Sedimentology, Mineral Facies, and Petrofabric of the Meaford–Dundas Formation (Upper Ordovician) in Southern Ontario

1973 ◽  
Vol 10 (12) ◽  
pp. 1790-1804 ◽  
Author(s):  
K. Czurda ◽  
C. G. Winder ◽  
R. M. Quigley
Keyword(s):  
Clay Minerals ◽  
Heavy Minerals ◽  
Carbonate Content ◽  
The South ◽  
Upper Ordovician ◽  
Quartz Content ◽  
Southern Ontario ◽  
The North ◽  
Bedding Planes ◽  
Diffraction Patterns

The Meaford–Dundas Formation in southern Ontario is a medium gray shale with good fissility and resistant interbeds of gray fossiliferous limestones and siltstones. The hard layers are up to 20 cm in thickness and comprise 10 to 20% of the formation. The shale layers vary in thickness from 50 cm to 2 m.The clay minerals are principally illite, iron-chlorite, and small amounts of vermiculite and mixed-layer types. The carbonate content seems constant across the area at about 4 to 5% of the formation, except for the southwestern area where the carbonate increases to 20 or 25%. This increase is chiefly in dolomite content, a feature which reflects such factors as original conditions of deposition and possibly diagenesis subsequent to burial. The quartz content in the shale beds, and especially in the hard interbeds, increases towards the north to an average of 35 to 40% compared with 10 to 15% in the south. Framboids (aggregates of pyrite grains in spheroidal clusters) are a striking feature of the shale beds of the Meaford–Dundas Formation in the Meaford area.Fabric studies by means of X-ray diffraction patterns and scanning electron photomicrographs reveal, in most cases, high parallelism of clay platelets in the bedding planes, resulting in the good fissility of the shale.The principal source rock areas are the Appalachian orogen in the east (Taconic Mountains), which probably supplied most of the clay minerals and some quartz, and the Canadian Shield in the north, which provided the basin of sedimentation in the south with heavy minerals and additional quartz.

scholarly journals Heavy minerals in the Wajid Sandstone from Abha-Khamis Mushayt area, southwestern Saudi Arabia: implications on provenance and regional tectonic setting

GeoArabia ◽  
2004 ◽  
Vol 9 (4) ◽  
pp. 77-102 ◽  
Author(s):  
Mahbub Hussain ◽  
Lameed O. Babalola ◽  
Mustafa M. Hariri
Keyword(s):  
Saudi Arabia ◽  
Tectonic Setting ◽  
Principal Component ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Coarse Grained ◽  
Distribution Data ◽  
The South ◽  
Quartz Content ◽  
The North

ABSTRACT The Wajid Sandstone (Ordovician-Permian) as exposed along the road-cut sections of the Abha and Khamis Mushayt areas in southwestern Saudi Arabia, is a mediun to coarse-grained, mineralogically mature quartz arenite with an average quartz content of over 95%. Monocrystalline quartz is the dominant framework grain followed by polycrystalline quartz, feldspar and micas. The non-opaque heavy mineral assemblage of the sandstone is dominated by zircon, tourmaline and rutile (ZTR). Additional heavy minerals, constituting a very minor fraction of the heavies, include epidote, hornblende, and kyanite. Statistical analysis showed significant correlations between zircon, tourmaline, rutile, epidote and hornblende. Principal component R-mode varimax factor analysis of the heavy mineral distribution data shows two strong associations: (1) tourmaline, zircon, rutile, and (2) epidote and hornblende suggesting several likely provenances including igneous, recycled sedimentary and metamorphic rocks. However, an abundance of the ZTR minerals favors a recycled sedimentary source over other possibilities. Mineralogical maturity coupled with characteristic heavy mineral associations, consistent north-directed paleoflow evidence, and the tectonic evolutionary history of the region indicate a provenance south of the study area. The most likely provenances of the lower part (Dibsiyah and Khusayyan members) of the Wajid Sandstone are the Neoproterozoic Afif, Abas, Al-Bayda, Al-Mahfid, and Al-Mukalla terranes, and older recycled sediments of the infra-Cambrian Ghabar Group in Yemen to the south. Because Neoproterozic (650-542 Ma) rocks are not widespread in Somalia, Eritrea and Ethiopia, a significant source further to the south is not likely. The dominance of the ultrastable minerals zircon, tourmaline and rutile and apparent absence of metastable, labile minerals in the heavy mineral suite preclude the exposed arc-derived oceanic terrains of the Arabian Shield in the west and north as a significant contributor of the sandstone. An abundance of finer-grained siliciclastic sequences of the same age in the north, is consistent with a northerly transport direction and the existence of a deeper basin (Tabuk Basin?) to the north. The tectonic and depositional model presented in this paper differs from the existing model that envisages sediment transportation and gradual basin filling from west to east during the Paleozoic.

