scholarly journals New interpretation of the provenance of crystalline material from Oligocene flysch deposits of the Skole Nappe, Poland: evidence from heavy minerals and clasts in the Nowy Borek section

Geologos ◽  
2019 ◽  
Vol 25 (2) ◽  
pp. 163-174
Author(s):  
Dorota Salata ◽  
Alfred Uchman
Keyword(s):  
Volcanic Rocks ◽  
Heavy Minerals ◽  
Coarse Grained ◽  
Local Source ◽  
Metamorphic Rocks ◽  
Secondary Sources ◽  
Rock Fragments ◽  
Carpathian Region ◽  
Mineral Assemblages ◽  
New Interpretation

Abstract The Futoma Member (Oligocene, Rupelian) of the Menilite Formation is present only in the northern part of the Skole Nappe. Some diatomitic layers of this member in the Nowy Borek section contain coarse-grained detrital material composed of a variety of metamorphic, volcanic and sedimentary rock fragments. The material derives from primary and secondary sources. Most abundant are debris of metamorphic rocks, mostly gneisses and mica schists. The metamorphic origin of these rocks is confirmed by the composition of heavy mineral assemblages and garnet chemistry. These rocks could have been transported from a local source located close to the margin of the Skole Basin or within that basin. The volcanic rocks reflect Paleogene volcanic activity that was widespread in the Carpathian region. Cherts, which could have been subjected to synsedimentary erosion, may have been derived from the older portions of the same formation.

scholarly journals Beachrock as a Paleoshoreline Indicator: Example from Wadi Al-Hamd, South Al-Wajh, Saudi Arabia

2021 ◽  
Vol 9 (9) ◽  
pp. 984 ◽  
Author(s):  
Ammar A. Mannaa ◽  
Rabea A. Haredy ◽  
Ibrahim M. Ghandour
Keyword(s):  
Saudi Arabia ◽  
Volcanic Rocks ◽  
Skeletal Remains ◽  
Heavy Minerals ◽  
Coarse Grained ◽  
Coralline Algae ◽  
Sea Level Changes ◽  
Pore Filling ◽  
Δ13c Values ◽  
Δ18o And Δ13c

The present study concerns the Holocene inland beachrocks that are exposed in the Red Sea coastal plain at the mouth of Wadi Al-Hamd, South Al-Wajh City, Saudi Arabia, and their utility as an indicator for Holocene climate and sea level changes. In addition, the framework composition, and carbon and oxygen isotopic data, are employed to interpret the origin of their cement. The beachrock consists mainly of gravel and coarse-grained terrigenous sediments dominated by lithic fragments of volcanic rocks, cherts and rare limestones along with quartz, feldspars and traces of amphiboles and heavy minerals. In addition, rare skeletal remains dominated by coralline algae, benthic foraminifera and mollusca remains are recognized. The allochems are cemented by high Mg-calcite (HMC) formed mainly in the intertidal zone under active marine phreatic conditions. The cement takes the form of isopachous to anisopachous rinds of bladed crystals, micritic rim non-selectively surrounding siliciclastic and skeletal remains, and pore-filling micrite. Pore-filling micrite cement occasionally displays a meniscus fabric, suggesting a vadose environment. The δ18O and δ13C values of carbonate cement range from −0.35‰ to 1‰ (mean 0.25‰) and −0.09‰ to 3.03‰ (mean 1.85‰), respectively, which are compatible with precipitation from marine waters. The slight depletion in δ18O and δ13C values in the proximal sample may suggest a slight meteoric contribution.

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.

scholarly journals MINERALOGICAL AND GEOCHEMICAL STUDY OF NEOGENE RED BEDS FROM MOUDANIA AND POTIDEA, CHALKIDIKI (MACEDONIA, GREECE)

2007 ◽  
Vol 40 (2) ◽  
pp. 1022
Author(s):  
A. Tsirambides ◽  
I. K. Georgiadis ◽  
A. A. Papadopoulos ◽  
A. A. Ziafetis ◽  
A. N. Giouri
Keyword(s):  
Source Area ◽  
Coarse Grained ◽  
Annual Rainfall ◽  
Metamorphic Rocks ◽  
Adjacent Area ◽  
Red Beds ◽  
Rock Fragments ◽  
Geochemical Study ◽  
Two Samples ◽  
Parent Rocks

