ALS) derivatives. On the basis of these complementary data, it was possible to create a general image of the distribution of archaeological sources in the study area. When trying to determine the potential range of the exploitation field, the most legible results were obtained from earth resistance survey and magnetic gradiometry methods. In the most fully explored fragment of the area, anomalies suggesting the presence of prehistoric mining facilities are located in a strip 40–60 m wide, running in the NW-SE direction. Surface studies showed the presence of anthropogenic limestone debris in a zone of similar width (50–75 m) and the direction of its course, while the spread of flint and erratic stone finds turned out to be even greater (a belt 70–90 m wide). Geophysical surveys indicate the possibility of the existence of flint workshops and settlement facilities around the mining field. This can be confirmed in future by further systematic studies of its surroundings.

Stratigraphic signature of the Perito Moreno ice-dammings during the Little Ice Age (southern Patagonia, Argentina)

The spectacular water outburst occurring semi-periodically when the ice-dam formed by the external front of the Perito Moreno glacier collapses, is one of the most attracting events in the UNESCO ‘Parque Nacional Los Glaciares’ of southern Patagonia. These occurrences have been documented since 1936. Instead, evidence of previous events has been only indirectly provided by dendrochronology analysis. Here we show for the first time radiocarbon-dated sediment cores collected within a small inlet of Brazo Sur, that is, the southern arm of Lago Argentino that record ice-dammings in the Little Ice Age, at 324–266 cal yrs BP, as measured on a vegetal fragment sampled at ca. 14 cm from the top of a core. A common characteristic of the three sediment cores is the abrupt change in the stratigraphic record found at variable depths of 14–18 cm from the top of the cores. This change is marked by a hiatus spanning ca. 3200 years, separating planar-laminated sediments below from an alternation of erosional and depositional events above it, indicating recurring high-energy conditions generated by the emptying of the lake basin. In addition, we observed significant changes in the abundance of environmental indicators as testate amoebae below and above the hiatus. These well-preserved stratigraphic records highlight the key role of glaciolacustine deposits in reconstructing the glacial dynamics and palaeoclimate evolution of a glaciated region.

Tectonics of the Greater India Proterozoic Fold Belt, with emphasis on the nature of curvature of the belt in west-central India

The Greater India Proterozoic Fold Belt (GIPFOB) is a curved highly tectonized zone dominated by Early Paleoproterozoic to Early Neoproterozoic magmatic and metamorphic rocks extending from NW India (Aravalli Delhi Fold Belt, ADFB) through central India (the Satpura Mobile Belt, SMB) to eastern India (the Chottanagpur Gneiss Complex, CGC). The continuity of the crustal domains within GIPFOB is obscured by the Gondwana Formation, the Mesozoic Deccan basalts, the intertrappean Bagh Beds and the infratrappean Lameta Formations, and younger alluvium. In supercontinent reconstructions the GIPFOB is speculated to be continuous with Proterozoic mobile belts in Western Australia and the Trans North China Orogen. The NNE-striking western arm (ADFB) of the GIPFOB is flanked by the North India Block (NIB) in the east and the Marwar Craton in the west, whereas the E-striking southern arm (CGC-SMB) is sandwiched between the South India Block (SIB) and the NIB. In the Godhra-Chhota Udepur sector (west-central India) the two arms converge. We synthesize and compare existing data on mesoscale structures, U-Pb (zircon) and monazite chemical ages, and magmatic and metamorphic histories in the Precambrian crystalline rocks in the three crustal blocks to constrain the accretion dynamics in the GIPFOB with an emphasis on the origin of the curvature in the Godhra-Chhota Udepur sector. The CGC and the central and southern domains of the SMB share considerable homogeneity in chronology and regional structures. In the CGC, the early, N-striking steep-dipping tectonic fabrics in ~1.6 Ga anatectic gneisses with ~1.45 Ga and 1.05–0.9 Ga granitoids are modified into a carapace of shallowly-dipping tectonic mélange of recumbently folded basement gneisses and granitoid mylonites thurst over by allochthonous supracrustal rocks at ~0.95 Ga. The central and southern domains within SMB also exhibit the shallowly-dipping foliations and the emplacement of 1.05–0.9 Ga granitoids. The unmodified basement and the overlying tectonic mélange in the CGC-SMB are traversed by 1.0–0.9 Ga E-striking steep-dipping sinistral (dominant) and dextral (uncommon) shear zones that accommodated the Early Neoproterozoic transpressive deformation induced by the NIB-SIB oblique collision. The mesoscale structures in the rocks of the Godhra-Chhota Udepur sector intruded by Early Neoproterozoic granitoids and followed by oblique collision are similar to CGC-SMB. In the ADFB, by contrast, the basement rocks are older (Archean to Early Paleoproterozoic), high-grade metamorphism and felsic magmatism are older (1.8–1.7 Ga), the expansive ~1.45 Ga granitoids are absent, nappe structures are locally present, and expansive domains of the shallowly-dipping foliations are lacking. Overall, the tectonic evolution of the ADFB is incoherent with those in CGC-SMB and the GC sector. We suggest that the structures in the N/NNE-striking western accretion arm terminate against the E-striking southern arm. The Early Neoproterozoic (1.0−0.9 Ga) integration of the crustal domains within the GIPFOB resulted due to broadly contemporaneous convergence of the NIB, the SIB and the Marwar Craton (?) during the Rodinia supercontinent assembly, but the accretion along the southern arm post-dated the accretion in the western arm. [482 words]

