scholarly journals SEDIMENT DISTRIBUTION AND ITS RELATIONS TO CIRCULATION PATTERNS IN BOLINAS BAY, CALIFORNIA

1970 ◽  
Vol 1 (12) ◽  
pp. 86
Author(s):  
P. Wilde ◽  
T. Yancey
Keyword(s):  
Grain Size ◽  
San Francisco ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Statistical Parameters ◽  
Sediment Distribution ◽  
Primary Mode ◽  
Marine Samples ◽  
Long Term Study ◽  
High Concentrations

Grain size and heavy mineral analyses of 6 cliff, 12 beach, and 44 marine sediment and rock samples from Bolmas Bay and its surrounding drainage area were done as part of a long term study of sediment transport on the continental shelf off Central California Sediments in the bay are predominately very fine sands Some samples, particularly adjacent to Duxbury Reef on the west, have a coarse sand to pebble component The primary mode of the marine samples is in the range 088 to 125 mm, whereas, the primary mode for beach material is from 175 to 25 mm The range of median diameters of the marine samples is from 07 to 14 mm The median diameters show a trend of decreasing grain size seaward parallel to the depth contours except opposite the entrance to Bolmas Lagoon where a tongue of relatively coarser material cuts across the depth contours The range of other statistical parameters are (1) sorting coefficient 1 10 to 1 41, (2) skewness 0 83 to 1 18, and (3) kurtosis 0 15 to 0 32 Our sediment studies indicate (1) The heavy mineral assemblage is predominantly green hornblende with secondary amounts of hypersthene and augite Glaucophane and jadeite occur in locally high concentrations near shore (2) The pattern of distribution of the heavy minerals shows (a) a tongue of high concentrations of minerals with a granitic source extending northwest from the San Francisco Bar, (b) flanked on the north and northeast by increasing landward concentrations of Franciscan metamorphic minerals (3) The major source of heavy minerals is the San Francisco Bar Secondary contributions come from Bolmas Lagoon and the adjacent cliffs (4) The circulation in the Bay is primarily counterclockwise, produced by a combination of wave refraction around Duxbury Reef and the tidal Coast Eddy Current The tidal influence, however, of Bolmas Lagoon is restricted to about one mile from the lagoon mouth.

Heavy minerals in stream sediments from Churchill Falls, Labrador—an aid in bedrock mapping

1980 ◽  
Vol 17 (2) ◽  
pp. 244-253
Author(s):  
John Edward Callahan
Keyword(s):  
Frequency Distribution ◽  
Mineral Content ◽  
Regional Metamorphism ◽  
Stream Sediments ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Sediment Samples ◽  
Fluvial Deposits ◽  
Geologic Map ◽  
High Concentrations

Stream sediments from a 13 000 km2 previously glaciated area in central Labrador near Churchill Falls were examined for their heavy mineral content. The minus 0.25 mm (60 mesh) nonmagnetic heavy mineral fraction from 846 stream sediment samples consists mainly of magnetite, ilmenite. garnet, hornblende, epidote and minor clinopyroxene, orthopyroxene. kyanite. sillimanite, biotite. apatite, and zircon. Changes in the frequency distribution of epidote, hornblende, garnet, and sillimanite in the stream sediments correspond well with those reported in previously mapped underlying bedrock lithologies. The occurrence of kyanite and sillimanite, high concentrations of garnet and opaques (mainly ilmenite), and lower concentrations of hornblende and epidote were used to determine grades of regional metamorphism, resulting in revision of the geologic map of this area. Heavy minerals in glacial drift or fluvial deposits may be useful as an aid in mapping in glaciated areas.

scholarly journals GRAIN-SIZE STATISTICAL PARAMETERS OF SANDY SEDIMENT IN KUALA GIGIENG, ACEH BESAR DISTRICT

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Syahrul Purnawan ◽  
Haekal A. Haridhi ◽  
Ichsan Setiawan ◽  
. Marwantim
Keyword(s):  
Grain Size ◽  
Sediment Load ◽  
Distribution Patterns ◽  
Sandy Sediment ◽  
Size Distributions ◽  
Statistical Parameters ◽  
Sediment Distribution ◽  
Coarse Grains ◽  
Load Transport ◽  
Grain Size Distributions

