Intensive forest management practices may differ from natural fire disturbances in its effects on soil properties, such as carbon (C) and nitrogen (N) storage, that may cause long-term changes in stand productivity.  This study compared soil properties of three black spruce (Picea mariana) stands in Northwestern Ontario, which included two disturbed stands and one recently undisturbed control stand.  Both disturbed stands are regenerating areas that had experienced disturbance 20 years prior to sampling; one represents conditions from a natural burn and the other represents conditions of a whole-tree havesting (WTH) with blading treatment.  Soil samples were collected in three established plots within each stand.  The organic layer of the forest floor and the mineral soil (0 - 50 cm) were sampled at three locations in each plot and bulk density samples in the mineral soil were determined.  Both the organic material and mineral soil were air analysed for organic C and N content.  The mineral soil was also analysed for its pH.  Significant differences were observed between the disturbed sties and the control site in these study areas, with disturbance effects being most significant within the WTH with blading treatment.  The burn site had forest floors with thicker organic layers, higher organic carbon masses, lower pH, higher concentrations of total C and N in the mineral soil, and higher C and N storage in the mineral soil compared to the WTH with blading site.  Although significant losses in total N stores within the burn site were observed, C stores did not appear to be affected by the burn.  This may be due, however, to the nature of the wildfire which was described as being a relatively low intensity burn with only a moderate depth of burn into the humus layer.  The WTH with blading site, as mentioned was the most significantly affected by disturbance and the forest floor at this site had significantly lower masses of organic material and significant losses of both C and N stores, with concentrations measuring approximately 45% and 60% less, respectively, than those of the control site.  The decreased organic material and subsequent diminished C content is a direct result of the great quantities of forest volumes taken away during harvesting activities and indicates that this type of harvesting is not a sustainable practice.  Also, this study suggested that WTH with blading can result in significant negative impacts to C  and N stores that are different from those produced by a naturally occurring wildfire.  A final notable finding of this study was that both C and N storage was significantly greater in the organic layer than the mineral soil for all treatments (by approximately 70%), indicating that a larger portion of the C and N content resides in the unprotected labile portion of the system which makes forest floors naturally vulnerable to disturance.  Further study is necessary to determine the stabilization mechanisms of the soil organic matter (SOM) to systematically characterize the physical protection mechanisms of the soil environment.

The North Caribou Greenstone Belt (NCGB), located within the North Caribou Terrane of the Archean Superior Province, is host to multiple ~3.0 Ga metavolcanic and metasedimentary assemblages.  The assemblages have been metamorphosed from greenschist to upper-amphibolite grade and are bounded by ~2.7-3.0 Ga granitoids and gneisses.  The study area is located approximately 5km south of Musselwhite Mine within what was previously thought to be the Opapimiskan-Markop metavolcanic assemblage. Three lithologies were identified within the study area (basaltic, komatiitic, and felsic volcanic flows) which have been subdivided into four separate volcanic suites: Volcanic Suite A, Volcanic Suite B, Volcanic Suite C, and the Felsic Volcanic Suite.

