Inside amber: New insights into the macromolecular structure of Class Ib resinite

Class Ib resinites are the most common subclass of amber and are found throughout the world. They have a macromolecular structure based on co-polymerized communic acid, communol and biformenes. Because this class of resinite does not contain succinic acid, crosslinking of the polymer through esterification of communol moieties has never been theorized. Analysis of Class Ib resinites from Grassy Lake and Cedar Lake in western Canada was performed using pyrolysis–gas chromatography–mass spectrometry with in situ hexamethyldisilazane derivatization, using a thermal separation probe to perform the pyrolysis and sample introduction. This has allowed larger, more complex fragments to be released from the polymer matrix than previously possible using instantaneous pyrolysis methodologies. The results show for the first time that Class Ib resinite can undergo self-crosslinking between the communol and communic acid moieties in the polylabdane matrix. The chromatographic results also show that a portion of the monoterpenes and non-polymerizable diterpenes in the resinite are bound to the polymer matrix and not fully occluded as was previously theorized. Fourier transform infrared (FTIR) spectra of the resinites are presented and a more accurate spectral interpretation is proposed, based on the chromatographic results.     

A new shoreline displacement model for the last 7 ka from eastern James Bay, Canada

The shoreline displacement history of the eastern James Bay lowlands in the last 7 ka has been investigated by means of AMS radiocarbon dating of sediments cored from wetlands. We present twelve radiocarbon dates on macrofossils from six sites spread along a gradient of increasing land age and elevation. Palynomorph analysis (pollen, spores, and dinoflagellate cysts) was used to define the isolation stratigraphy. During the last 7 ka the shoreline elevation has regressed at a decreasing rate. The rate of shoreline emergence was initially rapid (6. 5 m/ 100 yr) between 6850 and  6400 cal yr BP then slowed down to 1.4– 2 m/ 100 yr during the late Holocene. Examination of previous relative sea level data based upon mollusc shells reveals high levels of uncertainty that mask potential temporal variability.     

Fluorescence spectral analysis of resinite macerals from coals of the Hanna Formation, Wyoming, U.S.A.

Flourescence spectral analysis indicates that resinite macerals from Tertiary Hanna Formation coals (Hanna Coal Field, southcentral Wyoming, U.S.A.) can be separated into five distinct groups. The first resinite group fluoresces a a medium green (in blue light); its average spectral maximum occurs at or below 440 mm with a red/green quotient of 0.22. The second resinite group fluoresces yellow-green with an average spectral maximum of 500 nm and a red/green quotient of 0.53. The third resinite group displays a yellow fluorescence having an average spectral maximum of 580 nm and a red/green quotient of 0.86. The fourth resinite group fluorescence orange-brown having an average spectral maximum of 610 nm and a red/green quotient of 1.20. These four groups mostly occur as primary globular resinites exhibiting scratches and fractures, indicating that they are brittle, solid substances. Primary cell-filling and secondary fracture-filling resinites also occur in these four groups. The fifth group only occurs as a secondary void-filling material and lacks evidence of br of brittle properties. It fluoresces a reddish-brown, has a spectral maximum at 690 nm, and a red/green quotient of 1.54. The fifth group has properties resembling exsudatinite. The five resinite groups can be separated on the basis of their nine spectral properties alone, without qualitative petrographic interpretation.The relative quantities of the five resinite groups vary among Hanna Formation coals. The origins of these five resinite groups are probably related to their botanical properties and pre- and post-depossitional conditions. Overall, Hanna Formation resinites have petrographic characteristics similar to other North American resinites; however, only four resinite groups have been distinguished in in certain coals from Utah and New Mexico (U.S.A.), and western Canada.     