Study of sediment distribution at Kuala Gigieng was to assess the information of sediment related to the occurrence of hydro-oceanographic processes. The sediment samples were collected from nine stations using coring method. Granulometric method was used to analyze the grain size distributions. The results showed different sediment distribution patterns in each area at estuary Kuala Gigieng. The outer area of estuary indicated skewed to coarse grains, while at the inner area of estuary indicated skewed to fine grains. Different sediment load transport process was suggested as the cause of differentiated sediment characters.   Keywords: granulometry, grain size, sediment statistic, Kuala Gigieng

scholarly journals GRAIN-SIZE STATISTICAL PARAMETERS OF SANDY SEDIMENT IN KUALA GIGIENG, ACEH BESAR DISTRICT

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Syahrul Purnawan ◽  
Haekal A. Haridhi ◽  
Ichsan Setiawan ◽  
. Marwantim
Keyword(s):  
Grain Size ◽  
Sediment Load ◽  
Distribution Patterns ◽  
Sandy Sediment ◽  
Size Distributions ◽  
Statistical Parameters ◽  
Sediment Distribution ◽  
Coarse Grains ◽  
Load Transport ◽  
Grain Size Distributions

<p><em>Study of sediment distribution at Kuala Gig</em><em>i</em><em>eng was to assess the information of sediment related to the occurrence of</em><em> </em><em>hydro-oceanographic processes. The sediment samples were collected from nine stations using coring method. Granulometri</em><em>c</em><em> method was used to analyze the grain size distributions. The results showed different sediment distribution patterns in each area at estuary Kuala Gig</em><em>i</em><em>eng. The outer area of estuary indicated skewed to coarse grains, while at the inner area of estuary indicat</em><em>e</em><em>d skewed to fine grains. Different sediment load transport process was suggested as the cause of differentiate</em><em>d</em><em> sediment characters.</em><em> </em></p> <p> </p> <strong><em>Keywords: </em></strong><em>granulometry, grain size, sediment statistic, Kuala Gigieng</em>

scholarly journals HEAVY MINERAL DISTRIBUTION PATTERNS AND CHARACTERISTICS OF SEA FLOOR SURFICIAL SEDIMENT AT EAST BALI WATERS, BALI PROVINCE

2016 ◽  
Vol 26 (2) ◽  
pp. 105
Author(s):  
I Wayan Lugra
Keyword(s):  
Grain Size ◽  
Distribution Patterns ◽  
Heavy Mineral ◽  
Surficial Sediment ◽  
Heavy Minerals ◽  
Distribution Area ◽  
Carbonate Group ◽  
Sandy Gravel ◽  
Sea Floor ◽  
Beach Sediments