Volcanic Suite A is comprised of a succession of massive and pillowed basaltic flows that have been metamorphosed to amphibolites.  These flows exhibit a mineral assemblage of amphibole, chlorite, and plagioclase with minor quartz, muscovite, titanite and epidote.  Major element geochemistry reveals that this suite is compositionally similar to that of a high-Mg tholeiitic basalt.  Primitive mantle normalized plots for this volcanic suite are characterized by a flat rare earth element (REE) pattern comparable to tholeiites from the South Rim Unit (SRU), which have been interpreted to represent ocean plateau basalts formed from a mantle plume.  Volcanic Suite B is comprised of pillowed and massive basaltic flows that have been metamorphosed to amphibolites.  The main mineral assemblage observed in this suite was amphibole and chlorite with minor plagioclase, clinozoisite, quartz, titanite and dolomite.  Major element geochemistry indicates that this suite is comprised of high-Mg tholeiitic basalts, komatiitic basalts, and a komatiite.  Primitive mantle normalized plots display a relatively flat REE pattern but with a negative Nb anomaly. The similar trace element geochemistry of Volcanic Suites A and B suggests that they are both derived from a plume source, however, the negative Nb anomaly in Volcanic Suite B indicates that it has undergone crustal contamination during emplacement.  Volcanic Suite C is also comprised of massive and pillowed basaltic flows with a main mineral assemblage of amphibole and chlorite.  A single sample was taken from this suite and it was determined to be a high-Fe tholeiitic basalt based on major element geochemistry.  Primitive mantle plots of this suite are light rare earth element (LREE) enriched with a negative Nb anomaly and positive Zr and Hf anomalies.  A similar REE pattern was observed in the tholeiitic basalts from the Opapimiskan-Markop Unit (OMU).   The Felsic Volcanic Suite overlies the mafic volcanic suites and is comprised of rhyolitic flows.  This suite is LREE enriched with a relatively flat heavy rare earth element (HREE) pattern and negative Nb and Ti anomalies in conjunction with positive Zr and Hf anomalies. Similar REE patterns were observed in the SRU and were interpreted to be derived from a subduction tectonic setting. 

The results of this study are consistent with previous work in the region and suggest that the early history of the area preserved the interaction of a mantle plume with pre-existing continental crust. In addition this study has refined the boundaries of the various assemblages within the NCGB.

The Hele Member of the Outan Island Formation, Sibley Group, is dominantly composed of fine-grained sediments, most commonly mudstone/siltstone to fine-grained sandstone.  Sedimentary structures consist of parallel lamination, soft sediment deformation features, in the form of load structures, and cross-stratified sandstone featuring a distinct lack of desiccation cracks, vegetation and evaporite formation.
The frequency of small-form ripples and parallel laminations in fine-grained sediment were taken to be representative of a low-energy system with a high suspended load.  The abundant load structures are indicative of frequent, flashing addition of sediment to a wet substrate.  The lack of desiccation cracks and evaporites indicate a non-arid environment ranging into the sub-humid.  Ancient, sub-humid dryland fluvial systems are sparsely researched and comparisons were instead drawn to modern dryland systems and ancient dryland systems, omitting or compensating for factors such as aridity conditions (formation of caliche and evaporites) and bioturbation (ruining the preservation of depositional structures.)

The Hele Member is theorized to be representative of an inland, basinal, sub-aerial, low-gradient, ephemeal, semi-humid, ancient, fluvial floodplain dominated environment based on the outcome of this study and data from Rogala, 2003.

An outcrop present along Hwy 11/17 east of Thunder Bay contains a sequence of stacked clastic rocks with dike intrusions.  The clastic units are dominated by surge flows and ash fallout deposits, with less common debris flows and fluvial reworking.  The presence of surge deposits and pyroclastic falls in association with one another show the sequence was deposited proximal to the source.  The ash beds are on average 3 cm in thickness and grade from medium-grained sand to very fine-grained sandy tops.  These normal graded beds are likely ash fallout deposits, and are frequent throughout the study outcrop.  The thin, very explosive and wet surge deposits likely formed from a maar volcano landform.  Deposition of the clastic units likely took place in a subaerial environment with subaqueous areas, such as a flooded plain or swamp.

Hornblendite dikes cut through the sequence and also occur as veinlets and sill-like intrusions infiltrating into the clastic material.  The intrusions incorporate the clastic material and often there is a dissipative zoning of sediment in the hornblendite intrusions.  This shows the sediment at the time of intrusion was wet.

The outcrop was formed in a volcanic environment within the Shebandowan Greenstone Belt of the Wawa Subprovince.

