Journal articles on the topic 'Rocks – Analysis – Maine'

Ordovician metamorphic rocks of the Casco Bay Group are exposed in an approximately 170 km long NE-trending belt (Liberty-Orrington belt) in southern and south-central Maine. Geochemical analysis of rocks within the Spring Point Formation (469±3 Ma) of the Casco Bay Group indicate that it is an assemblage of metamorphosed bimodal volcanic rocks. The mafic rocks (originally basalts) have trace element and Nd isotopic characteristics consistent with derivation from a mantle source enriched by a crustal and/or subduction component. The felsic rocks (originally rhyolites and dacites) were likely generated through partial melting of continental crust in response to intrusion of the mafic magma. Relatively low initial εNd values for both the mafic (−1.3 to +0.6) and felsic (−4.1 to −3.8) rocks suggest interactions with Gander zone continental crust and support a correlation between the Casco Bay Group and the Bathurst Supergroup in the Miramichi belt of New Brunswick. This correlation suggests that elements of the Early to Middle Ordovician Tetagouche-Exploits back-arc basin can be traced well into southern Maine. A possible tectonic model for the evolution of the Casco Bay Group involves the initiation of arc volcanism in Early Ordovician time along the Gander continental margin on the eastern side of the Iapetus Ocean basin. Slab rollback and trenchward migration of arc magmatism initiated crustal thinning and rifting of the volcanic arc around 470 Ma and resulted in the eruption of the Spring Point volcanic rocks in a back-arc tectonic setting.

An analysis of the potential for deposits of critical minerals and elements in Maine presented here includes data and discussions for antimony, beryllium, cesium, chromium, cobalt, graphite, lithium, manganese, niobium, platinum group elements, rhenium, rare earth elements, tin, tantalum, tellurium, titanium, uranium, vanadium, tungsten, and zirconium. Deposits are divided into two groups based on geological settings and common ore-deposit terminology. One group consists of known deposits (sediment-hosted manganese, volcanogenic massive sulphide, porphyry copper-molybdenum, mafic- and ultramafic-hosted nickel-copper [-cobalt-platinum group elements], pegmatitic lithium-cesium-tantalum) that are in most cases relatively large, well-documented, and have been explored extensively in the past. The second, and much larger group of different minerals and elements, comprises small deposits, prospects, and occurrences that are minimally explored or unexplored. The qualitative assessment used in this study relies on three key criteria: (1) the presence of known deposits, prospects, or mineral occurrences; (2) favourable geologic settings for having certain deposit types based on current ore deposit models; and (3) geochemical anomalies in rocks or stream sediments, including panned concentrates. Among 20 different deposit types considered herein, a high resource potential is assigned only to three: (1) sediment-hosted manganese, (2) mafic- and ultramafic-hosted nickel-copper(-cobalt-platinum group elements), and (3) pegmatitic lithium-cesium-tantalum. Moderate potential is assigned to 11 other deposit types, including: (1) porphyry copper-molybdenum (-rhenium, selenium, tellurium, bismuth, platinum group elements); (2) chromium in ophiolites; (3) platinum group elements in ophiolitic ultramafic rocks; (4) granite-hosted uranium-thorium; (5) tin in granitic plutons and veins; (6) niobium, tantalum, and rare earth elements in alkaline intrusions; (7) tungsten and bismuth in polymetallic veins; (8) vanadium in black shales; (9) antimony in orogenic veins and replacements; (10) tellurium in epithermal deposits; and (11) uranium in peat.

The fault-bounded Nashoba–Putnam terrane, a metamorphosed early Paleozoic, Ganderian arc/back-arc complex in SE New England, lies between rocks of Avalonian affinity to the southeast and middle Paleozoic sedimentary rocks, interpreted as cover on Ganderian basement, in the Merrimack belt to the northwest. U–Pb detrital zircon laser ablation inductively coupled plasma mass spectrometry analysis were conduced on six samples from the Nashoba terrane in Massachusetts and seven samples associated with the Merrimack belt in Massachusetts and SE New Hampshire to investigate their depositional ages and provenance. Samples from the Nashoba terrane yielded major age populations between ~560 and ~540 Ma, consistent with input from local sources formed during the Ediacaran–Cambrian Penobscot orogenic cycle and its basement rocks. Youngest detrital zircons in the terrane, however, are as young as the Early to Middle Ordovician. Six formations from the Merrimack belt were deposited between ~435 and 420 Ma based on youngest zircon age populations and crosscutting plutons, and yielded large ~470–443 Ma age populations. Three of these formations show only Gondwanan provenance. Three others have a mixed Gondwanan-Laurentian signal, which is known to be typical for younger and/or more westerly sedimentary rocks and may indicate that they are the youngest deposits in the Merrimack belt (late Silurian to early Devonian) and/or have been deposited in the equivalent of the more westerly Central Maine basin. Detrital zircon age populations from the Tower Hill Formation, along the faulted contact between the Merrimack belt and Nashoba terrane, are different from either of these tectonic domains and may indicate that the boundary is complex.

