Cogent Geoscience最新文献_第2页

Regression models for intrinsic constants of reconstituted clays 重构粘土本征常数的回归模型

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2018.1546978

F. Habibbeygi, H. Nikraz, B. K. Koul

引用次数: 5

Quantitative planktonic foraminifers taphonomy and palaeoceanographic implications over the last 1 My from IODP Sites U1436 and U1437 U1436和U1437站点近1年来浮游有孔虫数量分布和古海洋学意义

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2018.1447263

M. J. Mleneck-Vautravers

{"title":"Quantitative planktonic foraminifers taphonomy and palaeoceanographic implications over the last 1 My from IODP Sites U1436 and U1437","authors":"M. J. Mleneck-Vautravers","doi":"10.1080/23312041.2018.1447263","DOIUrl":"https://doi.org/10.1080/23312041.2018.1447263","url":null,"abstract":"Abstract International Ocean Discovery Program Sites U1437 and U1436, two intermediate water depth sites located near the Kuroshio Current were studied for planktonic proxies, shell weights, percent fragments, foraminifers concentrations, and benthic/planktonic ratios. Over the last 1 My, the foraminifers assemblages responded to local temperature changes. The taphonomy of these assemblages limits their usefulness as palaeoclimatic records but greatly inform qualitatively of intermediate water mass changes on each side of the Izu Rise. Carbonate dissolution (CD) is pervasive and always more intense during interglacials at the shallowest Site U1436 to the East. Carbonate preservation improved during glacials after 0.6 Ma at U1437B (West) likely signaling changes within the glacial Antarctic Intermediate Water and therefore, its source water the Glacial North Atlantic Intermediate Water from Marine Isotope Stage 16. The first occurrence of a very large Laurentide ice-sheet at the time is proposed as a potential indirect cause for this observation. Both the intensification of carbonate dissolution during each interglacials from MIS17 onwards and the better preservation during succeeding glacials after that are attributed to the increasing influence of the North Atlantic Deep Water and the Glacial North Atlantic Intermediate Water via the Antarctic Intermediate Water during Interglacial and Glacial intervals, respectively.","PeriodicalId":42883,"journal":{"name":"Cogent Geoscience","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312041.2018.1447263","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60091792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Women in Geoscience: An interview with Emily Fischer 地球科学领域的女性:对艾米丽·费舍尔的采访

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2018.1432284

E. Fischer

引用次数: 0

Women in Geoscience: An interview with Michele Tobias 地球科学中的女性:对米歇尔·托比亚斯的采访

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2018.1432291

M. Tobias

引用次数: 0

Spatial and temporal distribution of natural ponds, using GIS and remote sensing, Northeast of Iraq 基于GIS和遥感的伊拉克东北部天然池塘时空分布

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2018.1541496

Sherwan Sharif Qurtas, H. Hashemi

{"title":"Spatial and temporal distribution of natural ponds, using GIS and remote sensing, Northeast of Iraq","authors":"Sherwan Sharif Qurtas, H. Hashemi","doi":"10.1080/23312041.2018.1541496","DOIUrl":"https://doi.org/10.1080/23312041.2018.1541496","url":null,"abstract":"Abstract The biggest nine well-known natural ponds in the highest elevations of Zagros thrust zone in the northeast of Erbil, Kurdistan region, Iraq, have been taken and synthesized with RS and GIS techniques to reveal the spatial and temporal distribution of the ponds, and to explore the sustainability of these ponds. ENVI 5.1 software was used to detect pond surface area and shapes in different seasons and for 33 years. RS was used to detect land surface temperature (LTS), but GIS was used for maps and calculations of pond area variation. Geology of the area is very complex; formations are different in genetics, age, thickness, and extensions. The regional tectonic forces highly deformed the succession and extension of the geologic formations. i.e. The forces that had made the mountains were very strongly affected the layers and the geologic formations, resulting in many types of folds, faults, overturning layers, thrusting, and many other highly deformed structures. Water-bearing formations are of restricted extensions due to the deformations, with limited and local productivity. The aquifers moved to face impermeable rocks or surface, discharging springs, ponds, and rivers. The ponds are sustaining permanently due to the following reasons: most of the ponds are located on semi-impermeable deposits, weather and LTS throughout the year are less than 25°C, high relative humidity and low evaporation, and they are recharging by direct groundwater and snowmelts.","PeriodicalId":42883,"journal":{"name":"Cogent Geoscience","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312041.2018.1541496","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46880568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Strike-slip deformation in the Inkisi Formation, Brazzaville, Republic of Congo 刚果共和国布拉柴维尔Inkisi组的走滑变形