The 2.8 Ga Archean Steep Rock Group of north-western Ontario, Canada, contains one of the oldest well-preserved carbonate ramps in the world.  The Mosher Carbonate is host to a number of unique ancient depositional textures.  The purpose of this thesis is to perform a thorough analysis of the depositional textures of carbonate precipitates in the Steep Rock group’s Mosher carbonate.  These textures include: columnar stromatolites, microbial mat and fenestrate microbialites, sheet cracks, and crystal fans.  Columnar stromatolites are found in walled and unwalled varieties.  Microbial mat, microbial supports, and carbonate-filled void spaces in differing ratios make up fenestrate microbialites.  The most common form of fenestrate microbialites at Steep Rock are tented microbialites and “net-like” microbialites.  These are a result of a lesser influence from microbial supports and void spaces and domination by horizontal filmy laminae.  Sheet crack structures are common and have shown up to 4 stages of successive growth in some samples.  Crystal fans at Steep Rock form distinctive giant domes, alternating in deposition with fenestrate microbialites.  Fans grow in all directions, though downwards is uncommon and lateral growth is blocked early on by other fans.  Crystals grow preferentially from the tops of microbial supports, and in some cases from a darkened surface that may represent dissolution.

The Lyon Lake – Claw Lake sulphide bearing graphitic shale is contained within a predominantly sedimentary sequence of coarse to fine clastics with minor carbonate and mafic volcanic rock.

Sulphide mineralogy consists mainly of pyrite and pyrrhotite occurring as nodules, lensoid pods and narrow bands conformable with bedding. Traces of chalcopyrite, sphalerite and arsenopyrite are present as well.

Cu, Zn, Ni, Co, Mn and As were analysed in sulphides, graphitic shale and wall rock. Results suggest: (1) Sulphides contain higher contents of Cu, Zn, Co, Ni, and As than graphitic shale or wall rock and (2) Mn, Zn, Co and Ni content decreases eastward along the formation in graphitic shale.

Analyses of a vertical section through the formation suggests: (1) Cu, Zn, and Mn are enriched in the footwall rocks as opposed to the hanging wall rocks, (2) Zn and As are concentrated in graphitic shale in comparison with hanging wall rocks and (3) Co and Ni content is relatively uniform throughout the section.

Element ratios have been used to investigate the depositional environment of sulphides and host rock. Results show: (1) Co:Ni ratios in sulphides and graphitic shale are consistent with other worker's data for a sedimentary origin and (2) Mn:Fe ratios are suggestive of volcanic contribution to the western margin of the formation.

Carbon content in the graphitic shale varies from 1.60% - 12.06%. X-Ray studies indicate carbon is either present in an amorphous form or below the detection limit of this technique.

X-Ray studies indicate the pyrrohtite present in monoclinic possibly derived by metamorphism from pyrite.

Evidence suggests that the graphitic shale is derived in a sedimentary basin in which there was volcanic activity at the western margin. This was followed by large scale mafic volcanism. Sulphides derived by sedimentary or diagenetic processes is likely, since there is no evidence for a direct volcanic exhalative source.

The 1878 ± 1Ma Gunflint Formation is a chemical-sedimentary unit deposited in the Animike Basin; it shows a sequence of transgressive-regressive cycles.  Wolff (1917) and Broderick (1923) divided the Gunflint into several individual members; lower cherty, lower slaty, upper cherty and upper slaty.  These members were then grouped into two different sequences; the upper and lower sequences.  The first and most extensive transgressive-regressive cycle is made up of the lower cherty member, while overlying transgressive-regressive cycles are made up of the lower slaty member, the lower cherty member and the upper slaty member.

