bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary report on resedimented carbonates associated with basaltic rocks of Cache Creek Group near Spad Lake, east of Fort St. James, central British Columbia
Authors: Sano H
Published: March 2017

A 220 m thick sequence of resedimented limestone and basaltic volcaniclastic rocks of the Pope formation is exposed in a quarry east of Fort St. James. The rocks are informally designated the Spad Lake member. Fragmented and abraded fusuline debris from the
limestone is preliminarily assessed an upper Asselian age. The base of the Spad Lake member is basalt breccia. The lower to middle part has disorganized, completely unsorted limestone breccia (debris flows) and crudely graded granule-pebble limestone conglomerate (basal Bouma sequence) of
shallow-marine affinity. The bedded, thick upper part has graded, densely packed granule-pebble limestone conglomerate, crudely laminated limestone sandstone, and stylonodular-bedded siliceous lime-mudstone with chert nodules, and is interpreted as turbidites resedimented by high-density turbidity
currents. The Spad Lake member was probably formed on an upper flank of a shallow-marine buildup resting upon a basaltic substratum probably of a plateau, or seamount. The Pope formation limestone may be from the platform top.
New conodont data from the Cache Creek Group, central British Columbia
Authors: Orchard M J , Struik L C , Taylor H
Published: March 2017

Forty-seven new collections of conodonts recovered from the Cache Creek Group in central British Columbia are reported and preliminary taxonomic and age determinations presented. The data confirms that most of the limestones of the Mt. Pope sequence near Fort St.
James are of Late Carboniferous age and only locally extend into the Lower Permian. A distinctive basalt unit within the limestone is constrained as Bashkirian to Moscovian in age. Upper Carboniferous limestones extend northward to Kloch Lake in Manson River sheet where much younger Permian
limestones predominate. In the latter area, Late Permian limestones are overlain by an Early Triassic sedimentary and volcanic sequence. Some limestones of the Mt. Pope sequence were evidently subject to weathering and erosion during or after the Middle Triassic because Permian and Triassic
conodonts are only known as cavity fill in Upper Carboniferous strata.
Field observations of the Tachie Pluton near Fort St. James, central British Columbia
Authors: Hrudey M G , Struik L C
Published: March 2017

The Tachie Pluton, found northwest of Fort St. James, consists of biotite diorite to tonalite. It is equigranular, medium grained, and composed of abundant plagioclase, quartz and biotite. Schlieren textures and enclaves occur with biotite pegmatite and mafic
concentrations in discrete bands. Aplite and pegmatite dykes, along with hornblende-rich dykes are late syn- to post-intrusion features found throughout the pluton. The pluton resembles diorite and quartz diorite of the McKnab Pluton south of Stuart Lake.
Magnetic and paleomagnetic constraints on Tertiary deformation in the Endako region, central British Columbia
Authors: Lowe C , Enkin R J , Dubois J
Published: March 2017

It has been proposed that the Nechako NATMAP Project area in central British Columbia records a significant history of Tertiary transtensional deformation. For evidence of this deformation, the magnetic response and record of rocks were examined in a 1300
km² area encompassing the Endako molybdenite deposit. Magnetic anomaly and rock property data distinguish subtle age and mineralogical differences within lithologically similar rock units. Mapped faults trend predominantly NE and NW and typically correspond to linear zones of steep magnetic
gradient. Other prominent northeast- and northwest-trending magnetic lineaments are also interpreted to be shallow faults, which divide the region into fault-bounded blocks. In the Endako mine, paleomagnetically determined tilts on Eocene dykes are aligned with ore-bearing veins, indicating that
deformation was Tertiary. A kilometre-scale anticline is recognized within the pit. Tilts tend to be ~20° eastward in map area 93K/2 and more random in map area 93K.
Jurassic to Tertiary volcanic, sedimentary, and intrusive rocks in the Hallett Lake area, central British Columbia
Authors: Anderson R G , Snyder L D
Published: March 2017

Distribution of and geological relationships amongst Middle Jurassic, Middle and Upper Jurassic, Mid- to Late Cretaceous, and Tertiary volcanic, sedimentary, and plutonic units are better known from bedrock mapping in the Hallett Lake (NTS 93F/15) area in 1997.
Undivided Hazelton Group rocks include maroon-grey heterolithic and monolithic laharic boulder breccia, volcanic grit, and mudstone that are localized in northeast-trending fault blocks. Middle Jurassic Naglico Formation (?) clinopyroxene-phyric volcaniclastic rocks, laharic breccia and siliceous
siltstone occur within one of these fault blocks.
Eocene Ootsa Lake Group dacitic and rhyolitic crystal tuff, pyroclastic rocks, breccia, flow-layered lavas, vitrophyre, glassy domes, and rare, amygdaloidal, plagioclase-porphyritic basalt overlie various Mesozoic basement units. Eocene Endako Group clinopyroxene-plagioclase porphyry basaltic flow
and flow breccia rocks conformably overlie the Ootsa Lake Group and with it, are gently tilted. Small- and large-scale, northeast-trending, down-to-the-southeast, synvolcanic faults apparently localized the distribution of Ootsa Lake Group and Endako Group.
Geology of the Big Bend Creek map area, central British Columbia
Authors: Anderson R G , Snyder L D , Resnick J , Barnes E
Published: March 2017