The Litchfield pluton is a poorly exposed 7 km2 composite alkalic intrusive complex that cuts previously deformed and metamorphosed Silurian turbidites in south-central Maine. The pluton includes a variety of alkaline syenites, including the type locality of “litchfieldite”, a coarse-grained cancrinite, sodalite, and lepidomelane bearing nepheline syenite first recognized over 150 years ago and common in many petrologic collections. A new U-Pb zircon age of 321 ± 2 Ma from the nepheline syenite is interpreted to represent the crystallization age of the plutonic complex. A new biotite 40Ar/39Ar age of 239 ± 1 Ma from the syenite is similar to previously published mica ages from the surrounding country rocks and dates the time of regional cooling in the area below ~ 300°C. Whole rock geochemical analyses from rocks of the Litchfield pluton are compatible with strongly alkaline A-type granitoid rocks that formed in a within plate or continental rift tectonic setting. The age and geochemical characteristics of the alkalic igneous rocks near Litchfield are consistent with a model that invokes the generation of a small volume of alkalic magma beneath south-central Maine during a period of Carboniferous transcurrent tectonism in the northern Appalachian orogen.

Volcanic rocks in the Miramichi inlier in Maine occur in two areas separated by the Bottle Lake plutonic complex: the Danforth segment (Stetson Mountain Formation) north of the complex and Greenfield segment to the south (Olamon Stream Formation). Both suites are dominantly pyroclastic, with abundant andesite, dacite, and rhyolite tuffs and subordinate lavas, breccias, and agglomerates. Rare basaltic tuffs and a small area of basaltic tuffs, agglomerates, and lavas are restricted to the Greenfield segment. U–Pb zircon geochronology dates Greenfield segment volcanism at ca. 469 Ma, the Floian–Dapingian boundary between the Lower and Middle Ordovician. Chemical analyses reveal a calc-alkaline suite erupted in a continental volcanic arc, either the Meductic or earliest Balmoral phase of Popelogan arc activity. The Maine Miramichi volcanic rocks are most likely correlative with the Meductic Group volcanic suite in west-central New Brunswick. Orogen-parallel lithologic and chemical variations from New Brunswick to east-central Maine may result from eruptions at different volcanic centers. The bimodal Poplar Mountain volcanic suite at the Maine–New Brunswick border is 10–20 myr younger than the Miramichi volcanic rocks and more likely an early phase of back-arc basin rifting than a late-stage Meductic phase event. Coeval calc-alkaline arc volcanism in the Miramichi, Weeksboro–Lunksoos Lake, and Munsungun Cambrian–Ordovician inliers in Maine is not consistent with tectonic models involving northwestward migration of arc volcanism. This >150 km span cannot be explained by a single east-facing subduction zone, suggesting more than one subduction zone/arc complex in the region.

Joints are among the most widespread geologic structures as they are found in most each exposure of rock. They differ greatly in appearance, dimensions, and arrangement, besides they occur in quite different tectonic environments. This study is important because joints provide evidence on what kind of stress produced them (history of deformation) and also because they change the characteristics of the rocks in which they occur. The Measured data of joints from the studied area which are located in the high folded zone – Northeast of Iraq, were classified according to their relationship with the tectonic axes by projecting them stereographically using Schmidt net in GEOrient ver.9.5.0 software. The joint systems revealed the orientation of the major stress field that caused the area deformation. Two dominant joint systems were found in most stations of the studied area, which are hko>a (first place) and hko>b (second place). The main stress field direction from the joint’s classification is North East – South West which coincides with the opening of the red sea and the collision between Arabian and Iranian tectonic plates. The North West direction (which comes in the second place) it might be due to the rotational movement (counterclockwise) of the Arabian plate in addition to the effect of local stress in the area.