The Neogene red beds from Moudania and Potidea (Chalkidiki) are studied in order to find the conditions under which they were formed. They are incoherent coarse grained sands, with poorly sorted grains. Angular to sub-angular rock fragments derived from the adjacent parent rocL· are very common. The red beds are texturally and mineralogically immature. Most of the samples are gravel sands. The extended presence of sand size grains (>0.063 mm) in the samples suggests high intensity of weathering of the parent rocks and rapid transportation and deposition of the weathered materials close to the source area. The detrital minerals present in the whole samples in decreasing abundance are quartz, feldspars (plagioclase + orthoclase), mica (+clay minerals), pyroxene, amphibole, pyrite and halite (except two samples which are rich in calcite). In the <0.063 mm fraction quartz decreases greatly, while feldspars increase. The presence of illite, smectite (+illite/smectite), and chlorite (+vermiculite) in the <0.063 mm fraction is evident. The most likely source minerals for the formation of the studied red beds are quartz, feldspars, micas, and various Fe-Mg silicates, which are primary constituents of the Mesozoic basement igneous and metamorphic rocks predominating in the adjacent area. In the poorly drained lowland of the studied area mean annual air temperature is 16.2° C, mean annual humidity 75%, and mean annual rainfall 59.5 cm. The samples may be considered ferromagnesian and potassic sandstones. The felsic igneous provenance signature is justified for most of the samples. The climate under which these Neogene red beds were formed was warm and semiarid.

scholarly journals Mineralogy of Lower Diyala River Sediments Northeastern Baghdad

2019 ◽  
pp. 1498-1506
Author(s):  
Mustafa Najm Al-Shamary ◽  
Mazin Yousif Tamar-Agha
Keyword(s):  
River Sediments ◽  
Source Area ◽  
Mineralogical Composition ◽  
Heavy Minerals ◽  
Heavy Liquid ◽  
Metamorphic Rocks ◽  
Northeastern Part ◽  
Upper Miocene ◽  
Rock Fragments ◽  
Diyala River

     The purpose of this study is to determine the mineralogical composition of Lower Diyala River, northeastern of Baghdad, and attempt to define the sources of sediments. 10 samples were collected from Lower Diyala River from the area between Himreen Dam to south Baghdad, where these samples are dealings by the heavy liquid to separated into light and heavy minerals. The light minerals contents are composed mainly of quartz, feldspars, and rock fragments. The main rocks fragments consist of; igneous, metamorphic, carbonate, chert rock fragments, and evaporites. The heavy minerals contents are opaques minerals, chlorite, amphiboles, pyroxenes, epidote, zircon, garnet, muscovite, biotite, kyanite, tourmaline, staurolite, and rutile. The source area of these sediments is the outcrops of Upper Miocene-Pliocene rocks at the northeastern part of the studied area, igneous, and metamorphic rocks in the northeastern Iraq and Iran.

Grain Size and Provenance of Bahia la Choya Sediments

1987 ◽  
Vol 2 ◽  
pp. 44-51 ◽  
Author(s):  
Lawrence T. Sumpter
Keyword(s):  
Grain Size ◽  
Tidal Flat ◽  
Volcanic Rocks ◽  
Heavy Minerals ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Rock Fragments ◽  
The North ◽  
Average Grain Size ◽  
Carbonate Shell

A grain size analysis (including the carbonate fraction) was performed on sediment samples from each of the following environments of Bahia la Choya: tidal flat, spit, beach, and estero. The sediments of the tidal flat have an average grain size of 2.88 phi, range from very well sorted to moderately well sorted, and have a carbonate shell fraction ranging from 1 to 30%. The spit sediments have an average grain size of 0.96 phi, are moderately to poorly sorted, and have a carbonate shell fraction of approximately 50%. The beach sediments have an average grain size of 1.22 phi, range from poorly sorted to moderately well sorted, and have a carbonate shell fraction of approximately 48%. The sediments of the estero average 39% sand, 40% silt, and 20% clay. The carbonate fraction in the estero is approximately 25%. The noncarbonate fraction in all the environments is made up of feldspar, quartz, biotite, heavy minerals, and igneous rock fragments.The major source for the sediment is the Pelican Point granite on the south side of the bay. Pleistocene rock in and around the bay provides a second source of sediment and volcanic rocks to the north may also contribute to the sediment.

TEM/AEM characterization of fine-grained clay minerals in very-low-grade rocks: Evaluation of contamination by empa involving celadonite family minerals

1996 ◽  
Vol 54 ◽  
pp. 694-695
Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi
Keyword(s):  
Electron Microscopy ◽  
Volcanic Rocks ◽  
Analytical Electron Microscopy ◽  
Metamorphic Rocks ◽  
New Mineral ◽  
Chemical Compositions ◽  
Low Grade ◽  
Fine Grained ◽  
Depth Analysis ◽  
Mineral Aggregates

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.

The Caledonoid faults of northern Lleyn (North Wales)

1970 ◽  
Vol 107 (3) ◽  
pp. 235-247 ◽  
Author(s):  
W. E. Tremlett
Keyword(s):  
Volcanic Rocks ◽  
Strike Slip ◽  
Metamorphic Rocks ◽  
Red Sandstone ◽  
North Wales ◽  
Dextral Strike Slip

SummaryEvidence of substantial dextral strike-slip displacements along the Caledonoid fault-set of northern Lleyn is revealed by the distribution of Pre-Cambrian igneous and metamorphic rocks, Ordovician volcanic rocks and Caledonian ‘early granodioritic’ intrusions. These apparently occurred prior to some smaller sinistral strike-slip movements which left total net dextral displacements of 91/2 km. Both types of movement were completed before the Caledonoid faults were disrupted by NNW sinistral faulting and more intrusions of Lower Old Red Sandstone age were emplaced.