The Big Bend Creek map area (NTS 93F/10) encompasses the southern extent and thickest accumulation of fault-bounded Middle and Upper Eocene (48-37 Ma) Endako Group basaltic flow and volcaniclastic rocks and the northern extent of well dated, extensive Jurassic
Hazelton and Bowser Lake groups volcanic and sedimentary rocks mapped so far in NTS 93F. Jurassic and Eocene plutons are important in the northern part of the map area.
Moderately to steeply dipping, deformed rocks of the undivided Hazelton Group, Naglico Formation, Bowser Lake Group and Eocene Ootsa Lake Group and (?)Cretaceous porphyry intrusion make up the basement for Endako Group basalt flows. An older deformation recorded in deformed pebble conglomerate of
Bowser Lake Group is likely post-Jurassic and pre-Late Cretaceous.
Brittle deformation of Mesozoic and Tertiary basement rocks accompanied initiation of the latest structures such as a north-trending graben developed synchronously with eruption of the Endako Group basalt flows.
Re-examination of Late Albian-Cenomanian conglomerate in Churn Creek, Gang Ranch area, southern British Columbia
Authors: Riesterer J W
Published: March 2017

Albian-Cenomanian strata are well exposed along Churn Creek at the southern end of the Chilcotin Plateau. Albian amygdaloidal andesite to massive, columnar-jointed basalt occupy the core of a northeast-trending, doubly plunging anticline. Unconformably overlying
the volcanic package is a thick (~1100 m) sequence of complexly interfingering Albian-Cenomanian chert, volcanic, and plutonic conglomerate and associated sandstone. Paleocurrent measurements indicate chert detritus was probably derived from the Bridge River terrane to the southwest. Volcanic
clasts were derived from a proximal volcanic source along the basin margin. Plutonic clasts were locally derived from a Jurassic-Cretaceous pluton uplifted along a northeast-directed thrust fault in the southwest portion of the study area. Strata in Churn Creek record Albian-Cenomanian contraction,
subsidence and coeval volcanism very similar to rocks immediately to the south in the Tyaughton basin. Proposed stratigraphic ties between the two outcrop belts are the subject of ongoing geochemical, isotopic, petrographic, and geochronological studies.
The Kalamalka Lake metamorphic assemblage, tectonic infrastructure in the Vernon map area, British Columbia
Authors: Erdmer P , Thompson R I , Daughtry K L
Published: March 2017

The oldest metamorphic rocks along Kalamalka Lake are heterogeneous paragneiss units several kilometres thick. Migmatitic biotite-sillimanite schist, calc-silicate and marble, and amphibolite, greenstone, and gneissic rocks are intruded by foliated granite to
granodiorite of inferred Middle Jurassic age. Mineral assemblages in pelite indicate peak metamorphic temperatures near 650°C and minimum pressures of 4 kb. The paragneiss sequence is also cut by leucocratic granite of inferred Jurassic age, by folded pegmatite dykes and sills, and by massive
alkali-feldspar porphyry dykes of inferred Eocene (Coryell) age. A shallow west-dipping zone of ductile mylonitic fabrics, several hundred metres thick and more than 20 km along strike, overprints the metamorphic rocks. It records stretching along west-northwest shallowly plunging axes in present
orientation. Coarse synkinematic sillimanite and amphibolite-grade mineral assemblages in other rock types are characteristic of this shear zone and of the Eagle River detachment in northern Vernon map area.
Neogene structural elements of northern Cascadia, British Columbia
Authors: Journeay J M , van Ulden J
Published: March 2017

Brittle structures in the Coast Mountain region of northern Cascadia record a history of inhomogeneous deformation that may shed light on the Neogene crustal response to oblique subduction and dextral transcurrent faulting along the Cordilleran plate margin of
western North America. Structures in the intra-arc and backarc regions record an older Paleogene history of dextral transpression, and a Neogene history of orogen-parallel compression that likely reflects distributed Pacific/North American plate motions, and the effects of mechanical buttressing at
the leading edge of the southern Cascadia forearc. Structures in the northern Cascadia forearc record effects of both orogen-normal and orogen-parallel compression, likely associated with oblique subduction of the Juan de Fuca plate. The pattern and history of strain partitioning provide an
important framework for natural hazards assessment, and for exploration of natural resources that may be localized, in part, by brittle faulting and fluid migration in the upper crust.
Geological evidence for past large earthquakes in southwest British Columbia
Authors: Clague J J , Bobrowsky P T , Hutchinson I , Mathewes R W
Published: March 2017

Large earthquakes have left evidence of land-level change, tsunamis, and strong shaking in coastal sediments in southwest British Columbia. Sudden lowering of the land during earthquakes accounts for buried tidal marsh and forest soils on Vancouver Island and
near Vancouver. Some sand layers in peaty and muddy marsh sediments on western Vancouver Island were deposited by tsunamis triggered by Pacific earthquakes. Liquefaction features, including dykes and blows of mainly sandy sediments, provide direct evidence for ground shaking, but have been
documented thus far only on the Fraser River delta south of Vancouver. Much of the evidence for subsidence, tsunamis, and shaking is attributed to great earthquakes at the boundary between the North America and Juan de Fuca plates, but some of the evidence probably results from one or more
earthquakes within the crust of North America. In addition, some tsunami deposits on Vancouver Island are products of great earthquakes in Alaska.
Evidence of catastrophic rock avalanche potential and past failures, east face of Mount Livingstone and Windsor Ridge, Alberta
Authors: Jackson L E , Lebel D
Published: March 2017