In the early 1980s, the National Oceanic and Atmospheric Administration (NOAA) initiated an ecosystem analysis of Gouldsboro Bay in eastern Maine as part of a planned marine sanctuary. The original report to NOAA by Walter H. Adey was not published after the sanctuary concept for Maine was abandoned. Because significant human-related climatic and ecosystem changes are underway in the Gulf of Maine, that report provides valuable baseline data and is included as the Appendix to this volume. After qualitatively describing the geological, physical, chemical, and biogeographical features of Gouldsboro Bay and adjacent Dyer Bay, we quantitatively describe the principal bay ecological communities with data collected during the 1981–1983 ecosystem assessment as well as additional measurements taken within the past decade. We then undertake a comparison of the primary productivity of these bays with the Google Earth Pro polygon tool to determine component areas. Benthic taxa are the dominant primary producers in both bays: rockweeds (primarily Ascophyllum nodosum, with Fucus vesiculosus secondary) in the intertidal; Irish moss (Chondrus crispus, with Fucus distichus secondary) as a near monoculture in the lowest intertidal (infralittoral); kelps (primarily Saccharina latissima, Laminaria digitata, and Agarum clathratum) in the rocky subtidal; and the angiosperm Zostera marina (seagrass) in soft bottom substrate. The rocky intertidal, dominated by Ascophyllum with a specific productivity of 10.6 kg/m2/year, provides nearly one-third of all bay productivity. Because of the proportionally greater shore length relative to area of Dyer Bay, it has 45% greater productivity for its surface area than Gouldsboro Bay. Kelp has a specific productivity value of 7.2 kg/m2/year, and Zostera of 1.2 kg/m2/year. The kelps provide approximately 20% of Gouldsboro Bay’s primary productivity and 35% of that of Dyer Bay. Zostera provides roughly 20% of total primary productivity in Gouldsboro Bay and 12% in Dyer Bay. With a primary productivity of 1.73 kg/m2/year, salt marshes provide only 3.7% (Gouldsboro) and 2.6% (Dyer) of total primary productivity. With a primary productivity of 0.06 kg/m2/year, plankton account for 23.8% of Gouldsboro Bay and 16% of Dyer Bay primary productivity.

The article presents the results of scientific investigation of the quality of waters of the Southern Bug. The control of the quality of waters of the Southern Bug on the territory of Vinnitsa isheld byaccredited laboratories of different organizations.The resultsof laboratory tests of the quality of the waters of the Southern Bug during the past year, as in previous years, showed the imbalance of the quality of waters in microbiological parameters. In particular, the data of the control for the month of July 2016 in monitoring points of the Southern Bug are: index of lactopositivecolibacilli is 35000 in dm. cube,colibacilli - 3600 in dm. cube, enterococcus less than 300 dm. cube,coliphage, salmonella and shigellaare absent. To address this issue, we can offer two ways to improve the water supply of quality water to the residents of Vinnytsia. The first is the construction of a gallery horizontal water intake in the Southern Bug River. Water intakes should be equipped with galleries in the cracks of crystalline rocks and fill them with filter material, which will ensure the inflow of clean water from the main aquifer of crystalline rocks and further feed the riverbed during peak water intake and reduce water pollution. Residential buildings with two water mains, where one pipe will supply technical water (which will be of low quality), and the other will supply water extracted from underground sources, which will be of high quality. Underground freshwater deposits in Vinnytsia region are Vinnytsia, Desniansky, Stryzhavsky and Voronovytsky). Ways to improve water quality, such as additional water treatment and water supply by the city's two water mains, can be cost-effective. This will reduce the cost of technical water and reduce the use of quality drinking water by the population for technical needs. In general, it will benefit both the state and the population.

In the thesis, I am interested to see the reasons for Jackson Maine, a famous and successful rock star to end his life based on the film A Star Is Born. To do that, I use Thomas Joiner’s Interpersonal Theory of Suicide. Joiner’s theory discusses the qualities and conditions in his life that may cause him to commit suicide. To see the reasons for Jackson Maine’s death as portrayed in the film, I also use David Brodwell and Kristin Thompson’s Mise-en-Scène theory. Using the approach, I can find the reasons behind his death by analyzing the film’s visual arrangement within the scenes. In my research, I find that Jackson Maine experiences great difficulties and disappointment that he fails to cope and encourages him to end his life. Social disconnections, burdensomeness beliefs, and suicide capabilities become the reasons behind his self-destruction decision. Keywords: Suicide, Mise-en-Scène, Film Analysis, Social Disconnections, Self-destruction.

AbstractI will consider mainly geothermobarometry in medium-grade pelitic rocks, including the garnet-biotite (GB) geothermometer, the Grossular-Al silicate-plagioclase (GASP) geobarometer, and the muscovite-almandine-biotite-sillimanite (MABS) geobarometer. For GB (Holdaway, 2000) experimental data and estimated biotite ΔWTi were used to optimize two exchange parameters and four biotite Margules parameters. Using stepwise linear regression, experimental vs. calculated T were constrained to lie on a line with slope of one and intercept of zero, maximizing r2. The best model involves experiments by Ferry and Spear (1978) and Perchuk and Lavrent’eva (1983), suggesting minimal viAl in the Ferry and Spear product biotite. For GASP (Holdaway, 2001), end-member experimental data do not adequately constrain the equilibrium. I used the GB model above, and allowed the end-member curve to rotate about the best-constrained part of the GASP end-member data. The end-member curve was further constrained with the kyanite-sillimanite (K-S) boundary using published chemical data on 76 pelitic schist samples from 11 localities, rejecting Low-Grs and low-An samples. The Fuhrman and Lindsley (1988) plagioclase model gives the best results. For MABS, work in progress involves 61 samples from the 11 localities which have muscovite analyses. Biotite Margules parameters were based on the GB model and McMullin et al. (1991). The MABS end-member curve was calibrated by comparison of P values determined using trial MABS data and GASP results. The P values for the 61 samples agree well with the K-S boundary, and sillimanite-bearing rocks of west-central Maine all fall in the sillimanite field. Preliminary biotite values are: GAnn = –5149198 – 412.05 T, WAlFe = –14023 + 28.14 T, WAlMg = –259582 + 308.44 T, WTiFe = 124842 – 98.67 T, WTiMg = –186148 + 271.72 T. For geobarometry, the Berman (1988, revised 1992) database was used with adjustable H and S of grossular for GASP and H and S of annite for MABS. The accuracy of currently available databases, activity models and mole fraction models is not adequate for good geothermobarometry, without further refinement. Adjustable parameters tend to compensate for error in activity models, mole fraction models and databases.