Evidence for pyroclastic emplacement of the Crowsnest Formation, Alberta

1996 ◽  
Vol 33 (5) ◽  
pp. 715-728 ◽  
Author(s):  
R.N. Adair ◽  
R.A. Burwash
Keyword(s):  
Elevated Temperatures ◽  
Pyroclastic Flows ◽  
Coarse Grained ◽  
Rock Fragment ◽  
Fine Grained ◽  
Rock Fragments ◽  
Explosive Phase ◽  
Graded Structures ◽  
Textural Evidence ◽  
Charred Wood

The middle Cretaceous Crowsnest Formation west of Coleman, Alberta, is composed of bedded alkaline volcanic deposits containing heterolithic volcanic rock fragments and crystal clasts. Comparison with modern examples of subaerial pyroclastic rocks suggests that pyroclastic flows, surges, fallout of material from vertical eruption columns, and minor mud flows emplaced the deposits. Textural evidence in the form of plastically deformed volcanic fragments, chilled deposit margins, baked rock fragment margins, recrystallization, and the presence of charred wood and charred wood molds indicate emplacement at elevated temperature. Massive deposits containing a fine-grained basal zone are interpreted as the product of pyroclastic flows, whereas deposits characterized by a block-rich base overlain by a thin layer of block-depleted stratified material are interpreted as the product of density-stratified surges. Deposits exhibiting pronounced stratification were emplaced by ash-cloud surges. Thickly bedded breccias exhibiting rheomorphic textures were emplaced as vent-proximal pyroclastic flows. Deposits characterized by parallel beds and graded structures are interpreted as fallout tephra deposits, and deposition by lahars is indicated by coarse-grained beds that lack evidence for emplacement at elevated temperatures. The eruptions of the Crowsnest Formation were cyclical. An initial explosive phase generated deposits by pyroclastic flows, surges, fallout, and lahars. As an eruption progressed, it evolved into a poorly gas-charged effusive stage that emplaced coarsely porphyritic domes, plugs, spines, and vent-proximal lava flows. Subsequent eruptions destroyed the effusive vent facies deposits and produced abundant heterolithic clasts typical of the formation.

2. Chapters on the Mineralogy of Scotland

1880 ◽  
Vol 10 ◽  
pp. 76-77
Author(s):  
Heddle
Keyword(s):  
Volcanic Rocks ◽  
Metamorphic Rocks

In this Chapter, Dr Heddle discussed the substances usually thrown together, under the term of Chloritic Minerals. He showed, by an extensive series of analyses, that they were to be divided into three groups—those which occurred in metamorphic rocks, in recent strata, and in volcanic rocks.He proposed to confine the term Chloritic to the minerals which are found in metamorphic rocks, and to apply the term, the Saponites, to those which occur in volcanic rocks.

Nd isotopic characteristics of metamorphic and plutonic rocks of the Coast Mountains near Prince Rupert, British Columbia

1998 ◽  
Vol 35 (5) ◽  
pp. 556-561 ◽  
Author(s):  
P J Patchett ◽  
G E Gehrels ◽  
C E Isachsen
Keyword(s):  
British Columbia ◽  
Volcanic Rocks ◽  
Metamorphic Rocks ◽  
Published Data ◽  
Isotopic Data ◽  
Crustal Component ◽  
Coast Mountains ◽  
Crustal Rocks ◽  
Metasedimentary Rocks ◽  
Plutonic Rocks

Nd isotopic data are presented for a suite of metamorphic and plutonic rocks from a traverse across the Coast Mountains between Terrace and Prince Rupert, British Columbia, and for three contrasting batholiths in the Omineca Belt of southern Yukon. A presumed metamorphic equivalent of Jurassic volcanic rocks of the Stikine terrane gives epsilon Nd = +6, and a number of other metaigneous and metasedimentary rocks in the core of the Coast Mountains give epsilon Nd values from +3 to +7. A single metasedimentary rock approximately 3 km east of the Work Channel shear zone gives a epsilon Nd value of -9. Coast Belt plutons in the traverse yield epsilon Nd from -1 to +2. The Omineca Belt plutons give epsilon Nd from -10 to -17. All results are consistent with published data in demonstrating that (i) juvenile origins for both igneous and metamorphic rocks are common in the Coast Belt; (ii) representatives of a continental-margin sedimentary sequence with Precambrian crustal Nd are tectonically interleaved in the Coast Mountains; (iii) Coast Mountains plutons can be interpreted as derived from a blend of metamorphic rocks like those seen at the surface, or as arc-type melts contaminated with the older crustal component; and (iv) Omineca Belt plutons are dominated by remelted Precambrian crustal rocks.

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