Pub Date : 2019-12-18DOI: 10.12789/geocanj.2019.46.153
K. Karlstrom, L. Crossey
The year 2019 is the 150th anniversary of John Wesley Powell’s epic exploration of the Colorado River through Grand Canyon and the 100th anniversary of the establishment of Grand Canyon National Park. This is an excellent moment to look back 150 years to think about where we have come from as a science and society, and look forward 100 years towards the accelerated change we expect in the future. For historians, archaeologists, geologists and astronomers, of course, this century-long time scale is short compared to other perspectives. They might choose also to celebrate the 479th anniversary of the first sighting of Grand Canyon by Europeans in 1540, the 1000th anniversary of Ancestral Puebloan farmers in Grand Canyon, the 12,000th anniversary of the arrival of humans migrating south from the Bering Land Bridge, the 5 millionth anniversary of the integration of the Colorado River through Grand Canyon to the Gulf of California, the 4.6 billionth anniversary of the formation of Earth, or the 13.75 billionth anniversary of the Big Bang and the formation of our Universe. Geology is all about time, and knowing some geology helps with the difficult endeavour of placing human timeframes into perspectives of deep time. This guide is for geology students of all levels and types visiting the South Rim of Grand Canyon. It is designed as a 3-day field trip and introduction to the rocks and landscapes. The term ‘students’ in our view also includes visitors who want to know about the basics of Grand Canyon geology while taking scenic hikes to see the geology first-hand. It is organized as if you enter the Park at its East entrance, near Cameron, and exit the Park at the South entrance, towards Flagstaff, but the three activities can be done in any order. As an introduction, we present a brief summary of the history of geologic maps and stratigraphic columns, and the geologists who made them. The maps and depictions of Grand Canyon geology over the past 160 years record a visual progression of how geoscience knowledge in general has developed and matured. The first sixty years, before the Park was founded, may have been the greatest in terms of the rapid growth that merged geology, art and public outreach. The second fifty years (to about 1969) saw important advances in stratigraphy and paleontology and solid efforts by the Park to apply and interpret Grand Canyon geology for the public. The most recent 50 years have seen major advances in regional geological mapping, dating of rocks, plate tectonics, and improved geoscience interpretation. The next 100 years will hopefully see additional innovative efforts to use the iconic field laboratory of Grand Canyon rocks and landscapes to resolve global geoscience debates, inform resource sustainability imperatives and contribute to science literacy for an international public. The three activities described are as follows: Activity 1 (an hour or two) is an overview from Lipan Point. This is a vehicle pull-out on the
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Pub Date : 2019-12-18DOI: 10.12789/geocanj.2019.46.152
Dène Tarkyth
It was my pleasure to serve as the president of this organization through 2018 and part of 2019, and such an experience cannot help but remind me of the effort that comes from GAC staff and our many volunteers, but it also brought home the challenges that all of us face in organizing our time and activities in this so-called Information Age. We live in a world where both space and time are increasingly compressed, and all of us at times struggle to manage the demands of our work and our lives beyond the office walls. So I will start this address by asking you all to imagine that you had one extra day a week given to you some time that you could spend on fun science and investigating exciting questions, or just catching up on work and life. Would we not all welcome such a gift? But then look back over the last few weeks, months or even years and think about how much time you spent searching for information, skimming papers to finding sample locations, compiling and cleaning up data, georeferencing maps....just some of the many basic things that need to get done before you can get to the fun part of your job as a geoscientist. There are estimates that geologists now spend 80% of their time searching for, formatting and organizing information and data, and I do not find these hard to believe. A recent article highlighted the approach taken by Cameco, one of Canada’s leading mining companies, to change how they manage data in order to save 20% of their geologists’ time – one day a week – so that they would not have to spend countless hours looking for data and could do geology instead (Heffernan 2015). There are many efforts to amalgamate and process data in ways that make this process easier and more amenable to automation. A young student geologist at Princeton University, Julia Wilcots, undertook a summer project with a senior researcher at University of Wisconsin to examine the distribution of stromatolites through geological time by searching