Two separate outcrops found near Mink Mountain UTM: 329,520 E/5,338,163N and off the Magnetic Rock Trail in Minnesota662034E/5329885N were examined and sampled.  These two outcrops show a complete section through the peak lower regressive-transgressive sequence.  Detailed stratigraphic columns were constructed from the logs takes through these sequences, which were divided into three main units; 1) a grainstone unit forms the bottom unit and lies directly below 2) stromatolites which are capped off by a 3) oncolithic unit.  At the outcrop behind Mink Mountain the grainstone directly below the stromatolites is brecciated and shows injection of jasper and hematite throughout.  Microscopically the grainstone unit is composed of angular to rounded grains of chert.  The cement is predominantly chert with some blocky quartz found forming at grain boundaries.  The stromatolite unit is present above the pre-lithified grainstone unit and contains distinct stratiform and columnar stromatolites.  The top unit is an oncolith-rich grainstone.  The grains have a nucleus composed of either microquartz-rich chert or blocky quartz.  The cement of the unit is composed of a combination of a chalcedony-rich chert and blocky quartz.  Samples were crushed and digested for ICP-AES analysis for major oxides and trace elements.  Several samples were collected up through this section and sent to the OGS lab in Sudbury for ICP-MS analysis of rare earth elements.  The results were normalized to Taylor and McLennan (1985) Post Archean Australian Shale values and plotted.  All the samples taken from the grainstone layer and three samples taken from the stromatolites show a characteristic europium anomaly and a distinct positive cerium anomaly.  The Ce anomaly is indicative of an oxidized environment where Ce (IV) was being precipitated and scavenged by the sediments.  This requires oxygen production in the near-shore, and precipitation of Ce from sea-water that had not been previously exposed to significant oxygen.

The ~3 Ga North Caribou greenstone belt in the North Caribou Terrane, Superior Province, comprises greenschist- to upper amphibolite-facies, ultramafic to felsic metavolcanic and metasedimentary rocks, intruded by 3000 to 2700 Ma felsic plutonic rocks. The study area was centered on a narrow (~100m wide), north-trending, felsic metavolcanic unit on the western side of Opapimiskan Lake, 5 km northwest of Musselwhite Mine, in the South Rim Volcanic Unit (SRV).  The felsic metavolcanic unit was mapped in detail over a distance of 2 km. Samples of the felsic rocks, as well as the associated metabasalts, metasedimentary, and intrusive units were collected and classified according to their petrography and whole rock geochemistry.

The metarhyolitic units are defined by mineral assemblage of quartz + plagioclase + K-feldspar with accessory muscovite + biotite + chlorite ± titanite ± clinozoisite ± zircon. Field observations identified some flows, tuffaceous and pyroclastic units as well as felsic dykes related to regional plutonism. The calculated anhydrous SiO₂ values for the felsic metavolcanic rocks in the SRV range from 75 – 81 wt%. These high-silica, calc-alkaline metarhyolites are classified as FII-type rhyolites. The unaltered felsic metavolcanic rocks are LREE-enriched with ε_Nd values of -2.79 and -0.89.

The tholeiitic metabasaltic and komatiitic-basalt units have been metamorphosed to amphibolites composed almost entirely of plagioclase and hornblende with accessory titanite + chlorite + opaques ± rutile ± biotite ± zircon. The komatiitic-basalt has a MgO value of 14 wt% (compared to 3 to 8 wt% MgO for the metabasalts) and has greater Ni and Cr (ppm) contents. The basalts can be subdivided into two classes based on their REE contents, those with flat REE and those that are LREE-enriched with negative Nb and Al anomalies. The ε_Nd values are +0.78 and +0.58 for the flat REE basalts and -1.58, -3.35, and -1.61 for the LREE-enriched basalts.

Metasedimentary rocks in the study area have been metamorphosed into schists and a quartzite. The protolith of the schists were probably pelitic sedimentary rocks. The mineral assemblage consists of strongly foliated quartz + biotite + muscovite + chlorite ± garnet ± zircon ± clinozoisite. These schists are associated with the felsic metavolcanic rocks. The quartzite is similar to the felsic metavolcanic units but does not contain feldspars. Its mineral assemblage comprises quartz + muscovite + biotite + garnet.

