Discovery of a Sphaeroschwagerina fusuline fauna from the Raggyorcaka Lake area, northern Tibet: implications for the origin of the Qiangtang Metamorphic Belt

2015 ◽  
Vol 153 (3) ◽  
pp. 537-543 ◽  
Author(s):  
YI-CHUN ZHANG ◽  
SHU-ZHONG SHEN ◽  
QING-GUO ZHAI ◽  
YU-JIE ZHANG ◽  
DONG-XUN YUAN
Keyword(s):  
Lake Area ◽  
Early Permian ◽  
Metamorphic Belt ◽  
Northern Tibet ◽  
The North ◽  
North And South

AbstractThe Qiangtang Metamorphic Belt (QMB) was considered to have either formed in situ by amalgmation of the North and South Qiangtang blocks or been underthrust from the Jinsha suture and exhumed in the interior of a single ‘Qiangtang Block’. A new Sphaeroschwagerina fusuline fauna discovered in the Raggyorcaka Lake area supports the interpretation that the North and South Qiangtang blocks were separated by a wide ocean during Asselian (Early Permian) time, indicating that the QMB was formed by the suturing of the Palaeotethys Ocean along the Longmu Co-Shuanghu suture.

Stratospheric aerosol following Pinatubo, comparison of the north and south mid latitudes using in situ measurements

1997 ◽  
Vol 20 (11) ◽  
pp. 2089-2095 ◽  
Author(s):  
Terry Deshler ◽  
J.Ben Liley ◽  
Gregory Bodeker ◽  
W.Andrew Matthews ◽  
David J Hoffmann
Keyword(s):  
Stratospheric Aerosol ◽  
In Situ Measurements ◽  
The North ◽  
North And South

scholarly journals The Archaeological Evidence of St. Clement of Ohrid’s Activities in the Ohrid Region

Slovene ◽  
2016 ◽  
Vol 5 (2) ◽  
pp. 136-178
Author(s):  
Pasko Kuzman
Keyword(s):  
Lake Area ◽  
Archaeological Evidence ◽  
The North ◽  
The Village ◽  
North And South ◽  
The Church ◽  
Archaeological Excavations

Among the activities of St. Clement of Ohrid was the construction of the church and monastery in Ohrid, which was carried out at the end of the 9th century at the location where some Byzantine basilicas had stood previously. As findings of archaeological excavations have shown, St. Clement first built a small triconch church at the location of the ruined basilica. This triconchos was later expanded by the addition of a capacious “pronaos” in inscribed-cross form, where St. Clement was interred. This “pronaos” was characterized by entrances on the north and south sides that were identical to those of the inscribed-cross church that existed near the village of Velcë along the Šušica River (in southern Albania) at the turn of the 9th‒10th century. During the tenure of Archbishop Dmitrios Chomatianos (1216–1236), the “pronaos” was replaced with a new church into which the relics of St. Clement were placed. In the Ottoman period, the Church and Monastery of St. Clement were disassembled to build a mosque. At the very beginning of the 10th century, the triconchal church in the Monastery of St. Clement served as a model for the church in the Monastery of St. Naum, in the southern part of the Ohrid lake area. The groundwork(s) of a further church in a triconchal shape, whose construction can be traced back to the time of St. Clement, has also been discovered at Gorica, near Ohrid. Ruins of yet another triconchal church which also belongs to the period under review can be found near the village of Zlesti, in the Dolna Debarca region, not far from Ohrid. In the vicinity of the village of Izdeglavje, in the Gorna Debarca region, there is also a church whose establishment is related to the activity of St. Clement of Ohrid as well.

scholarly journals Monitoring the Influence of the Mesoscale Ocean Dynamics on Phytoplanktonic Plumes around the Marquesas Islands Using Multi-Satellite Missions