descriptive literature. Anyone who has worked in the Precambrian, or indeed in sedimentary rocks of any Eon or Era, can well imagine the immensity of that search. However, through the use of computer search techniques and the ‘Geodeepdive’ database, she was quickly able to identify over 10,000 papers that mentioned stromatolites (in the text, but not necessarily in the title) and extract the associated rock unit names from 10% of them. Then, by linking these results to the ‘Macrostat’ database, she was then able to come up with an estimate of the percentage of shallow marine rocks that contain stromatolites within different geological time periods. A more senior researcher at the University involved with the project estimated that doing this same search would have taken him sixteen months of tedium. The overall conclusions of the study – that the distribution of stromatolites is most closely linked to the abundance of dolomitic carbonate rocks (Peters et al. 2017) – are important, but the methodology demons
{"title":"The Challenges of Big Data in Expanding Geoscience: Embracing New Initiatives to Untangle our World","authors":"Dène Tarkyth","doi":"10.12789/geocanj.2019.46.152","DOIUrl":"https://doi.org/10.12789/geocanj.2019.46.152","url":null,"abstract":"It was my pleasure to serve as the president of this organization through 2018 and part of 2019, and such an experience cannot help but remind me of the effort that comes from GAC staff and our many volunteers, but it also brought home the challenges that all of us face in organizing our time and activities in this so-called Information Age. We live in a world where both space and time are increasingly compressed, and all of us at times struggle to manage the demands of our work and our lives beyond the office walls. So I will start this address by asking you all to imagine that you had one extra day a week given to you some time that you could spend on fun science and investigating exciting questions, or just catching up on work and life. Would we not all welcome such a gift? But then look back over the last few weeks, months or even years and think about how much time you spent searching for information, skimming papers to finding sample locations, compiling and cleaning up data, georeferencing maps....just some of the many basic things that need to get done before you can get to the fun part of your job as a geoscientist. There are estimates that geologists now spend 80% of their time searching for, formatting and organizing information and data, and I do not find these hard to believe. A recent article highlighted the approach taken by Cameco, one of Canada’s leading mining companies, to change how they manage data in order to save 20% of their geologists’ time – one day a week – so that they would not have to spend countless hours looking for data and could do geology instead (Heffernan 2015). There are many efforts to amalgamate and process data in ways that make this process easier and more amenable to automation. A young student geologist at Princeton University, Julia Wilcots, undertook a summer project with a senior researcher at University of Wisconsin to examine the distribution of stromatolites through geological time by searching descriptive literature. Anyone who has worked in the Precambrian, or indeed in sedimentary rocks of any Eon or Era, can well imagine the immensity of that search. However, through the use of computer search techniques and the ‘Geodeepdive’ database, she was quickly able to identify over 10,000 papers that mentioned stromatolites (in the text, but not necessarily in the title) and extract the associated rock unit names from 10% of them. Then, by linking these results to the ‘Macrostat’ database, she was then able to come up with an estimate of the percentage of shallow marine rocks that contain stromatolites within different geological time periods. A more senior researcher at the University involved with the project estimated that doing this same search would have taken him sixteen months of tedium. The overall conclusions of the study – that the distribution of stromatolites is most closely linked to the abundance of dolomitic carbonate rocks (Peters et al. 2017) – are important, but the methodology demons","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49488220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-31DOI: 10.12789/geocanj.2019.46.151
T. Rivers
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Pub Date : 2019-10-31DOI: 10.12789/geocanj.2019.46.150
S. Mccutcheon, J. Walker