scholarly journals Effect of slope aspect on transformation of clay minerals in Alpine soils

Clay Minerals ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 373-398 ◽  
Author(s):  
M. Egli ◽  
A. Mirabella ◽  
G. Sartori ◽  
D. Giaccai ◽  
R. Zanelli ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Soil Profile ◽  
Water Flux ◽  
Layer Charge ◽  
Slope Aspect ◽  
X Ray Diffraction ◽  
The South ◽  
Octahedral Sheet ◽  
The North ◽  
Low Charge

AbstractTwo soil profile sequences on paragneiss debris in the Val di Rabbi (Northern Italy) along an altitude gradient ranging from 1200 to 2400 m a.s.l. were studied to evaluate the effect of aspect on the weathering of clay minerals. All the soils had a coarse structure, a sandy texture and a low pH. Greater weathering intensities of clay-sized phyllosilicates (greater content of smectites) were observed in soils on the north-facing slope. On the south-facing slope, smectite was found only in the surface horizon of the soil profile at the highest altitude. Hot citrate treatment of north-facing soils revealed the presence of low-charged 2:1 clay minerals, the expansion of which was hindered in the untreated state by interlayered polymers. However, the hot citrate treatment encountered some problems with the samples of the south-facing soils: as confirmed by Fourier transform infrared spectroscopy, the hot citrate treatment was unable to remove all interlayer Al polymers. The 2:1 phyllosilicates were not expanded by ethylene glycol solvation in several samples, although thermogravimetric analyses indicated the presence of clay minerals with interlayer H2O. At the same time, the collapse of clay minerals to 1.0 nm following K-saturation was evident. Theoretically, this should indicate that 2:1 phyllosilicates had no evident substitution of trioctahedral cations (Mg2+, Fe2+) by dioctahedral cations (Al3+ and Fe3+). X-ray diffraction analysis of the d060 region and determination of the layer charge of clay minerals by the long-chain (C18) alkylammonium ion, however, did not confirm this. A transformation from trioctahedral to dioctahedral species was observed and low-charge clay minerals (ξ ~0.30) were identified in the surface horizons of the south-facing sites. In the south-facing soils, the podzolization process was less pronounced because of a lower water flux through the soil and probably less complexing organic molecules that would remove the interlayer polymers. Besides the eluviation process, clay minerals underwent a process of ionic substitutions in the octahedral sheet that led to the reduction of the layer charge. This process was more obvious in the north-facing sites.

VI.—The Petrology and Sedimentation of Upper Ordovician Rocks in the Rhinns of Galloway, South-west Scotland

1962 ◽  
Vol 65 (6) ◽  
pp. 107-137 ◽  
Author(s):  
Gilbert Kelling
Keyword(s):  
Source Area ◽  
Heavy Minerals ◽  
Coarse Grained ◽  
Upper Ordovician ◽  
Rock Fragments ◽  
North East ◽  
The North ◽  
South West ◽  
Wide Range ◽  
Nearby Source

SynopsisThe petrology of a group of geosynclinal rudites and arenites of Upper Ordovician age from the Rhinns of Galloway, south-west Scotland, is described. The rudites are confined to the oldest formation, the Corsewall Group, and consist of pebbly microbreccias and “boulder-beds” interbedded with coarse greywackes and platy siltstones. The composition of the microbreccias and boulder-beds varies little with stratigraphic level.The arenites comprise lithic, coarse-grained greywackes with occasional quartzose or feldspathic varieties. They carry, in aggregate, a wide range of igneous, metamorphic and sedimentary rock-fragments, quartz of variable source, a variety of feldspars, ferromagnesian minerals, micas, chlorites and a common to conspicuous argillaceous matrix. The greywackes are well defined stratigraphically as regards both overall composition and the character of the large mineral grains and rock-fragments (“granules”). Moreover composition appears to be related to grain-size in a consistent manner. The size-distribution, sorting and skewness of the greywackes based on thin section measurements show little stratigraphic variation.The aggregate suite of heavy minerals is meagre and only minor differences exist in the individual formation-suites.The character of the rock-fragments and mineral grains suggests that the earlier formations were derived from a nearby source-area in which plutonic and hypabyssal acid and basic igneous rocks were extensively exposed, together with spilitic lavas and glaucophane schists. The petrology of the upper formations reveals that a metamorphic terrain of Southern Highlands aspect became an important additional source of material. However, the highest beds were derived from a region dominated by andesitic and spilitic tuffs and lavas.The principal directional sedimentary structures are described briefly and it is suggested that the lower part of the Corsewall Group, derived mainly from the north and north-east, was deposited in a sheltered pro-delta environment, but that the boulder-beds and associated rocks were formed within a more boisterous region. The Kirkcolm Group is a turbidite-sequence deposited in a marine trough of moderate depth by currents which at first flowed dominantly in opposing directions, towards either north-east or south-west. However, transport from the north-east became progressively established. The Portpatrick Group is another turbidite-sequence but this formation was deposited by currents flowing from the west or south-west.