The species of Artemisia are well known in the Mediterranean region, especially in Morocco, for their traditional uses and health benefit. In this study, we were interested in two species of Artemisia, namely A. herba alba Asso and A. mesatlantica Maire. These species were collected from different soils of the Central Middle Atlas (loamy, stony, limestone and rocky soil) with different atmospheres. Extraction of essential oils from the leaves and flowering tops was carried out by hydrodistillation in Clevenger apparatus. Chemical composition analysis was further carried out using gas chromatography coupled with mass spectrometry (GC-MS). Principal component analysis (PCA) was performed to determine the similarities and dissimilarities in the chemical compositions of these six essential oils. The results obtained showed that the essential oil contents extracted from the flowering tops vary from one species to another according to the place of harvest, altitude, soil type and climate. The essential oil yield is between 0.84% and 2.19% (mL/100 g). Chemical analysis revealed that the chemotype of A. herba alba in limestone soil with a subhumid to humid atmosphere is trans-thujone (33.78%), while camphor (46.19%) is for limestone soil with a semi-arid atmosphere, vetivenic acid (14.91%) and davana ether (14.64%) are for limestone soil with a semi-arid and arid atmosphere and camphor (18.39%) is for loamy and stony soil with a semi-arid atmosphere. As for A. mesatlantica from a rocky soil on limestone with a subhumid to humid atmosphere, the main component is camphor (44.86%), and that of limestone soil with a subhumid to the humid atmosphere trans-thujone (41.08%). In addition, HCA affirmed the PCA and allowed us to distinguish between four groups. Our findings observed differences in the chemical compositions of the isolated essential oils most likely related to many factors such as the climates in the regions of the samples collected, altitudes and soil types.