The Bathurst Mining Camp of northern New Brunswick is approximately 3800 km2 in area, encompassed by a circle of radius 35 km. It is known worldwide for its volcanogenic massive sulphide deposits, especially for the Brunswick No. 12 Mine, which was in production from 1964 to 2013. The camp was born in October of 1952, with the discovery of the Brunswick No. 6 deposit, and this sparked a staking rush with more hectares claimed in the province than at any time since. In 1952, little was known about the geology of the Bathurst Mining Camp or the depositional settings of its mineral deposits, because access was poor and the area was largely forest covered. We have learned a lot since that time. The camp was glaciated during the last ice age and various ice-flow directions are reflected on the physiographic map of the area. Despite abundant glacial deposits, we now know that the camp comprises several groups of Ordovician predominantly volcanic rocks, belonging to the Dunnage Zone, which overlie older sedimentary rocks belonging to the Gander Zone. The volcanic rocks formed during rifting of a submarine volcanic arc on the continental margin of Ganderia, ultimately leading to the formation of a Sea of Japan-style basin that is referred to as the Tetagouche-Exploits back-arc basin. The massive sulphide deposits are mostly associated with early-stage, felsic volcanic rocks and formed during the Middle Ordovician upon or near the sea floor by precipitation from metalliferous fluids escaping from submarine hot springs. The history of mineral exploration in the Bathurst Mining Camp can be divided into six periods: a) pre-1952, b) 1952-1958, c) 1959-1973, d) 1974-1988, and e) 1989-2000, over which time 45 massive sulphide deposits were discovered. Prior to 1952, only one deposit was known, but the efforts of three men, Patrick (Paddy) W. Meahan, Dr. William J. Wright, and Dr. Graham S. MacKenzie, focused attention on the mineral potential of northern New Brunswick, which led to the discovery of the Brunswick No. 6 deposit in October 1952. In the 1950s, 29 deposits were discovered, largely resulting from the application of airborne surveys, followed by ground geophysical methods. From 1959 to 1973, six deposits were discovered, mostly satellite bodies to known deposits. From 1974 to 1988, five deposits were found, largely because of the application of new low-cost analytical and geophysical techniques. From 1989 to 2000, four more deposits were discovered; three were deep drilling targets but one was at surface. RÉSUMÉLe camp minier de Bathurst, dans le nord du Nouveau-Brunswick, s’étend sur environ 3 800 km2 à l’intérieur d’un cercle de 35 km de rayon. Il est connu dans le monde entier pour ses gisements de sulfures massifs volcanogènes, en particulier pour la mine Brunswick n° 12, exploitée de 1964 à 2013. Le camp est né en octobre 1952 avec la découverte du gisement Brunswick n° 6 et a suscité une ruée au jalonnement sans précédent avec le plus d’hec
新不伦瑞克北部的巴瑟斯特采矿营地面积约为3800平方公里，周围环绕着一个半径为35公里的圆圈。它以其火山块状硫化物矿床而闻名于世，特别是1964年至2013年生产的Brunswick No. 12矿。该营地诞生于1952年10月，当时发现了不伦瑞克6号矿床，这引发了一股圈地热潮，该省声称拥有的土地面积比以往任何时候都多。1952年，人们对巴瑟斯特采矿营地的地质情况或其矿藏的沉积环境知之甚少，因为交通不便，而且该地区大部分被森林覆盖。从那时起，我们学到了很多。该营地在最后一个冰河时期被冰川覆盖，各种冰流方向反映在该地区的地理地图上。尽管有大量的冰川沉积，但我们现在知道该营地由几组奥陶系火山岩组成，这些火山岩主要属于垫内格带，它们覆盖在属于甘德带的更古老的沉积岩上。这些火山岩形成于Ganderia大陆边缘海底火山弧的裂谷过程中，最终形成日本海式盆地，称为Tetagouche-Exploits弧后盆地。块状硫化物矿床主要与早期长英质火山岩有关，形成于中奥陶世，由海底温泉中逸出的含金属流体沉淀而成。巴瑟斯特矿营的矿产勘探历史可分为6个时期:a) 1952年以前，b) 1952-1958年，c) 1959-1973年，d) 1974-1988年，e) 1989-2000年，在此期间共发现块状硫化物矿床45个。在1952年之前，只有一个矿床是已知的，但是Patrick (Paddy) W. Meahan博士、William J. Wright博士和Graham S. MacKenzie博士三个人的努力将注意力集中在新不伦瑞克北部的矿产潜力上，这导致了1952年10月发现了不伦瑞克6号矿床。在20世纪50年代，发现了29个矿床，主要是由于应用了航空测量，然后是地面地球物理方法。从1959年到1973年，发现了6个矿床，大多数是已知矿床的卫星体。从1974年到1988年，发现了5个矿床，主要是因为应用了新的低成本分析和地球物理技术。从1989年到2000年，又发现了四个矿床;三个是深层钻探目标，但一个在地面。RÉSUMÉLe新不伦瑞克省北部的巴瑟斯特长官，在3 800平方公里的范围内，在3 800平方公里的范围内，在35公里的范围内，在3 800平方公里的范围内，在3 800平方公里的范围内。在1964年至2013年期间开采的不伦瑞克矿，特别是在2013年开采的不伦瑞克矿。用la decouverte营地est ne en octobre 1952 du坐标偏角不伦瑞克n 6°等suscite一ruee盟jalonnement sans先例用+ d 'hectares revendiques瞿在省现在。En 1952年savait一些东西关于la学界du阵营如矿坑的德巴瑟斯特欧苏尔德莱斯条件沉积de ses坐标偏角mineraux,车l 'acces是非常接近于等拉区恩格兰德一部分recouverte de foret。“我的美丽，我的美丽，我的美丽，我的美丽。”在不同的方向上，在不同的方向上，在不同的方向上，在不同的方向上，在不同的方向上，在不同的方向上，在不同的方向上，在不同的方向上，在不同的方向上，在不同的方向上，在不同的方向上。Malgre des仓库glaciaires abondants,常识肥皂comprend几个营的小组号现在罗氏ordoviciennes优势volcanique, appartenant拉区衬垫,,recouvrent de + vieilles罗氏sedimentaires de la区闲逛。莱斯洛什火山群被命名为sous-marin - sur - la marge de Ganderia大陆上的火山群，这是关于它的形成的最后定论d 'un盆地类型的日本，又称盆地d ' arri<s:1> -arc de tetagouche -开发。Les坐标偏角de硫渣土是principalement过渡群系辅助罗氏volcaniques felsiques德施塔德precoce et se是形式分为de l 'Ordovicien平均苏尔或者接近du木板oceanique par la降水de流体metalliferes年代'echappant德源一边咕哝sous-marines。1 .关于勘探的历史:1)在1952年、b) 1952年至1958年、c) 1959年至1973年、d) 1974年至1988年和e) 1989年至2000年，分别对6种不同的<s:2> <s:2>或其他类型的<s:2>或其他类型的<s:2>或其他类型的<s:2>或其他类型的<s:2>或其他类型的<s:2>或其他类型的<s:2>或其他类型的<s:2>或其他类型的<s:2>或其他类型的<s:2>或其他类型的<s:2>进行了分类。1952年10月6日，新不伦瑞克北部潜在部长帕特里克(帕迪)W.米汉、威廉J.赖特和格雷厄姆S.麦肯齐，以及新不伦瑞克北部潜在部长的注意力，在1952年10月6日，新不伦瑞克北部潜在部长的注意力集中在了新不伦瑞克北部。 在20世纪50年代，发现了29个矿床，主要是利用航空调查和地面地球物理活动的结果。从1959年到1973年，发现了6个矿床。这些主要是已知矿床的卫星地层。从1974年到1988年，发现了5个矿床，主要是通过使用新的低成本分析和地球物理技术。从1989年到2000年，又发现了4个矿床。其中三个是深井目标，但一个在水面上。