Extensive rockslides and the potential for catastrophic rock avalanches were discovered in two areas of the Rocky Mountains: 1) an extensive fissure system was noted near the summit of Mount Livingstone at the northern end of the Livingstone Range, and 2) a
postglacial rockslide complex was mapped and investigated near Windsor Ridge, northwest of Waterton Lakes National Park in the headwaters of the east fork of Castle River and Mill Creek. Active fractures and the geological setting observed at this locality suggest that the area is prone to
rockslides and possibly catastrophic rock avalanches. This report describes these features and identifies the possible hazards that they represent. Monitoring of these failures and proactive measures to identify similar situations elsewhere in nearby areas of the Rocky Mountains are
suggested.
Part I: Stratigraphy and brachiopod faunas
Authors: Norris A W
Published: March 2017

From the richly fossiliferous Bituminous limestone member, 21 brachiopod taxa are described of which 5 are new, comprising: Rhyssochonetes aurora medialis n. subsp., Emanuella caldwelli n. sp., Warrenella parafranklinii n. sp., W. posteruskirki n. sp., and W.
whittakeri n. sp. The Bituminous limestone member yields conodonts of the upper ensensis Zone, and the Lower and part of the Middle varcus subzones of Givetian, late Middle Devonian, age. Associated tentaculitids in the Bituminous limestone member include Nowakia otomari, Striatostyliolina roemeri
and Styliolina fissurella, which occur typically in lower to middle Givetian rocks of Czechoslovakia. Some associated rhynchonellid brachiopods in the Bituminous limestone member, which are important for correlation and as zonal fossils, include: Eliorhynchus castanea, Stenoglossaiorhynchus awokanak
and Droharhynchia intermissa.
From the reefal Sulphur Point Formation at Presqu'ile Point, 4 brachiopod taxa are described of which one is new (Gypidula? presquilensis n. sp.). Other important fossils include: Elita? sp., Stringocephalus sp. B, and Hypothyridina cameroni, which indicate correlation with the conodont hermanni
Zone of late Givetian age.
The described Devonian succession along and west of Slave River includes the La Loche, Fitzgerald (Ernestina Lake), Cold Lake (equivalent), Evaporite and Hay Camp members of the Chinchaga Formation. The Devonian sequence along the south side of Great Slave Lake includes the Keg River Formation and
equivalent rock units; Fine-grained dolostone, Bituminous limestone, and Buffalo River members of the Pine Point Formation; and the Sulphur Point, Watt Mountain, Slave Point, and Hay River formations.
Seismostratigraphic investigations of the southern Fraser River delta
Authors: Pullan S E , Hunter J A , Jol H M , Roberts M
C , Burns R A H , Harris J
B
Published: March 2017

Between 1985 and 1995, the Geological Survey of Canada acquired approximately 60 line-kilometres of shallow seismic reflection data on the Fraser River delta. Most of these data were obtained on the southern delta in the mid 1980s using the `optimum offset'
technique. The fine- grained, water-saturated surface sediments provide an excellent medium for application of high-resolution, compressional-wave, seismic reflection methods, and data with dominant frequencies of 200-300 Hz were consistently obtained. These data have provided an opportunity for
detailed examination of the subsurface structure of the delta to depths of up to 170 m. Unfortunately, in many areas the depth of investigation was severely limited by the presence of gas in the shallow sediments. More recently, common-midpoint (CMP) data, using both compressional and shear waves,
have been acquired in an attempt to find alternative methods for exploring the deeper structure of the delta.
Testing and application of near-surface geophysical techniques for earthquake hazards studies, Fraser River delta, British Columbia
Authors: Hunter J A , Douma M , Burns R A , Good R L , Pullan S
E , Harris J B , Luternauer J L , Best M E
Published: March 2017

Geophysical techniques have been tested and applied on the Fraser River delta to determine the structure and geotechnical parameters of Quaternary sediments as a contribution towards earthquake hazards studies. Information has been obtained on the buried bedrock
surface, Pleistocene glacial deposits, and overlying Holocene deltaic sediments using surface and borehole geophysical techniques. Considerable progress has been made in developing and testing methods for determining the shear-wave velocity structure of Fraser delta sediments. Knowledge of the
shear-wave velocity structure of the delta is important for earthquake ground-motion amplification studies as well as cyclic liquefaction investigations.
Plant macrofossil, pollen, diatom, and foraminiferal biofacies of the Fraser delta
Authors: Hutchinson I , Patterson R T , Mathewes R W
Published: March 2017

The Fraser River delta plain supports a diverse array of marine and terrestrial ecological communities. A mosaic of marshes, sand flats, and mud flats in the intertidal zone and wet meadows, shrub lands, bogs, and riparian woodlands above the limit of tides can
be linked by a successional model that relates ecological communities to elevation and substrate characteristics. Paleoecological investigations of plant macrofossils, pollen, diatom, and foraminifers have proven useful in 1) reconstructing late-glacial and early Holocene conditions in the Strait of
Georgia, 2) reconstructing small-scale changes in relative sea level, 3) assessing flood frequency, and 4) explaining autogenic changes related to fire occurrence in raised bogs on the delta plain.
Geological evidence for prehistoric earthquakes
Authors: Clague J J , Naesgaard E , Mathewes R W
Published: March 2017

Geological and paleoecological evidence for two large, late Holocene earthquakes was found on the Fraser River delta and nearby Serpentine River floodplain. Both earthquakes triggered sudden land-level changes, and one caused extensive liquefaction. The younger
quake occurred about 1700 years ago and is marked by submergence throughout the south-coastal region. Sand dykes, sand blows, and deformed strata at many sites on and near the Fraser delta may be products of the same earthquake; if so, earthquakes large and close enough to the delta to produce
extensive liquefaction may be rare events. The land-level change and liquefaction may record a great (magnitude (M) = 8+) plate-boundary earthquake on the Cascadia subduction zone, for which there is considerable evidence on the Pacific coasts of southern Washington and northern Oregon. However,
they are more likely the result of a large crustal earthquake of about the same age within the North America plate. An older earthquake, which occurred about 3600 years ago, is marked by slight emergence of the Fraser delta and submergence on southern Vancouver Island. This pattern of deformation is
consistent with a plate-boundary earthquake.
Site amplification modelling of the Fraser delta, British Columbia
Authors: Harris J B , Hunter J A , Luternauer J L , Finn W D L
Published: March 2017