2020 ◽  
Vol 12 (16) ◽  
pp. 2520 ◽  
Author(s):  
Angelina Cassianides ◽  
Elodie Martinez ◽  
Christophe Maes ◽  
Xavier Carton ◽  
Thomas Gorgues
Keyword(s):  
Finite Size ◽  
Ocean Dynamics ◽  
Dynamic Activity ◽  
Marquesas Islands ◽  
The North ◽  
Run Off ◽  
Dynamical Regimes ◽  
North And South

The Marquesas islands are a place of strong phytoplanktonic enhancement, whose original mechanisms have not been explained yet. Several mechanisms such as current−bathymetry interactions or island run-off can fertilize waters in the immediate vicinity or downstream of the islands, allowing phytoplankton enhancement. Here, we took the opportunity of an oceanographic cruise carried out at the end of 2018, to combine in situ and satellite observations to investigate two phytoplanktonic blooms occurring north and south of the archipelago. First, Lagrangian diagnostics show that both chlorophyll-a concentrations (Chl) plumes are advected from the islands. Second, the use of Finite-size Lyaponov Exponent and frontogenesis diagnostics reveal how the Chl plumes are shaped by the passage of a mesoscale cyclonic eddy in the south and by a converging front and finer-scale dynamic activity in the north. Our results based on these observations provide clues to the hypothesis of a fertilization from the islands themselves allowing phytoplankton to thrive. They also highlight the role of advection to disperse and shape the Chl plumes in two regions with contrasting dynamical regimes.

scholarly journals The Hell Creek Formation, Montana: A Stratigraphic Review and Revision Based on a Sequence Stratigraphic Approach

Geosciences ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 435
Author(s):  
Denver Fowler
Keyword(s):  
South Dakota ◽  
Lake Area ◽  
Sequence Stratigraphic ◽  
Hell Creek Formation ◽  
Accommodation Space ◽  
The North ◽  
Marine Influence ◽  
Sequence Boundaries ◽  
North And South ◽  
Upper Maastrichtian

The Upper Maastrichtian fluvial Hell Creek Formation of the Fort Peck Lake area, Montana (and regional equivalents) is notable for its vertebrate fossils and for the K-Pg mass extinction at or near its upper contact. Despite intense study, internal stratigraphy of the Hell Creek Formation is still poorly constrained, hindering study. This work reviews the stratigraphy of the Hell Creek Formation, as currently understood, and proposes important revisions to the recently proposed type section, particularly concerning complexity of the Hell Creek Formation basal contact. This work also subdivides the Montanan Hell Creek Formation into four 4th order depositional sequences, superimposed over a 3rd order marine transgression. Sequence boundaries are defined by four, laterally continuous disconformities formed by pauses in the creation of accommodation space, marked by overlying amalgamated channel complexes, or less commonly, correlative interfluve paleosols. Cyclicity in Montana may be correlative with similar 4th order cyclicity and marine influence documented in North and South Dakota, Alberta, and Saskatchewan. Magnetostratigraphy and new biostratigraphic data support correlation of the upper Montanan sequence with the North Dakotan Cantapeta tongue (and overlying fines) and Canadian Scollard and Frenchman Formations.

scholarly journals REMOTE SENSING APPLICATION OF THE GEOPHYSICAL CHANGES IN THE COASTLINES AND RIVERS OF ZAMBALES, PHILIPPINES

2016 ◽  
Vol XLI-B8 ◽  
pp. 379-386
Author(s):  
Annie Melinda Paz-Alberto ◽  
Melissa Joy M. Sison ◽  
Edmark Pablo Bulaong ◽  
Marietta A. Pakaigue
Keyword(s):  
Field Measurements ◽  
River Bank ◽  
Mount Pinatubo ◽  
Natural Processes ◽  
The North ◽  
Ground Validation ◽  
After Effect ◽  
Anthropogenic Processes ◽  
North And South

