Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 2. The Mackenzie Delta–Tuktoyaktuk Coastlands

1996 ◽  
Vol 33 (1) ◽  
pp. 62-71 ◽  
Author(s):  
Alan E. Taylor ◽  
Scott R. Dallimore ◽  
Alan S. Judge
Keyword(s):  
Late Quaternary ◽  
Mackenzie Delta ◽  
Delta Front ◽  
The Holocene ◽  
Ground Temperatures ◽  
Delta Plain ◽  
Hydrocarbon Fields ◽  
History Of ◽  
Lake Drainage ◽  
A Site

In the Mackenzie–Beaufort region, maximum permafrost thickness is 750 m in the Pleistocene Tuktoyaktuk Coastlands, less than 100 m in the Holocene Mackenzie Delta, and 500 m and anomalously warm in the Big Lake Delta Plain between the two areas. Numerical modelling has been used to derive surface temperature histories that fit ground temperatures and permafrost conditions at 12 wells in the Unipkat, Kumak, and Taglu hydrocarbon fields. The models indicate that the present Holocene Mackenzie Delta was built by fluvial processes into a submarine trough. The delta front passed a site presently some 20 km from the coast about 4.5 ka, and subsequently 58 m of ice-bonded permafrost has aggraded. In contrast, the Big Lake Delta Plain was a subaerial platform for much of the Wisconsinan. It experienced several thousand years of inundation in the Holocene, probably due to widespread development of thermokarst lakes. At sites 8–12 km from the coast, the present subaerial conditions were established 0.5–1.5 ka through lake drainage and fluvial–deltaic deposition.

Late Quaternary Geological History of the Dead Sea Area, Israel

1993 ◽  
Vol 39 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Y. Yechieli ◽  
M. Magaritz ◽  
Y. Levy ◽  
U. Weber ◽  
U. Kafri ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Thick Layer ◽  
Time Frame ◽  
Dead Sea ◽  
Polar Regions ◽  
Geological History ◽  
The Holocene ◽  
History Of ◽  
The Dead ◽  
Sea Area

AbstractA 34.5 m borehole, which was drilled near the Dead Sea coast (altitude -394 m) in the southern part of the fan delta of Wadi Zeelim, reveals the geological history of that area from the latest Pleistocene to present. The depositional time frame is based on six 14C dates and two U-Th dates. An erosional (or nondepositional) period is implied by the hiatus between 21,100 yr B.P. (U-Th age, depth 33 m) and 11,315 yr B.P. (14C age, depth 32 m). A subsequent arid phase is recorded by a 6.5-m-thick layer of halite; based on 14C dates this phase relates to the abrupt Younger Dryas cold period reported in temperate to polar regions. The fragility of the environment in this region is indicated by the fact that the region experienced such a severe, short aridification phase (less than 1000 yr), evidence of which is found widely in the desert fringes of the Middle East and North Africa. The aragonite found in most of the Holocene section indicates that the well site was covered by the lake for most of the Holocene. Exceptions are the intervals at 0-3 and 10-14 m depths which represent low stands of the lake.

Late Quaternary Climate and Vegetation of the Sudanian Zone of Northeast Nigeria

2002 ◽  
Vol 58 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Ulrich Salzmann ◽  
Philipp Hoelzmann ◽  
Irena Morczinek
Keyword(s):  
Environmental History ◽  
Late Pleistocene ◽  
Late Quaternary ◽  
Climatic Conditions ◽  
Lake Levels ◽  
The Holocene ◽  
Quaternary Climate ◽  
History Of ◽  
Sudanian Zone ◽  
Humid Period

AbstractThe Lake Tilla crater lake in northeastern Nigeria (10°23′N, 12°08′E) provides a ca. 17,000 14C yr multiproxy record of the environmental history of a Sudanian savanna in West Africa. Evaluation of pollen, diatoms, and sedimentary geochemistry from cores suggests that dry climatic conditions prevailed throughout the late Pleistocene. Before the onset of the Holocene, the slow rise in lake levels was interrupted by a distinct dry event between ca. 10,900 and 10,500 14C yr B.P., which may coincide with the Younger Dryas episode. The onset of the Holocene is marked by an abrupt increase in lake levels and a subsequent spread of Guinean and Sudanian tree taxa into the open grass savanna that predominated throughout the Late Pleistocene. The dominance of the mountain olive Olea hochstetteri suggests cool climatic conditions prior to ca. 8600 14C yr B.P. The early to mid-Holocene humid period culminated between ca. 8500 and 7000 14C yr B.P. with the establishment of a dense Guinean savanna during high lake levels. Frequent fires were important in promoting the open character of the vegetation. The palynological and palaeolimnological data demonstrate that the humid period terminated after ca. 7000 14C yr B.P. in a gradual decline of the precipitation/evaporation ratio and was not interrupted by abrupt climatic events. The aridification trend intensified after ca. 3800 14C yr B.P. and continued until the present.

