Geochemistry and geodynamic implications of the Mesoproterozoic English Bay granite–rhyolite complex, northwestern Ontario

2004 ◽  
Vol 41 (11) ◽  
pp. 1329-1338 ◽  
Author(s):  
Pete Hollings ◽  
Philip Fralick ◽  
Stephen Kissin
Keyword(s):  
Trace Element Geochemistry ◽  
The South ◽  
Element Geochemistry ◽  
The North ◽  
Northwestern Ontario ◽  
Suprasubduction Zone ◽  
Heating Event ◽  
Igneous Activity ◽  
Northern Portion ◽  
Basin Formation

The Mesoproterozoic English Bay Complex consists of a granite-rhyolite assemblage outcropping on the shores of Lake Nipigon in western Superior Province, Canada. It intrudes Neoarchean rocks and is disconformably overlain by a rift–infracratonic basin sedimentary succession recording subsidence following a heating event. The granites and rhyolites are characterized by light rare-earth element (LREE) enrichment (La/Smn = 2.8–5.1) and only weakly fractionated heavy REE (HREE; Gd/Ybn = 1.1–1.6). The felsic igneous rocks are high-K, enriched in Zr, Nb, Y, and REE satisfying all the criteria for an A-type suite. Trace element geochemistry, particularly the absence of any negative Nb anomalies, indicates this melt did not originate in a suprasubduction zone setting, unlike the St. Francois Mountain Complex to the south. The English Bay Complex may record the northern portion of a Mesoproterozoic plume track— a plume that possibly led to earlier igneous activity and infracratonic basin formation to the north and would later interact with a suprasubduction zone margin to the south.

Evaluating the Lower Cruse and Navet Formations Within the Wd-8 Lease Operatorship Block

2021 ◽  
Author(s):  
Mark Emmanuel Bishop ◽  
Wilson Lalla ◽  
Xavier Ravi Moonan
Keyword(s):  
Well Testing ◽  
Geological Model ◽  
The South ◽  
Forest Reserve ◽  
The North ◽  
Well Spacing ◽  
Northern Portion ◽  
Channel Deposits ◽  
Sand Bodies ◽  
Slope Channel

Abstract Lease Operatorship block WD-8, lies within the Forest Reserve oilfield. Forest Reserve is known for having the ENE-WSW trending, south easterly verging Forest Reserve anticline which plunges into NW-SE trending Los Bajos Fault. Regionally to the south of the Forest Reserve anticline lies the south westerly plunging Siparia syncline and to the north of the Forest Reserve anticline is the Morne L′ Enfer syncline. WD-8 is situated on the northern flank of the Forest Reserve anticline with the axis of the anticline occurring within the southern part of the block. Prior to 2018, TETL last drilled within the WD-8 block in the year 2014. Drilling within the WD-8 block pre-2018 was mainly in the southern portion of the block. The year 2018 saw TETL drill five wells in the northern part of the WD-8 block. The results from these wells prompted an evaluation within the Northern portion of the WD-8 block to determine the structure and extent of the Lower Cruse and Navet reservoirs. Field wide mapping post 2018 drills within the block highlighted the sand trend at the Cruse level is in a WSW-ENE direction and that these sands in northern WD-8 are very narrow with maximum widths ranging between 100 ft – 150 ft. Additionally, it showed that by using a smaller well spacing, wells would encounter different producing sand bodies not seen in adjacent wells. Differences in the sand character between wells in the Southern part of the block to wells in the northern part of the block at the Lower Cruse level were also seen. The Lower Cruse section in the southern part of the WD-8 block tends to have thick stacked slope channel sand deposits, while the northern part of WD-8 has relatively thin stacked slope/base of slope channel deposits. Structurally, the presence of an ENE-WSW fault which separates the southern wells from the northern wells was also revealed. Abnormal stratigraphy was also found in Northern WD-8 where the Eocene Navet formation was encountered below the Late Miocene Lower Cruse formation. Two (2) wells in the northern portion of the block found the Navet formation resistive with only one well testing this reservoir. This then presents a new under exploited target reservoir with the block. Mapping of the Navet Formation indicates that this reservoir trends in a WSW-ENE direction. This updated geological model for the WD-8 block resulted in six infill developmental wells being identified to further exploit the remaining reserves within the Lower Cruse and Navet Formations in the WD-8 block.

Rb–Sr geochronology of the Coldwell Complex, northwestern Ontario, Canada

1982 ◽  
Vol 19 (9) ◽  
pp. 1796-1801 ◽  
Author(s):  
R. Garth Platt ◽  
Roger H. Mitchell
Keyword(s):  
Upper Mantle ◽  
Lake Superior ◽  
Parental Magma ◽  
Initial Ratio ◽  
North Shore ◽  
The North ◽  
Northwestern Ontario ◽  
Alkaline Intrusion ◽  
Intrusive Rocks ◽  
Igneous Activity

The Coldwell Complex of Northwestern Ontario is North America's largest structurally and petrologically complex alkaline intrusion. Situated on the north shore of Lake Superior, it consists of at least three intrusive centres and is cross-cut by a diverse suite of coeval–cogenetic dikes. The main intrusive rocks range from gabbros to ferroaugite syenites, nepheline syenites, and quartz syenites. The dikes are predominantly lamprophyric. A seventeen point whole rock Rb–Sr isochron (MSWD 2.22) gives an age of 1044.5 ± 6.2 Ma (2σ) and an initial ratio of 0.70354 ± 0.00016 (2σ). The age is late Neohelikian and is younger than the bulk of igneous activity (Keweenawan activity) prevalent in the Lake Superior Basin during the Neohelikian. The low initial ratio indicates an upper mantle origin for the parental magma of the complex.

