Multiple grain-size fraction analysis of heavy minerals and the provenance identification of sediments from the abandoned Huanghe River,eastern China

The quantitative analysis of sediment sources in a sink is an important scientific topic and challenge in provenance research.The characteristics of heavy minerals,combined with the geochemical constituents of detrital grains,provide a reliable provenance-tracing approach.We developed a mineral identification method to analyze the multiple grain-size fraction of sediments,from which the elemental geochemistry of hornblende was used to compare the characteristics of sediments from the Huaihe River and Huanghe(Yellow)River in eastern China.Elements that were statistically identified as being able to discriminate sediment provenance were employed to perform a quantitative analysis of the sources of sediments of the abandoned Huanghe River.Results reveal that the Huaihe River is characterized by a high amphibole content of>60%and that the Huanghe and abandoned Huanghe rivers have greater abundances of limonite and carbonate minerals compared with those of the Huaihe River.The contents of trace elements and rare earth elements in hornblende show that the sediments of the abandoned Huanghe River are similar to those of the Huanghe River but different from those of the Huaihe River.Furthermore,chemical mass balance was used to calculate the relative contributions of different provenances of sediment from the abandoned Huanghe River,and nine trace elements of hornblende were identified as discriminators of provenance.Approximately 2%of the hornblende in the abandoned Huanghe River is derived from the Huaihe River and 98%from the Huanghe River.Considering the proportion of hornblende in the total sediment,it is inferred that the contribution of Huaihe River sediment to the abandoned Huanghe River is approximately 0.5%.This study shows that mineral analysis using multiple grain-size fractions(within the wide range of 1Φto 6Φ)with assessment in elemental geochemistry of hornblende can characterize the provenance of fluvial material in coastal zones.

A heavy mineral viewpoint on sediment provenance and environment in the Qiongdongnan Basin

Based on heavy mineral data in core samples from eleven drillings, supplemented by paleontological, element geochemical and seismic data, the evolution of sediment provenance and environment in the Qiongdongnan Basin （QDNB） was analysed. The results show that the basement in the QDNB was predominantly composed of terrigenous sediments. Since the Oligocene the QDNB has gradually undergone transgressions and evolution processes in sedimentary environment from terrestrial-marine transitional to littoral-neritic, neritic, and bathyal roughly. The water depth showed a gradually increasing trend and was generally greater in the southern region than that in the northern region in the same time. With changes in sedimentary environment, provenances of the strata （from the Yacheng Formation to the Yinggehai Formation） showed principal characteristics of multi-sources, evolving from autochthonous source, short source to distant source step by step. During the Early Oligocene, the sediments were mainly proximal basaltic pyroclastic source and adjacent terrigenous clastic source, afterwards were becoming distant terrigenous clastic sources, including Hainan Island on the north, Yongle Uplift on the south, Shenhu Uplift on the northeast, the Red River System on the northwest and Indochina Peninsula on the southwest, or even a wider region. The Hainan Island provenance began to develop during the Early Oligocene and has become a main provenance in the QDNB since the Middle Miocene. The provenances from Yongle Uplift and Shenhu Uplift most developed from the Late Oligocene to the Early Miocene and gradually subsided during the Middle Miocene. During the Late Miocene, as a main source of sediments filled in the central canyon, the Red River System provenance added to the QDNB massively, whose impact terminated at the end of the Pliocene. The western Yinggehai Basin （YGHB） provenance derived from Indochina Peninsula had developed from the Pliocene on to the Pleistocene. In addition, the material contribution of marine authigenous source to the basin （especially to the southern region） could not be ignored.

Mineralogical Characterization of Heavy Mineral Concentrates from Senegalese Great Cost by Using Qemscan and SEM

The heavy mineral sands of Senegal are exploited to extract titanium oxides and zircon. Mining is carried out first by means of a floating dredge and concentration plant which produces a heavy mineral concentrate (HMC) containing on average 78% titanium oxides, 11% zircon and a set of silicate and alumino-silicate minerals. This heavy mineral concentrate is then treated by gravity, magnetic and electrostatic separation to produce titanium oxide concentrates (ilmenite, leucoxene, rutile) and three varieties of zircon concentrates (Premium zircon, standard zircon and medium grade zircon standard). In this study, we describe the various mineral concentrates in terms of mineralogical assemblages, and textural variability within grains, using Qemscan and Scanning Electron Microscopy. The titanium oxide concentrates are differentiated by their TiO2 content and vary from ilmenite to rutile. The zircon concentrates are characterized by the presence of impurities in the zircons, which consist in numerous inclusions of titanium oxides and silicate minerals. The mineralogical characteristics determined by scanning electron microscopy and by Qemscan showed great variability within the grains themselves. Heavy minerals contain many mineral inclusions and show strong chemical zoning.