{"title":"Great Mining Camps of Canada 7. The Bathurst Mining Camp, New Brunswick, Part 1: Geology and Exploration History","authors":"S. Mccutcheon, J. Walker","doi":"10.12789/geocanj.2019.46.150","DOIUrl":"https://doi.org/10.12789/geocanj.2019.46.150","url":null,"abstract":"The Bathurst Mining Camp of northern New Brunswick is approximately 3800 km2 in area, encompassed by a circle of radius 35 km. It is known worldwide for its volcanogenic massive sulphide deposits, especially for the Brunswick No. 12 Mine, which was in production from 1964 to 2013. The camp was born in October of 1952, with the discovery of the Brunswick No. 6 deposit, and this sparked a staking rush with more hectares claimed in the province than at any time since. In 1952, little was known about the geology of the Bathurst Mining Camp or the depositional settings of its mineral deposits, because access was poor and the area was largely forest covered. We have learned a lot since that time. The camp was glaciated during the last ice age and various ice-flow directions are reflected on the physiographic map of the area. Despite abundant glacial deposits, we now know that the camp comprises several groups of Ordovician predominantly volcanic rocks, belonging to the Dunnage Zone, which overlie older sedimentary rocks belonging to the Gander Zone. The volcanic rocks formed during rifting of a submarine volcanic arc on the continental margin of Ganderia, ultimately leading to the formation of a Sea of Japan-style basin that is referred to as the Tetagouche-Exploits back-arc basin. The massive sulphide deposits are mostly associated with early-stage, felsic volcanic rocks and formed during the Middle Ordovician upon or near the sea floor by precipitation from metalliferous fluids escaping from submarine hot springs. The history of mineral exploration in the Bathurst Mining Camp can be divided into six periods: a) pre-1952, b) 1952-1958, c) 1959-1973, d) 1974-1988, and e) 1989-2000, over which time 45 massive sulphide deposits were discovered. Prior to 1952, only one deposit was known, but the efforts of three men, Patrick (Paddy) W. Meahan, Dr. William J. Wright, and Dr. Graham S. MacKenzie, focused attention on the mineral potential of northern New Brunswick, which led to the discovery of the Brunswick No. 6 deposit in October 1952. In the 1950s, 29 deposits were discovered, largely resulting from the application of airborne surveys, followed by ground geophysical methods. From 1959 to 1973, six deposits were discovered, mostly satellite bodies to known deposits. From 1974 to 1988, five deposits were found, largely because of the application of new low-cost analytical and geophysical techniques. From 1989 to 2000, four more deposits were discovered; three were deep drilling targets but one was at surface. \u0000RÉSUMÉLe camp minier de Bathurst, dans le nord du Nouveau-Brunswick, s’étend sur environ 3 800 km2 à l’intérieur d’un cercle de 35 km de rayon. Il est connu dans le monde entier pour ses gisements de sulfures massifs volcanogènes, en particulier pour la mine Brunswick n° 12, exploitée de 1964 à 2013. Le camp est né en octobre 1952 avec la découverte du gisement Brunswick n° 6 et a suscité une ruée au jalonnement sans précédent avec le plus d’hec","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43612822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-31DOI: 10.12789/geocanj.2019.46.149
A. Kerr
Ophiolites are complex assemblages of ultramafic and mafic igneous rocks that are now widely considered to be pieces of ancient oceanic crust that were emplaced on to the continents courtesy of global plate tectonics. However, most examples were originally considered parts of enormous layered mafic intrusions and so were interpreted in that light. The new understanding of ophiolites in the late 1960s and early 1970s was a crucial part of the global Earth Science revolution, and they are now central to all plate tectonic models developed for ancient orogenic belts. Although their equivalence to oceanic crust is now well established, many ophiolites may not be ‘typical’ examples of such, and not all examples are identical. Most ophiolites likely formed in subduction-influenced environments rather than at mid-ocean ridges. Ophiolites remain important foci for research in the 21st century, and many questions remain about their environments of formation and especially their mechanisms of emplacement onto the continents. Although it was not the first to be seen as a relic of a vanished ocean, the Bay of Islands Igneous Complex in western Newfoundland is one of the best preserved and most easily accessible ophiolites in the world. In the late 20th century, research work in this area proved highly influential in understanding the oceanic crust, and in unravelling the diachronous events involved in the progressive destruction of an ancient stable continental margin as arcs and microcontinental blocks were accreted along it. Parts of the Tablelands Ophiolite lie within Gros Morne National Park, which is a UNESCO world heritage site because of its importance to our understanding of global tectonics. The wider region around the park also includes the Cabox Aspiring Geopark Project, now also in the process of seeking recognition through UNESCO. This article provides background information on ophiolites and the development of our ideas about them, and links this material to four self-guided field excursions that allow examination of many classic features. These excursions range from a collection of roadside outcrops, to some relatively easy hiking excursions on official National Park trails, and eventually to a more challenging off-trail hike that ascends to the summit plateau of the Tablelands to visit rare exposures of the Moho (the Mohorovičić Discontinuity, i.e. the lower boundary of the Earth’s crust) and the underlying upper mantle rocks. Collectively, the field stops should allow geologically-minded visitors to experience some amazing geology in a spectacular and sometimes surreal landscape. RÉSUMÉLes ophiolites sont des assemblages complexes de roches ignées ultramafiques et mafiques qui sont maintenant généralement considérées comme des fragments de croûte océanique ancienne qui ont été charriés sur les continents grâce à la tectoniqueglobale des plaques. Cependant, la plupart des exemples étaient à l'origine considérés comme faisant partie de vast