The metarhyolites plot as calc-alkaline rocks with consistent LREE enrichment with Nb and Ti depletions. This trend (including the LREE-enriched metabasalts and komatiitic-basalt) suggests a bimodal volcanic arc tectonic environment. The relative enrichment of LREEs occurs as the LILE enriched fluids are driven off the downgoing slab and modify the overlying mantle wedge. The negative Nb anomalies and negative ε_Nd value suggests that the melt interacted with and assimilated older continental crust. The tholeiitic metabasalts with flat REE patterns suggest an oceanic island plateau environment generated by a mantle plume. The positive ε_Nd values of these rocks suggest that the melts were derived from a depleted mantle source possibly a mix of upper depleted mantle and plume material. These geochemical signatures are seen in both the South Rim and Opapimiskan-Markop metavolcanic units. The interpretation of a plume-sourced oceanic island plateau arriving at a continental arc subduction zone validates the models of early proto-continental crust development of plume-sourced crustal material being accreted through subduction processes in the Superior Province.

The Gunflint and Biwabik Formations form the middle unit of the sedimentary- metasedimentary Animikie group. In an attempt to further understanding of the history of the Gunflint Formation a series of samples for chemical analysis were taken from five drill-holes (MC-1-89, ON-06, MGS-02, MGS-08, and 18279) throughout the formation. Special attention was given to the siliciclastic–volcaniclastic material that mixes with the chemical sediment at some horizons in the formation. Two areas of siliciclastics were defined through graphing Al₂O₃ vs depth, TiO₂ vs Depth and Na₂O/TiO₂ vs Depth.

The first, middle, area rich in volcaniclastics–siliciclastics was observed in drill-hole MC-1-89 at 103.2 meters from the top of the formation, ON-06 at 103.6 meters from the top of the formation, MGS-02 at 95.7 meters from the top of the formation, and MGS-08 at 64.1 meters from the top of the formation. The relationship between Zr/TiO₂ was analyzed through the use of a scatter point graph. It revealed a slope with an average of 166. The relationship between zirconium and titanium oxide was compared to possible volcanics to define a source. The most likely source, the Gunflint volcanics analyzed at Mink Mountain, revealed no correlation with the volcaniclastics - siliciclastics. However, the slope revealed the Zr/TiO₂ ratio of the siliciclastics – volcaniclastics had some similarities with the dacitic volcanic flows from the Emperor volcanics. A similar study of the relationship between V/TiO₂ revealed similar results in comparison with the Gunflint volcanics from Mink Mountain, However, it could not be compared successfully to the Emperor volcanics.

The top unit containing volcaniclastics - siliciclastics was observed in drill-hole MC-1-89 at 22.7 meters from the top of the formation, ON-06 at 26.7 meters from the top of the formation, and MGS-02 at 24.6 meters from the top of the formation. The volcaniclastics – siliciclastics do not appear in drill-hole MGS-08. The material continues to the top of the formation. The material was isolated and the relationship between Zr/TiO₂ was analyzed through the use of scatter point graphs. They revealed a slope with an average of 317.8. This slope differed from the ratio of the middle siliciclastics – volcaniclastics. The relationship between zirconium and titanium oxide was compared to possible volcanics for a source. It was found the most likely source for the siliciclastics is eroded average continental crust.

Lapilli tuffs were also analyzed and a comparison of Zr/TiO₂ and V/TiO₂ to the Gunflint volcanics indicated that it is likely that the Mink Mountain Gunflint volcanics were deposited in the area surrounding the flows as reworked Lapilli tuffs. These are interlayered with the middle siliciclastic-rich unit.

Two periods of alteration were observed in the vertical bar graphs of K₂O/Na₂O vs depth and vertical bar graphs of Al₂O₃/Fe₂O₃ vs Depth. In drill-hole MC-1-89 there is an area of alteration from 95.1 to 86.6 meters from the top of the formation and in ON-06 it occurs at 91.5 meters to 87.2 meters from the top of the formation. This period of alteration ended there in the north. This probably indicates a regression and drop in sealevel not exposing sediment in the offshore to the south. A second area of alteration was observed in MC-1-89 from 4.6 to 2.5 meters from the top of the formation, in ON-06 at 19.5 meters to 4.5 meters from the top of the formation, in MGS-02 there is only one noticeable region of alteration at 7.4 meters to 2.2 meters from the top of the formation, and in MGS-08 the upper area of alteration is at 3.4 meters to the top of the formation. Using Al₂O₃/Fe₂O₃ vs depth of depletion in iron is only seen in this top region of alteration. This depletion might exist because of dissolution and hydrolysis caused by infiltrating of rain water, probable due to a period of subaerial exposure.