Monazite Recovery by Magnetic and Gravity Separation of Medium Grade Zircon Concentrate from Senegalese Heavy Mineral Sands Deposit

Gravity, magnetic and electrostatic separation methods allowed to obtain different titanium oxide concentrates (ilmenite, leucoxene, rutile) and different varieties of zircon concentrates (premium zircon, standard zircon, medium grade zircon standard) from Senegal’s heavy mineral sands. During mining separation, monazite, which is a paramagnetic mineral, was found in a non-negligible concentration of 0.57 wt% on average in the medium grade zircon standard which also contains 37.96 wt% zircon and 44.46 wt% titanium oxides. Magnetic and gravity separation tests were carried out on the Medium grade zircon standard (MGZS) to produce a monazite concentrate at Eramet Ideas laboratory. Magnetic separation at 1.5 teslas intensity resulted in the recovery of 94.8% of the monazite from the MGZS. Gravity separation also recovered 76.6% of the monazite from the MGZS. The combination of these two treatment methods can thus produce three concentrates from MGZS (a monazite concentrate, a zircon concentrate, and a titanium oxide concentrate).

Sediment Characteristics, Sources, and Transport Patterns in Kompong Som Bay, Cambodia: Indications from Grain Size and Heavy Minerals

In this paper, we analyzed the grain size and heavy mineral compositions of 52 surface sediment samples collected from the Kompong Som Bay of Cambodia and the adjacent rivers to depict the marine sedimentary environments and transport processes. Heavy minerals in sediments are dominated by authigenic pyrite, siderite, and tourmaline, with average percentages of 36.52%, 29.02%, and 10.94%, respectively. Two provinces can be divided according to the spatial similarity of minerals. The sediments from Province I, covered by silt grains in the northern bay, are characterized by autogenic pyrite, indicating a weakly reducing environment;whereas in Province II, covered by sand grains in the southern bay, the siderite-tourmaline-authigenic pyrite-zircon-hornblende assemblage occurs, indicating a mild reducing environment and locally oxidizing environment. Most of the sediments in the Kompong Som Bay are introduced from the Preak Piphot River and Srae Ambel River, except that some of them in the south areas come from coastal erosion. Generally, the sediments are difficult to be transported because of the low sediment loads entering the sea and weak hydrodynamic conditions. However, they are transported from the north to the south during the tide ebbing when the hydrodynamic force is much stronger. The sediment distribution and transport patterns are controlled by many factors, including submarine topography, hydrodynamic conditions, the southwest monsoon, land contours, and sediment supply.

MATHEMATICAL STATISTICS OF HEAVY MINERALS AND THEIR REE AND TRACE ELEMENTS IN THE NORTHWESTERN SEA AREA OF ANTARCTIC PENINSULA

Based on the analysis and mathematical statistics of quantitative data on both the heavy minerals and their REE (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu), trace (Zr, Hf, Th, Ta, U, Rb, Sr, Zn, Co, Ni, Cr, As, Sc) and major (Fe) elements in the surface sediments in the northwestern sea area of Antarctic Peninsula, the authors find that the heavy minerals as the carriers of REE and trace elements should not be overlooked.Q-mode factor analysis of the heavy minerals provides a 3-factor model of the heavy mineral assemblages in the study area, which is mainly controlled by the origin of materials and sea currents. The common factor P1, composed mainly of pyroxene and metal minerals, and common factor P2, composed of hornblende, epidote and accessory minerals, represent two heavy mineral assemblages which are different from each other in both lithological characters and origin of materials. And common factor P3 probably results from mixing of two end members of the above-mentioned assemblages. R-mode group analysis of the heavy minerals indicates that there are two heavy mineral groups in the sea area, which are different from each other in both genesis and origin of materials. With the help of R-mode analysis, 22 elements are divided into 3 groups and 9 subgroups. These element assemblages show that they are genetically related and that they are different in geochemical behaviors during diagenesis and mineral-forming process. In addition, the relationship between the heavy mineral assemblages and the element subgroups is also discussed.