Newly acquired and interpreted geological and geophysical data from two borehole sites on the Fraser River delta, and a newly prepared map of the depth to bedrock underlying the delta, indicate that the architecture of the delta is significantly different from
that used for current site response models. SHAKE analysis for the two borehole sites shows that there is likely to be considerable long-period response (3.5 to 5.0 s) because the deltaic and/or Pleistocene sequences at these locations are interpreted to be thicker and, at depth, less dense than
previously assumed. The presence of significant long-period ground motions has important implications for the stability of large structures on the delta. Seismic response of the delta will also likely be affected by the highly irregular bedrock surface beneath the delta which may focus or disperse
earthquake energy.
Seismic liquefaction potential of the southwestern margin of the Fraser River delta
Authors: Christian H A
Published: March 2017

Geotechnical investigations at the southwestern margin of the Fraser delta indicate that seismic liquefaction failure is possible and might result in lateral spreading, slope flattening, and flow sliding. Comparisons were made between cone-derived parameters and
cyclic stress ratios predicted from empirical relationships between earthquake magnitude, peak horizontal acceleration, and overburden stress. Loose sandy silt and sand at the crest of the delta slope appear susceptible to cyclic liquefaction to a depth of about 25 m below the seafloor.
Post-liquefaction deformations could potentially include lateral spreading of the area behind the crest of the slope, as well as localized flow sliding at and immediately below the crest of Roberts Bank slope.
Geochemistry of seafloor sediments from the Strait of Georgia, British Columbia
Authors: Dunn C E
Published: March 2017

Sediment samples from 127 seafloor sites in the Strait of Georgia were analyzed to determine the spatial distribution of a wide range of chemical elements. Concentrations are mostly close to normal background levels for marine mud; however, locally several groups
of elements are relatively enriched. West of Burrard Inlet enrichments of Al, Fe, K, and Mg coincide with slightly elevated levels of Hg, Pb, Sb, Cu, F, Nb, and Rb, reflecting clay minerals, derived mostly from the Fraser River, but also from Howe Sound and Burrard Inlet. Other multi-element
associations include a resistate fraction (REEs, Ti, Th, U, Be, Au); elements deposited under reducing conditions in relatively deep water (Na, Br, S, B, Mn, Co); a carbonate fraction (Ca, Sr, CO2) with Zr and Hf; and an organic fraction (C, P, As, Zn). Factor analysis provides insight to element
associations and indicates a possible anthropogenic component for Ag, Ba, Cu, F, Hg, Ni, Pb, Sb, and Zn.
Geology of the Euchiniko map area, central British Columbia
Authors: Struik L C , Anderson R G , Plouffe A
Published: March 2017

Euchiniko map area is a composite of the Euchiniko River (93 F/8) and Suscha Creek (93 F/1) map areas. The region was last glaciated during the Late Wisconsinan Fraser Glaciation that left important accumulations of glaciofluvial sand and gravel in the major
valleys, and till in the higher areas. Rogen moraines might be present in the southern part of the region, which suggest an active ice retreat. Bedrock of the area has suffered at least four tectonic episodes since the Permian, involving the generation of the Triassic-Jurassic Takla and Hazelton
Group volcanic arc; Cretaceous plutonism, volcanism, and compression; Eocene volcanism and extension; and Miocene volcanism and faulting or fault remobilization.
Geology of the Eocene Ootsa Lake Group in northern Nechako River and southern Fort Fraser map areas, central British Columbia
Authors: Grainger N C , Anderson R G
Published: March 2017

Eocene Ootsa Lake Group in northern Nechako River map area comprises variegated, flow-laminated rhyolitic flows and domes, crystal and lithic-crystal tuff, less common pyroclastic and autoclastic breccia, and minor dacite and andesite flows. Rotated rhyolite
clasts, flow folding, vesicles, perlite and spherulites, and minor lithophysae and eutaxitic textures and phenocrysts of plagioclase, biotite, alkali feldspar, quartz, and rare hornblende are distinctive.
A local stratigraphy comprises basal hornblende-plagioclase porphyritic andesite with distinctive amethyst-bearing amygdules, medial flow- laminated rhyolite flow rocks and breccia, and upper felsic tuff and breccia. Distinct rhyolite ash-lignite beds mark the top of the unit and in addition to
glassy quenched flow bases and reworking of lithic rhyolite tuff units, suggest local shallow-water environments.
The Dayeezcha Mountain, Henson Hills, and Mackenzie Lake study areas provide the most complete stratigraphy. Ongoing petrographic, geochronological, geochemical, and isotopic tracer studies will elucidate the age, correlation, composition, tectonic setting, and petrogenesis of the
unit.
Ordovician stratigraphy of Dobbin Bay, Radmore Harbour, and John Richardson Bay, east-central Ellesmere Island
Authors: Turner E C , Mayr U
Published: March 2017

