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Ancient lacustrine and aeolian sediments have been separately identified in a variety of locations on Mars. In this work, we interpret the depositional history of Barth crater and its surrounding area in Arabia Terra where exposed geologic units preserve a record of lacustrine and aeolian interaction. Aeolian sandstone in the study area overlies lacustrine strata and is interbedded with easily eroded interdune deposits. The aeolian sandstone preserves dune strata with structures that indicate paleo‐sediment transport toward the northwest. The aeolian unit also preserves a transition up‐section from separated barchan dunes to continuous transverse dunes, capturing the development of the ancient dune field from sediment limited to sediment rich. Inverted fluvial channels provide evidence that water was delivered to the area at the same time the dune field was present, providing a simple mechanism, via wetting and cementation, for aeolian strata preservation. This example of wet‐system aeolian accumulation preserves an upward drying sequence in the sedimentary record that may have been coincident with the widely hypothesized global climate transition. The terrains described in this work provide a framework for interpreting similar aeolian units in elsewhere on Mars, even where cross‐strata cannot be easily resolved. Plain Language Summary: Sedimentary rocks on Mars preserve evidence of the past environmental conditions on the planet. In and around Barth crater in Arabia Terra, Mars, the rock‐record preserves evidence of a wet‐to‐dry environmental transition much like the transition undergone at some point by the entire planet. Based on the surface expressions and characteristic structures in the sedimentary units, we interpret that Barth crater once hosted an ancient lake fed by rivers from the northeast. After the lake dried, dune fields formed on top of lake sediments, but intermittent re‐wetting of the region by flooding streams preserved some of the dune sands and deposited soft sediments between dunes. The lake, river, dune, and interdune deposits were later eroded by the wind, revealing the sedimentary structures (including crescent‐shaped forms) discussed in this work. Such patterns in deposition may reflect the wet‐to‐dry climatic transition that occurred on ancient Mars. Key Points: Curvilinear‐textured terrain in Arabia Terra preserves paleo‐dune strataSedimentary units in Barth crater preserve a record of ancient interactions between fluvio‐lacustrine and aeolian depositionAncient aeolian transport differed from modern transport by roughly 90° of azimuth [ABSTRACT FROM AUTHOR]

At the south‐western margin of the North China Craton (NCC), there existed a lot of Mesoproterozoic strata. However, it is hardly known about the Mesoproterozoic stratigraphic sequence and deep structures of the south‐western part of NCC (most is the Ordos Block) due to the thick Phanerozoic sedimentary cover above the Precambrian basement and strata. Combining the drilling well data, seismic profiles, and outcrops around the whole Ordos Block, it becomes possible to reveal the deep structure and distribution of Mesoproterozoic strata. The distribution and sedimentation of Mesoproterozoic at the southwestern margin of NCC were controlled by a series of NE–SW extension deep faults just existed in Mesoproterozoic Changcheng System and Jixian System. According to the drilling well data, the Changchang System includes several various thickness volcanic rocks, and the stratigraphic sequence and lithological combination are similar to the Yanliao Rift. During the sedimentation from Longjiayuan Formation to Duguan Formation, the water got deeper revealed by the content of Ce element gradually decreasing. However, the content of Ce element unusually increases during the steady subsidence of the Mesoproterozoic basin, while the Xunjiansi Formation sedimented. The deposition of tephra or hydrothermal might contribute a lot to the increase of the Ce element's content. Besides that, numerous soft‐sediment deformation structures developed in carbonate rocks of Mesoproterozoic Xunjiansi Formation at the south‐western margin of NCC. What's more, the Xunjiansi Formation with soft‐sediment deformation structures can be regarded as a marker bed for the comparison with the Wumishan Formation in Yanliao Rift. Besides that, there is a set of residual sandstone conformably covered the dolomite of Mesoproterozoic Fengjiawan Formation. It corresponds with Xiamaling Formation of Building System in Yanliao Rift System based on the stratigraphic sequence and relative sedimentary time limited by the youngest zircon U–Pb age peak 1,511.1 ± 10 Ma (n = 7) and single zircon U–Pb age 1,436 ± 28 Ma. Therefore, the south‐western part of NCC have high similarity of stratigraphic sequence and sedimentary framework with Yanliao Rift. Moreover, the development of volcanic rocks in Changcheng System, soft‐sediment deformation structures, and Ce abnormal increasing in Xunjiansi Formation might suggest that there developed an active Mesoproterozoic Rift in the south‐western part of the NCC similar to Yanliao Rift. Generally, the south‐western part of NCC share similar tectonic background with Yanliao Rift. [ABSTRACT FROM AUTHOR]

The article focuses on a study related to the distribution of Baoligaomiao Formation in the Zhanlantun Area, Mongolia and discusses their sedimentary age. It includes information on the presence of Angara biological fossils in the formation. It also includes information on the results of zircon uranium-lead dating.

The tunnels of the railway project Stuttgart-Ulm are located in sedimentary rock of the Keuper Formation, the Black Jurassic, the Brown Jurassic and the White Jurassic formation. The two longest tunnels are excavated by tunnel boring machine over most of their length. The remaining tunnels, which the authors are involved in, are excavated by conventional tunnelling. All tunnels are designed on the basis of the AJRM-method. This method is based on an anisotropic, elasto-viscoplastic model for jointed rock and corresponding FE-software, which has been extended to seepage and swelling. The method has been applied to practical projects for the last 40 years. By means of rock mechanical test programs and back-analyses of projects in a variety of rocks, the reliability of the predictions is quite high and the application leads to safe and economic solutions. Special emphasis is given to tunnels located in swelling gypsum Keuper. The phenomena of swelling and leaching are described and a swelling model is outlined. The evaluation of the rock mechanical parameters and a method of analyses are explained. On this basis, the design principles and package of measures applied for the tunnels located in anhydrite-bearing rock are described. Some important aspects with regards to tunnelling in leached Gypsum Keuper and in the other Keuper layers as well as the Black Jurassic are addressed. For the 8.8 km long Boßler Tunnel, located in the Brown and White Jurassic, for an approx. 900 m long section in the Aalenium 2 with a maximum overburden of 280 m squeezing rock conditions had to be anticipated. By means of a vertical exploration shaft and a connecting exploration gallery, an improvement of the predicted characteristic rock mechanical parameters could be justified, thus enabling TBM-tunnelling also in this section, with an increase of the segment thickness from 45 to 65 cm. For the Steinbühltunnel located in White Jurassic, special emphasis was placed on karstic rocks. The corresponding measures are described. [ABSTRACT FROM AUTHOR]