Late Pleistocene sedimentary history of multiple glacially dammed lake episodes along the Yarlung-Tsangpo river, southeast Tibet

2014 ◽  
Vol 82 (2) ◽  
pp. 430-440 ◽  
Author(s):  
Shao-Yi Huang ◽  
Yue-Gau Chen ◽  
George S. Burr ◽  
Manoj K. Jaiswal ◽  
Yunung Nina Lin ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Depositional Environments ◽  
Optically Stimulated Luminescence ◽  
Delta Front ◽  
Delta Plain ◽  
History Of ◽  
Southeast Tibet ◽  
Yarlung Tsangpo ◽  
Dammed Lake ◽  
Yarlung Tsangpo River

AbstractWe present a reconstructed lithologic column compiled from a series of lacustrine outcrops along a tributary of the Nyang River, a major tributary of the Yarlung-Tsangpo in southeast Tibet. The deposits were preserved between terraces at altitudes of 2950–3100 m asl. The stratigraphic record features at least two sets of coarsening-upward sequences depicting episodic aggradation and progradation of a glacially dammed lake related delta. Recognized facies changes illustrate the evolution cycles of depositional environments from pro-delta, delta front, to delta plain. Radiocarbon and optically stimulated luminescence dates reveal an aging-downward trend in stratigraphic order and provide an approximate timeline for the formation of glacially dammed lakes in late Pleistocene. This result reflects that the Zelunglung Glacier had progressively advanced to block the Yarlung-Tsangpo river and the dam materials had stepwise stacked up to an altitude of 3095 m asl during Marine Oxygen Isotope Stages 4 to 2.

scholarly journals Assessment of Storm Surge History as Recorded by Driftwood in the Mackenzie Delta and Tuktoyaktuk Coastlands, Arctic Canada

2021 ◽  
Vol 9 ◽  
Author(s):  
Roger F. MacLeod ◽  
Scott R. Dallimore
Keyword(s):  
Storm Surge ◽  
Tide Gauge ◽  
Storm Surges ◽  
Aerial Photographs ◽  
Surface Model ◽  
Mackenzie Delta ◽  
Tide Gauge Records ◽  
History Of ◽  
Study Sites ◽  
A Site

The southern Beaufort coastline in Canada experiences significant storm surge events that are thought to play an important role in coastal erosion and influence permafrost dynamics. Unfortunately, many of these events have not been documented with tide gauge records. In this paper, we evaluate coastal driftwood accumulations as a proxy for estimating maximum storm surge heights and the history of these events. We use historical air photos and data derived from Unoccupied Aerial Vehicle (UAV) imagery to resurvey four coastal stranded driftwood study sites that were first appraised in 1985–86 and assess two new regional sites in the Mackenzie Delta. Maximum storm surge heights were found to be similar to observations carried out in the 1980s, however, we refine the elevations with more accuracy and reference these to a vertical datum appropriate for incorporating into sea level hazard assessments. Detailed mapping, historical air photo comparisons and the UAV acquired imagery at a site close to Tuktoyaktuk demonstrate that the highest storm surge at this site (1.98 m CGVD2013) occurred in association with a severe storm in 1970. This event shifted driftwood and floated material slightly upslope from an older event thought to occur in 1944 that reached 1.85 m (CGVD2013) elevation. The quality and accuracy of the high-resolution Digital Surface Model (DSM) and orthophoto derived from Structure from Motion (SfM) processing of the UAV photographs allowed mapping of four distinct stratigraphic units within the driftwood piles. Based on variations in anthropogenic debris composition, weathering characteristics and history of movement on aerial photographs, we conclude that no storm surge events at Tuktoyaktuk have exceeded ∼1.3 m (CGVD2013) since 1970. While there has been some speculation that ongoing climate change may lead to more frequent large magnitude storm surges along the Beaufort coast, our study and available tide gauge measurements, suggest that while moderate elevation storm surges may be more frequent in the past several decades, they have not approached the magnitude of the 1970 event.

LATE QUATERNARY GEOLOGICAL HISTORY OF RIO GRANGE DO SUL COASTAL PLAIN, SOUTHERN BRAZIL

2000 ◽  
Vol 30 (3) ◽  
pp. 474-476 ◽  
Author(s):  
LUIZ JOSÉ TOMAZELLI ◽  
SÉRGIO REBELLO DILLENBURG ◽  
JORGE ALBERTO VILLWOCK
Keyword(s):  
Coastal Plain ◽  
Late Quaternary ◽  
Geological History ◽  
Southern Brazil ◽  
History Of

The Reformation of Prophecy

2018 ◽  
Author(s):  
G. Sujin Pak
Keyword(s):  
Old Testament ◽  
Word Of God ◽  
Priesthood Of All Believers ◽  
Beliefs And Practices ◽  
The People ◽  
The Reformation ◽  
History Of ◽  
A Site ◽  
Developmental Analysis ◽  
Sacred History

The Reformation of Prophecy presents and supports the case for viewing the prophet and biblical prophecy as a powerful lens by which to illuminate many aspects of the reforming work of the Protestant reformers in the sixteenth and seventeenth centuries. It provides a chronological and developmental analysis of the significance of the prophet and biblical prophecy across leading Protestant reformers in articulating a theology of the priesthood of all believers, a biblical model of the pastoral office, a biblical vision of the reform of worship, and biblical processes for discerning right interpretation of Scripture. Through the tool of the prophet and biblical prophecy, the reformers framed their work under, within, and in support of the authority of Scripture—for the true prophet speaks the Word of God alone and calls the people, their worship and their beliefs and practices, back to the Word of God. The book also demonstrates how interpretations and understandings of the prophet and biblical prophecy contributed to the formation and consolidation of distinctive confessional identities, especially around differences in their visions of sacred history, Christological exegesis of Old Testament prophecy, and interpretation of Old Testament metaphors. This book illuminates the significant shifts in the history of Protestant reformers’ engagement with the prophet and biblical prophecy—shifts from these serving as a tool to advance the priesthood of all believers to a tool to clarify and buttress clerical identity and authority to a site of polemical-confessional exchange concerning right interpretations of Scripture.

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