Stratigraphic sections were measured and described at three localities on east-central Ellesmere Island, providing two, nearly continuous composite sections through more than 2 km of Ordovician strata. These successions conform to previously established
formations from the Arctic Archipelago and northwest Greenland.
All units are platformal in character: restricted-marine carbonates deposited above storm wave-base are the rocks of the Christian Elv Formation and of part of the Baumann Fiord, Eleanor River, and Bay Fiord formations; normal- marine, lagoonal carbonates are represented by the Cape Clay, Eleanor
River, Thumb Mountain, Irene Bay, and Allen Bay formations, as well as parts of the Bay Fiord Formation. Peritidal deposits are present in parts of the Eleanor River and Bay Fiord formations. Lagoonal evaporites are present in the Baumann Fiord and Bay Fiord formations.
Clastic and chemical sedimentary sequences, Woodburn Lake group, Amarulik Lake to Tehek Lake, western Churchill Province, Northwest Territories (Nunavut)
Authors: Zaleski E , Duke N , L'Heureux R , Davis W J , Wilkinson L
Published: March 2017

In the Amarulik-Tehek lakes area, the Archean Woodburn Lake group comprises psammitic greywacke interlayered with iron-formation and amphibole hornfels, the latter interpreted as metamorphosed rocks of mixed chemical and clastic sedimentary parentage. Amphibole
hornfels extends northward to the Meadowbank gold deposits and includes rocks previously mapped as intermediate volcanic rocks. New mapping implies that a reported age of ca. 2.8 Ga for volcanic rocks is invalid, as the area is underlain by greywacke, albeit with volcanogenic components. A
structural dome, centred on Amarulik Lake, is defined by outward-dipping bedding and schistosity, and encompasses smaller scale structural complexities such as concentric dip reversals. Orthoquartzite and metacarbonate lie near the eastern margin of the dome and the distribution of units suggests
fold interference patterns. Mineral assemblages are typical of amphibolite-facies metamorphic grade, whereas to the north, chloritoid-bearing greenschist-facies assemblages prevail, suggesting that the Meadowbank gold deposit lies near the greenschist- amphibolite
transition.
Proterozoic reworking in western Churchill Province, Gibson Lake-Cross Bay area, Northwest Territories (Kivalliq region, Nunavut). Part 1: general geology
Authors: Hanmer S , Tella S , Sandeman H A , Ryan J J , Hadlari T , Mills A
Published: March 2017

The northeastern part of the Neoarchean MacQuoid supracrustal belt comprises the Gibson- MacQuoid homoclinal belt of homogeneous metasedimentary rocks, tonalitic orthogneiss units and plutons, structurally overlain to the north by a belt of mafic to intermediate
volcanic flows and volcaniclastic rocks, intruded by tonalitic to granodiorite plutons. The Cross Bay plutonic complex is separated from the supracrustal belt by the Big lake shear zone. Metamorphosed, ca. 2.19 Ga, mafic dykes are involved in Paleoproterozoic regional deformation in both the
plutonic complex and the shear zone.
Precambrian geology, northern Angikuni Lake, and a transect across the Snowbird tectonic zone, western Angikuni Lake, Northwest Territories (Nunavut)
Authors: Aspler L B , Chiarenzelli J R , Cousens B L , Valentino D
Published: March 2017

Greenschist-grade remnants of 2.68 Ga volcanic, siliciclastic, and carbonate sequences were deposited in shallow water on transitional or continental crust. Tholeiitic major-element trends, MORB-like trace-element patterns with signatures of crustal
contamination, and mostly positive epsilon Nd t values suggest back-arc basin or continental-rift deposition. Granitic to gabbroic gneiss complexes disrupt supracrustal domains. Geochemical and isotopic data suggest upper-mantle derivation of the gabbro, and granite production by crustal melting,
presumably during 2.61 Ga intracontinental lithospheric shearing. Amphibolite-grade mylonitic rocks and younger greenschist-grade cataclasites, distributed throughout western Angikuni Lake, continue across the geophysically defined Snowbird tectonic zone. High- and low-grade tectonism, and changes
in structural level between Archean domains occurred before Christopher Island volcanism (ca. 1.83 Ga). The Angikuni Formation (conglomerate, arkose, semipelite) reflects continental sedimentation in an isolated fault- bounded trough tilted before the onset of Christopher Island volcanism. It is
probably tectonostratigraphically equivalent to the South Channel and Kazan formations in southern Baker Lake Basin.
Tectonic assembly and Proterozoic reworking of the northern Yathkyed greenstone belt, Northwest Territories (Nunavut)
Authors: Relf C , MacLachlan K , Irwin D
Published: March 2017

Regional mapping in the Yathkyed greenstone belt has revealed two distinct tectonostratigraphic units in the hanging wall of the Tyrrell shear zone. The geometrically lower tectonostratigraphic unit comprises mainly amphibolite and monzogranite, whereas the
structurally higher unit consists of a package of mixed flows and associated volcaniclastic and clastic sedimentary rocks intruded by foliation-parallel sheets of tonalite. A shear zone of unknown displacement sense separates the two tectonostratigraphic units. The Tyrrell shear zone at the base of
the greenstone belt records early (possibly Archean) reverse displacement, followed by Paleoproterozoic dextral-normal movement.
Foliation- parallel gossans with strike lengths up to 3 km and alteration assemblages containing sericite±chlorite±carbonate were documented in volcanic rocks of the upper tectonostratigraphic unit. The timing of formation of these mineralized zones is unclear, although evidence for a
Proterozoic thermal overprint suggests late remobilization of metals may have contributed to the mineral potential of the area.
Preliminary investigation of significant mineral occurrences in the central Rankin-Ennadai supracrustal belt, Kaminak Lake area, Northwest Territories (Nunavut)
Authors: Goff S P , Kerswill J A
Published: March 2017