<p align="center"><strong>ABSTRACT</strong></p><p align="center"><strong><em> </em></strong></p><p><strong><em>Effect of Source Rocks and Soil Chemical Towards Land Fertility Potential in Sula Kepulauan District, North Maluku Province.</em></strong><em> </em><em>The study</em><em> aimed to determine the condition of soil fertility potential. Parameters used as the basis of assessment of potential fertility of the soil were the type of </em><em>main rock, weathering processes and mineral content of the native rock while chemically research was emphased on organic matter content, soil pH, CEC, base saturity and essential nutrients (N, P, K). General lithology in the study area </em><em>were grouped </em><em>into rocks and rock volkan sediman. Aluvio-marine sedimentary rocks and aluvio-collovium were deposition materials from a variety of rocks in the study contain</em><em>ed a number of nutrients and organic matter. Meanhile volkan rocks included basalt and andesite-granidiorit neutral to alkaline</em><em>. Contain</em><em>ed elements that produced fertile lands both physically and chemically. Based on the analysis, the average soil</em><em> was classified as slightly acid (pH 5.6). The lower layers of soil reaction on average relatively</em><em> was acidic (pH 5.1). Soil organic matter in the form of organic-C showed the top layer of a low average (1.58%), whilst the layer below average </em><em>was very low (0.83%). CEC soil layers above and below the average were moderate (20.66 me/100 g) and (19.6 me/100 g). Base saturations (KB) to these two layers of soil on top and below the average were</em><em> classified as moderate (55%) and (51%). Levels of nitrogen (N-total) topsoil with layers below average </em><em>are low</em><em> valued (0.18%) and (0.11%). Classified as very low, phosporus level in both layers were above the average which were 5.40 ppm and 3.10 ppm respectively. Potassiums were very low in the second layer of 5.13 mg/100 g and 3.81 mg/100 g. The parameters used to assess soil fertility status were CEC, KB, P2O5 which were extracted with HCl 25%, and K2O was extracted with HCl 25% and C-organic soil. Potential assessment of soil fertility status based on lithology and soil chemistry acquired the status of soil fertility was low.</em><em></em></p><p><strong>Key</strong><strong>words</strong>:<em> </em><em>potential soil fertility, maint rock, chemical</em></p><p><strong><em> </em></strong></p><p align="center"><strong> </strong></p><p align="center"><strong>ABSTRAK</strong></p><p align="center"><strong> </strong></p><p>Kajian ini bertujuan untuk mengetahui kondisi kesuburan tanah potensial. Parameter yang dijadikan dasar penilaian potensi kesuburan tanah adalah jenis, proses pelapukan, dan kandungan mineral batuan induk sedangkan secara kimia penelitian ditekankan pada kandungan bahan organik, pH tanah, KTK, KB, dan unsur hara esensial (N, P, K). Secara umum litologi di wilayah studi dikelompokan ke dalam batuan sediman dan batuan volkan. Batuan sedimen aluvio-marine dan aluvio-koluvium merupakan bahan-bahan endapan dari berbagai batuan di wilayah studi yang banyak mengandung unsur hara dan bahan organik. Batuan volkan meliputi andesit-basal dan granidiorit bersifat netral sampai basa, mengandung unsur-unsur yang menghasilkan tanah-tanah subur baik secara fisik maupun kimia. Berdasarkan hasil analisis tanah pH rata-rata tergolong agak masam (pH 5,6). Lapisan bawah reaksi tanah rata-rata tergolong masam (pH 5,1). Bahan organik tanah dalam bentuk C-organik menunjukkan pada lapisan atas rata-rata rendah (1,58%), sementara lapisan bawah rata-rata sangat rendah (0,83%). KTK tanah lapisan atas maupun bawah rata-rata tergolong sedang (20,7 me/100 gram) dan (19,6 me/100 gram). Kejenuhan basa (KB) tanah pada keduan lapisan atas dan bawah rata-rata tergolong sedang yaitu (55%) dan (51%). Kadar nitrogen (N-total) tanah lapisan atas sama dengan lapisan bawah rata-rata tergolong rendah (0,18%) dan (0,11%). Kadar fosor (P₂O₅) tergolong sangat rendah, di kedua lapisan atas rata-rata sebesar 5,40 dan 3,10 me/100g. Unsur hara kalium (K₂O) sangat rendah pada kedua lapisan 5,13 mg/100 gram dan 3,81 mg/100 gram. Parameter yang digunakan untuk menilai status kesuburan tanah yaitu KTK, KB, P₂O₅ yang diesktrak dengan HCl 25%, sedangkan K₂O diekstrak dengan HCl 25% dan C-organik tanah. Penilaian potensi status kesuburan tanah berdasarkan litologi dan kimia tanah diperoleh status kesuburan tanah tergolong rendah.</p><p><strong>Kata </strong><strong>k</strong><strong>unci: </strong><em>kesuburan tanah potensial, batuan induk, kimia</em></p><em></em>

Purpose. To identify features of methane-air mixture flow within the steel degassing pipelines as well as within those ones made of composite materials, to develop engineering solutions improving their reliability for actual use. Methodology. To solve the problem of increasing the capacity of mine degassing pipelines, an analysis of fundamental studies on the physical and mechanical properties of mine methane and the processes of its recovery in a mine environment is conducted. Schemes of operating gas-transmission systems and peculiarities of functioning of zonal vacuum gas pipelines in the conditions of intensive removal of rocks of the bottom of underground workings and deformations of the massif are considered. Based on the results of expert assessment of production situations, potential reserves for enhancing the efficiency of in-mine gas pipelines have been determined. Reliability indicators of traditionally applied steel pipes and their analogues from composite materials used abroad are established, innovative technological and technical solutions for their construction at Ukrainian mines are recommended. Findings. According to the expert evaluation of the operation modes of mine degassing lines and analysis of the world practices to apply pipes made of composite materials for mining industry, an engineering solution concerning the improvement of operating degassing systems as well as their capacity has been substantiated. Originality. Innovative engineering solutions as for the modernization of the underground degassing systems, which allow increasing the capacity of mine pipelines, and provide maintaining of the quality the captured methane-air mixture in the process of its transportation from wells to vacuum pump stations, have been substantiated. Practical value. Implementation of the research results to decrease hydraulic resistance within the degassing mains as well as introduction of innovative engineering solutions for the construction of main degassing pipelines from long links of composite pipes with a minimum number of butt joints has been scheduled for Ukrainian mines dealing with the development of gassy coal seams.