Basement-controlled faulting of Paleozoic strata in southern Ontario, Canada: new evidence from geophysical lineament mapping

Basement fault reactivation is now recognized as an important control on sedimentation and fault propagation in intracratonic basins. In southern Ontario, the basement consists of complexly structured mid-Proterozoic (ca. 1.2 Ga) crystalline rocks and metasedimentary rocks that are overlain by up to 1500 m of Paleozoic sedimentary strata. Reactivation of basement structures is suspected to control the location of Paleozoic fault and fracture systems, but evaluation has been hindered by a limited understanding of the regional structural characteristics of the buried basement. New aeromagnetic- and gravimetric-lineament mapping presented in this paper better resolves the location of basement discontinuities and provides further evidence for basement controls on the distribution of Paleozoic fault and fracture systems. Lineament mapping was facilitated by reprocessing and digital image enhancement (micro-levelling, regional residual separation, derivative filtering) of existing regional gravity and aeromagnetic datasets. Reprocessed images identify new details of the structural fabric of the basement below southern Ontario and delineate several previously unrecognized aeromagnetic and gravity lineaments and linear zones. Linear zones parallel the projected trends of mid-Proterozoic terrane boundaries identified by field mapping on the exposed shield to the north of the study area, and are interpreted as zones of shearing and basement faulting. Mapped aeromagnetic and gravity lineaments show similar trends to Paleozoic faults and fracture networks and broad zones of seismicity in southern Ontario. These new data support an ‘inheritance model’ for Paleozoic faulting, involving repeated reactivation and upward propagation of basement faults and fractures into overlying cover strata.     

Distinguishing between naturally and culturally flaked cobbles: A test case from Alberta,Canada

Distinguishing between naturally and culturally produced, simply flaked cobbles has been a problem for proponents of a pre‐Clovis occupation in the Americas. Several sites in Alberta have been assigned a pre‐Clovis status based on the presence of simply flaked cobbles found in Late Pleistocene till deposits. Historically, these types of assemblages have been assigned a cultural status based on subjective criteria and appeals to the analyst's expertise. To determine the archaeological status of two such assemblages from Alberta (Varsity Estates and Silver Springs), they were compared to a known natural assemblage and two known cultural assemblages. Chi‐square testing was used to evaluate several lithic attributes. Only those attributes that statistically differentiated between natural and cultural assemblages were used for further analyses. All cobbles were then scored using these attributes. A point was awarded when a statistically significant attribute of human‐manufacture was present. These points were then totaled, providing an aggregate score for each cobble. These scores were plotted to determine whether the test assemblages had closer affinities with the known natural or known cultural assemblages. The results indicate that the proposed pre‐Clovis assemblages have closer affinities to known natural assemblages than to cultural assemblages. Our results suggest that these sites provide no evidence for a pre‐Clovis occupation in the Americas. © 2004 Wiley Periodicals, Inc.     

A new interpretation of the structure of the Sept Iles Intrusive suite, Canada

The layered mafic intrusion at Sept Iles, Canada, is one of the largest intrusions in the world. A new interpretation of its structure is proposed, based on a review of its geology and a comparison with the Skaergaard intrusion, Greenland. Several different magmatic components are recognized; hence the name Sept Iles Intrusive suite (SIIS) is proposed. Emplacement of the suite may have been preceded by eruption of flood basalts. The first magmas of the suite rose in the crust to accumulate beneath the density filter afforded by the basalts. The largest component is the Sept Iles Mafic intrusion (SIMI). The Lower series of the SIMI is dominated by leucotroctolites and leucogabbros. Above it lie the Layered series, which is largely comprised of gabbro and troctolite. Both these units are unchanged from earlier interpretations. The anorthosites (s.l.), gabbros and monzogabbros, formerly called the Transitional series, are now considered to be the Upper Border series, developed by floatation of plagioclase. Common autoliths in the Layered series are parts of the hydrothermally altered Upper Border series from towards the interior of the intrusion, which have foundered and settled through the magma. The contamination of the magma that accompanied this event oxidised iron in the magma and led to the precipitation of magnetite around the periphery of the intrusion. The subsequent depletion of Fe³⁺ and/or increase in SiO₂, CaO and P₂O₅ may have induced apatite saturation and accumulation to form two layers rich in apatite, near the base and at top of the Layered series. Granitic magma was developed by fractional crystallisation and was emplaced along the roof of the chamber, where it acquired large quantities of xenoliths. These were probably derived from the flood basalts, their evolved members and fragments of mafic dykes chilled by the granitic magma. Accumulations of monzonite pillows in this unit testify to another magmatic event and a floor to the granitic magma chamber, indicating lateral transport of magma. Chemically distinct syenites in the upper part of the intrusion are part of the Point du Criade intrusion, a large, late composite sill. Diabase and leucogabbro components show a close link with the SIMI and all the acidic magmas may have originally formed by differentiation of the main magma in cupolas towards the centre of the intrusion. A series of late gabbro intrusions that cut the SIMI may represent a rejuvenation of magmatism. The Border zone is a mass of fine-grained rocks that occurs along the border of the SIMI: it may be another magmatic component, or just the lateral border series of the SIMI.     