The Determination of Promising Mineral Zones in 1:100,000 Varamin Sheet Based on Geochemical Studies (Heavy Minerals)

In many parts of the world, data obtained from geochemical exploration of stream sediments are integrated with geological and geophysical data as one of the most efficient methods of exploring potential deposits at regional and semi-detailed scales. The aim of regional investigation is to study large areas to identify anomalies that might have been arisen from increased concentrations of an element or some elements in a region. A total of 78 geochemical samples were taken from Varamin sheet to identify regions of anomalies. The following information was used to perform a detailed geochemical exploration, in particular for geochemical sampling. 1) 1:100,000 geological map of Varamin. 2) 1:50,000 topographic maps of the region. 3) 1:100,000 airborne geophysical map of the region to locate shallow intrusions and hidden faults. The sampling network was designed using the above data and the analysis of 1:500,000 topographic maps. The sampling density was higher around faults and apparent and hidden intrusions, and lower in plains and lowlands.

Heavy Minerals in Sands along Brahmaputra (Jamuna) River of Bangladesh

Sands along Brahmaputra River of Bangladesh have long been considered to be a source of heavy minerals (HMs) since it traversed a long way through various terrains. An attempt has been made under this research work to determine the kinds and amounts of heavy minerals in the sands sourced from the river system. Samples from 14 locations along Brahmaputra River covering 30 km distance from upstream to downstream of the river are found to contain different heavy minerals concentration with a range of 7.92 - 25.16 weight% with the remaining of the sample comprising silicate and aluminosilicates. Mineral characterization from peak positions in diffractogram of X-ray Diffraction (XRD) evaluate quartz, feldspar and mica are major categories light mineral while rutile, magnetite, illmenite, zircon, monazite, garnet, uranium arsenide and uranium fluoride are the major types heavy minerals. Ilmenite and rutile are main contributors of total heavy mineral (THM). Titanium bearing minerals ilmenite and rutile contributes 26.22% - 31.01% and 14.57% - 23.50% of THM. In the present study area, most of the sands are found to be fine and medium grained as obtained from the particle sizes analysis using 18- to 230-mesh.

Heavy Minerals in Sands along Brahmaputra (Jamuna) River of Bangladesh

Sands along Brahmaputra River of Bangladesh have long been considered to be a source of heavy minerals (HMs) since it traversed a long way through various terrains. An attempt has been made under this research work to determine the kinds and amounts of heavy minerals in the sands sourced from the river system. Samples from 14 locations along Brahmaputra River covering 30 km distance from upstream to downstream of the river are found to contain different heavy minerals concentration with a range of 7.92 - 25.16 weight% with the remaining of the sample comprising silicate and aluminosilicates. Mineral characterization from peak positions in diffractogram of X-ray Diffraction (XRD) evaluate quartz, feldspar and mica are major categories light mineral while rutile, magnetite, illmenite, zircon, monazite, garnet, uranium arsenide and uranium fluoride are the major types heavy minerals. Ilmenite and rutile are main contributors of total heavy mineral (THM). Titanium bearing minerals ilmenite and rutile contributes 26.22% - 31.01% and 14.57% - 23.50% of THM. In the present study area, most of the sands are found to be fine and medium grained as obtained from the particle sizes analysis using 18- to 230-mesh.

Recovery of Total Heavy Minerals from Badlands of Basanputti Village,Odisha

The badland topography of Basanputti Village, Ganjam District, Odisha, possesses red sediments. The typical red sediment deposit, on average, consists of 71.8% total heavy minerals （THM）, out of which 62.1% are ilmenite. The other heavy minerals sillimanite, zircon, garnet, monazite, and pyriboles are in the order of abundance identified. In this present study, Mozley mineral separator has been used to recover THM from red sediment. Mineral separator results indicate that a product ob- tained contains 72.2% by weight with 94.4% THM and 95% recovery. The ilmenite concentrate recov- ered using dry low-intensity magnetic separator from the THM concentrate can be used in pigment in- dustries after suitable pyrometallurgical/chemical processing methods.

