Mesozoic-Cenozoic thermal history of Turpan-Hami Basin: apatite fission track constraints

Apatite fission track dating is carried out on nine samples collected from the central part (Lianmuqin section) and from both northern and southern margins of Turpan-Hami Basin. The fission-track ages of seven Jurassic samples are distinctly younger than depositional ages. In contrast, the fission-track ages of two Cretaceous samples are older than, or as old as depositional ages. These observations indicate that the Jurassic samples have been annealed or partially annealed, whereas the Cretaceous samples have not been annealed.The further thermal modelling results show that Turpan-Hami Basin experienced a Late Cretaceous period (120-100 Ma) of tectonic uplift with rapid cooling and exhumation of sediments. The samples underwent a Cenozoic period of reburial and re-heating and were exhumed again at 10-8 Ma.     

Late Cretaceous-Cenozoic exhumation history of Tiantangzhai region of Dabieshan Orogen： Constraints from （U-Th）／He and fission track analysis

Integrated fission track and (U-Th)/He analysis is carried out on 6 apatite and 6 zircon samples from a near vertical section in The Tiantangzhai region at the core of the present Dabieshan orogen. The result shows that the region experienced cooling/exhumation during the Late Cretaceousand Early Tertiary period. Age-elevation relationships for different dating systems and different minerals suggest a pulse of rapid exhumation at ～110 Ma before present, preserved in the structurally highest samples. At lower elevations, ages begin to decrease with decreasing elevation, suggesting lower exhumation rates since 90 Ma. Two periods of different exhumation rates are identified since 90 Ma. The average apparent exhumation rate for the period of 43.4—22.5 is 0.062 km/Ma, whereas that for the period of 76.4—47.4 Ma is 0.039 km/Ma.     

New evidence Ⅱ for MDD model of thermal evolution history of Gangdese batholith

The cooling curves are obtained using specific 40Ar/39Ar stage heating procedure and MDD modeling. In addition to the results of dating hornblende (K-Ar) and apatite (FT), the widespread existence of rapid cooling events has further been confirmed. A new knowledge of the starting time of Gangdese overthrust faulting in the east of Zedang, which was earlier in south and later in north is acquired.     

The age of Xiannü Mountain fracture belt in Three-Gorge region——A fission track study

Apatite was separated from fault-clay, fracture-cliff rock and fracture wall rock, which were collected from Huangkou fracture north to Xiannu Mountain lying 20 km southwest to Three Gorges Dam Project-Sandouping dam. The fission tract characters and their length variations of apatite show that Xiannu Mountain fracture belt was formed at (0.7 ± 0.04)Ma, but its wall rock at (25.31 ±2.8) Ma. This result and previous studies show that no activity has happened since the Holocene, and the Three Gorges Dam Project is not affected by activity of the Xiannu Mountain fracture belt.     

Zircon (U-Th)/He thermochronological constraints on Cretaceous thermal extension of Dabieshan orogen

：(U-Th)/He ages of 13 samples from Yuexi-Luotian core and its flanks in Dabieshan orogen fall in the range of 155～85 Ma. He ages for samples from the core range between 85～107 Ma, while those from the flanks range between 114～155 Ma. The result shows that the Yuexi-Luotian core was a thermal dome in Cretaceous with core temperature being much higher than those of the flanks. The thermal extension which resulted in the formation of Dabie core complex lasted until ca. 85 Ma. The magnitude of exhumation in the core is approximately 1528.8 m more than that in the flanks.     

Origin of Gymnocypris przewalskii and phylogenetic history of Gymnocypris eckloni (Teleostei: Cyprinidae)

The origins and phylogenetic patterns were assessed for G. przewalskii and G. eckloni by analyzing the complete mtDNA cytochrome b gene sequence (1140bp). Phylogenetic analyses further supported that there were three mtDNA lineages (A-C) identified in G. przewalskii and G. eckloni, demonstrating that outer rakers of the first gill have little significance in the phylogeny of the Gymnocypris fishes. The network established showed that G . eckloni of the Yellow River specific haplotype Al was a founder and it radiated all haplotypes of G. przewalskii which suggested G . przewalskii might only originate from one of two maternals of G . eckloni from the Yellow River. Fs test and mismatch analysis showed at least two expansion events in the population of G. przewalskii about 0.2734 Ma and 0.0658 Ma, while G. eckloni from Qaidam Basin could have experienced severe bottleneck effect about 0.0693 Ma. The population expansion was detected in subclades Al and A21 with the most recent common ancestor (TMRCA) about 0. 2308±0.01 Ma and 0.1319±0. 015 Ma, respectively, which were within the geological age range of "Gonghe Movement" event that caused the separation of Lake Qinghai from the upper Yellow River. These results suggested the effect of the fish diversification by rapid uplift of the Qing-hai-Tibetan Plateau in the Late Pleistocene.     

