Nova Scotia Department of Energy

Abstract. The Scotian Slope in the North Atlantic Ocean extends for ∼ 500 km along the coast of Nova Scotia, Canada. Its surface sediments host microbial communities, which respond to complex geochemical drivers that not only include communication with the overlying water column, but also potential advection from deeper basinal fluids. Archaea are fundamental components of these communities, and their lipids act as important historical indicators of environmental geochemical change and microbial interactions within marine sediments. This study evaluates the spatial abundance and diversity of archaeal lipids preserved in shallow Scotian Slope sediments to better understand processes. Seventy-four sediment samples from 32 gravity and piston cores, reaching a maximum of 9 m below seafloor (m b.s.f.) were collected during three survey cruises. In total, 14 archaeal lipid classes comprising 42 unique compounds were detected. The lipid distributions reflect a high contribution of anaerobic methanotrophic (ANME) archaeal groups, such as ANME-1 to -3. Hierarchical cluster analysis and principal components analysis were used to show varying contributions of four lipid classes that included distinct assemblages of intact polar lipids (IPLs), core lipids (CLs), and their degradation products (CL-DPs). IPL to CL and CL to CL-DP turnover rates were estimated for the various lipid classes. Four stratigraphically distinct archaeal lipidomes were observed. The first, reflects a unique community influenced by a nearby cold seep. Three additional ambient sediment lipidomes were detected with overlapping depth intervals. These lipidomes contained varying abundances of IPL, CL, and CL-DPs, which likely mark geochemically controlled, microbial community variations that are further accompanied by a systematic increase to the stockpile of diagenetically altered lipids. The ambient sediment lipidomes appear to be highly spatially conserved across the latitudinal extent of the study area marking a resolvable shallow sediment lipostratigraphy that occupies a sediment stratigraphy that spans ∼ 27 000±4000 years of basin evolution for the Scotian Slope.

<strong class="journal-contentHeaderColor">Abstract.</strong> The Scotian Slope in the North Atlantic Ocean extends ~500 km along the coast of Nova Scotia, Canada, descending from 400 m to 5 km water depth. With a maximum sediment thickness of ~24 km, large portions of the deeper basin are affected by salt tectonism, which has greatly impacted the basin stratigraphy and locally facilitated hydrocarbon seepage to the ocean seafloor. The surface sediments along the slope may therefore be home to microbial communities, which respond to complex geochemical drivers that not only include communication with the overlying water column, but also potential advection of deeper basinal fluids. Archaea are fundamental components of these communities, and their lipids act as important indicators of environmental conditions and microbial interactions within marine sediments. This study evaluates the spatial abundance and diversity of archaeal lipids preserved in shallow buried Scotian Slope sediments to better understand deep marine archaea community dynamics. Seventy-four sediment samples from 32 gravity and piston cores reaching a maximum depth of 9 meters below seafloor (mbsf) were collected during three survey cruises across a large region of the Scotian Slope. The survey area extends across ~40,000 km², marking ~3&deg; of latitudinal change over a water column depth that increases from ~1500 to 3500 m, of which one sampling site was a suspected cold seep environment. In total, 14 archaeal lipid classes comprising 42 unique compounds were detected. The lipid distributions reflect a high contribution of anaerobic methanotrophic (ANME) archaeal groups, such as ANME-1 to -3. Hierarchical cluster analysis (HCA) and principal components analysis (PCA) were used to show varying contributions of four lipid classes that included distinct assemblages of intact polar lipids (IPLs), which are largely sourced from living cells as well as core lipids (CLs), and their degradation products (CL-DPs) that collectively are sourced from different alteration stages following the death of the cell. From this, four stratigraphically distinct archaeal lipidomes, marking varying relative abundances of the lipid classes were observed in the upper 9 m of the surveyed slope sediments. One lipidome likely reflects archaeal communities impacted by a cold seep based on hydrocarbon head space gas analyses and high methane index and GDGT/Cren ratios. The other three lipidomes occur across overlapping sediment depth intervals in which the diversity and abundance of living, fossil, and degraded core lipids systematically change in what is likely depth. These changes likely mark systematic geochemically controlled, microbial community variations that are accompanying an increasing stockpile of diagenetic altered CLs. The three ambient sediment lipidomes appear to be highly conserved across the latitudinal extent of the study area marking a resolvable shallow sediment lipostratigraphy for the Scotian Slope.

The pulp and paper industry is a major contributor to water and air pollution globally. Pulp and paper processing is an intensive energy consuming process that produces multiple contaminants that pollute water, air, and affect ecological and human health. In Canada, the National Pollutant Release Inventory (NPRI) is used to assess the release of air pollutants into the atmosphere from industrial facilities (including pulp and paper mills) and provides a repository of annual emissions reported by individual facilities. This study compared annual air emissions of carbon monoxide, nitrogen oxides, total particulate matter (TPM), PM2.5, PM10, sulphur dioxide, and volatile organic compounds from nine different pulp and/or paper mills in Atlantic Canada from three provinces (Nova Scotia, New Brunswick, and Newfoundland and Labrador) between 2002 and 2019. Results revealed that annual releases were several orders of magnitude higher than federal reporting thresholds suggested by Environment and Climate Change Canada. Pulp mills emit higher pollutant loads than those producing paper. The highest exceedance of a reporting threshold was for particulate matter (PM2.5) at Northern Pulp in Nova Scotia. The emissions of PM2.5 were on average (over a 17-year period) about 100,000% above the reporting threshold of 0.3 tonnes per year.

Abstracts from the Atlantic Universities Geoscience Conference (AUGC) are published annually in Atlantic Geology. Such publication provides a permanent record of the abstracts, and also focuses attention on the excellent quality of the oral presentations and posters at the conference and the interesting and varied geoscience topics that they cover. Due to the COVID-19 pandemic and related travel restrictions the conference included both virtual and in-person presentations. The conference concluded with a field trip to the gypsum quarries in Hants County on Sunday afternoon.

