A Cretaceous‐Eocene depositional age for the Fenghuoshan Group, Hoh Xil Basin: Implications for the tectonic evolution of the northern Tibet Plateau

The Fenghuoshan Group marks the initiation of terrestrial deposition in the Hoh Xil Basin and preserves the first evidence of uplift above sea level of northern Tibet. The depositional age of the Fenghuoshan Group is debated as are the stratigraphic relationships between the Fenghuoshan Group and other terrestrial sedimentary units in the Hoh Xil Basin. We present new radiometric dates and a compilation of published biostratigraphic data which are used to reinterpret existing magnetostratigraphic data from the Fenghuoshan Group. From these data, we infer an 85–51 Ma depositional age range for the Fenghuoshan Group. U‐Pb detrital zircon age spectra from this unit are compared to age spectra from Tibetan terranes and Mesozoic sedimentary sequences to determine a possible source terrane for Fenghuoshan Group strata. We propose that these strata were sourced from the Qiangtang Terrane and may share a common sediment source with Cretaceous sedimentary rocks in Nima Basin. Field relationships and compiled biostratigraphic data indicate that the Fenghuoshan and Tuotuohe Groups are temporally distinct units. We report late Oligocene ages for undeformed basalt flows that cap tilted Fenghuoshan Group strata. Together, our age constraints and field relationships imply exhumation of the central Qiangtang Terrane from the Late Cretaceous to earliest Eocene, followed by Eocene‐Oligocene deformation, and shortening of the northern Qiangtang and southern Songpan‐Ganzi terranes. Crustal shortening within the Hoh Xil Basin ceased by late Oligocene time as is evident from flat‐lying basaltic rocks, which cap older, deformed strata. Key Points The Fenghuoshan Group was deposited from late Cretaceous to early Eocene time The Fenghuoshan Group was likely sourced from the central Qiangtang Terrane Crustal shortening of the Hoh Xil Basin occurred from Eocene to Oligocene timePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/1/ts02.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/2/fs02.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/3/tect20113.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/4/ts06.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/5/fs06.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/6/ts03.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/7/fs03.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/8/ts07.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/9/fs07.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/10/fs04.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/11/ts04.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/12/fs01.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/13/ts08.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/14/ts01.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/15/fs05.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106814/16/ts05.pd

"We googled the definition of gender, since we didn´t have any knowledge about what it means" : A qualitative study on how preschool teachers´constructs gender in northenmost Sweden (Tornedalen area)

Denna studie syftar till att analysera hur förskollärare i Tornedalen konstruerar genus i förskolan. Studien är av kvalitativ karaktär med utgångspunkt i det socialkonstruktionistiska perspektivet. Datainsamling till studien har skett genom skriftliga intervjuer med 13 förskollärare som är verksamma inom yrket i Tornedalen. Resultatet visa att förskollärarna konstruerar genus utifrån tre områden: Förhållningssätt, miljö och språk. Vidare visar resultatet på en osäkerhet kring begreppet genus men även olika utmaningar som konstrueras i förskollärarnas arbete att motverka traditionella könsnormer.

Eocene to late Oligocene history of crustal shortening within the Hoh Xil Basin and implications for the uplift history of the northern Tibetan Plateau

The timing and magnitude of deformation across the northern Tibetan Plateau are poorly constrained but feature prominently in geodynamic models of the plateau's evolution. The Fenghuoshan fold and thrust belt, located in the Hoh Xil Basin, provides a valuable record of the Cenozoic deformation history of the northern Tibetan Plateau. Here we integrate fault gouge geochronology, low-temperature thermochronology, geologic mapping, and a balanced cross section to resolve the deformation history of Hoh Xil Basin. Chronologic data suggest that deformation initiated in the mid-Eocene continued until at least 34 Ma and ceased by 27 Ma. The balanced cross section resolves 34 +/- 12 km upper crustal shortening (24 +/- 9%). We explore whether the observed Cenozoic shortening can account for the modern elevation and lithospheric thickness in the northern Tibetan Plateau. For a range of reasonable preshortening conditions, we conclude that the observed shortening alone cannot achieve modern crustal and mantle lithospheric thicknesses or modern elevation without either the removal of lithospheric mantle, the influx of lower crustal material, or some combination of these processes. Our results, along with previous studies, suggest that crustal shortening propagated into the northern Tibetan Plateau shortly after the onset of the Indo-Asian collision. The small magnitude of shortening and the late Oligocene cessation of deformation in the northern Tibetan Plateau raise questions of how and where the remaining Indo-Asian convergence was accommodated between Eocene to mid-Miocene time, prior to the approximately late Miocene establishment of the deformation patterns observed in the present day