The Gunflint and Biwabik Formations form the middle unit of the sedimentary-metasedimentary Animikie group.  In an attempt to further understanding of the history of the Gunflint Formation a series of samples for chemical analysis were taken from five drill-holes (MC-1-89, ON-06, MGS-02, MGS-08, and 18279) throughout the formation.  Special attention was given to the siliciclastic-volcaniclastic material that mixes with the chemical sediment at some horizons in the formation.  Two areas of siliciclastics were defined through graphing Al₂O₃ vs depth, TiO₂ vs Depth and Na₂O/TiO₂ vs Depth.

The first, middle, area rich in volcaniclastics-siliciclastics was observed in drill-hole MC-1-89 at 103.2 meters from the top of the formation, ON-06 at 103.6 meters from the top of the formation, MGS-02 at 95.7 meters from the top of the formation, and MGS-08 at 64.1 meters from the top of the formation.  The relationship between Zr/TiO₂ was analyzed through the use of a scatter point graph.  It revealed a slope with an average of 166.  The relationship between zirconium and titanium oxide was compared to possible volcanics to define a source.  The most likely source, the Gunflint volcanics analyzed at Mink Mountain, revealed no correlation with the volcaniclastics – siliciclastics.  However, the slope revealed the Zr/TiO₂ ratio of the siliciclastics – volcaniclastics had some similarities with the dacitic volcanic flows from the Emperor volcanics.  A similar study of the relationship between V/TiO₂ revealed similar results in comparison with the Gunflint volcanics from Mink Mountain.  However, it could not be compared successfully to the Emperor volcanics.

The top unit containing volcaniclastics – siliclastics was observed in drill-hole MC-1-89 at 22.7 meters from the top of the formation, ON-06 at 26.7 meters from the top of the formation, and MGS-02 at 24.6 meters from the top of the formation.  The volcaniclastics – siliciclastics do not appear in drill-hole MGS-08.  The material continues to the top of the formation.  The material was isolated and the relationship between Zr/TiO₂ was analyzed through the use of scatter point graphs.  They revealed a slope with an average of 317.8.  This slope differed from the ratio of the middle siliciclastics – volcaniclastics.  The relationship between zirconium and titanium oxide was compared to possible volcanics for a source.  It was found the most likely source for the siliciclastics is eroded average continental crust.

Lapilli tuffs were also analyzed and a comparison of Zr/TiO₂ and V/TiO₂ to the Gunflint volcanics indicated that it is likely that the Mink Mountain Gunflint volcanics were deposited in the area surrounding the flows as reworked Lapilli tuffs.  These are interlayered with the middle siliciclastic-rich units.

Two periods of alteration were observed in the vertical bar graphs of K₂O/Na₂O vs depth and vertical bar graphs of Al₂O₃/Fe₂O₃ vs Depth.  In drill-hole MC-1-89 there is an area of alteration from 95.1 to 86.6 meters from the top of the formation and in ON-06 it occurs at 91.5 meters to 87.2 meters from the top of the formation.  This period of alteration ended there in the north.  This probably indicates a regression and drop in sealevel not exposing sediment in the offshore to the south.  A second area of alteration was observed in MC-1-89 from 4.6 to 2.5 meters from the top of the formation, in ON-06 at 19.5 meters to 4.5 meters from the top of the formation, in MGS-02 there is only one noticeable region of alteration at 7.4 meters to 2.2 meters from the top of the formation, and in MGS-08 the upper area of alteration is at 3.4 meters to the top of the formation.  Using Al₂O₃/Fe₂O₃ vs depth of depletion in iron is only seen in this top region of alteration.  This depletion might exist because of dissolution and hydrolysis caused by infiltrating of rain water, probable due to a period of subaerial exposure.