蛇绿岩是超基性和基性火成岩的复杂组合，现在被广泛认为是由于全球板块构造而放置在大陆上的古代海洋地壳的碎片。然而，大多数样本最初被认为是巨大层状基性侵入的一部分，因此被据此解释。20世纪60年代末和70年代初对蛇绿岩的新认识是全球地球科学革命的重要组成部分，它们现在是所有古代造山带板块构造模型的核心。虽然它们与海洋地壳的等价性现在已经得到了很好的确立，但许多蛇绿岩可能不是这种“典型”的例子，而且并不是所有的例子都是相同的。大多数蛇绿岩可能形成于受俯冲影响的环境，而不是洋中脊。蛇绿岩在21世纪仍是重要的研究热点，但其形成环境，特别是其在大陆上的侵位机制仍存在许多问题。虽然它不是第一个被视为消失海洋的遗迹，但纽芬兰西部的岛屿湾火成岩复合体是世界上保存最完好、最容易接近的蛇绿岩之一。在20世纪后期，这一领域的研究工作被证明对理解海洋地壳具有重大影响，并揭示了古稳定大陆边缘随着弧和微大陆块体的增生而逐渐被破坏的历时性事件。部分高原蛇绿岩位于格罗斯莫恩国家公园内，该公园因其对我们理解全球构造的重要性而被联合国教科文组织列为世界遗产。公园周围更广阔的区域还包括“卡博克斯有志地质公园项目”，该项目目前也在向联合国教科文组织寻求认可。这篇文章提供了蛇绿岩的背景信息和我们对它们的看法的发展，并将这些材料与四个自我指导的实地考察联系起来，这些考察允许检查许多经典特征。这些短途旅行的范围从路边露头的集合，到在官方国家公园小径上进行一些相对容易的徒步旅行，最后是更具挑战性的徒步旅行，上升到高原的高峰高原，参观罕见的Moho (mohorovi<e:1> iki不连续，即地壳的下边界)和下面的上地幔岩石。总的来说，实地停留应该让地质头脑的游客在壮观的，有时超现实的景观中体验一些惊人的地质。RESUMELes蛇绿岩组合是复合物de罗氏ignees ultramafiques et mafiques是现在generalement同样像des碎片de croute oceanique ancienne校正樱桃苏尔les大洲恩典那儿tectoniqueglobale斑块。在此之前，许多例子都认为，原先的<s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -La nouvelle comcomsion des ophiolites, La La La machiolites, La La machiolites, La La machiolites, La La machiolites, La La machiolites, La La machiolites, La La machiolites, La La machiolites, La La machiolites, La La machiolites, La La machiolites, La La machiolites。蛇绿岩(蛇绿岩)是指人类的遗传变异，是指人类的遗传变异，是指人类的遗传变异，是指人类的遗传变异。不确定的相同的交换条件是不确定的相同的交换条件，不确定的交换条件是不确定的，不确定的交换条件是不确定的，不确定的交换条件是不确定的。蛇绿岩的多部份可能是由于环境的影响而形成的，例如:plutôt qu 'au niveau des dorsalis ocsamaniques。在研究过程中，研究人员的行为是非常重要的。在研究过程中，研究人员的行为是非常重要的。在研究过程中，研究人员的行为是非常重要的。在研究过程中，研究人员的行为是非常重要的。在此之前，我们将继续研究与其他国家的<s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> <s:1> - <s:1>)的<s:1> <s:1> <s:1> <s:1> - <s:1> (<s:1> - <s:1>)和其他国家的<s:1> - <s:1> (<s:1> - <s:1>)，我们将继续研究与其他国家的<s:1> - <s:1> (<s:1> - <s:1>)和其他国家的<s:1> - <s:1> (<s:1>)和其他国家的<s:1> - <s:1>)的联系。拉在世纪末du XXe,里面的减速de矫揉造作的在ce葡萄园joue联合国作用在理解行列式de la croute oceanique et在理解des evenements diachrones impliques在毁灭进步一ancienne玛吉continentale稳定的非盟毛皮等序de l 'accretion d microcontinentaux 'arcs et de集团。“高原蛇绿岩”是联合国教科文组织世界遗产的重要组成部分，也是全球构造的重要组成部分。该项目由联合国教科文组织(unesco)的大型项目和大型项目组成。 这篇文章提供了关于蛇石的基本信息和我们对它们的想法的发展，并将这些材料与四个自助游览联系起来，让我们检查许多经典特征。收藏的这些游览参观1,000,000至路边,相对轻松的徒步小径上官方的国家公园,并最终导致最难登山滑雪在通往sommital高原珍稀的露头Tablelands来参观的Moho(中断Mohorovičić,即下限)的地壳和地幔岩高等基础。总的来说，实地考察应该让地质爱好者在壮观的、有时是超现实的风景中体验非凡的地质。
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Pub Date : 2019-07-09DOI: 10.12789/GEOCANJ.2019.46.147
Liam Innis, G. Osinski
The extraction of natural resources located beyond Earth to create products can be described as space resource utilization (SRU). SRU is under active investigation in both the public and private sectors. Near-Earth asteroids (NEAs) are particularly promising early SRU targets due to their relative proximity and enrichments in two key resources: water and platinum group elements (PGEs). Water can be used to create rocket propellant, making it the only resource with significant demand given the current nascent state of the space market. Platinum group elements are valuable enough that their import to the Earth market is potentially economical, making them the other prospective resource in the current embryonic state of SRU. While it is possible to retrieve material from a NEA, doing so on an economical scale will require significant developments in areas such as autonomous robotics and propulsion technology. A parameterization accounting for asteroid size, resource concentration, and accessibility yields just seven and three potentially viable NEA targets in the known population for water and PGEs, respectively. A greater emphasis on spectral observation of asteroids is required to better inform target selection for early prospecting spacecraft. A further complication is the lack of a legal precedent for the sale of extraterrestrial resources. The Outer Space Treaty prohibits the appropriation of celestial bodies but makes no explicit reference to their resources while the U.S.A. and Luxembourg have passed legislation entitling their citizens to own and sell space resources. Whether these laws are a matter of clarification or contradiction is the matter of some debate. RÉSUMÉL'extraction de ressources naturelles situées au-delà de la Terre pour créer des produits peut être décrite comme une utilisation des ressources spatiales (URS). L’URS est actuellement examinée à la fois dans les secteurs public et privé. Les astéroïdes proches de la Terre (NEA) sont des cibles URS particulièrement prometteuses en