Origin of Gymnocypris przewalskii and phylogenetic history of Gymnocypris eckloni (Teleostei: Cyprinidae)

The origins and phylogenetic patterns were assessed for G. przewalskii and G. eckloni by analyzing the complete mtDNA cytochrome b gene sequence （1140bp）. Phylogenetic analyses further supported that there were three mtDNA lineages (A-C) identified in G. przewalskii and G. eckloni, demonstrating that outer rakers of the first gill have little significance in the phylogeny of the Gymnocypris fishes. The network established showed that G. eckloni of the Yellow River specific haplotype A1 was a founder and it radiated all haplotypes of G. przewalskii which suggested G. przewalskii might only originate from one of two maternals of G. eckloni from the Yellow River. Fs test and mismatch analysis showed at least two expansion events in the population of G. przewalskii about 0.2734 Ma and 0.0658 Ma, while G. eckloni from Qaidam Basin could have experienced severe bottleneck effect about 0.0693 Ma. The population expansion was detected in subclades A1 and A21 with the most recent common ancestor (TMRCA) about 0.2308±0.01 Ma and 0.1319±0.015 Ma, respectively, which were within the geological age range of “Gonghe Movement” event that caused the separation of Lake Qinghai from the upper Yellow River. These results suggested the effect of the fish diversification by rapid uplift of the Qinghai-Tibetan Plateau in the Late Pleistocene.     

Fission track age of granite batholith from Southern Tibet:implications for the plateau uplift

Fission track (FT) ages of apatite and zircon from four granite batholiths from Lhasa and Shannan areas are measured.The FT ages of apatite range from 3.2±8.3 Ma, corresponding to the uplift rates of 0.12±0.20 mm·a~(-1) during this period. The upliftheight is 580m, showing that there is not large-scale rapid uplifting in southern Tibet from 3.2 to 8.3 Ma. The zircon FT ages of Lhasabatholith are 25.9±1.7 and 32.7±2.8 Ma, yielding an uplift rate of 0.08 mm·a~(-1) between 26 and 33 Ma. Combining this work withother studies, it is suggested that the average uplift rate in southern Tibet is low from the time of collision between India and Asian conti-nents to ～3Ma. The uplift of Tibetan Plateau seems to have finished in multi-stage processes with varied rates.     

Opening of the Longmu Co–Shuanghu–Lancangjiang ocean:constraints from plagiogranites

This paper reports new zircon U-Pb ages,and Hf isotope and whole-rock major and trace element data for Cambrian plagiogranites from the Tuobeiling ophiolite in central Qiangtang,Tibetan Plateau.Zircon SIMS and LAICP-MS U-Pb dating of the plagiogranites yield weighted mean ages of 504.8±4.2 and 491.6±1.5 Ma,respectively.The zircons from plagiogranites exhibit positive eHf(t)values(ranging from 11.46 to 15.16),indicating that the plagiogranites are derived from depleted mantle.These plagiogranites are characterized by high SiO2and Na2O,low K2O,low REE contents,and flat REE distribution patterns.These rocks have geochemical compositions typical of oceanic plagiogranite and,considered along with their petrography and field relationships,are interpreted to have derived from anatexis of hydrated amphibolites by ductile shearing during transports of the oceanic crust.The formation age of such type of plagiogranite is slightly younger than that of the associated section of oceanic crust.Thus the new results from these plagiogranites suggest that the Longmu Co–Shuanghu–Lancangjiang ocean had probably opened before the Middle Cambrian.     

Diagnosis of prostate cancer by quantitative analysis of 3DMRSI data: A new model

Prostatecancer (PC)hasthehighestmorbidityrateinmaleurinarysystemdisordersinEuropeandAmerica ,anditisoneoftheprimaryreasonsofmaledeath[1] .InChina ,althoughtheattackofPCisrela tivelylow ,ithasa growingtrendinrecent 10years[2— 4 ] .Inclinicalpractice ,magneticresonanceimaging (MRI)could providehighresolutionmor phologicalstructureandhasthecapabilityofmulti parameterimaging ,butitcannotreliablydifferentiatePCfrombenignprostatehyperplasia (BPH)andnor maltissues ,particularlyforthepatientswi…     

Variation of the FeMn ratio of ferromanganese crusts from the Central North Pacific: implication for paleoclimate changes