Geological Studies in the Dublin District. I. The Heavy Minerals of the Granite and the Contiguous Rocks in the Ballycorus District

1928 ◽  
Vol 65 (1) ◽  
pp. 12-25 ◽  
Author(s):  
F. Smithson
Keyword(s):  
Geological Structure ◽  
Heavy Minerals ◽  
East Side ◽  
The South ◽  
Large Area ◽  
Lower Carboniferous ◽  
North West ◽  
The North ◽  
South West ◽  
The Hill

From the southern shores of Dublin Bay there stretches to the south-west a broad granite intrusion with rocks of supposed Ordovician age on both sides of it. These rocks are metamorphosed near the granite, and the belt of metamorphism is wider on the south-east than on the north-west side, indicating, no doubt, that the plane of junction dips more steeply on the latter side. Near Dublin the Lower Carboniferous rocks rest unaltered upon the granite. On the south-east side, in the northern part of the county of Wicklow, the belt of Ordovician rocks is only some 2 miles wide, and a large area of supposed Cambrian rocks lies between it and the sea. Around the hill of Carrickgollogan a. patch of similar rocks appears incongruously in the middle of the Ordovician belt. After a study of the region to the south of Dublin one seems to be naturally drawn towards this small area around Carrickgollogan, for it presents a problem, the key to which may explain the geological structure of a much wider area.

Mélange development in the Boones Point Complex, north-central Newfoundland

1981 ◽  
Vol 18 (3) ◽  
pp. 433-442 ◽  
Author(s):  
K. Douglas Nelson
Keyword(s):  
Debris Flow ◽  
Late Ordovician ◽  
The South ◽  
Upper Ordovician ◽  
North Central ◽  
Clastic Rocks ◽  
The North ◽  
Volcaniclastic Rocks ◽  
Acadian Orogeny

The Boones Point Complex in north-central Newfoundland is a narrow mélange belt separating Roberts Arm terrain volcanic and volcaniclastic rocks to the north from Upper Ordovician westerly derived clastic rocks to the south and east. The mélange has a sedimentary matrix and contains a polymict assemblage of blocks. Limestone blocks have yielded Llanvirn–Llandeilo conodont faunas. Sedimentologic and structural analyses indicate that the complex is composed of subaqueous debris flow deposits, which are the proximal facies equivalent of the Late Ordovician clastics to the south. This debris flow material was tectonically deformed prior to the Medial Devonian 'Acadian' orogeny, probably as a result of earlier 'Taconic' thrusting.

Upper Ordovician conodont biostratigraphy and the age of the Collingwood Member, southern Ontario, Canada1Earth Science Sector (ESS) Contribution 20100302.

2011 ◽  
Vol 48 (11) ◽  
pp. 1497-1522 ◽  
Author(s):  
Shunxin Zhang ◽  
Glen A. Tarrant ◽  
Christopher R. Barnes
Keyword(s):  
North Atlantic ◽  
Carbonate Platform ◽  
Upper Ordovician ◽  
Hydrocarbon Source Rock ◽  
Southern Ontario ◽  
Blue Mountain ◽  
The North ◽  
Atlantic Province ◽  
Taconic Orogeny ◽  
A New Species