黄龙嗜冷细菌胞外琥珀酸组分对碳酸钙矿化的影响

为探索黄龙钙华的生物成因,本研究以黄龙嗜冷细菌的胞外特征有机酸组分——琥珀酸为研究对象,通过模拟黄龙水体的低温沉积环境,利用X射线粉末衍射(XRD)和扫描电镜(SEM),考察了琥珀酸对钙化体系中的钙化动力学过程、碳酸钙晶型和形貌的影响。结果表明： ① 高浓度琥珀酸、低pH值,低温都会在一定程度上抑制碳酸钙沉积。② 高浓度琥珀酸可以诱导球霰石型碳酸钙的形成; ③ 高温促进了体系中碳酸钙微晶的聚合。综上可见,黄龙嗜冷细菌的胞外琥珀酸组分在一定程度上参与了碳酸钙的沉积过程,对晶体的晶型和形貌具有一定的调控作用。其结果可为黄龙钙华生物成因的探究提供理论基础。     

加拿大卡西碧玉宝石学性质与特征研究

对中国碧玉市场上销售的加拿大卡西碧玉样品进行了电子探针成分分析(EPMA).卡西碧玉的矿物成分主要为透闪石.碧玉的常规宝石学性质与特征与GB/T16553-2011国标数据一致.显微硬度测试其维氏硬度在813.6～605.7 N/mm²之间.利用压片法和粉末法分别测试获得了卡西碧玉的红外光谱特征,KBr压片法相比较压片法可以揭示碧玉更多的结构特征.     

A new map of glacigenic features and glacial landsystems in central mainland Nunavut,Canada

A new digital map of glacial geomorphic features and interpreted glacial landsystems was produced for an area covering ~415 000 km² in the Keewatin Sector of the Laurentide Ice Sheet (LIS) in Nunavut. The map integrates information from previous surficial geology maps and >14 000 field stations, and is significantly improved by the detailed inventory of ~152 000 glacigenic features using high-resolution ArcticDEM data and Landsat 8 imagery. From this, we identify and map coherent patterns of landform development (landsystems) between the Manitoba border and the Arctic coast, many of which are entirely new and others that are significantly modified or updated. In particular, we recognize six separate ice streams, including one probable remnant ice stream, and we delineate numerous palimpsest streamlined landscapes with associated ice-flow trends and relative ages. A continuum of relict terrains with varying basal ice thermal conditions is mapped for the first time in the ice divide migration zone between Baker Lake and Wager Bay. In addition, deglacial cold-based retreat terrains and preserved warm-based landscapes unaffected by younger glacial events have been identified. These new georeferenced, multi-scale data sets and interpreted glacial landsystems provide a comprehensive framework to strengthen reconstructions of the glacial history and dynamics of one of the largest ice domes of the LIS, identify distinct glacial sediment transport paths for applications to mineral exploration, and test numerical modelling of the LIS in support of climate change studies and long-term evolution of modern ice sheets.     