Analyses result of the heavy minerals that was took from beach sediments and sea floor surficial sediments was founded ten heavy minerals namely hematite, magnetite, limonite and rutile from oxide and hydroxide group, pyroxene, amphibol and zircon from silicate group, biotit from mica group, barite from sulfide group and dolomite from carbonate group. From 10 minerals identified, only magnetit distributes in the whole area, with the highest percentage of 34,15% in the sea and 35,14 % on beaches. Other heavy minerals distribute locally with the percentage of less than 0,01 %. Grain size analyses result of sea floor surficial sediment had identified six units sediment such as sand, sand with few gravel, sandy gravel, gravely sand, gravel and reef. Distribution area of the six units sediment as follows sand and sandy gravel are occupied 25 % respectively of the study area, reef 20%, sand 15 %, gravel 10 % and gravely sand occupied 5%. The best sediment for making art goods is sand sizes which is rich of heavy minerals such as magnetite, hematitre, limonite, zircon, pyroxene and amphibol. If will be exploited of the sand sediment on beach or sea floor surficial sediment, should be considering of the environment sustainable. Keyword: grain size analyses, heavy mineral, seafloor surficial sediment, besach sediment, Karang Asem Hasil analisis mineral berat dari sedimen pantai dan permukaan dasar laut dijumpai sepuluh jenis mineral berat yaitu magnetit, hematit, limonit, rutil dari kelompok oksida & hidroksida, piroksen, ampibol, sirkon dari kelompok silikat, biotit dari kelompok mika, barit dari kelompok sulfida dan dolomit dari kelompok karbonat. Dari sepuluh jenis mineral berat yang teridentifikasi hanya magnetit yang sebarannya merata di seluruh daerah penyelidikan baik di laut maupun di pantai dengan persentase tertinggi 34,15 % di laut dan 35,14% di pantai, sedangkan sembilan mineral lainnya sebarannya tidak merata atau setempat-setempat dengan persentase umumnya di bawah 0,01 %. Hasil analisis besar butir sedimen permukaan dasar laut dapat di bedakan menjadi 6 satuan yaitu pasir, pasir sedikit krikilan, pasir krikilan, krikil pasiran, krikil dan terumbu karang. Luas sebaran ke enam jenis sedimen tersebut terhadap luas daerah penelitian adalah pasir sedikit krikilan menempati 25%, pasir krikilan 25%, terumbu karang 20%, pasir 15%, krikil 10% dan menempati pasir krikilan 5%. Jenis sedimen yang baik untuk pembuatan benda seni adalah sedimen berukuran pasir dengan kandungan mineral berat yang tinggi seperti magnetit, hematit, limonit, sirkon, piroksen, dan ampibol. Bila akan dilakukan eksploitasi terhadap sedimen jenis pasir baik di laut maupun di pantai, harus memperhatikan kelestarian lingkungan. Kata kunci: analisis besar butir, mineral berat, sedimen permukaan dasar laut, sedimen pantai, Karang Asem

Depositional mode and Provenance of Kopili sandstones from parts of Dima Hasao District, Assam, NE India: Evidence from Grain size distribution and Heavy mineral assemblage

2021 ◽  
Vol 14 (12) ◽  
pp. 33-47
Author(s):  
Joya Moni Mout ◽  
Ranjan Kumar Sarmah
Keyword(s):  
Grain Size ◽  
Mineral Assemblage ◽  
Function Analysis ◽  
Heavy Mineral ◽  
Mineral Analysis ◽  
Statistical Parameters ◽  
Linear Discriminant ◽  
Fine Grained ◽  
Ne India ◽  
Heavy Mineral Analysis

This study presents a record of the depositional mode and provenance of the Kopili sandstones outcropped in and around Umrangso, the Dima Hasao district of Assam, India using proxies such as grain size and heavy mineral study. The Grain size study reveals that the sandstones of the Kopili formation consist predominantly of fine-grained sands mixed with medium sands. The grain size statistical parameters divulge that the sandstones are characterized mostly by moderately sorted sands, coarse skewed to near symmetrical, leptokurtic to extremely leptokurtic nature. The frequency distribution curves reflect mostly bimodal as well as polymodal distribution of sediments. The Linear Discriminant Function analysis indicates shallow marine beach sub environment in agitated water depositional condition for the Kopili sediments. The CM pattern discloses that saltation and suspension are the dominant transporting modes. The Heavy mineral analysis discerns that opaques dominate over transparent heavies. Transparent heavies in decreasing order of abundance are zircon, tourmaline, rutile, clinopyroxene, staurolite, hornblende, garnet, chlorite and epidote. The zircontourmaline- rutile (ZTR) maturity index (average 53.15%) discloses sub-mature to mature nature of the Kopili sandstones. The heavy mineral assemblage corroborates their mixed provenance (silicic igneous and metamorphic) for the Kopili sandstones.

Characteristics of heavy minerals and grain size of surface sediments on the continental shelf of Prydz Bay: implications for sediment provenance

2015 ◽  
Vol 28 (2) ◽  
pp. 103-114 ◽  
Author(s):  
Haozhuang Wang ◽  
Zhihua Chen ◽  
Kunshan Wang ◽  
Helin Liu ◽  
Zheng Tang ◽  
...  
Keyword(s):  
Grain Size ◽  
Continental Shelf ◽  
Mineral Composition ◽  
Water Depth ◽  
Surface Sediments ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Prydz Bay ◽  
Ice Shelf ◽  
Amery Ice Shelf