Devonian granitoid plutons comprise a major part of the bedrock of northwestern Maine representing the magmatic expression of the Acadian orogeny in this part of the northern Appalachian orogen. They are petrographically diverse with minerals characteristic of both I- and S-type granites, in some cases within the same intrusion, and some are compositionally zoned. New LA-ICP-MS ages presented here elucidate the timing and duration of this magmatism. The earliest phase of granitoid magmatism began around 410–405 Ma with the emplacement of the Flagstaff Lake Igneous Complex, and the presence of contemporaneous mafic rocks suggests that mantle-derived magmas were also produced at this time. Late Devonian ages, ca. 365 Ma, for many intrusions, such as the Chain of Ponds and Songo plutons, reveal that magmatism continued for 45 million years during which compositionally diverse I- and S-type magmas were produced. In addition, there is evidence that intrusive activity was prolonged within some plutons, for example the Rome-Norridgewock pluton and the Mooselookmeguntic Igneous Complex, with 10–15 myr between intrusive units. The new ages suggest a break in magmatism between 400 Ma and 390 Ma apparently separating Acadian magmatism into early and late pulses. The production of lower crustal I-type magmas appears to have been concentrated later, ca. 380–365 Ma, although several S-type granitoids were also emplaced during this period. These Late Devonian plutons display abundant zircon inheritance with ages around 385 Ma, which suggests that the crust was experiencing enhanced thermal perturbations during this extended timeframe. The new data for granitoid plutons in northwestern Maine are consistent with tectonic models for other parts of Ganderia which propose initial flat slab subduction followed by slab breakoff and delamination.

The Trafalgar Plutonic Suite intruded metasedimentary rocks of the Goldenville and Halifax groups in the northeastern part of the Meguma terrane of southern Nova Scotia at about 374 Ma, based on previously published U–Pb and 40Ar/39Ar mineral ages. Using field and petrographic observations, the suite is divided into 20 different plutons on the combined basis of variations in grain size (fine, medium, or coarse), texture (equigranular or porphyritic) and modal mineralogy (quartz diorite/tonalite, granodiorite, monzogranite, and syenogranite). The granodiorite, monzogranite, and syenogranite plutons are relatively uniform in composition with little variation in mineralogy or chemistry within each pluton or between plutons of the same lithology. In contrast the quartz diorite/tonalite plutons show mineralogical and chemical variation, both within and between plutons. The granodiorite, monzogranite, and syenogranite plutons closely resemble other peraluminous granitoid plutons characteristic of the Meguma terrane. The quartz diorite/tonalite plutons are varied but chemically resemble minor Devonian mafic intrusions elsewhere in the Meguma terrane. Like other plutons of the Meguma terrane, the Trafalgar Plutonic Suite has chemical characteristics of volcanic-arc to syn-collisional granitoid rocks and likely has experienced extensive contamination by metasedimentary material as documented by previous studies of plutons in the Meguma terrane. The minor quartz diorite/tonalite plutons are additional examples of the mafic rocks that have been proposed in tectonic models of the Meguma terrane to have facilitated melting of the lower crust to generate granodioritic parent magmas, followed by crystal fractionation and extensive contamination by metasedimentary material.

The Symposium was part of the celebration of the 10th anniversary of the designation of Joggins Fossil Cliffs as a UNESCO World Heritage Site. Its purpose was to highlight recent and current research at the site. The Joggins Fossil Institute staff and Science Advisory Committee facilitated a fruitful meeting, with 12 submitted abstracts and over 25 participants, including academic and government scientists and representatives from the Nova Scotia Museum and the Fundy Geological Museum. Not surprisingly, the conference also included a field trip to the Joggins Fossil Cliffs beach

The late Devonian South Mountain Batholith (SMB) of southwestern Nova Scotia is the largest plutonic igneous body emplaced in the Appalachian orogen, with a current surface expression of 73 000 km 2 . The batholith is composed of 13 distinct plutons that are broadly peraluminous in composition, ranging from tonalite to syenogranite. A parameter that has been particularly difficult to quantify for the SMB is the redox state, as measured by the oxygen fugacity (O 2 ), which exerts a profound control on magmatic phase stabil-ity, element partitioning, and importantly, the potential for economic mineral deposits. Here we present a redox state survey of mineralised and unmineralised units of the SMB using the newly calibrated Ce-in-zircon oxygen barometer. This method combines bulk rock and zircon compositions to calculate apparent zircon/melt partition coefficients for Ce, a parameter which varies with the Ce 4+ / Ce 3+ in the melt, and hence oxygen fugacity.

The likelihood of fish encountering an MHK device, and therefore the risk posed to fish, depends largely on the natural distribution of fish at tidal energy development sites. In temperate locations, such as the Bay of Fundy, seasonal changes in the environment and fish assemblage may alter the likelihood of fish encounters with MHK devices. We examined two one-month hydroacoustic datasets collected in winter 2015 and summer 2016 by an upward-facing echosounder deployed at the Fundy Ocean Research Center for Energy test site in the Minas Passage. Fish density was higher and less variable in winter than in summer, likely due to the presence of migratory vs. overwintering fish. The vertical distribution of fish varied with sample period, diel stage, and tidal stage. The proportion of fish at MHK device depth was greater, but more variable, in summer than in winter. Encounter probability, or potential for spatial overlap of fish with an MHK device, was &lt; 0.002 for winter and summer vertical distributions. More information on the distribution of fish (horizontal and vertical), species present, fish sensory and locomotory abilities, and nearfield behaviours in response to MHK devices is needed to improve our understanding of likely device effects on fish.