Abstract The historic geodetic data base in the eastern United States dates back over 100 years. Although instrumentation and hence measurement precision has improved since the initial observations, the basic techniques [leveling, triangulation, water level gauging] remained unchanged until the recent introduction of space geodesy [Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Positioning System (GPS)]. Because of this, it has been possible to compare repeated observations to identify apparent changes in relative positions. Such “changes” can reflect observational errors, non-tectonic movements (water level effects, monument instability, loading, etc.) or tectonic/isostatic deformation. A number of possible deformation features in the eastern U. S. have been reported in the literature, including uplift of the southern Appalachian and Adirondack mountains, doming of the Gulf coast inland of the Mississippi delta, subsidence of Chesapeak Bay and along the coast of Maine, horizontal deformation in New York and Connecticut, and possible fault related deformation near Charleston and in the New Madrid area. Unfortunately, it is not dear to what extent any of these features represent tectonic deformations and hence what their significance may be for the earthquake problem. An important recent development in monitoring regional deformation has been the establishment of the eastern U. S. GPS strain network by the National Geodetic Survey. The network consists of roughly 45 sites uniformly distributed east of the Rocky Mountains. The network was established in 1987 and will be reobserved in 1989. Subsequent reobservations will be made at 2 to 5 year intervals depending on analysis of the early measurements. Given the precision of the GPS measurements (few cm in 3-D relative positions), a considerable time period will be required to detect the subtle deformations expected for this intraplate region. Perhaps more immediate information will result from recent progress in recognizing and correcting systematic errors in the historic geodetic data base. This, together with the newly automated historic data base, and improved techniques for integrating and analyzing these extensive observations, provide the necessary basis for effectively evaluating the deformational features listed above. Given the potential importance of these data for understanding tectonic processes (and the huge expense of collecting these measurements over the pst century), such studies should be an integral part of future earthquake studies in the eastern U. S.

Summary In a number of experiments, the efficiency of solution-gas drive for both light and heavy oils was studied. In these experiments a special coreholder was used to visually observe the formation of gas bubbles on the rock surface of a Berea core and the production from the core outlet. The results from all the experiments reveal that the critical gas saturation for three hydrocarbon liquids; 1. a light model oil, 2. an 11-API gravity oil, and 3. a 35-API gravity oil, does not exceed 3%. However, the gas mobility for the heavy oil is very low and for the light model oil very high. Consequently, solution-gas drive for a heavy oil of 11-API gravity is more efficient than for a light oil. Introduction Solution-gas drive is a basic recovery mechanism. The two parameters that affect the efficiency of this process are: critical gas saturation, and mobility of the gas and liquid phases. A high critical gas saturation implies a high recovery; a 30% critical gas saturation would result in 30% oil recovery provided the oil shrinkage is negligible. On the other hand, a low critical gas saturation does not necessarily imply a low recovery; a low gas mobility or a high liquid mobility would result in high recovery. Generally, solution-gas drive may not be efficient for very light oils. Factors which are believed to contribute to the low recovery are low critical gas saturation and high gas mobility. However, for a heavy oil, the recovery in solution-gas drive could be high either when the critical gas saturation is high or when the gas mobility is low and the liquid mobility is high. One purpose of this paper is to understand solution-gas drive for both light and heavy oils. Solution-gas drive is initiated with bubble nucleation, where at some critical supersaturation pressure (the pressure at which gas evolves from the supersaturated liquid) below the bubblepoint pressure, the formation of gas bubbles occurs. The bubbles may form instantaneously or according to the progressive nucleation theory.1 In progressive nucleation, the rate of bubble formation is related to the supersaturation. Recently, based on theoretical analysis, we have postulated that bubble nucleation in porous media can be an instantaneous nucleation process; all bubbles form instantaneously at the critical supersaturation pressure.1 Another objective of this work is to establish experimentally the instantaneous nature of nucleation in porous media. It has been known for some time that a number of heavy oil reservoirs in Canada (viscosity in the range of 200 to 20,000 cp) have high recovery efficiencies—around 15% to 20% by primary depletion.2,3 The high recovery occurs in the absence of gravity drainage and water drive. A number of authors have made attempts to explain the high recovery from heavy oil reservoirs. In an earlier paper, Smith2 hypothesized that solution-gas drive in heavy oil reservoirs is a two-phase flow, with the gas in the form of tiny bubbles moving with oil. Based on the work of Ward et al.,4 Smith argued that the radius of a stable bubble for a finite volume should be much smaller than the average pore throat. Ward et al.4 had estimated that for a bubble density of 103 cm3, the stable bubble may have a radius of 40 µm. These bubble densities and stable sizes may not apply to a heavy oil in porous media. Further theoretical work is needed to establish the bubble density and stable bubble size for heavy oils. In a later attempt, Islam and Chakma5 used both a long capillary tube and a horizontal core packed with unconsolidated sand to study mechanisms of bubble flow in heavy oil reservoirs. They used Dow Corning oils of 10, 1,000, and 5,000 cp viscosity and heavy oils to conduct flow experiments by simultaneous injection of gas bubbles and liquid. These experiments revealed that bubbles in a flowing stream of a viscous fluid will reduce the apparent viscosity. Islam and Chakma suggested a gas-oil relative permeability with a critical gas saturation of 40%. In-situ gas bubble formation and injection of gas bubbles in a liquid phase are fundamentally different processes. The work of these authors may not directly apply to solution-gas drive in heavy oil reservoirs. In a more recent study, Maini et al.,6 conducted many experiments using unconsolidated sand and heavy oils to study solution-gas drive. A 2-m long sand pack was employed by these authors. The recovery factor was obtained by dropping the pressure suddenly at the core outlet from a saturation pressure of some 700 psi to atmospheric pressure. More than 20% of the original heavy oil was produced in the primary depletion process. As has been observed by Islam and Chakma5 and others,1 a sudden drop in pressure may result in a higher recovery than a gradual pressure drop. From a number of tests, Maini et al. concluded that the critical gas saturation for the formation of a continuous gas phase could be about 40%. The critical gas saturation for heavy oils in the work of Islam and Chakma et al., and Maini et al., are much higher than the values for light oils.7 The above brief review reveals that further work is needed to understand the solution-gas drive in heavy oil reservoirs. The main objectives of this study are to: resolve the issue of very high critical gas saturations; find out whether tiny gas bubbles move with the oil phase; and determine the nature of bubble nucleation and bubble density and to better understand the efficiency of solution-gas drive for heavy oils in porous media. In this work, experiments with both light and heavy oils are performed in order to compare the solution-gas drive for light and heavy oils. A new visual coreholder is used to visually observe the appearance and flow of the gas phase. Experiment A schematic of the experimental apparatus is shown in Fig. 1. The setup, with slight differences, was used for the three sets of experiments. The main components of the apparatus include: the visual coreholder, a high pressure chromatography pump, pressure transducers, a system for providing a constant temperature of 77°F (±0.3°F) and a video recording system. The specially designed visual coreholder consists of an 8 in. long, 2 in. diameter Berea sandstone core (pore volume˜95 cm3, permeability˜500 md), capped at either end with a plexiglass cap (the top cap was machined with a dead end for trapping gas evolved from the core) and sealed with a heat-shrunk teflon sleeve. Surrounding the core is a water-filled translucent chamber, which is pressurized and acts as an overburden sleeve. Plumbed to the coreholder is a constant flow/pressure pump. The pump is used both for saturating the core system and for pressure decline through volume expansion.