AbstractData on grain size and heavy mineral composition for surface sediments on the Prydz Bay continental shelf was analysed to identify sediment features and provenance. The grain size composition of surface sediments indicate spatial variations in the glaciomarine environment and the key factors influencing sedimentation, which on the shelf include topography/water depth, currents and icebergs. The study area was divided into two sections by Q-type factor analysis: section I included Prydz Channel, Amery Basin and Svenner Channel, and section II included Four Ladies Bank, Fram Bank and the area in front of the Amery Ice Shelf. Sedimentation in section I is mainly controlled by currents and topography/water depth. However, in section II, icebergs/floating ice masses, the Amery Ice Shelf and currents have prominent effects on sedimentation. The heavy mineral composition indicates that surface sediments on the eastern side of the bay, including Four Ladies Bank, are primarily derived from Princess Elizabeth Land. Sediments in the area in front of the Amery Ice Shelf, Svenner Channel, Amery Basin and Prydz Channel have a mixed source from the eastern regions around the bay, including the Prince Charles Mountains and Princess Elizabeth Land. The contribution from Mac. Robertson Land to sediment at Fram Bank is limited.

scholarly journals Gravimetric Separation of Heavy Minerals in Sediments and Rocks

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 273 ◽  
Author(s):  
Sergio Andò
Keyword(s):  
Grain Size ◽  
Size Range ◽  
Classical Method ◽  
Bulk Sample ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Practical Reasons ◽  
Provenance Analysis ◽  
Geological Research

The potential of heavy minerals studies in provenance analysis can be enhanced conspicuously by using a state-of-the-art protocol for sample preparation in the laboratory, which represents the first fundamental step of any geological research. The classical method of gravimetric separation is based on the properties of detrital minerals, principally their grain size and density, and its efficiency depends on the procedure followed and on the technical skills of the operator. Heavy-mineral studies in the past have been traditionally focused on the sand fraction, generally choosing a narrow grain-size window for analysis, an approach that is bound to introduce a serious bias by neglecting a large, and sometimes very large, part of the heavy-mineral spectrum present in the sample. In order to minimize bias, not only the largest possible size range in each sample should be considered, but also, the same quantitative analytical methods should be applied to the largest possible grain-size range occurring in the sediment system down to 5 μm or less, thus including suspended load in rivers, loess deposits, and shallow to deep-marine muds. Wherever the bulk sample cannot be used for practical reasons, we need to routinely analyze the medium silt to medium sand range (15–500 μm) for sand and the fine silt to sand range (5–63 or > 63 μm) for silt. This article is conceived as a practical handbook dedicated specifically to Master and PhD students at the beginning of their heavy-mineral apprenticeship, as to more expert operators from the industry and academy to help improving the quality of heavy-mineral separation for any possible field of application.

scholarly journals Anomalous radioactivity level and high concentrations of heavy minerals in Lemme area, South-West Estonia

Baltica ◽  
2014 ◽  
Vol 27 (2) ◽  
pp. 93-104 ◽  
Author(s):  
Anto Raukas ◽  
Rein Koch ◽  
Krista Jüriado ◽  
Johanna-Iisebel Järvelill
Keyword(s):  
Heavy Mineral ◽  
Heavy Minerals ◽  
Radiocarbon Dates ◽  
Radioactivity Level ◽  
Near Shore ◽  
Buried Soil ◽  
High Concentrations ◽  
The 1960S ◽  
The Baltic ◽  
Mineral Concentrations

Abstract As early as in the 1960s, extensive heavy-mineral concentrations containing zircon, monazite, and xenotime were discovered in the Lemme region of south-western Estonia. These concentrations contribute to the elevated radioactivity levels of the enclosing sediments. The near shore sands of the Litorina Sea contain up to 10-cm-thick interlayers with a heavy mineral content of up to 80%. These anomalous layers were formed during the transgressive phase and result from a complicated cross- and alongshore migration of sedimentary material, derived mainly from local Devonian bedrock. Radioactivity level in the study area is higher relative to the majority of the Devonian plateau. The Lemmeoja buried soil has 13 radiocarbon dates in an area of renewed interest for the investigation of the Baltic Sea history.

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