Removal of benzotriazole derivatives by biochar

Benzotriazole and its derivatives (BTAs) are commonly present in wastewater due to their extensive use in industrial processes, yet their removal is still unexplored. Here, we test the removal of these pollutants using two functionalised biochars, synthesised from wild plum (WpOH) and apricot (AsPhA) kernels. The aim of this work was to optimise the adsorption process against various BTAs (i.e., benzotriazole (BTZ), 4-hydroxy-1H-benzotriazole (OHBZ), 4-methyl-1H-benzotriazole (4 MBZ), 5-methyl-1H-benzotriazole (5 MBZ), 5-chloro-1H-benzotriazole (ClBZ), 5,6-dimethyl-1H-benzotriazole (DMBZ)), and determine the adsorption mechanisms at play, using real wastewater matrices. Batch studies showed that the optimal adsorption pH ranged between 4 and 6 for WpOH and AsPhA, respectively, and equilibrium was reached after 240 min. The kinetic models that best described the adsorption process were in the following order: Elovich model > pseudo-second order model > pseudo-first order model. The equilibrium data showed the highest correlation with the Freundlich isotherm, indicating multilayer adsorption. The maximum adsorption capacity obtained in mixtures was 379 mg/g on WpOH and 526 mg/g on AsPhA. The mechanistic work revealed that the BTAs became bound to the biochar primarily through H-bonding, n-π and π-π EDA interactions. In wastewater, obtained before and after conventional treatment, the concentration of OHBZ and BTZ was reduced by >40%, while the concentration of the other compounds studied fell below the detection limit (∼2.0–90 ng/L). Finally, using a Vibrio fischeri assay, we showed that adsorption onto AsPhA significantly reduced the relative toxicity of both raw and treated wastewater

Quantitative Determination of Antidepressants and Their Select Degradates by Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry in Biosolids Destined for Land Application

Antidepressants are one of the most widely dispensed classes of pharmaceuticals in the United States. As wastewater treatment plants are a primary source of pharmaceuticals in the environment, the use of biosolids as fertilizer is a potential route for antidepressants to enter the terrestrial environment. A microsolvent extraction method, utilizing green chemistry, was developed for extraction of the target antidepressants and degradation products from biosolids, or more specifically lagoon biosolids. Liquid chromatography/tandem mass spectrometry was used for quantitative determination of antidepressants in the lagoon biosolid extracts. Recoveries from matrix spiking experiments for the individual antidepressants had an average of 96%. The limits of detection for antidepressant pharmaceuticals and degradates ranged from 0.36 to 8.0 ng/kg wet weight. The method was applied to biosolids destined for land application. A suite of antidepressants was consistently detected in the lagoon biosolid samples, and thus antidepressants are being introduced to terrestrial environments through the land application of these biosolids. Sertraline and norsertraline were the most abundant antidepressant and degradation product detected in the biosolid samples. Detected, individual antidepressant concentrations ranged from 8.5 ng/kg (norfluoxetine) to 420 ng/kg wet weight (norsertraline)

A Cretaceous-Eocene depositional age for the Fenghuoshan Group, Hoh Xil Basin: Implications for the tectonic evolution of the northern Tibet Plateau

The Fenghuoshan Group marks the initiation of terrestrial deposition in the Hoh Xil Basin and preserves the first evidence of uplift above sea level of northern Tibet. The depositional age of the Fenghuoshan Group is debated as are the stratigraphic relationships between the Fenghuoshan Group and other terrestrial sedimentary units in the Hoh Xil Basin. We present new radiometric dates and a compilation of published biostratigraphic data which are used to reinterpret existing magnetostratigraphic data from the Fenghuoshan Group. From these data, we infer an 85-51Ma depositional age range for the Fenghuoshan Group. U-Pb detrital zircon age spectra from this unit are compared to age spectra from Tibetan terranes and Mesozoic sedimentary sequences to determine a possible source terrane for Fenghuoshan Group strata. We propose that these strata were sourced from the Qiangtang Terrane and may share a common sediment source with Cretaceous sedimentary rocks in Nima Basin. Field relationships and compiled biostratigraphic data indicate that the Fenghuoshan and Tuotuohe Groups are temporally distinct units. We report late Oligocene ages for undeformed basalt flows that cap tilted Fenghuoshan Group strata. Together, our age constraints and field relationships imply exhumation of the central Qiangtang Terrane from the Late Cretaceous to earliest Eocene, followed by Eocene-Oligocene deformation, and shortening of the northern Qiangtang and southern Songpan-Ganzi terranes. Crustal shortening within the Hoh Xil Basin ceased by late Oligocene time as is evident from flat-lying basaltic rocks, which cap older, deformed strata.</p