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2018.1542762

Timothée Miyouna, Hardy Medry Dieu-Veill Nkodia, Olivier Florent Essouli, M. Dabo, F. Boudzoumou, D. Delvaux

{"title":"Strike-slip deformation in the Inkisi Formation, Brazzaville, Republic of Congo","authors":"Timothée Miyouna, Hardy Medry Dieu-Veill Nkodia, Olivier Florent Essouli, M. Dabo, F. Boudzoumou, D. Delvaux","doi":"10.1080/23312041.2018.1542762","DOIUrl":"https://doi.org/10.1080/23312041.2018.1542762","url":null,"abstract":"Abstract Evidence of strike-slip deformation in the Inkisi Formation was overlooked for a long time. After controversial characterization, this paper demonstrates that the Inkisi Formation underwent at least two phases of strike-slip deformation accompanied with a compressive component, which created faults that help determine paleostress. Field observations permitted to characterize NW–SE trends sinistral strike-slip faults systems and NE–SW oriented dextral strike-slip faults systems. The strike-slip faults are associated with flower structures in profile view and with damage zones along tips, wall and linking zones in plan view. Both faults systems (sinistral and dextral) initiated from joints, which show similar orientations with faults. Many kinematic indicators of slip sense or extension have enabled to determine the stress stages and the evolution of the structures. The first tectonic phase has a horizontal maximum principal compressive stress σ1 of 319 ± 21,1/03, which probably have a potential correlation with far-field stress propagation which occurs during the subduction of Gondwana south margin in the Permo-Trias. The second tectonic phase with a slightly inclined maximum principal compressive stress σ1 of 264°± 22,3/12 potentially results from the intraplate stress propagation, due to the opening of the Southern Atlantic Ocean.","PeriodicalId":42883,"journal":{"name":"Cogent Geoscience","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312041.2018.1542762","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47200310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Impacts of 40 years of land cover change on water quality in Tampa Bay, Florida 佛罗里达州坦帕湾40年土地覆盖变化对水质的影响

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2017.1422956

M. McCarthy, F. Muller‐Karger, Daniel B. Otis, P. Méndez-Lázaro

引用次数: 10

Effect of shear rate on the residual shear strength of pre-sheared clays 剪切速率对预剪粘土残余抗剪强度的影响

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2018.1453989

F. Habibbeygi, H. Nikraz

引用次数: 10

Acknowledgement of reviewers 评审员致谢

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2018.1519236

Senior Editors

引用次数: 0

Petrology and crustal inheritance of the Cloudy Bay Volcanics as derived from a fluvial conglomerate, Papuan Peninsula (Papua New Guinea): An example of geological inquiry in the absence of in situ outcrop 巴布亚半岛(巴布亚新几内亚)源自河流砾岩的云湾火山的岩石学和地壳继承:在没有原位露头的情况下进行地质调查的一个例子

Cogent Geoscience Pub Date : 2018-01-01 DOI: 10.1080/23312041.2018.1450198

R. Holm, Benny Poke

{"title":"Petrology and crustal inheritance of the Cloudy Bay Volcanics as derived from a fluvial conglomerate, Papuan Peninsula (Papua New Guinea): An example of geological inquiry in the absence of in situ outcrop","authors":"R. Holm, Benny Poke","doi":"10.1080/23312041.2018.1450198","DOIUrl":"https://doi.org/10.1080/23312041.2018.1450198","url":null,"abstract":"Abstract In regions of enhanced weathering and erosion, such as Papua New Guinea, our ability to examine a complete geological record can become compromised by the absence of in situ outcrops. In this study, we provide an example of the insights that can be gained from investigations of secondary deposits. We sampled matrix material and clasts derived from an isolated conglomerate outcrop within a landscape dominated by lowland tropical forest of the southeast Papuan Peninsula, and mapped as belonging to the Cloudy Bay Volcanics. Nine variations of volcanic rock types were identified that range from basalts to trachyandesites. Major and trace element geochemistry characterize the volcanic arc assemblage as shoshonites and provide evidence for differential magma evolution pathways with a subset of samples marked by heavy REE- and Y-depletion, indicative of high-pressure magma fractionation. Zircon U–Pb dating of the individual volcanic clasts indicates activity of the Cloudy Bay Volcanics was largely constrained to the latest Miocene, between ca. 7 and 5 Ma. Of the analyzed zircons, the majority are xenocrystic zircons that provide insight into the provenance of the Papuan Peninsula with potentially significant implications for South West Pacific tectonics. Additional Hf-isotope analysis of the primary igneous zircons suggests a relatively unradiogenic crustal component contributed to magma compositions, which cannot be readily explained by current regional tectonic paradigms.","PeriodicalId":42883,"journal":{"name":"Cogent Geoscience","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312041.2018.1450198","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45666256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10