scholarly journals Regional-scale paleofluid system across the Tuscan Nappe – Umbria Marche Arcuate Ridge (northern Apennines) as revealed by mesostructural and isotopic analyses of stylolite-vein networks

2020 ◽  
Author(s):  
Nicolas Beaudoin ◽  
Aurélie Labeur ◽  
Olivier Lacombe ◽  
Daniel Koehn ◽  
Andrea Billi ◽  
...  
Keyword(s):  
Late Stage ◽  
Regional Scale ◽  
Northern Apennines ◽  
Burial Depth ◽  
Calcite Vein ◽  
Structural Style ◽  
Isotopic Analyses ◽  
Absolute Dating ◽  
Isotopic Characterization ◽  
The Difference

Abstract. We report the results of a multi-proxy study that combines structural analysis of fracture-stylolite network and isotopic characterization of calcite vein cements/fault coating. Together with new paleopiezometric and radiometric constraints on burial evolution and deformation timing, these results provide a first-order picture of the regional fluid pathways network during the main stages of contraction in the Tuscan Nappe and Umbria Marche arcuate ridge (Northern Apennines).We reconstruct four continuous steps of deformation at the scale of the belt: burial that developed sedimentary stylolites, Apenninic-related layer parallel shortening with a contraction striking NE-SW, local extension related to folding, then a late stage of fold tightening under a contraction still striking NE-SW. In order to assess the timing and burial depth of strata at all stages, we combine a paleopiezometric tool based on inversion of the roughness of sedimentary stylolites that constrains the range of burial depth of strata prior to layer-parallel shortening, with burial models and U-Pb absolute dating of fault coatings. In the western part of the ridge, layer-parallel shortening started in Serravalian time (~ 12 Ma), then folding started at Tortonian time (~ 8 Ma), late stage fold tightening started in early Zanclean (~ 5 Ma) and likely lasted until recent/modern extension occurred (~ 3 Ma onward). This timing provides important constraints on the temperature that expectedly prevailed in the studied strata through its history. The textural and geochemical (δ18O, δ13C, Δ47CO2 and 87Sr/86Sr) study of calcite vein cements and fault coatings reveals that most of the fluids involved in the belt during deformation are local, or flowed laterally from the same reservoir. However, the western edge of the ridge recorded pulses of eastward squeegee-type migration of hydrothermal fluids (> 140 °C), that can be related to the difference in structural style of the subsurface between the eastern Tuscan Nappe and the Umbria Marche Ridge.

scholarly journals Regional-scale paleofluid system across the Tuscan Nappe–Umbria–Marche Apennine Ridge (northern Apennines) as revealed by mesostructural and isotopic analyses of stylolite–vein networks

Solid Earth ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 1617-1641 ◽  
Author(s):  
Nicolas E. Beaudoin ◽  
Aurélie Labeur ◽  
Olivier Lacombe ◽  
Daniel Koehn ◽  
Andrea Billi ◽  
...  
Keyword(s):  
Late Stage ◽  
Regional Scale ◽  
Northern Apennines ◽  
Burial Depth ◽  
Calcite Vein ◽  
Structural Style ◽  
Fluid Systems ◽  
Isotopic Analyses ◽  
Isotopic Characterization ◽  
The Difference

Abstract. We report the results of a multiproxy study that combines structural analysis of a fracture–stylolite network and isotopic characterization of calcite vein cements and/or fault coating. Together with new paleopiezometric and radiometric constraints on burial evolution and deformation timing, these results provide a first-order picture of the regional fluid systems and pathways that were present during the main stages of contraction in the Tuscan Nappe and Umbria–Marche Apennine Ridge (northern Apennines). We reconstruct four steps of deformation at the scale of the belt: burial-related stylolitization, Apenninic-related layer-parallel shortening with a contraction trending NE–SW, local extension related to folding, and late-stage fold tightening under a contraction still striking NE–SW. We combine the paleopiezometric inversion of the roughness of sedimentary stylolites – that constrains the range of burial depth of strata prior to layer-parallel shortening – with burial models and U–Pb absolute dating of fault coatings in order to determine the timing of development of mesostructures. In the western part of the ridge, layer-parallel shortening started in Langhian time (∼15 Ma), and then folding started at Tortonian time (∼8 Ma); late-stage fold tightening started by the early Pliocene (∼5 Ma) and likely lasted until recent/modern extension occurred (∼3 Ma onward). The textural and geochemical (δ18O, δ13C, Δ47CO2 and 87Sr∕86Sr) study of calcite vein cements and fault coatings reveals that most of the fluids involved in the belt during deformation either are local or flowed laterally from the same reservoir. However, the western edge of the ridge recorded pulses of eastward migration of hydrothermal fluids (>140 ∘C), driven by the tectonic contraction and by the difference in structural style of the subsurface between the eastern Tuscan Nappe and the Umbria–Marche Apennine Ridge.