raison de leur proximité relative et de leur enrichissement en deux ressources clés : l’eau et les éléments du groupe du platine (EGP). L'eau peut être utilisée pour créer des agents de propulsion pour vaisseaux spatiaux, ce qui en fait la seule ressource pour laquelle la demande est importante compte tenu de l’émergence du marché spatial actuel. Les EGP sont suffisamment précieux pour que leur importation sur le marché terrestre soit potentiellement économique, ce qui en fait l’autre ressource potentielle étant donné l’état embryonnaire actuel de l’URS. Bien qu'il soit possible de récupérer des matériaux sur un NEA, le faire à une échelle économique nécessitera des développements importants dans des domaines tels que la robotique autonome et la technologie de propulsion. Un paramétrage tenant compte de la taille des astéroïdes, de la concentration des ressources et de l'accessibilité conduit à seulement sept et trois cibles NEA parmi la population c
提取地球以外的自然资源以创造产品可以被描述为空间资源利用。公共和私营部门都在积极调查战略行动队。近地小行星(NEAs)是特别有希望的早期SRU目标，因为它们相对较近，并且富含两种关键资源:水和铂族元素(PGEs)。水可以用来制造火箭推进剂，鉴于目前太空市场的新生状态，水是唯一需求巨大的资源。铂族元素的价值足以使其进口到地球市场具有潜在的经济性，使其成为SRU目前萌芽状态下的另一种有前景的资源。虽然从NEA中回收材料是可能的，但要实现经济规模，需要在自主机器人和推进技术等领域取得重大进展。考虑到小行星大小、资源集中度和可达性的参数化，在已知的水和PGEs种群中，分别只产生了7个和3个潜在可行的NEA目标。为了更好地为早期勘探航天器选择目标提供信息，需要更加重视对小行星的光谱观测。更复杂的是，在出售地外资源方面缺乏法律先例。《外层空间条约》禁止占用天体，但没有明确提及其资源，而美国和卢森堡已通过立法，使其公民有权拥有和出售空间资源。这些法律是澄清的问题还是矛盾的问题，是有一些争论的问题。RÉSUMÉL“自然资源的提取”是指在陆地和陆地上进行的获取，是指在产品上进行的获取，être“自然资源的提取”是指在空间资源的利用上进行的获取。我们的测试执行审查了公共部门和私人部门的财务状况。“地球的途径”(NEA)为“地球的途径”(URS)提供了特别的建议，即“地球的原因”，“地球的接近”，“地球的丰富”，“地球的资源”，“地球的资源”，“地球的资源”，“地球的资源”。L'eau peut être利用空间与空间之间的交换，利用空间与空间之间的交换，利用空间与空间之间的交换，利用空间与空间之间的交换，交换空间与空间之间的交换。在这两个例子中，有一个例子是:1 .在这两个例子中，有一个例子是:1 .在这两个例子中，有一个例子是:1 .在这两个例子中，有一个例子是:1 .在这两个例子中，有一个例子是:1 .在这两个例子中，有一个例子:我们将有可能将所有的运输和运输系统中的所有的运输和运输系统中的所有的运输和运输系统中的所有的运输和运输系统中的所有的运输和运输系统中的所有的运输和运输系统中的所有的运输和运输系统中的所有的运输系统。联合国parametrage房客考虑de la身材des小行星,de la浓度des ressources et de l 'accessibilite管道seulement 9月等三个已NEA parmi la人口connue potentiellement利用倒威尼斯les出路,respectivement。我将在我的观测光谱中找到我的位置，我将在我的文件中找到我的位置，我将在我的勘探者中找到我的位置。在资源资源以外的情况下，不存在pracimacimement juridique，即不存在pracimacimement。“空间交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”规定，“交换法”。我们的目标是澄清我们的矛盾。
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Pub Date : 2019-07-09DOI: 10.12789/GEOCANJ.2019.46.148
Jeffrey Pollock
The Wabana iron mines were in operation from 1895 to 1966, during which time they produced over 80 million tonnes of iron ore. They are hosted by Early Ordovician rocks that contain Clinton-type stratiform ironstones. Mineralization is characterized by oölitic, dark red to purple-red to reddish brown beds of hematite-rich fossiliferous sandstone, siltstone, and shale. Three ironstone beds are of economic importance: the Lower (Dominion Formation), Middle (Scotia Formation) and Upper (Gull Island Formation) with the Lower bed extending over 3.8 km beneath Conception Bay. The iron content in all beds ranges from 45 to 61% with a silica concentration of 6 to 20%. Reports of iron on Bell Island go back to at least 1578, when a Bristol merchant reported retrieving ore samples for shipment to England. The deposits, however, remained undeveloped for over three centuries until their rediscovery by local fishermen in the late 1880s. In 1895, the Nova Scotia Steel & Coal Company acquired the mining lease for the claims and first ore was produced at surface from No. 1 mine in the Lower bed along the island’s northwest coast. By the turn of the twentieth century the Dominion Iron and Steel Company Limited acquired a share of the Bell Island claims, and with surface reserves exhausted, the decision was made by both companies to proceed underground and develop submarine mines. Over the next five decades mining operations were operated by several owners at a steady and at times an expanding rate, with periodic setbacks through two world wars and the Great Depression. The worldwide increase in demand for iron after World War II meant the mines were in full production and exporting over 1.5 million tonnes of ore per annum. In 1950, the unprofitable No. 2 mine was closed, and a series of major expansion projects were launched with the goal to double annual production to 3 million tonnes. By the 1960s, the Wabana mines faced increased competition from foreign producers, who flooded the world iron market with high-quality ore from low-cost open-pit deposits. The last mine at Wabana ceased operation in 1966 because the high-phosphorus content of the ore was incompatible with the newest steel-making technology and the market for Wabana ore all but disappeared. Over 35 million tonnes of ore was exported to Canada (Nova Scotia) while the remainder was shipped to the United Kingdom and Germany. At the time of closure, the Wabana mines were the oldest, continually producing mine in the country. Annual production peaked in 1960 when over 2.8 million tonnes of concentrated ore were shipped. Enormous potential reserves of several billion tonnes, grading 50% iron, remain in place beneath Conception Bay but the high cost of submarine mining and absence of a market for non-Bessemer ore present obstacles to any future re-development. RÉSUMÉLes mines de fer de Wabana ont été en activité de 1895 à 1966, période durant laquelle elles ont produit plus de 80 millions de tonnes d