Geochemical Orientation Study of Stream Sediment Samples in the Southern Part of Nuggihalli Schist Belt: Ore Mineral Phases and Their Implications on the Bedrock Potential for Ores

Stream sediment sampling is a significant tool in geochemical exploration. The stream sediment composition reflects the bedrock geology, overburden cover, and metalliferous mineralization. This research article focuses on assessing selected trace element concentrations in stream sediments and interpreting their inter-element relationships using multivariate statistical methods. Tagadur Ranganathaswamy Gudda and its surroundings in the Nuggihalli schist belt of southern India have been investigated in the present work. The geology of the study area is complex, with a diverse range of litho units and evidence of strong structural deformation. The area is known for its mineralization potential for chromite, vanadiferous titanomagnetite, and sulfides. The topography of the region is characterized by an undulating terrain with a radial drainage pattern. Most part of the schist belt is soil covered except the Tagadur Ranganathaswamy Gudda area. For this study, a discrete stream sediment sampling method was adopted to collect the samples. Stream sediment samples were collected using a discrete sampling method and analyzed for trace elements using an ICP-AES spectrophotometer: Fe, Cr, Ti, V, Cu, Ni, Zn, Pb, Mn, Cd, and As have been analyzed. The analytical data were statistically treated using the SPSS software, including descriptive statistics, normalization of data using natural log transformation, and factor analysis with varimax rotation. The transformed data showed a log-normal distribution, indicating the presence of geochemical anomalies. The results of the study provide valuable insights into the geochemical processes and mineralization potential of the study area. The statistical analysis helps in understanding the inter-element relationships and identifying element groups and their implications on bedrock potential mineralization. Additionally, spatial analysis using inverse distance weighting interpolation provides information about the distribution of geochemical parameters across the study area. Overall, this research contributes to the understanding of stream sediment geochemistry and its application in mineral exploration. The findings have implications for future exploration efforts and can aid in the identification of potential ore deposits in the Nuggihalli schist belt and similar geological settings.

In vivo and in vitro inductively coupled plasma mass spectrometry quantification of minerals and heavy metals in Qishiwei Zhenzhu pill and their effect on intestinal flora

OBJECTIVE Cerebral ischemia or ischemic stroke is due to insufficient blood supply to the brain,which causes hypoxia or ischemia in some areas.This work aimed to quantify the minerals and heavy metals in Qishiwei Zhenzhu pill in vivo and in vitro,analyze its effect on the types and abundance of intestinal flora,and study its mechanism on inflammation and apoptosis pathways as a treatment for cerebral ischemia.METHODS Microwave digestion and inductively coupled plasma mass spectrometry(ICP-MS)were used to determine the minerals and heavy metals in 10 batches of Qishiwei Zhenzhu pill in vitro.With the use of the middle cerebral artery obstruction(MCAO)model,ICP-MS was applied to determine the content of minerals and heavy metals in hepatic portal vein blood,abdominal aortic blood,brain,liver,kidney,hair,urine and feces at different time periods.On this model,the ileum,cecum,and colon tissues were tested for intestinal pathology,and 16S rRNA was used for sequencing.Species taxonomy,αdiversity,and species microbial composition and structure analysis were also performed.Polymerase chain reaction and Western blotting were employed to determine the mRNA and protein expression of p38 MAPK,caspase-3,IL^(-1)βand TNF-αin the ischemic brain tissues of rats.RESULTS The average content of heavy metals in the 10 batches of Qishiwei Zhenzhu pill samples is in the descending order Hg>Cu>Pb.Significant differences in the metal elements are found among Qishiwei Zhenzhu pill from different manufacturers but not among the different batches of the same manufacturer.An extremely low content of heavy metals are absorbed into the blood or accumulated in the brain,liver,kidney,and other tissues.Stool is the main excretion route of minerals and heavy metals from Qishiwei Zhenzhu pill.This medicine helps repair the intestinal mucosa in MCAO rats.At the phylum level,it can regulate the abundance of Firmicutes and Proteobacteria in the intestinal flora of rats with cerebral ischemia.At the genus level,it can adjust the abundance of Escherichia Shigella.At the species level,it can adjust the abundance of Lactobacillus yoelii and Lactobacillus reuteri.Cluster classification results show that Qishiwei Zhenzhu pill can improve the intestinal flora of rats with cerebral ischemia,reduce the mRNA and protein expression of caspase-3 and IL^(-1)βin rat brain tissues,and have a tendency to decrease the mRNA expression of p38 MAPK and TNF-α.CONCLUSION Quantifying the minerals and heavy metals in Qishiwei Zhenzhu pill in vivo and in vitro will help improve their quality standards.Minerals and heavy metals are mainly excreted in feces,accumulate in extremely low levels in various tissues,and do not damage the intestinal mucosa.The effective material basis of Qishiwei Zhenzhu pill in treating cerebral ischemia may be related to their Li,Cr,and Cd elements.These pills can improve the environment of intestinal flora,and their mechanism of treatment for cerebral ischemia may be related to the down-regulation of IL^(-1)βinflammatory factor and inhibition of cell apoptosis.