Long-term orogenic-scale paleofluid system across the Tuscan Nappe – Umbria-Marche Apennine Ridge (northern Apennines, Italy) as revealed by mesostructural and isotopic analyses of stylolite-vein networks

2021 ◽  
Author(s):  
Nicolas Beaudoin ◽  
Aurélie Labeur ◽  
Olivier Lacombe ◽  
Daniel Koehn ◽  
Andrea Billi ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Late Stage ◽  
Northern Apennines ◽  
Burial Depth ◽  
Burial History ◽  
Calcite Vein ◽  
The Past ◽  
Structural Style ◽  
Isotopic Analyses ◽  
Isotopic Characterization

<p>Faults, joints and stylolites are ubiquitous features in fold-and-thrust belts commonly used to reconstruct the past fluid flow (or plumbing system) at the scale of folded reservoir/basins. Through the textural and geochemical study of the minerals that fills the fractures, it is possible to understand the history of fluid flow in an orogen, requiring a good knowledge of the burial history and/or of the past thermal gradient. In most of the case, the latter derives from the former, itself often argued over, limiting the interpretations of past fluid temperatures. We present the results of a multi-proxy study that combines novel development in both structural analysis of a fracture-stylolite network and isotopic characterization of calcite vein cements/fault coating. Together with new paleopiezometric and radiometric constraints on burial evolution and deformation timing, these results provide a first-order picture of the regional fluid systems and pathways that were present during the main stages of contraction in the Tuscan Nappe and Umbria-Marche Apennine Ridge (Northern Apennines). We reconstruct four steps of deformation at the scale of the belt: burial-related stylolitization, Apenninic-related layer-parallel shortening with a contraction trending NE-SW, local extension related to folding and late stage fold tightening under a contraction still striking NE-SW. We combine the paleopiezometric inversion of the roughness of sedimentary stylolites - that provides a temperature-free constraint on the range of burial depth of strata prior to layer-parallel shortening -, with burial models and U-Pb absolute dating of fault coatings in order to determine the timing of development of mesostructures. In the western part of the ridge, layer-parallel shortening started in Langhian time (~15 Ma), then folding started at Tortonian time (~8 Ma), late stage fold tightening started by the early Pliocene (~5 Ma) and likely lasted until recent/modern extension occurred (~3 Ma onward). The textural and geochemical (δ<sup>18</sup>O, δ<sup>13</sup>C, ∆<sub>47</sub>CO<sub>2</sub> and <sup>87</sup>Sr/<sup>86</sup>Sr) study of calcite vein cements and fault coatings reveals that most of the fluids involved in the belt during deformation are basinal brines evolved from various degree of fluid rock interactions between pristine marine fluids (δ<sup>18</sup>O<sub>fluids</sub> = 0‰ SMOW) and surrounding limestones (δ<sup>18</sup>O<sub>fluids</sub> = 10‰ SMOW). The precipitation temperatures (35°C to 75°C) appear consistent with the burial history unraveled by sedimentary stylolite roughness paleopiezometry (600 m to 1500m in the range) and geothermal gradient (23°C/km). However, the western edge of the ridge recorded isotopically depleted past fluids of which corresponding precipitation temperature (100°C to 130°C) are inconsistent with local burial history (1500m). We interpret then pulses of eastward migration of hydrothermal fluids (>140°C), driven by the tectonic contraction and by the difference in structural style of the subsurface between the eastern Tuscan Nappe and the Umbria-Marche Apennine Ridge. Allowed by an unprecedented combination of paleopiezometry and isotopic geochemistry, this fluid flow model illustrates how the larger scale structures control the fluid system at the scale of the range.</p>

scholarly journals Comparing two years of Saharan dust source activation obtained by regional modeling and satellite observations

2012 ◽  
Vol 12 (10) ◽  
pp. 27667-27691
Author(s):  
I. Tegen ◽  
K. Schepanski ◽  
B. Heinold
Keyword(s):  
Regional Scale ◽  
Dust Emission ◽  
Saharan Dust ◽  
Strong Increase ◽  
Dust Source ◽  
Low Level ◽  
Mountainous Regions ◽  
Emission Fluxes ◽  
Low Level Jets ◽  
The Difference