The central portion of the Rankin-Ennadai supracrustal belt contains a large number of mineral occurrences, including several major vein gold, polymetallic vein, and volcanic-associated massive sulphide deposits.
Work to date indicates that most significant gold occurrences contain complex multistage, carbonate-bearing vein systems in which at least some gold-rich veins clearly predate regional deformation and metamorphism. Deformed, pyritic, quartz-sericite schists of similar character to alteration zones
in massive sulphide deposits are present in some gold occurrences.
Polymetallic vein occurrences contain high Au, Ag, Cu, and Zn, high Ag/Au ratios, locally anomalous Bi, Se, Te, As, and Mo, and pyritic quartz-sericite schist. Both the veins and schistose alteration zones are deformed and metamorphosed
The critical features of polymetallic vein and some vein gold occurrences are similar to those of many porphyry and/or epithermal deposits and suggest a major contribution to metal concentration by synvolcanic processes.
Lithotectonic framework of the Trans-Hudson Orogen in the northwestern Reindeer Zone, Saskatchewan: an update from recent mapping along the Reindeer Lake transect
Authors: Corrigan D , Pehrsson S J , MacHattie T G , Piper L , Wright D , Lassen B , Chakungal J
Published: March 2017

The northwestern Reindeer Zone along Reindeer Lake, Saskatchewan, consists of a stack of juvenile lithotectonic terranes and sedimentary basins accreted to the Archean Hearne Province during Paleoproterozoic collision, and a younger molasse basin (McLennan
(Sickle) Group) deformed with the above during postcollisional convergence. Along the southern shore of Reindeer Lake, the McLennan Group fluvial-littoral sediments are folded and imbricated with older supracrustal rocks tentatively correlated with the Central Metavolcanic Belt, which are themselves
thrust onto meta-turbidites of the Burntwood Group. La Ronge Domain lithologies have been mapped as far north as the southern margin of the Wathaman Batholith, calling into question the existence of the Rottenstone Domain. The structural geometry along the transect is dominated by large-scale
recumbent folds (F1), orogen-parallel, south-verging reclined to recumbent non-cylindrical folds (F2) contemporaneous with south-directed thrusting, and large-wavelength upright cross folds (F3).
Geology of the Mesoarchean Wallace Lake greenstone belt, southeastern Manitoba
Authors: Sasseville C , Tomlinson K Y
Published: March 2017

The Wallace Lake greenstone belt at the southern margin of the North Caribou terrane contains a basal panel of Mesoarchean platformal sediments, the Conley Formation. The sequence is transgressive and presumably in unconformable contact with a tonalitic basement.
Ultramafic volcanic rocks including spinifex-textured komatiite units occur in the upper Conley Formation. It is conformably overlain by a predominantly mafic volcanic succession, the Big Island Formation. On Siderock Lake a volcanogenic polymictic conglomerate occurs at the base of the Siderock
Formation which overlies, possibly unconformably, the mafic volcanic rocks of the Big Island Formation. Four folding events are recognized in the Wallace Lake area, only two of which define the map-scale interference geometry. Mineralization and alteration appear to be structurally controlled in the
northern Wallace Lake belt. The Wallace Lake stratigraphy may correlate with that in the Steep Rock belt of the Wabigoon Subprovince, forming strong evidence for rifting of a 3 Ga Superior protocraton.
Tectonic assembly of continental margin and oceanic terranes at 2.7 Ga in the Savant Lake-Sturgeon Lake greenstone belt, Ontario
Authors: Sanborn-Barrie M , Skulski T
Published: March 2017

The Savant Lake-Sturgeon Lake greenstone belt formed between continental crust, represented by granitoid rocks to the east within which vestiges of ca. 3.0 Ga basement and Mesoarchean cover sequences occur, and oceanic crust, represented by Neoarchean greenstone
belts of the western Wabigoon Subprovince to the west. The belt can be subdivided into three major components, 1) a <2.9 Ga volcanic rift margin dominated by tholeiitic basalt with basal quartz-rich clastic rocks; 2) diverse oceanic crust comprising a conformable sequence of 2.775 Ga
basaltic basement, 2.745-2.704 Ga island arc crust, and 2.718 Ga arc rift deposits; and 3) a <2.704 Ga turbiditic succession (foredeep) that rests unconformably on the rift margin but conformably on oceanic rocks. Penetrative, ductile deformation after ca. 2.703 Ga, but before ca. 2.68
Ga, is interpreted to record collision between the volcanic rift margin and the diverse oceanic terrane following 2.71 Ga continental arc magmatism.
Archean carbonate-bearing alkaline igneous complexes of the western Quetico metasedimentary belt, Superior Province, Ontario
Authors: Hattori K , Percival J A
Published: March 2017

Archean carbonate-bearing alkalic igneous complexes are under study in the Harnett Lake, Beaverhouse Lake, and Whalen Lake complexes of the western Quetico metasedimentary belt. Isotopic compositions of calcite indicate a high-temperature origin and are similar
to those of carbonatites of all geological ages. The alkaline intrusions are cut by peraluminous granite dykes of 2.67-2.65 Ga. The Archean ages of the intrusions are further supported by low measured values of 87Sr/86Sr for apatite and titanite: initial 87Sr/86Sr values of 0.701094 and 0.701323
indicate mildly depleted to bulk- earth-like signatures. Bulk-rock compositions show high concentrations of large-ion-lithophile elements (LILE) with negative anomalies for high-field-strength elements. High concentrations of LILE in cumulus clinopyroxenites support an intrinsically alkaline nature
for the parental magmas. Combined with low 87Sr/86Sr, the data are consistent with derivation of the parental magmas from a depleted mantle wedge which had undergone metasomatism not long before the igneous activity.
Preliminary observations on the Oso Pluton, Frontenac suite, Grenville Province, Ontario
Authors: Ijewliw O
Published: March 2017