Geophysical changes in river outlet, river upstream and coastlines near the rivers of Bucao and Santo Tomas in Zambales, Philippines were analyzed using the Google Earth’s historical satellite imageries from 2004 to 2013. Data in 2015 were gathered from in situ field measurements ground validation. The study aimed to measure and determine changes in the width of river outlet, width of river bank upstream and shifting of coastline. <br><br> Results revealed that there was a decrease and increase in the width size of the Bucao and Santo Tomas river outlets, respectively during the study period. Geophysical changes occurred in the two rivers due to the continuous supply of lahar as an after effect of the Mount Pinatubo eruption in 1991. Coastline positions near the two rivers also changed. The highest rate of erosion along the coastal area was prevalently observed near the river outlet of both rivers. Moreover, accretion was observed in the coastline of Santo Tomas and erosion phenomenon was observed in the North and South coastlines of Bucao River. The shifting was caused by natural processes such as erosion, sedimentation and natural calamities as well as anthropogenic processes such as reclamation/quarrying. Occurrence of erosion and sedimentation played active roles in the changes of coastlines during the study period. <br><br> Furthermore, the upstream of the Bucao river changed physically due to deposits of lahar present in the upstream which are being discharged directly and continuously going down to the river. Generally, the width of the Bucao River upstream decreased its size because of the accumulated sediment in the riverbank. On the other hand, the observed erosion is caused by high velocity of river during heavy rains and typhoons. The width of the Santo Tomas river bank upstream did not change due to the construction of concrete dikes which prevent the lahar-filled river from breaching the embankment and flooding the agricultural, residential and commercial areas near the river.

scholarly journals Development of Improved Characteristic Equations for Lake Rukwa in Tanzania

2019 ◽  
Vol 38 (1) ◽  
pp. 83-96
Author(s):  
Patric C. Valimba
Keyword(s):  
Change Point Analysis ◽  
Lake Area ◽  
Characteristic Equations ◽  
Surface Areas ◽  
Boundary Change ◽  
The North ◽  
Point Analysis ◽  
Contour Boundary ◽  
North And South ◽  
Topographical Maps

Often Lake Rukwa characteristics have been misreported in literature giving different volumes and surface areas at similar water surface elevations. This study aimed at establishing reliable lake characteristics elevation-area-storage equations for Lake Rukwa by utilising all available data and information to define the bathymetry and derive characteristic equations. A procedure was developed that combines historical lake extents, spot heights from topographical maps and surveyed lake bathymetry to define refined bathymetry to levels it has never reached. It combined spot heights around the lake and selected 13,934 surveyed points (from 107,938 available) within the lake confined by the 820 m land contour boundary and define topographical raster image, which was used to extract lake volumes and surface areas between the lowest point (778 m) and 820 m boundary. Change-point analysis was used to detect segmentation of the elevation-area and elevation-volume relationships, which were fitted to a shifted power model. Contours generated from a refined bathymetry raster indicated Lake Rukwa to comprise two north and south lake basins, which are separated by a ridge lying at an altitude of 794.3 m. The north and south lakes consist respectively of five (5) and three (3) deeper depressions (pools) paralleling the northwest- southeast Konongo Scarp, which are disconnected below altitudes 792 m (north) and 789.4 m (south). Characteristic elevation-area and elevation-volume equations are segmented for lake below ridge altitude (794.3 m) whereas single relationships prevail for a single Lake Rukwa. Comparison of lake volumes estimated by refined and old equations indicated underestimation of lake stored volumes between 782.2 m and 805.65 m altitudes and overestimation thereafter by the old equations although the under/over-estimation remained within 10% between 801 m and 812 m. Old elevation-area equations underestimate lake surface area of up to 796.8 m, thereafter overestimate the lake area up to an altitude of 804.85 m and above this altitude underestimation re-appear. The old equations under/over-estimation, however, remains within 11% for altitudes between 794.3 m and 810 m. The refined equations indicate surface areas of north and south lakes at ridge altitude to be 2,554.4 and 837.1 km2 , respectively forming a 3,391.5 km2 lake while at its highest recorded historical elevation of 804.69 m, Lake Rukwa is 183 km long and 17-51 km wide occupying an area of 5,614.7 km2 (north: 4,409.8 km2; south: 1,204.9 km2) and containing 58.243 km3 of water (north: 44.318 km3; south: 13.925 km3). The developed characteristic equations can be used for water management studies of Lake Rukwa.