scholarly journals Chemostratigraphy and provenance of clays and other non-carbonate minerals in chalks of Campanian age (Upper Cretaceous) from Sussex, southern England

Clay Minerals ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 327-340 ◽  
Author(s):  
D. S. Wray ◽  
C. V. Jeans
Keyword(s):  
Trace Element ◽  
Upper Cretaceous ◽  
Mineralogical Composition ◽  
Insoluble Residue ◽  
Trace Element Geochemistry ◽  
Geochemical Analysis ◽  
Element Geochemistry ◽  
The North ◽  
Eu Anomaly ◽  
Residue Composition

AbstractGeochemical analysis of acid-insoluble residues derived from white chalks and marl seams of Campanian age from Sussex, UK, has been undertaken. All display a broadly similar <2 μm mineralogical composition consisting of smectite or smectite-rich illite-smectite with subordinate illite and minor amounts of talc. Plots of K2O/Al2O3 and TiO2/Al2O3 indicate that most marl seams have an acid-insoluble residue composition which is slightly different to that of the over- and underlying white chalk, implying that marl seams are primary sedimentary features not formed through white chalk dissolution. On the basis of a negative Eu anomaly and trace element geochemistry one marl seam, the Old Nore Marl, is considered to be volcanically derived and best classified as a bentonite; it is considered to correlate with the bentonite M1 of the north German succession.

The Hudesheng mafic–ultramafic intrusions in the Oulongbuluke Block, Qinghai Province, NW China: chronology, geochemistry, isotopic systematics and tectonic implications

2018 ◽  
Vol 156 (9) ◽  
pp. 1527-1546 ◽  
Author(s):  
Haoran Li ◽  
Fengyue Sun ◽  
Liang Li ◽  
Jiaming Yan
Keyword(s):  
Crustal Contamination ◽  
Geochemical Data ◽  
Trace Element Geochemistry ◽  
Field Observations ◽  
Element Geochemistry ◽  
Qinghai Province ◽  
Nw China ◽  
The North ◽  
Depleted Mantle ◽  
Regional Tectonic

AbstractThe Hudesheng mafic–ultramafic intrusions are located in the Oulongbuluke Block, north of the Qaidam Block in Qinghai Province, NW China. We carried out a detailed study of the intrusions, including field observations, petrology, zircon U–Pb geochronology, Lu–Hf isotopes, bulk-rock major- and trace-element geochemistry, and mineral compositions, to provide a better understanding of their properties and the regional tectonic evolution. Zircon U–Pb dating on gabbro and pyroxenite samples yielded ages of 465 and 455 Ma, respectively. Geochemical data, in conjunction with the field observations and petrological features, suggest that the complex is Alaskan-type and the magma was derived from a depleted mantle source that was hydrous picritic basalt in composition and influenced by crustal contamination and slab-derived fluid metasomatism. Based on all the chronological, petrological, mineralogical and geochemical and regional geological data, we conclude that the palaeo-ocean closed diachronously from west to east between the Qaidam and Oulongbuluke blocks, and that the ocean in the east of the North Qaidam region closed after ∼455 Ma.

Holocene evolution of a barrier-spit complex and the interaction of tidal and wave processes, Inskip Peninsula, SE Queensland, Australia

The Holocene ◽  
2021 ◽  
pp. 095968362110190
Author(s):  
Martin Köhler ◽  
James Shulmeister ◽  
Nicholas R Patton ◽  
Tammy M Rittenour ◽  
Sarah McSweeney ◽  
...  
Keyword(s):  
Late Holocene ◽  
Beach Ridge ◽  
The South ◽  
Coastal Evolution ◽  
Beach Ridges ◽  
The North ◽  
Highly Active ◽  
Longshore Sediment Transport ◽  
Complex Development ◽  
Northern Portion

This paper presents a reconstruction of the Holocene evolution of the Inskip Peninsula in SE Queensland. The peninsula links two major dune fields, the Cooloola Sand Mass to the south and K’gari (Fraser Island) to the north. Geomorphic features of this peninsula include remnant parabolic dunes, numerous beach ridges with foredunes, and a series of spits. Together these features provide insight into Holocene coastal evolution and changing marine conditions. A remnant beach ridge/foredune complex at the northern portion of Inskip may have been connected to K’gari and a river/tidal channel near Rainbow Beach township which separated it from the Cooloola Sand Mass to the south. This channel avulsed northward in the early mid-Holocene (after 8.8 ka) with spit development from the south. This was followed by a phase of beach-ridge/foredune complex development that started by ~6.7 ka. Stratigraphic evidence from the highest and best developed parabolic dunes in the northern portion of Inskip Peninsula indicates dune development from the mid-Holocene beach complex by 4.8 ka. Beach ridges with foredunes continued to prograde but notably declined in size during the late-Holocene. In the latest Holocene (<4.8 ka) many of the late-Holocene beach ridges/foredune complexes have been truncated by a re-orientation of the shoreline and longshore sediment transport has promoted the growth of the modern spit at the northern end of the peninsula. Erosive and longshore processes continue to be highly active because of tidal interactions between Great Sandy Strait and the Coral Sea. This detailed study of Inskip Peninsula’s evolution aids significantly in future coastal management decisions, and provides evidence for World Heritage Area extension for the Cooloola Sand Mass, including the incorporation of Inskip Peninsula itself. It also contributes to the global understanding to coastal evolution in an area of strong wave and tidal interaction.

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