Contents of Fe, Mn and other elements in four ferromanganese crusts recovered from the central North Pacific are analyzed at high depth-resolution by electron microprobe for reconstructing factors controlling their deposition. Manganese (IV) in hydrogenetic ferromanganese crusts is mainly supplied as colloidal precipitates from the Oxygen Minimum Zone (OMZ), which concentrates high amounts of dissolved Mn (II). The iron is derived from carbonate dissolution and silicate particles of eolian dust. An increase in paleoproductivity during cooler climate would potentially lead to a decrease in Mn deposition due to enlargement of the OMZ which has a “temporary storage” effect for Mn. On the other hand, not affected by the OMZ, the iron entering the Fe-Mn crust would likely increase with the eolian dust input and surface productivity at glacial stages. As a result, the increasing FeMn ratio should indicate a cooling climate. This is supported by the following observations. In the profile of the past 1 Ma, the variations of FeMn ratio coincide with benthic oxygen isotope fluctuation in glacial-interglacial cycles. Three episodes with high FeMn ratios, approximately at 2.6, 1.8 and 0.8 Ma, are detected within the past 3 Ma and coincide with major climate transitions and cooling events. The secular evolution pattern of FeMn ratio in the Cenozoic is similar to the Pb isotope evolution which is mainly controlled by eolian dust and related to climate. The FeMn evolution pattern is also broadly consistent with the global deep-sea oxygen isotope records. Therefore, FeMn ratio recorded in the ferromanganese crusts may be a new proxy for climate change.     

Zircon U–Pb and Hf isotopic study of Neoproterozoic granitic gneisses from the Alatage area,Xinjiang:constraints on the Precambrian crustal evolution in the Central Tianshan Block

The architecture and growth history of Precambrian crustal basements in the Central Tianshan Block play a key role in understanding the tectonic evolution of the Chinese Tianshan Orogenic Belt.In this study,we present precise LA-ICP-MS zircon U–Pb dating and LAMC-ICPMS zircon Hf isotopic data for two granitic gneisses from Alatage area in the Central Tianshan Block.The magmatic zircons from both samples yield similar protolith ages of 945±6 and 942±6 Ma,indicating that the early Neoproterozoic magmatism is prevailed in the Alatage area.These zircons have crustal Hf model ages of1.82–2.22 and 1.70–2.03 Ga,respectively,which are significantly older than their crystallization ages.It indicates that their parental magmas were derived from the reworking of ancient crust.However,we suggest that these Paleoproterozoic Hf model ages might result from mixing of continental materials with different ages in the Neoproterozoic crust.The inherited(detrital)zircon cores not only yield a wide age range of ca.989–1617 Ma,but also exhibit large Hf-isotope variations with Hf model ages of1.54–2.30 Ga.In particular,some 1.4–1.6 Ga zircons show high initial176Hf/177Hf ratios,consistent with those of depleted mantle,which indicates that the Mesoproterozoic event involved both reworking of older crust and generation of juvenile crust.The Central Tianshan Block has different Precambrian crustal growth history from the Tarim Craton.Therefore,it would not be a fragment of the Precambrian basement of the Tarim Craton.     

Detrital zircon U–Pb geochronology and Hf isotopic compositions of Middle–Upper Ordovician sandstones from the Quruqtagh area,eastern Tarim Basin:implications for sedimentary provenance and tectonic evolution

Figuring out whether the sedimentary provenance regions of the thick deep-water turbidite systems deposited during Middle–Upper Ordovician in South Quruqtagh are the intracontinental uplifts or the peripheral orogenic belts is of great significance for us to understand the tectono-sedimentary nature of the northeastern Tarim Basin and basin-range coupling processes in the middle Paleozoic.This paper reports the in situ LA-ICP-MS U–Pb ages and Hf isotope data on detrital zircons from two Middle–Upper Ordovician sandstone samples which were collected from the Charchag Formation and the Zatupo Formation in South Quruqtagh,respectively.The results show that the studied two samples have extremely similar U–Pb age patterns and Hf isotopic compositions,reflecting multiphase tectonothermal events with age groups of 527–694,713–870 Ma(peaking at 760 Ma),904–1,090,1,787–2,094 Ma(peaking at 1,975 Ma)and 2,419–2,517 Ma.Combining previous studies,the presence of age groups of 713–1,090 and1,787–2,094 Ma,respectively,demonstrates that Tarim had ever been a part of Rodinia and Columbia supercontinent.Moreover,98%of 713–870 Ma detrital zircons are characterized by negative e Hf(t)values ranging from-38.07 to-0.61,which are highly consistent with those of Neoproterozoic granites from the Quruqtagh area.No Early Paleozoic ages(*470–500 Ma)signifying subduction or collision events in Altyn Tagh were detected in the two samples,indicating that the Middle–Late Ordovician sediments in South Quruqtagh and northern Mangar depression were mainly derived from intracontinental uplifts,i.e.,the North Quruqtagh uplift or the Tabei paleo-uplift,rather than the Altyn Tagh.In conjunction with regional sedimentary-tectonic background and previous studies,we proposed preliminarily that the northeastern Tarim remained as a passive continental margin in Late Ordovician and changed into an active-continental margin in Silurian due to the southward subduction of the South-Tianshan Ocean.