Analysis Method and Application of Multiple Antiquities Sources in the Shahejie Formation of the Paleogene in the Southern Bohai Sea

B Oilfield is the most representative mid to deep oil field in the Bohai Sea, with the main oil bearing intervals being the upper and middle Shahejie-3 sections of the Paleogene Shahejie Formation. Through the development of ancient landforms, characterization of material source channels, analysis of missing heavy mineral sources, and seismic reflection characteristics of multiple material source missing, the material sources of the middle and upper Shahejie-3 sections are analyzed. During the sedimentation period of the II oil formation in the middle section of the Shasan Formation, the study area was mainly dominated by the Kendong Uplift source rocks;During the sedimentation period of the I oil formation in the middle section of the Shasan Formation, there were three material sources in the study area, namely the Kendong Uplift, the Laibei Low Uplift, and the Weibei Uplift. The Kendong Uplift was the main material source, followed by the Laibei Low Uplift;During the sedimentation period of the Upper Shasan Formation, the study area still had three sources of material supply simultaneously. At this time, the Laibei Low Uplift was the main source area, while the Kendong Uplift and Weibei Uplift had a relatively small supply capacity for the study area. In the analysis of archaeological sources, the distribution characteristics of the sedimentary system in the third section of the Shahejie Formation have been clarified, providing a research basis for the later development and adjustment of the oilfield.

Characteristics and provenance implication of detrital minerals since Marine Isotope Stage 3 in Core SYS-0701 in the western South Huanghai Sea

The previous studies of the sedimentology and chronology of sediment core SYS-0701, which was recovered from the western South Huanghai Sea （Yellow Sea）, have revealed the changes in the sea-level and sedimen- tary evolution during the late Quaternary in the region. The present study used mineralogical data from the section of the core deposited since Marine Isotope Stage （MIS） 3, to decipher the provenance of sediments of the paleo-delta deposited during MIS 3 and MIS 1. Based on the lithologic features and the variations with depth of the concentrations of carbonates and both heavy and light minerals in bulk samples, the up- per part of Core SYS-0701 can be divided into three units designated DU1, DU4, and DU5, in accord with previouslyused terminology. Sub-units of units DU1 （DU1-1 and DU1-2） and DU4 （DU4-1 and DU4-2） have also been identified. DU1 was deposited during MIS 1, and DIJ4 and DU 5 were formed during MIS 3. All data pertaining to dominant heavy mineral assemblages, diagnostic minerals, ratios of diagnostic minerals, light mineral associations, textural maturities, and carbonate contents, indicate that the sediments of Core SYS-0701 are comparable with Huanghe River （Yellow River） sediments. Moreover, the mineralogy of the sediment evidenced its dependence on supply rates and hydrodynamic conditions. Weak hydrodynamics （DU5 and DU4-2） and/or low sediment supply （DU1-2） led to sediment containing less hornblende and epidote, with a large specific gravity and high content of flaky minerals, and vice versa in cases of strong hydrodynamics （DIJ4-1） and very large sediment supply （DUI-1）.

Mineralogy and geochemistry of sands of the lower course of the Sanaga River, Cameroon: implications for weathering,provenance, and tectonic setting