This study describes a new technique for measuring the head profile in a geologic formation. The technique provides rapid, low cost information on the depth of water-producing zones and aquitards in heterogeneous aquifers, yielding estimates of hydraulic heads in each zone while identifying any potential for cross contamination between zones. The measurements can be performed in a typical borehole in just a few hours. The procedure uses both the continuous transmissivity profile obtained by the installation (eversion) of a flexible borehole liner into an open borehole and the subsequent removal (inversion) of the same liner from the borehole. The method is possible because of the continuous transmissivity profile ( T profile described by Keller et al. 2014) obtained by measuring the rate of liner eversion under a constant driving head. The hydraulic heads of producing zones are measured using the reverse head profile ( RHP) method (patent no. 9,008,971) based on a stepwise inversion of the borehole liner. As each interval of the borehole is uncovered by inversion of the liner, the head beneath the liner is allowed to equilibrate to a steady-state value. The individual hydraulic heads contributing to each measurement are calculated using the measured transmissivity for each zone. Application of the RHP method to a sedimentary bedrock borehole in New Jersey verified that it reproduced the head distribution obtained the same day in the same borehole instrumented with a multilevel sampling system. [ABSTRACT FROM AUTHOR]

ABSTRACT A detailed magnetotelluric survey was conducted in 2013 in the Sehqanat oil field, southwestern Iran to map the geoelectrical structures of the sedimentary Zagros zone, particularly the boundary between the Gachsaran Formation acting as cap rock and the Asmari Formation as the reservoir. According to the electrical well logs, a large resistivity contrast exists between the two formations. The Gachsaran Formation is formed by tens to hundreds of metres of evaporites and it is highly conductive (ca. 1 Ωm-10 Ωm), and the Asmari Formation consists of dense carbonates, which are considerably more resistive (more than 100 Ωm). Broadband magnetotelluric data were collected along five southwest-northeast directed parallel lines with more than 600 stations crossing the main geological trend. Although dimensionality and strike analysis of the magnetotelluric transfer functions showed that overall they satisfied local 2D conditions, there were also strong 3D conditions found in some of the sites. Therefore, in order to obtain a more reliable image of the resistivity distribution in the Sehqanat oil field, in addition to standard 2D inversion, we investigated to what extent 3D inversion of the data was feasible and what improvements in the resistivity image could be obtained. The 2D inversion models using the determinant average of the impedance tensor depict the main resistivity structures well, whereas the estimated 3D model shows significantly more details although problems were encountered in fitting the data with the latter. Both approaches resolved the Gachsaran-Asmari transition from high conductivity to moderate conductivity. The well-known Sehqanat anticline could also be delineated throughout the 2D and 3D resistivity models as a resistive dome-shaped body in the middle parts of the magnetotelluric profiles. [ABSTRACT FROM AUTHOR]

This paper presents the results of pollen and charcoal analyses carried out in the sedimentary formation of Ponta da Passadeira, south of the Tejo River estuary, Portugal. The data provide information regarding the evolution of the coastline and ecosystem of the estuary during the mid and late Holocene. The study focuses on a group of upright woody fossilized tree remains that, together with those identified earlier by García- Amorena et al. (2007), form part of the fossil forest of Ponta da Passadeira. Eight remains were identified as Pinus pinaster, four as Pinus pinea and one as Pinus sp . Two specimens of these species were dated to 6523 and 5805 cal. a BP. Pollen analysis was undertaken in a clay layer located at the same point as the fossil forest, which is currently below sea level; the base of the clay layer was dated to 4906 cal. a BP. The pollen spectra reflect the dynamics of the vegetation that grew on this deposit, whereas the sporopollinic input masks the contribution of the regional vegetation. Wood charcoal remains recovered at an adjacent Final Neolithic settlement were also analysed, and a Pinus sp. specimen was radiocarbon dated to 5050 cal. a BP. The correlation amongst the three records provides key ecological markers for the understanding of the evolution of coastline ecosystems, and helps to clarify and understand the Holocene sea rise on the Atlantic seaboard of Iberia. The geographical location of Ponta da Passadeira is strategic because it enables a more clear definition of the configuration of landscapes that show an inflection point in this area of central Portugal. [ABSTRACT FROM AUTHOR]

The article focuses on the uranium-lead age of Badu Dolerite. It includes information on the presence of cluster of carlin-like gold deposits in Youjiang basin in China. It also includes information on zircon uranium-lead analysis, cathodoluminescence images of zircon grains, and sedimentary rocks of the Yanguan Formation.

The article focuses on findings of a study on geochemical characteristics and geological significance of picritic rocks in Permian Tiaohu Formation from Santanghu Basin, Xinjiang of China. Topics include magmatic activity of Permian in Santanghu Basin; characteristics of picritic rocks, such as SiO2 amount of picritic rocks; and voluminous postcollisional granitoids and Armantai and Karamaili suture zone formation age.