SHRIMP U–Pb zircon ages from Ganderia in eastern Maine clarify the ages and provenance of basement units in the Miramichi and St. Croix terranes and of cover rocks in the Fredericton trough and Central Maine/Aroostook-Matapedia basin (CMAM). These new data constrain timing of orogenic events and help understand the origin of the cover rock depocenters.Detrital zircon data generally confirm suggested ages of the formations sampled. Zircon grains with ages of ca. 430 Ma in both depocenters, only slightly older than their host rocks, were probably derived from the earliest volcanic eruptions in the Eastport-Mascarene belt. Their presence indicates that unnamed CMAM sandstone units may be as young as Pridoli and their absence from the Appleton Ridge and Digdeguash formations suggests that these formations are older than initial Eastport-Mascarene volcanism. Detrital and volcanic zircon ages confirm a Late Cambrian to Middle Ordovician age for the Miramichi succession and date Miramichi volcanism at 469.3 ± 4.6 Ma. In the St. Croix terrane, zircon grain with an age of 477.4 ± 3.7 Ma from an ashfall at the base of the Kendall Mountain Formation and age spectra and fossils from overlying quartz arenite suggest that the formation may span Floian to Sandbian time. The main source of CMAM and Fredericton sediment was recycled Ganderian basement from terranes emergent after Late Ordovician orogenesis, supplemented by Silurian tephra. Zircon barcodes and lithofacies and tectonic models suggest little, if any, input from Laurentia or Avalonia.Zircon- and fossil-based ages indicate coeval Upper Ordovician deformation in the St. Croix (ca. 453 to 442 Ma) and Miramichi (ca. 453 to 446 Ma) terranes. Salinic folding in the southeastern Fredericton trough is bracketed between the 421.9 ± 2.4 Ma age of the Pocomoonshine gabbro-diorite and 430 Ma detrital zircons in the Flume Ridge Formation. Zircon ages, lithofacies analysis, and paleontological evidence support the origin of the Fredericton trough as a Salinic foredeep. The CMAM basin cannot have been an Acadian foreland basin, as sedimentation began millions of years before Acadian subduction.

The Ellsworth belt is one of several fault-bounded blocks exposed along the southeastern coast of Maine that formed within Ganderia. New ID-TIMS U–Pb geochronological data integrated with field relationships provide additional insights into the timing of magmatism and deformation in the Ellsworth belt. The deformed Lamoine Granite was selected for U–Pb zircon analysis in order to: i) establish the protolith age; ii) provide direct temporal constraints on regional low-grade metamorphism and deformation; and iii) elucidate relationships between the Ellsworth belt and coeval rocks elsewhere in the Appalachian orogen. The Lamoine Granite was emplaced within the Ellsworth Schist at 492 ± 1.7 Ma; this is the first unequivocal evidence for a Furongian magmatic event in the Ellsworth belt. The schistosity in the Lamoine Granite is parallel to the main fabric of the host Ellsworth Schist and provides a maximum estimate for timing of the regional metamorphic overprint. Widespread deformation in the Ellsworth belt where kinematic indicators indicate a top-to-northwest sense of shear is attributed to thrusting during which progressive horizontal shortening, caused crustal thickening and peak greenschist facies metamorphism. The Cambrian U–Pb age permits correlation of the Lamoine Granite with the Cameron Road Granite in the Annidale belt of New Brunswick where subduction-related magmas intruded the Penobscot arc–back-arc and were subsequently deformed during the Penobscot Orogeny.