The undeformed Oso pluton lies between two shear zones in the Central Metasedimentary Belt of the Grenville Province and intrudes deformed supracrustal rocks previously metamorphosed to lower amphibolite facies. This polyphase intrusion, ranging in composition
from the oldest gabbro to the youngest syenite units, provides evidence for multistage intrusion, and magma commingling and mixing. Quartz tourmaline veins are found on the margins and periphery.
Characterization of the chemical composition and 40Ar-39Ar systematics of intralaboratory standard MAC-83 biotite
Authors: Sandeman H A , Archibald D A , Grant J W , Villeneuve M E , Ford F D
Published: March 2017

The composition and Ar systematics of biotite (710-355 µm) from MAC-83, a glassy, rhyodacitic crystal-lapilli tuff, have been characterized by electron microprobe and laser 40Ar-39Ar analysis. Fifty electron microprobe analyses demonstrate that the biotites
are homogeneous in composition. Twenty-six laser total-fusion, 40Ar-39Ar analyses of the biotite, calibrated against Taylor Creek Rhyolite sanidine (28.34 Ma) and Fish Canyon Tuff sanidine (28.02 Ma), yielded a weighted mean age (based on the respective errors) of 24.36 ± 0.17 Ma. Mass
spectrometric determinations of Ca/K and Cl/K were reproducible yielding Cl/K = 0.050 ± 0.002, Ca/K = 0.025 ± 0.040 (errors at 2s). Both conventional furnace and laser step-heating analysis of MAC-83 biotite reveals that it is characterized by minor excess argon, but that overall it yields
a well-defined, internally concordant spectrum. These data indicate chemical homogeneity and regular', reproducible argon-release behaviour, implying suitability as a reference material for 40Ar-39Ar laser geochronology.
Drilling operations, JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well
Authors: Ohara T , Dallimore S R , Fercho E
Published: March 2017

The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well, located in the Mackenzie Delta, Northwest Territories, Canada, was completed to 1150 m on March 30, 1998, after 39 days. Operations were undertaken through a collaborative agreement between the Japan
National Oil Corporation and the Geological Survey of Canada. Research goals included evaluation of engineering technologies used to drill and core gas-hydrate-bearing strata. Eight coring runs were conducted within the permafrost interval (0 640 m) in a surface hole drilled to 687 m. Subsequently,
a 340 mm surface casing was installed and the main hole was advanced to a depth of 1150 m with 16 coring runs. A cooled (~2°C) KCl/polymer drilling mud and Drilltreat, a chemical mud additive, successfully stabilized gas hydrate within cores and formation sediments. No serious hole
problems, accidents, or mishaps occurred; however, delays caused by adverse weather and mechanical problems caused cancellation of planned production testing. Coring in the main hole was successful, allowing the evaluation of four different core barrels. Gas-hydrate-bearing cores were collected in a
variety of sediments between 896 and 952 m.
Regional gas hydrate occurrences, permafrost conditions, and Cenozoic geology, Mackenzie Delta area
Authors: Dallimore S R , Collett T S
Published: March 2017

The occurrence of natural gas hydrate within Cenozoic sediments of the Mackenzie Delta Beaufort Sea region has been well documented. In preparation for the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well, a detailed evaluation of terrestrial gas hydrate
occurrences was undertaken to assess the geological setting, sediment associations, pressure and temperature conditions, and the presence of free gas in the Mackenzie Delta Beaufort Sea region. After an exhaustive review, it was determined that the Mallik L-38 site, drilled by Imperial Oil in 1972,
offered the highest probability of encountering a thick gas hydrate occurrence with high gas hydrate concentrations. On the basis of open-hole well-log evaluation, it was estimated that about 111 m of gas-hydrate-bearing strata occur at this location from 810.1 to 1102.3 m, within the zone of
predicted methane hydrate stability and below the base of ice-bearing permafrost, estimated to be at 640 m.
Review of ground temperatures in the Mallik field area: a constraint to the methane hydrate stability
Authors: Majorowicz J A , Smith S L
Published: March 2017

Analysis of data from 32 industrial exploration wells in the Mallik field and surrounding area in the Mackenzie Delta-Beaufort Sea region allowed construction of temperature-depth profiles using regional heat-flow values, temperature at the base of ice-bearing
permafrost, and models of thermal conductivity with depth. An analysis of the stability conditions for methane hydrate showed that it is stable in the Mallik field area and that the depth to the base of the methane hydrate stability zone can be as deep as 1500 ± 100 m in areas of thick
permafrost. The depth to the base of the methane hydrate stability zone, calculated in this study using reconstructed temperature-depth profiles, was found in a majority of the wells to be 50-150 m deeper than that previously determined using linear temperature profiles and a constant thermal
conductivity with depth.
Micropaleontology of the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well
Authors: McNeil D H
Published: March 2017