Coalbed methane producibility from the Mannville coals in Alberta, Canada: A comparison of two areas

Selenium concentrations were measured in five rock cores from a mine in Boone County, West Virginia to determine their relationship to sulfur, rock type and stratigraphic location. The samples spanned the Winifrede and Coalburg coal beds of the Middle Pennsylvania upper Kanawha Formation and included coals and clastic lithologies. The coals generally contained the highest concentrations of Se and the sandstones the lowest. No correlation was observed between total Se and sulfur concentrations for either the entire data set or for individual lithologies. Better correlations were identified for log concentrations between total Se and total organic carbon. Principal component analysis identified a strong sulfur–acid component, interpreted to be due to sulfide mineral presence, which correlates well with S but not with Se. Coal sample chemistry is more likely to load onto this component while clastic rock chemistry is more likely to load onto the second, non-sulfur component. Se concentrations load onto both components indicating they are not controlled by a single overriding chemistry. Selective extractions indicate that Se is distributed between both sulfide and organically-bound fractions, as defined by the test. Overall, the lack of correlation between Se and S, the distribution of Se among extracted fractions, and the loading of Se onto both sulfur and non-sulfur components support that the Se in these rock layers is distributed in more than one chemically-bound form. Non-coal rock units with the highest concentrations of Se were found adjacent to coal beds, suggesting that redistribution of Se may have occurred post-deposition. The acidic domed swamps that formed these coals were low in sulfur and a reasonable chemical setting to accumulate Se if it were introduced. The preservation of Se in the domed swamp peat coupled with post-depositional redistribution may partly explain the data presented.     

Groundwater occurrence in cold environments: examples from Nunavik,Canada

Water availability and management issues related to the supply of drinking water in northern communities are problematic in Canada. While rivers and lakes are abundant, they are vulnerable to contamination and may become dry in winter due to freezing. Groundwater can often provide a more secure and sustainable water source, however its availability is limited in northern Canada due to the presence of permafrost. Moreover, the exploitation of northern aquifers poses a dual challenge of identifying not only permafrost-free areas, but also permeable areas which will allow groundwater recharge and exploitation. Suitable aquifers are not as common in northern Canada since the shallow subsurface is mostly composed of low-permeability crystalline rocks or unconsolidated sediments of glacial origin that are highly heterogeneous. In order to investigate groundwater occurrence and associated geological contexts in Nunavik (northern Quebec, Canada), along with exploring how these resources will evolve in response to climate change, field and compilation work were conducted in the surroundings of the four villages of Salluit, Kuujjuaq, Umiujaq and Whapmagoostui-Kuujjuarapik. These villages are located in different permafrost zones, ranging from continuous to discontinuous, as well as in different geological environments. It was found that despite the ubiquitous presence of permafrost, unfrozen aquifers could be identified, which suggests that groundwater may be available as a source of drinking water for small communities. Expected climate change, with predicted permafrost thawing and increases in temperature and precipitation, should enhance groundwater availability and may contribute to a more secure source of drinking water for northern communities.     

Lepidostrobus haslingdenensis: A new species from the Lancashire Millstone Grit

A collection of microsporangiate cones is described from the topmost Namurian of Rossendale, Lancashire. The microspores are closely comparable with the dispersed spore species Lycospora noctuina, being of a type that has not been previously recorded from a fructification.     

Hydrogen isotopic compositions of individual alkanes as a new approach to petroleum correlation: case studies from the Western Canada Sedimentary Basin

Isotopic compositions of carbon-bound hydrogen in individual n-alkanes and acyclic isoprenoid alkanes, from a number of crude oil samples, were measured using gas chromatography-thermal conversion-isotope ratio mass spectrometry. The precision of this technique is better than 3‰ for most alkanes, compared to the large range of δD variation among the samples (up to 160‰). The oils were selected from major genetic oil families in the Western Canada Sedimentary Basin, with source rocks ranging in age from Ordovician (and possibly Cambrian) to Cretaceous. The hydrogen isotopic composition of alkanes in crude oils is controlled by three factors: isotopic compositions of biosynthetic precursors, source water δD values, and postdepositional processes. The inherited difference in the lipid's biosynthetic origins and/or pathways is reflected by a small hydrogen isotopic variability within n-alkanes, but much larger differences in the δD values between n-alkanes and pristane/phytane. The shift toward lighter hydrogen isotopic compositions from Paleozoic to Upper Cretaceous oils in the WCSB reflects a special depositional setting and/or a minor contribution of terrestrial organic matter. The strong influence of source water δD values is demonstrated by the distinctively lower δD values of lacustrine oils than marine oils, and also by the high values for oils with source rocks deposited in evaporative environments. Thermal maturation may alter the δD values of the alkanes in the oil to some extent, but secondary oil migration does not appear to have had any significant impact. The fact that oils derived from source rocks that could be of Cambrian age still retain a strong signature of the hydrogen isotopic compositions of source organic matter, and source water, indicates that δD values are very useful for oil-source correlation and for paleoenvironmental reconstructions.     