The Upper Ordovician stratigraphy in southern Ontario represents the clastic foredeep associated with the Appalachian Taconic Orogeny transitioning northwest into coeval carbonate platform facies. Ten measured and sampled sections in both the Collingwood area and on Manitoulin Island, Lake Huron, provide two relatively complete composite sections (277 and 95 m, respectively) through the marine part of the sequence. A total of 100 2 kg samples collected for a conodont biostratigraphic study yielded 77 215 well-preserved specimens. Taxonomic study of the fauna, illustrated herein, identified 34 species representing 22 genera and three taxa in open nomenclature. Taxonomic revisions are made to five species of Pseudobelodina and one of Rhipidognathus ; a new species, Pseudobelodina microdentata , is established. The fauna primarily represents the Midcontinent Province with incursions from the North Atlantic Province primarily in the Collingwood area. Four conodont zones are recognized that help refine the ages for the Upper Ordovician upper Lindsay (Collingwood Member), Blue Mountain, Georgian Bay, and Queenston formations. In particular, the Collingwood Member of the Lindsay Formation, a regionally distributed organic-rich shale of hydrocarbon source rock potential, is demonstrated to lie within the Amorphognathus ordovicicus Zone of North Atlantic Province and the Oulodus robustus Zone of Midcontinent Province and to be early Richmondian age.

scholarly journals Quality characteristics of Ilmenit minerals in the south central of Vietnam by SEM and QEMSCAN analysis

2020 ◽  
Vol 61 (1) ◽  
pp. 72-81
Author(s):  
Nguyen Huu Hiep ◽  
Andrew Carter ◽  
Dao Bui Din ◽  
Trinh The Luc ◽  
Ngo Thi Kim Chi ◽  
...  
Keyword(s):  
Mineral Exploration ◽  
Grain Structure ◽  
Heavy Minerals ◽  
The South ◽  
Central Coast ◽  
Erosion And Deposition ◽  
The North ◽  
South Central ◽  
Deposition Processes

Placer deposit along the South Central Coast of Viet Nam is formed by the enrichment of heavy minerals through a combination of transportation, weathering, erosion and deposition processes. Ilmenite placer forms continuously along the South Central Coast from local origin when the shoreline is far from the modern shoreline formed during the marine transgression process from the late Plestocene to Holocene. The morphological and localization characteristics of Ilmenite have been clarified on the distribution trend with SEM method combined with QEMSCAN. Meticulous research on Ilmenite's grain structure and chemical composition in the study area has shown a tendency to significantly enrich the quality of Ti placer according to the upward trend in the north-south direction. In the south, the Ilmenite placer has smaller particle size but better selective roundness and better quality than in the northern part of the study area. The enrichment of TiO2 content with increasing trend from North to South was observed due to the strong weathering process associated with ancient coastline which is very far away from current shoreline so heavy minerals are accumulates locally and light minerals are carried away. The southern region of the South Central Coast region is home to the highest gap between the ancient shoreline and the current coastline. This study has shown the trend of the quality distribution of Ilmenite as well as of other heavy minerals as the basis for future mineral exploration planning.

scholarly journals Texture and mineralogical composition of Quaternary terrestrial and marine sediments from Macedonia and Thrace, Greece

2019 ◽  
Vol 55 (1) ◽  
pp. 137
Author(s):  
Ananias Tsirambides
Keyword(s):  
Clay Minerals ◽  
Clay Fraction ◽  
Mineralogical Composition ◽  
Climatic Conditions ◽  
Coarse Grained ◽  
Quartz Content ◽  
Fine Grained ◽  
Weathering Processes ◽  
The North ◽  
Interstratified Phase

Clastic sediments collected from land and gulfs of Macedonia and Thrace in Greece are examined on the basis of their texture and mineral composition. All terrestrial samples are coarse-grained and poorly sorted, with angular to sub-angular grains. These are mainly composed of quartz and feldspars, followed by micas, calcite and Fe-Mg minerals. Among the clay minerals illite predominates over smectite and smectite over vermiculite (+chlorite+kaolinite). In addition, the interstratified phases illite/smectite, chlorite/vermiculite, and smectite/vermiculite are present in significant amounts in the clay fraction (<2 μm), signifying the incomplete weathering of the primary minerals. Mixing during transportation, flocculation, differential settling processes and organic matter are the main mechanisms for the distribution of the discharged terrigenous load into the North Aegean Gulfs. All gulf bottom samples are coarse to fine grained and medium sorted, and their grains are angular to sub-angular. Quartz and feldspars predominate. In addition, biogenic calcite, micas and various Fe-Mg minerals exist as primary and/or accessory minerals. Among clay minerals, illite predominates over smectite and smectite over kaolinite (+chlorite+vermiculite). Almost in all gulf sediments the interstratified phase illite/smectite is apparent. The presence of feldspars and Fe-Mg minerals, as well as the high content of clay minerals and the polymodal grain-size distribution with angular to sub-angular grains, signify mineralogical and textural immaturity of all the examined sediments, as well as predominance of mild climatic conditions and thus mild weathering processes. The quartz content in these sediments is usually <70%. Therefore, a sedimentation cycle of these materials has not been completed.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

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