The first <i>in situ</i> collection of a mosasaurine from the marine Breien Member of the Hell Creek Formation in south-central North Dakota, USA

The upper Maastrichtian Breien Member situated within the lower portion of the Hell Creek Formation in south-central North Dakota records one of the last transgressions of the Western Interior Seaway (WIS) during the terminal Cretaceous. A fragmentary articular-prearticular complex and isolated vertebra belonging to a mosasauroid were recovered in 2016 from sandstones and mudstones deposited in a nearshore marine paleoenvironment within the southern arm of the bisected WIS. The medially-rotated retroarticular process on the articular-prearticular complex, the shape of the glenoid fossa, along with the morphology of the isolated vertebra, facilitate a conservative referral to a large-bodied mosasaurine such as Mosasaurus or Prognathodon. The rocks of the Breien Member provide paleontologists a unique glimpse of intracontinental marine ecosystems immediately prior to the end of the Cretaceous Period. This discovery provides additional evidence that the latest Maastrichtian marine fauna is a continuation of the fauna preserved in the underlying Fox Hills Formation and that the marine faunal turnover that gave rise to the subsequent Cannonball Sea fauna recorded in Paleocene rocks in North Dakota occurred at the Cretaceous-Paleogene boundary.

Peculiarities of the chemical abundance distribution in galaxies NGC 3963 and NGC 7292

ABSTRACT Spectroscopic observations of 32 H ii regions in the spiral galaxy NGC 3963 and the barred irregular galaxy NGC 7292 were carried out with the 2.5-m telescope of the Caucasus Mountain Observatory of the Sternberg Astronomical Institute using the Transient Double-beam Spectrograph with a dispersion of ≈1 Å pixel−1 and a spectral resolution of ≈3 Å. These observations were used to estimate the oxygen and nitrogen abundances and the electron temperatures in H ii regions through modern strong-line methods. In general, the galaxies have oxygen and nitrogen abundances typical of stellar systems with similar luminosities, sizes, and morphology. However, we have found some peculiarities in chemical abundance distributions in both galaxies. The distorted outer segment of the southern arm of NGC 3963 shows an excess oxygen and nitrogen abundances. Chemical elements abundances in NGC 7292 are constant and do not depend on the galactocentric distance. These peculiarities can be explained in terms of external gas accretion in the case of NGC 3963 and major merging for NGC 7292.

Seiche Effects in Lake Tekapo, New Zealand, in an Mw8.2 Alpine Fault Earthquake

This study investigates the potential for seismic seiches in Lake Tekapo, New Zealand, triggered by ground shaking from an Mw8.2 Alpine Fault earthquake. Synthetic ground motions are used as a forcing boundary to drive lake water motions by further developing a tsunami simulation model—COMCOT—and coupling it with earthquake simulation model outputs. Our modelling results reveal that lake water oscillations are mobilised immediately by the ground movement and further amplified by cross-lake seiches. Amplitudes of lake oscillations can reach up to 4.0 m in the lake’s narrow southern arm, over 1.0 m along the shore of Lake Tekapo township, and about 1.5–2.5 m along many other parts of the lake shore. Large-amplitude water oscillations quickly attenuate in the first 5–10 min after the earthquake due to their relatively short periods, while long-period oscillations continue for a long time, albeit with much smaller amplitudes. Spectral analysis clearly reveals that the ground motions trigger both fundamental and higher modes in the lake whose oscillation periods are consistent with theoretical estimates. We find that large-amplitude lake water oscillations are better correlated with low-frequency, less energetic ground motion content than with high-frequency large-amplitude ground motions. Ground motion-triggered lake oscillations are large enough to pose potential threat to tourists, residents, boats and infrastructure both in the lake water and onshore near the waterfront. In contrast, vertical co-seismic displacements in the lake area, the conventional mechanism for tsunami generation, are too small to trigger tsunami waves of concern.