Core and cuttings samples from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well in the Mackenzie Delta have yielded sparse terrestrial microfossils and abundant reworked Cretaceous foraminifers (silicified) and plant microfossils. No definitely in situ
marine microfossils were recovered in the borehole (total depth 1150 m; gas hydrate at 896-1110 m). Cores from 110-118 m and 173-175 m contained terrestrial microfossils including fungi, seeds, insect fragments, and abundant macerated plant fragments typical of the Pliocene-Pleistocene Iperk
Sequence in the Mackenzie-Beaufort Basin. Core from 886-951 m and cuttings samples from 670-870 and 960-1140 m yielded reworked algal cysts, seed casings, and megaspores. In addition, cuttings contained reworked Cretaceous agglutinated foraminifers. Core and cuttings samples were also characterized
by quartz, chert, brownish-black lignite, coaly fragments, and rare amber. The lithology of the section below 670 m is characteristic of the Oligocene Kugmallit Sequence in the Mackenzie-Beaufort Basin.
Microbial communities from core intervals, JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well
Authors: Colwell F S , Delwiche M E , Blackwelder D , Wilson M S , Lehman R
M , Uchida T
Published: March 2017

Microbial cell distribution in sediment core samples from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well on the Mackenzie Delta (Canada) was studied using acridine orange direct counts of stained cells for total cell estimation, and by most probable
number statistical enumeration for culturable methanogens. The purpose was to characterize the microbial communities in gas-hydrate-bearing sediments. Results indicated that the total cell count values were in the range of 1.1x105 cells/g to 2.8x106 cells/g with culturable methanogens present at
1x10-4% to 1.0% of those values. These results also indicated that culturable methanogens may be more numerous in the porous sandy strata of the Mackenzie Bay Sequence than in clay and silt units of the Kugmallit Sequence. These data expand the known distribution of methanogens in deep
sediments and establish the presence of microbial communities in subpermafrost environments.
Occurrences and X-ray computerized tomography (CT) observations of natural gas hydrate, JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well
Authors: Uchida T , Dallimore S R , Mikami J , Nixon F M
Published: March 2017

The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well was drilled through a thick interbedded sequence of gas-hydrate-bearing sediments between 896 and 1106 m. In total, 37.3 m of core were collected between 886 and 952.6 m, using a variety of coring systems.
Visual observations at the drill site identified a predominance of pore-space gas hydrate in varying concentrations within framework-supported sands and pebbly sands. Gas hydrate was mainly fine grained (<2 mm), filling the intergranular pores and/or coating mineral grains. Although rare,
thin veins (1-2 mm) and clasts or nodules of gas hydrate (up to 0.5 mm) were also observed. The largest gas hydrate occurrence (2 cm in diameter) formed the matrix of a granular sand at 913 m.

X-ray CT imagery, carried out in Japan, has identified eight well constrained signatures of the constituent components of the gas-hydrate-bearing sands and granular sands. These images have been used to establish textural characteristics and the relationship between sediment grains and gas
hydrate.
Dissociation properties of natural gas hydrate from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well by X-ray computerized tomography (CT) experiments
Authors: Uchida T , Mikami J , Masuda Y , Satoh T
Published: March 2017

Core samples from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well contained a variety of forms of gas hydrate within sands and granular sands in the interval from 896 to 926 m. A number of these samples were placed inside pressure vessels charged with
nitrogen gas and subsequently transported to Japan for specialized dissociation experiments. X-Ray CT images were acquired, at constant intervals, from a granular sand (collected from 913.76 m) containing pore-space gas hydrate during warming from -35 to 4°C, and subsequently during stepped
decreases in cell pressures (0.1 MPa) below assumed threshold stability conditions. Dissociated gas flow and sample temperatures were monitored continuously.

Changes in CT values indicated that gas hydrate dissociated simultaneously, both on the exposed surfaces and within the pore spaces of the sample, in response to pressure changes. This suggested that pressure reductions were effectively transmitted through the sample, most likely because the
samples were not fully saturated with gas hydrate. Gas-flow measurements indicated that a larger pressure drawdown caused a higher dissociation rate.
Influence of grain size and salinity on pressure-temperature thresholds for methane hydrate stability in JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research-well sediments
Authors: Wright J F , Dallimore S R , Nixon F
M
Published: March 2017

This paper summarizes laboratory determinations of the pressure-temperature (P-T) phase equilibrium conditions for methane hydrate stability in sediments recovered from the gas-hydrate-bearing interval at JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well.
Three test samples consisted of quartz-rich sand with in situ pore-water salinities of 4 ppt (parts per thousand), 20 ppt, and 40 ppt. A fourth sample was dominated by silt, with a salinity of 31 ppt. Initially, methane hydrate was regrown in the sediments, followed by the determination of P-T
stability thresholds between 0°C and 12°C. Comparisons with published data for methane hydrate stability in pure gas-water systems indicate no appreciable shift in P-T stability conditions in sand with salinity of 4 ppt, but suggest a progressively increasing shift towards the higher
pressure, lower temperature region for sand samples with elevated salinity. Test results for the saline silt sample indicate an additional shift in the stability threshold attributed to the effect of the porous medium in fine-grained sediments.
Storage and handling of natural gas hydrate
Authors: Tulk C A , Wright J F , Ratcliffe C I , Ripmeester J A
Published: March 2017

Gas hydrate samples that are recovered from natural deposits usually need to be preserved for subsequent analysis in a laboratory setting remote from the recovery site. The preservation of integrity of the gas hydrate and the quality of the subsequent sample
analysis will depend on the details of sample storage and handling. Previously, massive gas hydrate samples, both natural and synthetic, have been stored in liquid nitrogen without apparent ill effects. We propose this method also for sediment-rich natural samples that are recovered for the
analysis of fundamental gas hydrate properties; liquid nitrogen storage is safe and convenient as long as some care is taken with the detailed handling procedure. This is rationalized in terms of the current state of knowledge of the dynamics and reactivity of gas hydrate and
ice.