Abstract Reported here are geological, geophysical, mineralogical, and geochemical data on a previously unknown trachyte-hosted rare earth element (REE)-Nb-Zr occurrence at Pennington Mountain in northern Maine, USA. This occurrence was newly discovered by a regional multiparameter, airborne radiometric survey that revealed anomalously high equivalent Th (eTh) and U (eU), confirmed by a detailed ground radiometric survey and by portable X-Ray fluorescence (pXRF) and whole-rock analyses of representative rock samples. The mineralized area occurs within an elongate trachyte body (~1.2 km2) that intrudes Ordovician volcanic rocks. Geologic constraints suggest that the trachyte is also Ordovician in age. The eastern lobe (~900 × ~400 m) of the trachyte is pervasively brecciated with a matrix containing seams, lenses, and veinlets composed mainly of potassium feldspar, albite, and fine-grained zircon and monazite. Barite is locally abundant. Minor minerals within the matrix include columbite, bastnäsite, euxenite, chlorite, pyrite, sphalerite, and magnetite. The pXRF analyses of 22 samples (App. Table A1) collected from the eastern lobe demonstrate that this entire part of the trachyte is highly mineralized. Whole-rock geochemical analyses for samples from the eastern lobe document high average contents of Zr (1.17 wt %), Nb (1,656 ppm), Ba (3,132 ppm), Y (1,140 ppm), Hf (324 ppm), Ta (122 ppm), Th (124 ppm), U (36.5 ppm), Zn (689 ppm), and Sn (106 ppm). Among light REE, the highest average concentrations are shown by La (763 ppm) and Ce (1,479 ppm). For heavy REE (HREE), Dy and Er are the most abundant on average (167 and 114 ppm, respectively). No HREE-rich minerals such as xenotime have been identified; the HREE may reside chiefly in monazite and bastnäsite, and within the fine-grained zircon. Very strong positive correlations (R2) of 0.92 to 0.98 exist between Th and Zr, Nb, Y, Ce, Yb, and Sn, indicating that the radiometric data for eTh are valid proxies for concentrations of these metals in the mineralized rocks. Trachyte-hosted REE-Nb-Zr deposits like the occurrence at Pennington Mountain also are known in eastern Australia and in the south Qinling belt of Central China. Based on comparisons with these deposits, and the lack of detailed geologic mapping in the Pennington Mountain region, we suggest that other rare-metal occurrences contained in trachyte may exist elsewhere in northern Maine, and more widely in the Appalachian-Caledonian orogen where volcanic and subvolcanic trachytes have been recognized.

Standardized methods for effectively and rapidly monitoring changes in the biodiversity of marine ecosystems are critical to assess status and trends in ways that are comparable between locations and over time. In intertidal and subtidal habitats, estimates of fractional cover and abundance of organisms are typically obtained with traditional quadrat-based methods, and collection of photoquadrat imagery is a standard practice. However, visual analysis of quadrats, either in the field or from photographs, can be very time-consuming. Cutting-edge machine learning tools are now being used to annotate species records from photoquadrat imagery automatically, significantly reducing processing time of image collections. However, it is not always clear whether information is lost, and if so to what degree, using automated approaches. In this study, we compared results from visual quadrats versus automated photoquadrat assessments of macroalgae and sessile organisms on rocky shores across the American continent, from Patagonia (Argentina), Galapagos Islands (Ecuador), Gorgona Island (Colombian Pacific), and the northeast coast of the United States (Gulf of Maine) using the automated software CoralNet. Photoquadrat imagery was collected at the same time as visual surveys following a protocol implemented across the Americas by the Marine Biodiversity Observation Network (MBON) Pole to Pole of the Americas program. Our results show that photoquadrat machine learning annotations can estimate percent cover levels of intertidal benthic cover categories and functional groups (algae, bare substrate, and invertebrate cover) nearly identical to those from visual quadrat analysis. We found no statistical differences of cover estimations of dominant groups in photoquadrat images annotated by humans and those processed in CoralNet (binomial generalized linear mixed model or GLMM). Differences between these analyses were not significant, resulting in a Bray-Curtis average distance of 0.13 (sd 0.11) for the full label set, and 0.12 (sd 0.14) for functional groups. This is the first time that CoralNet automated annotation software has been used to monitor “Invertebrate Abundance and Distribution” and “Macroalgal Canopy Cover and Composition” Essential Ocean Variables (EOVs) in intertidal habitats. We recommend its use for rapid, continuous surveys over expanded geographical scales and monitoring of intertidal areas globally.