瓦巴纳铁矿从1895年到1966年一直在运营，在此期间，它们生产了超过8000万吨的铁矿石。它们由早奥陶世岩石托管，这些岩石含有克林顿型层状铁矿。矿化的特征是富含赤铁矿的化石砂岩、粉砂岩和页岩的橄榄岩、暗红色至紫红色至红棕色矿层。三个铁矿床具有重要的经济意义：下部（Dominion组）、中部（Scotia组）和上部（Gull Island组），下部床在Concept湾下方延伸超过3.8km。所有床层中的铁含量范围为45-61%，二氧化硅浓度为6-20%。关于贝尔岛铁的报道至少可以追溯到1578年，当时布里斯托尔的一名商人报告称，他们取回了运往英国的矿石样本。然而，这些矿床在三个多世纪以来一直未开发，直到19世纪80年代末被当地渔民重新发现。1895年，新斯科舍省钢铁和煤炭公司获得了采矿租约，第一块矿石是从该岛西北海岸下矿层的1号矿山开采出来的。到了20世纪之交，多米尼克钢铁有限公司获得了贝尔岛的部分开采权，随着地表储量的耗尽，两家公司都决定转入地下并开发海底矿山。在接下来的五十年里，几位所有者以稳定的、有时甚至不断扩大的速度经营采矿业务，在两次世界大战和大萧条期间，采矿业务出现了周期性的挫折。第二次世界大战后，全球对铁的需求增加，这意味着这些矿山已全面生产，每年出口超过150万吨矿石。1950年，无利可图的2号矿山关闭，并启动了一系列重大扩建项目，目标是将年产量提高一倍，达到300万吨。到了20世纪60年代，瓦巴纳矿山面临着来自外国生产商的日益激烈的竞争，这些生产商从低成本的露天矿床中获得了大量优质矿石，涌入了世界钢铁市场。瓦巴纳的最后一座矿山于1966年停止运营，因为矿石中的高磷含量与最新的炼钢技术不兼容，瓦巴纳矿石的市场几乎消失了。超过3500万吨矿石出口到加拿大（新斯科舍省），其余矿石运往英国和德国。在关闭时，瓦巴纳矿山是该国最古老、持续生产的矿山。年产量在1960年达到顶峰，当时运输了280多万吨浓缩矿石。Concept Bay下方仍有数十亿吨的巨大潜在储量，铁品位为50%，但海底采矿的高成本和非Bessemer矿石市场的缺乏阻碍了未来的任何再开发。RÉSUMÉLes mines de fer de Wabana ontétéen activitéde 1895à1966，生产期超过8000万吨矿石。奥尔多维奇人的关系与克林顿类型的铁元素关系密切相关。最小化是一种与鲕粒、粉粒和泥粒一样的红色沙发、紫罗兰色、深色、化石和丰富的岩石。铁元素的三个立法对经济具有重要意义：自治领（Formation Dominion）、斯科舍（Formation Scotia）和古尔岛（Formation Gull Island），以及概念区3.8公里外的基础设施。沙发的价格变化幅度为45%至61%，而集中度为6%至20%。1578年，在贝尔河畔的一个信号部门，布里斯托尔的商业区建立了一个融洽的关系，以避免在安格尔特雷的经验丰富的矿产资源。事实上，其余的法律都是不可执行的，再加上1880年年底的三驾马车。1895年，新斯科舍省钢铁和煤炭公司获得了对采矿权的保释，并在北爱尔兰北部的Inférieure沙发上的一个位置上开采了未来的首要矿产。在二十世纪二十年代的比赛中，多米尼克钢铁有限公司获得了贝尔权利的一部分。这是一个表面服务的组织，两个社会优先决定海军陆战队水雷的开采和开发过程。在五年的自杀过程中，再加上在未来和扩张过程中开采矿山的固有权利，以及在世界和大萧条时期的两次开采。随着世界需求的增加，世界第二游击队的最大传统是矿山生产和每年150多万吨的矿产出口。
{"title":"Great Mining Camps of Canada 6. Geology and History of the Wabana Iron Mines, Bell Island, Newfoundland","authors":"Jeffrey Pollock","doi":"10.12789/GEOCANJ.2019.46.148","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2019.46.148","url":null,"abstract":"The Wabana iron mines were in operation from 1895 to 1966, during which time they produced over 80 million tonnes of iron ore. They are hosted by Early Ordovician rocks that contain Clinton-type stratiform ironstones. Mineralization is characterized by oölitic, dark red to purple-red to reddish brown beds of hematite-rich fossiliferous sandstone, siltstone, and shale. Three ironstone beds are of economic importance: the Lower (Dominion Formation), Middle (Scotia Formation) and Upper (Gull Island Formation) with the Lower bed extending over 3.8 km beneath Conception Bay. The iron content in all beds ranges from 45 to 61% with a silica concentration of 6 to 20%. Reports of iron on Bell Island go back to at least 1578, when a Bristol merchant reported retrieving ore samples for shipment to England. The deposits, however, remained undeveloped for over three centuries until their rediscovery by local fishermen in the late 1880s. In 1895, the Nova Scotia Steel & Coal Company acquired the mining lease for the claims and first ore was produced at surface from No. 1 mine in the Lower bed along the island’s northwest coast. By the turn of the twentieth century the Dominion Iron and Steel Company Limited acquired a share of the Bell Island claims, and with surface reserves exhausted, the decision was made by both companies to proceed underground and develop submarine mines. Over the next five decades mining operations were operated by several owners at a steady and at times an expanding rate, with periodic setbacks through two world wars and the Great Depression. The worldwide increase in demand for iron after World War II meant the mines were in full production and exporting over 1.5 million tonnes of ore per annum. In 1950, the unprofitable No. 2 mine was closed, and a series of major expansion projects were launched with the goal to double annual production to 3 million tonnes. By the 1960s, the Wabana mines faced increased competition from foreign producers, who flooded the world iron market with high-quality ore from low-cost open-pit deposits. The last mine at Wabana ceased operation in 1966 because the high-phosphorus content of the ore was incompatible with the newest steel-making technology and the market for Wabana ore all but disappeared. Over 35 million tonnes of ore was exported to Canada (Nova Scotia) while the remainder was shipped to the United Kingdom and Germany. At the time of closure, the Wabana mines were the oldest, continually producing mine in the country. Annual production peaked in 1960 when over 2.8 million tonnes of concentrated ore were shipped. Enormous potential reserves of several billion tonnes, grading 50% iron, remain in place beneath Conception Bay but the high cost of submarine mining and absence of a market for non-Bessemer ore present obstacles to any future re-development. \u0000RÉSUMÉLes mines de fer de Wabana ont été en activité de 1895 à 1966, période durant laquelle elles ont produit plus de 80 millions de tonnes d","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43370038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-03-29DOI: 10.12789/GEOCANJ.2019.46.144
J. Murphy, R. Nance, Logan B. Gabler, A. Martell, D. Archibald