A densely feathered ornithomimid (Dinosauria: Theropoda) from the Upper Cretaceous Dinosaur Park Formation,Alberta, Canada: A comment

The presence of feathers in Ornithomimus is questioned on poor evidence and a failure to observe scientific process and procedure.     

A multi-sensor logger for rock cores: Methodology and preliminary results from the Matagami mining camp,Canada

Diamond drilling typically constitutes a major part of costs in advanced mineral exploration programs. This generates thousands of meters of rock cores during major exploration campaigns, but the cores are not currently utilized to their full potential. They could supply three-dimensional information on physical properties, geochemistry and mineralogy; such data could be used to model the geology or physical properties in 3D, characterize hydrothermal alteration, or provide chemo-stratigraphic constraints, for example. But measuring all the parameters one by one at high spatial resolution by traditional methods would be impractical due to cost or time considerations and, for some parameters, it would destroy the core (e.g. geochemistry).In this paper we describe a multi-sensor core logger and its use on rock cores from exploration diamond drill holes. This semi-automated system can measure near-simultaneously, non-destructively and at high spatial resolution, the following parameters: (1) volumetric magnetic susceptibility; (2) density using gamma-ray attenuation; (3) several chemical elements through energy-dispersive X-ray fluorescence spectrometry; and (4) visible/near infrared spectrometry, which allows numerous minerals to be detected and characterized. The logger also acquires a continuous image of the core using a line-scan camera, which allows the user to compare other properties with the visual aspect of the core and creates a complete virtual archive. The aim of this mostly methodological paper is to describe the logger as a whole and then each instrument or sensor separately, outlining the numerous tests that have been performed to assess and improve data quality. We also present preliminary results from the Matagami mining camp of Canada, a base metal district.     

辽宁西部一新的帆翼龙类化石

根据发现于辽西朝阳九佛堂组一具有部分头骨的不完整骨架,命名一新的帆翼龙——赵氏龙城翼龙（新属新种）。头骨和牙齿形态显示龙城翼龙与宽齿帆翼龙的关系要比与其他翼龙的关系密切,龙城翼龙是目前辽西九佛堂组中发现的唯一的帆翼龙类。帆翼龙科原仅一属种,发现于英国早白垩世地层中,辽西早白垩世新帆翼龙的发现,不但扩大了其地理分布,也证明辽西是晚侏罗世至早白垩世翼龙辐射、分异的重要地区。这对研究翼龙的起源和演化有重要意义。     

Tel Hajar: A new Cenomanian-lower Turonian stratigraphic unit from north-west Iraq

A new stratigraphic unit is defined from north-west Iraq called the Tel Hajar Formation. This unit is represented by about 110 m of conglomeratic beds alternating with thin beds of sandy-detrital limestone. This new stratigraphic unit is overlain by the Kometan Formation (Late Turonian-Early Campanian) and underlain by the Qamchuqa Formation (Albian-Aptian).The Tel Hajar Formation is devoid of characteristic fossils but contains reworked foraminifers of Albian age.This new formation has been recorded from other parts of Iraq [Ain Zahal Well No. 16, Kaddouri (1979)]; a similar unit has been reported from the north-eastern part of Syria Ponikarov, 1966 and from the Sheik Sollak well No. 1 Kaddouri (1979).