This study focuses on the mineralogy and bulk chemical composition of 19 sediment samples,collected from the Sanaga River bed,between Nanga-Eboko and the Atlantic Ocean in Cameroon,to infer provenance,weathering,and tectonic setting.The textural analysis revealed that these sediments are mainly coarse-grained sands.X-ray diffraction and heavy mineral analyses show that these sands are made of quartz,microcline,plagioclase,muscovite,ilmenite,anatase,magnetite,opaques,and epidote.The Index of Chemical Variability values(1.07–2.68)indicates that the sands are immature.The Chemical Index of Alteration(53–66%),Plagioclase Index of Alteration(PIA;57–75%),and Mafic Index of Alteration(54–67%)values revealed a moderate intensity of weathering for these sediments.According to the compositional maturity diagram,the sands are mainly litharenites.The studied sands show enrichment in light rare earth elements relative to heavy rare earth elements and a negative anomaly in Eu(Eu/Eu*=0.32–0.83).These sands were derived from felsic metamorphic rocks dated Meso to Neoproterozoic from the Pan-African(700–1000 Ma)domain of south Cameroon.Th/U ratios(mean=5.40;n=19)reveal that these sands originating from felsic source rocks and are low to moderately recycled.On the tectonic discrimination diagrams,all the samples are plotted in the rift and passive margin domains,which is consistent with the tectonic history of Pan African in southern Cameroon.

The Mamfe Basin in the southern Benue trough extension between Cameroon and Nigeria:Gem origin and problem of lithostratigraphic nomenclature and marine transgression

The Mamfe Basin has been the subject of many studies,but some debates persist,especially concerning the stratigraphic nomenclature,corundum origin,and marine transgression.The aims of this work are(1)to propose a new lithostratigraphic nomenclature of the Mamfe Basin formation based on new field observations,(2)to determine the source rock distribution and the origin of gem deposits and(3)to correlate the Cameroon section of the Mamfe Basin with the Nigerian deposits.The main results show that the name Manyu River Group is more appropriate as the Manyu River crosses all the facies in the Mamfe sedimentary Basin belonging to the Manyu Division.According to the facies analysis,the age of deposition,the mineralogic and geochemical data such as the V vs.Al2O3andΣREE vs.Al_(2)O_(3),TiO_(2)MgO,Na_(2)O,P_(2)O_(5),and CaO diagrams,this Group is composed of at least five Formations,including four Cretaceous Formations,from bottom to top:the Etoko Formation(alluvial and fluvial channel to fluvio-lacustrine deposits),the Nfaitok Formation(lagoonal deposits),the Bachuo Ntai Formation(fluvial braided channels or fluvio-deltaic environment)and the Eyumojock/NsanaragatiFormation(fluvio-lacustrine deposits)and the new Cenozoic Formation named Bakebe Formation(fluvio-lacustrine deposits).The gem minerals such as corundum,rutile,or tourmaline in the Cretaceous deposits of the Mamfe Basin are mainly detrital as indicated by the presence of worn shapes and fragments of these minerals.The presence of sapphire in the AlboCenomanian deposits indicates a Precambrian age of the felsic source rock,likely the plutonic rocks such as granite or pegmatite as indicated by the abundance of tourmaline and high LREE/HREE ratios(14.81–34.29)and slightly negative and positive Eu anomalies(0.85–1.15).This marine incursion in the Mamfe Basin was probably from West Nigeria,according to the geographic location of the Mamfe Basin and the general palaeogeographic evolution of the Benue Trough.

Sequence structure, sedimentary evolution and their controlling factors of the Jurassic Lianggaoshan Formation in the East Sichuan Basin, SW China

Based on the data of outcrops, seismic sections, thin sections, heavy mineral assemblages and detrital zircon U-Pb dating, the sedimentary characteristics, lake level fluctuation and provenance characteristics of the Middle Jurassic Lianggaoshan Formation(J_(2)l) in eastern Sichuan Basin, SW China, were investigated to reveal the control of tectonic movements of the surrounding orogenic belts on the sedimentary systems. The J_(2)lmainly developed a delta–lake sedimentary system, which contained a complete third-order sequence that was subdivided into four lake level up-down cycles(fourth-order sequence).The lake basins of cycles Ⅰ and Ⅱ were mainly distributed in eastern Sichuan Basin, while the lake basins of cycles Ⅲ and Ⅳ migrated to central Sichuan Basin, resulting in the significant difference in sedimentary characteristics between the north and the south of eastern Sichuan Basin. The provenance analysis shows that there were three types of provenances for J_(2)l. Specifically, the parent rocks of Type Ⅰ were mainly acidic igneous rocks and from the proximal northern margin of the Yangtze Plate;the parent rocks of Type Ⅱ were intermediate-acid igneous rocks and metamorphic rocks and from the central parts of the southern and northern Qinling orogenic belts;the parent rocks of Type Ⅲ were mainly metamorphic rocks followed by intermediate–acid igneous rocks, and from the North Daba Mountain area. It is recognized from the changes of sedimentary system and provenance characteristics that the sedimentary evolution of J_(2)lin eastern Sichuan Basin was controlled by the tectonic compression of the Qinling orogenic belt. In the early stage, the lake basin was restricted to the east of the study area, and Type Ⅰ provenance was dominant. With the intensifying north-south compression of the Qinling orogenic belt, the lake basin expanded rapidly and migrated northward, and the supply of Type Ⅱ provenance increased. In the middle and late stages, the uplift of the North Daba Mountain led to the lake basin migration and the gradual increase in the supply of Type Ⅲ provenance.