In northwest Donegal, Ireland, a large number of coeval appinitic (hornblende-plagioclase-rich) plutons and lamprophyre dykes occur around the Ardara pluton, a granitic satellite body and one of the oldest phases of the ca. 428–400 Ma composite Donegal Batholith. The appinite units form a bimodal (mafic–felsic) suite in which hornblende is the dominant mafic mineral and typically occurs as large prismatic phenocrysts within a finer grained matrix. Lamprophyre dykes are mafic in composition with a geochemistry that is very similar to that of the mafic appinite bodies. Both mafic rocks are subalkalic, with calc-alkalic and tholeiitic tendencies, and show trace element abundances indicating that the mantle source was contaminated by subduction zone fluids. 40Ar/39Ar analysis of hornblende separated from two samples of appinite yield mid-Silurian (434.2 ± 2.1 Ma and 433.7 ± 5.5 Ma) cooling ages that are interpreted to closely date the time of intrusion. Hence, according to the available age data, the appinite bodies slightly predate, or were coeval with, the earliest phases of the Donegal Batholith. Sm–Nd isotopic analyses yield a range of initial εNd values (+3.1 to –4.8 at t = 435 Ma) that, together with trace element data, indicate that the appinitic magmas were likely derived from melting of metasomatized sub-continental lithospheric mantle and/or underplated mafic crust, with only limited crustal contamination during magma ascent. The appinitic intrusions are interpreted to have been emplaced along deep-seated crustal fractures that allowed for mafic and felsic magma to mingle. The magmas are thought to be the products of collisional asthenospheric upwelling associated with the closure of Iapetus and the ensuing Caledonian orogeny, either as a result of an orogen-wide delamination event or as a consequence of more localized slab break-off.RÉSUMÉDans le nord-ouest du Donegal, en Irlande, un grand nombre de plutons appinitiques (riches en hornblendes ou en plagioclases) et de dykes de lamprophyres contemporains se retrouvent autour du pluton d’Ardara, un corps satellite granitique et l’une des phases les plus anciennes du batholite composite de Donegal, âgé d’environ 428–400 Ma. Les unités de l’appinite forment une suite bimodale (mafique–felsique) dans laquelle la hornblende est le minéral mafique dominant et se présente généralement sous forme de grands phénocristaux prismatiques au sein d’une matrice à grains plus fins. Les dykes de lamprophyres ont une composition mafique dont la géochimie est très similaire à celle des corps d’appinite mafique. Les deux roches mafiques sont subalcaliques, avec des tendances calcoalcalines et tholéiitiques, et elles montrent des teneurs en éléments traces indiquant que la source du manteau a été contaminée par des fluides de zone de subduction. L'analyse 40Ar/39Ar des hornblendes provenant de deux échantillons d'appinite donne des âges de refroidissement du Silurien moyen (434,2 ± 2,1 Ma et 433,7 ± 5,5 Ma) qui
在爱尔兰多尼戈尔西北部，Ardara岩体(花岗岩卫星体，约428 ~ 400 Ma复合多尼戈尔基最古老的阶段之一)周围发育大量同时期的斜长岩(富含角闪岩-斜长岩)和煌斑岩脉。斜晶岩单元形成一个双峰(镁质-长英质)套，其中角闪石是主要的镁质矿物，通常以较大的棱柱状斑晶出现在更细粒度的基质中。煌斑岩脉在组成上是基性的，其地球化学特征与基性磷灰岩非常相似。两种基性岩石均为亚碱性，具有钙碱性和拉斑岩倾向，微量元素丰度表明地幔源受到了俯冲带流体的污染。从两个斜铁矿样品中分离的角闪石的40Ar/39Ar分析得出中志留世(434.2±2.1 Ma和433.7±5.5 Ma)冷却年龄，解释为与入侵时间接近。因此，根据现有的年龄数据，这些石体略早于或与多尼戈尔基岩的最早阶段同时存在。Sm-Nd同位素分析得出的初始εNd值范围(t = 435 Ma时为+3.1 ~ -4.8)，结合微量元素数据表明，顶辉岩浆岩可能来源于交代的次大陆岩石圈地幔和/或下镀基性地壳的熔融，岩浆上升过程中只有有限的地壳污染。据解释，这些斜长岩侵入体是沿着深部地壳裂缝侵入的，这使得镁质岩浆和长英质岩浆可以混合在一起。岩浆被认为是碰撞软流圈上升流的产物，这种上升流与Iapetus的关闭和随后的加里东造山运动有关，要么是造山带范围的分层事件的结果，要么是更局部的板块断裂的结果。RÉSUMÉDans de Donegal西北，en Irlande, un grand nombre de plutons appinitiques(丰富的角闪岩和斜长岩)，de dikes de煌斑岩当代，de ardara, un corps卫星花岗岩等，de Donegal, l 'une des phases + anciennes du batholite composite， d 'environ 428-400 Ma。Les统一de l 'appinite forment一套房bimodale (mafique-felsique)在该角闪石是矿物mafique主导等形式下的se介绍generalement德芳phenocristaux prismatiques盟盛一个矩阵谷物加鳍。煌斑岩的岩脉不属于单一的合成技术，不属于化学合成技术，也不属于类似的合成技术。三种方法分别为亚碱基对，三种方法分别为碱基对，三种方法分别为碱基对，三种方法分别为碱基对，三种方法分别为碱基对，三种方法分别为碱基对，三种方法分别为碱基对，三种方法分别为碱基对，三种方法分别为碱基对。L'analyse 40Ar/39Ar des hornblendes provant de deux。同样的，不合格的，不合格的，不合格的，不合格的，不合格的，不合格的，不合格的，不合格的，不合格的，不合格的。Les分析isotopiques Sm-Nd aboutissent有一个全音阶值εNd初始(1 + 3、4、8 t = 435 Ma), associees des的数据元素痕迹,indiquent变量的岩浆appinitiques是probablement派生de la融合d一个披风lithospherique souscontinental metasomatise et /或者一个croute mafique sousplaquee,用一个污染crustale limitee当时de l 'ascension du岩浆。小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体、小侵入体。上花费,les岩浆是莱斯的de la上山(上升流)asthenospherique collisionnelle associee la fermeture de l 'ocean“土卫八”et l 'orogenese caledonienne qui s 'ensuit,所以拉套件用品delaminage l 'echelle de l 'orogene,所以一个破裂+ localisee de la la套件斑块。
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Pub Date : 2019-03-29DOI: 10.12789/geocanj.2019.46.146
{"title":"Thank You to 2017–2018 Guest Editors and Reviewers","authors":"","doi":"10.12789/geocanj.2019.46.146","DOIUrl":"https://doi.org/10.12789/geocanj.2019.46.146","url":null,"abstract":"","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42227462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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