The V-Fields, Blocks 49/16, 49/21/, 48/20a, 48/25b, UK North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 861-870
Author(s):  
James Courtier ◽  
Hugh Riches
Keyword(s):  
North Sea ◽  
Early Permian ◽  
The North ◽  
Recoverable Reserves ◽  
Production Wells ◽  
Exploration Drilling ◽  
Structural Relief ◽  
The Uk ◽  
Gas Fields ◽  
North And South

AbstractThe Vulcan, Vanguard, North and South Valiant gas fields are collectively known as the V-Fields and lie on the eastern flank of the Sole Pit Basin in the southern sector of the UK North Sea. They are contained within blocks 49/16, 49/21, 48/20a and 48/25b and are operated by Conoco (UK) Ltd. The first field to be discovered was South Valiant, in 1970, and the initial phase of exploration drilling continued until 1983, with the discovery of the North Valiant, Vanguard and Vulcan fields. Prominent faults and dip closures define the limits of the fields and gas is contained within aeolian sands of Early Permian age. The gross average reservoir thickness is approximately 900 ft with porosities ranging from 3-23% and permeabilities varying from 0.1 mD to 2 Darcies in producing zones. The development of the V-Fields consisted of drilling centrally located production wells in each field, targeting higher quality reservoir zones in areas of maximum structural relief. Initial gas-in-place is estimated at 2.6 TCF with recoverable reserves of about 1.6 TCF. The fields were brought on-stream in October 1988 and currently produce, as of November 1999, up to 260MMSCFD of gas through the LOGGS complex to the Conoco terminal at Theedle-thorpe, Lincolnshire.

Quaternary events in the Elkwater Lake area of southeastern Alberta

1986 ◽  
Vol 23 (12) ◽  
pp. 2024-2038 ◽  
Author(s):  
Willem J. Vreeken
Keyword(s):  
Volcanic Eruption ◽  
Middle Miocene ◽  
Lake Area ◽  
Present Level ◽  
Maximum Extent ◽  
The North ◽  
Green Lake ◽  
South Saskatchewan River ◽  
Late Wisconsinan ◽  
North And South

New data necessitate revisions in the Quaternary chronology of the Elkwater Lake area. Relicts of post-Middle Miocene preglacial erosion surfaces descend to the north and south from the Middle Miocene depositional surface on the Cypress Hills plateau. Both sets of surfaces are marked by oxidized weathering zones, locally culminating in relicts of preglacial paleosols. Both surfaces are overlain by a loess replete with cryogenic imprints. Deposition of this loess with cryogenic imprints shortly predates arrival of the Green Lake glacier at its terminus.The Green Lake end moraine marks the maximum extent of Laurentide ice in this area. Features previously attributed to the older Elkwater glacier can be explained with reference to proglacial meltwater action associated with the Green Lake glacier. The concept of Elkwater drift is no longer valid.Younger loesses, called upper loess, mantle nonglaciated terrain and the Green Lake end moraine and began accumulating just before Glacier Peak tephra was deposited (ca. 12 000 years ago). Because there is no evidence of weathering on the Green Lake end moraine beneath the upper loess, Green Lake drift dates from the late Wisconsinan. Most of the upper loess was deposited during the early Holocene and some since the Mazama volcanic eruption, 6600 years ago.Elkwater Lake reached its highest postglacial level, i.e., at least 6.6 m above the present level, well after the Mazama eruption, before spilling across the Green Lake end moraine into the Ross Creek system. This event irrevocably changed the regimen of Ross Creek, probably to its confluence with the South Saskatchewan River, at Medicine Hat.

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