The Sedimentary Record in Northern Qaidam Basin and its Response to the Uplift of the South Qilian Mountain at around 30 Ma

The thick, Eocene to Pliocene, sedimentary sequence in Qaidam Basin at the northern margin of the Tibetan Plateau records the surface uplift history of the northeastern Tibetan plateau. In this study, we present detailed geochemistry, heavy mineral, and clay mineralogy data of the well preserved sedimentary record in the Dahongou section in the northeast of the Qaidam Basin. The results suggest that the sedimentary sequence recorded a 30 Ma young uplift/unroofing event in the northern edge of the Qaidam Basin, which is characterized by high ZTR index value and chlorite content, and low CIW＇. The results are consistent with previous sedimentological studies of the Qaidam Basin, which indicated rapid increase of the accumulation rates around 30 Ma. Based on past thermochronological data from the mountains around the Qaidam Basin and the accumulation rates of the Cenozoic basins in the northeastern Tibetan Plateau, we infer a regional uplift and denudation event along the northeastern Tibetan Plateau during early Oligocene （-30 Ma）, indicating that the Tibetan Plateau had expanded north-eastward of the study area at that time.

Tectonics induced switching of provenance during the Late Quaternary aggradation of the Indus River Valley, Ladakh, India

The Indus River flows through Ladakh, one of the driest and coldest places on earth, in a tectonically active domain. Fluvial, glaciofluvial, lacustrine and debris dominated sequences represent the Late Quaternary sedimentary record along the river course. Karakoram Fault, a major crustal scaled feature reported to be active during the Quaternary, is associated with the Indus River drainage. Linkages between a major, active fault and deposits formed during the activity period of the fault are explored using heavy mineral deduced provenance and Optically Stimulated Luminescence(OSL) chronology.Five deposits in a ~200 km long stretch of the Indus River have been examined for a ~80 ka period to decipher the climate linked aggradation history. Damming of the Indus River at ~79 ka and existence of the Spituk Lake for >30 ka is demonstrated. Using geology of the provenance in relation to the mineralogical attributes of the Quaternary deposits, the major drainage reorganization when the connection of the Tangtse Valley to the Indus was blocked, is inferred at ~73 ka. It is supported by the geologicalgeomorphological evidence. The study demonstrates the application of provenance linked mineralogy in terrestrial aggradation in a tectonically active region.

Sedimentological Characterization of Alluvial Gold Deposits of Betrare-Oya and Its Surroundings (Cameroon Eastern Region)

Sedimentological methods such as granulometry, morphoscopy and heavy minerals analysis have been carried out to characterize alluvial gold deposits of Betare-Oya and its surroundings, with the aim to determine their origin and conditions in which they are formed and also to determine the mineralogical content of these deposits, their nature and distribution. It came out from this study the following: The alluvial deposits studied are sand, constituting of coarse fraction (grains), medium grains in abundant and fine grains. The average values of sorting index (S0) and coefficient of asymmetry (A) are respectively 2.53 and 0.73. These values indicate that the sand is poorly arranged and poorly sorted with a better classification or arrangement in the coarse fraction (grains). These are sediments that are deposited together by high competent currents. It would therefore probably be torrential deposits and or streams from short transport. Unused grains are dominating (80.5%) which translate a proximal source of the sediments. So it would be probably from the dismantling of the surrounding landforms. The heavy minerals studied revealed the presence of the following minerals;zircon, gold, sphene, green hornblende, tourmaline, rutile, augite, hypersthene, sillimanite, glau-cophane, biotite, staurotide, and the opaque. These minerals belong to the cortege of plutonic and metamorphic rocks from a single proximal distributing province.