Abstract. A regional-scale dust model is used to simulate Saharan dust emissions and atmospheric distributions in the years 2007 and 2008. The model results are compared to dust source activation events compiled from infrared dust index imagery from the geostationary Meteosat Second Generation (MSG) satellite. The observed morning maximum in dust source activation frequencies indicates that the breakdown of nocturnal low-level jets is responsible for a considerable number of dust source activation events in the Sahara. The comparison shows that the time of the day of the onset of dust emission is delayed in the model compared to the observations. Also, the simulated number of dust emission events associated with nocturnal low level jets in mountainous regions is underestimated in the model. The MSG dust index observations indicate a strong increase in dust source activation frequencies in the year 2008 compared to 2007, the difference between the two years is less pronounced in the model. The quantitative comparison of simulated dust optical thicknesses with observations at stations of the sunphotometer network AERONET shows, however, good agreement for both years, indicating that the number of observed dust activation events is only of limited use for estimating actual dust emission fluxes in the Sahara.

scholarly journals Comparing two years of Saharan dust source activation obtained by regional modelling and satellite observations

2013 ◽  
Vol 13 (5) ◽  
pp. 2381-2390 ◽  
Author(s):  
I. Tegen ◽  
K. Schepanski ◽  
B. Heinold
Keyword(s):  
Regional Scale ◽  
Dust Emission ◽  
Saharan Dust ◽  
Strong Increase ◽  
Regional Modelling ◽  
Dust Source ◽  
Low Level ◽  
Mountainous Regions ◽  
Low Level Jets ◽  
The Difference

Abstract. A regional-scale dust model is used to simulate Saharan dust emissions and atmospheric distributions in the years 2007 and 2008. The model results are compared to dust source activation events compiled from infrared dust index imagery from the geostationary Meteosat Second Generation (MSG) satellite. The observed morning maximum in dust source activation frequencies indicates that the breakdown of nocturnal low level jets is an important mechanism for dust source activation in the Sahara. The comparison shows that the time of the day of the onset of dust emission is delayed in the model compared to the observations. Also, the simulated number of dust emission events associated with nocturnal low level jets in mountainous regions is underestimated in the model. The MSG dust index observations indicate a strong increase in dust source activation frequencies in the year 2008 compared to 2007. The difference between the two years is less pronounced in the model. Observations of dust optical thickness, e.g. at stations of the sunphotometer network AERONET, do not show such increase, in agreement with the model results. This indicates that the number of observed dust activation events is only of limited use for estimating actual dust emission fluxes in the Sahara. The ability to reproduce interannual variability of Saharan dust with models remains an important challenge for understanding the controls of the atmospheric dust load.

Inversion of Reservoir Parameters by Ultra-High Temperature and High Pressure CO2 Gas Reservoirs with Nuclear Logging

2021 ◽  
Author(s):  
Hengrong Zhang ◽  
Lizhi Xiao ◽  
Wensheng Wu ◽  
Xinyue Fu ◽  
Shenglin He
Keyword(s):  
Joint Inversion ◽  
Simulation Method ◽  
Inversion Method ◽  
Burial Depth ◽  
Gas Reservoirs ◽  
Co2 Gas ◽  
Carbonate Cement ◽  
Response Equation ◽  
Temperature And Pressure ◽  
The Difference

Abstract The Yinggehai basin is located in the western part of the South China Sea, the burial depth of the Huangliu and Meishan formations in the target layer is close to 4000 meters, the formation temperature is close to 200 degrees Celsius, and the formation pressure is up to 100 MPa. The reservoir is characterized by low porosity-ultra-low permeability, heavy carbonate cement, complex CO2 content, this leads to complex neutron and density logging effects. The solubility of CO2 Above CH4, the solubility change with temperature and pressure is different from CH4, which makes it difficult to identify the CO2 gas layer. In this paper, based on the difference in the physical characteristics of CO2 and CH4, the Boltzmann equation combined with MCNP software was used to simulate the neutron and density logging responses under different CO2 saturations. Environmental factors such as temperature and pressure, carbonate cement, mud content and pores were studied To measure the effect of logging response, the LM inversion method is used to jointly invert CO2 saturation of density and neutron logs. The purpose of the inversion is to reduce the non-uniqueness of the evaluation of porosity and CO2 saturation. By introducing the Levenberg-Marquardt (LM) method, the neutron logging response equation of the porosity, argillaceous content, CO2, CH4 in the rock and the corresponding temperature and pressure is solved, and also the response equation of above parameters to density logging, where porosity and CO2 content are the key parameters, and the calculation results prove the effectiveness of the method by comparing the sampling data. The results show that the accuracy of the estimated CO2 saturation is increased by 10% compared with the conventional interpretation method, and the new simulation method improves the calculation speed several times compared to the MCNP software. The joint inversion method has been successfully applied to field data, which has greatly improved the saturation evaluation results of traditional logging interpretation methods, can be extended to other fields of nuclear logging simulation and inversion.

scholarly journals Late pregnancy analysis with Yunban’s remote fetal monitoring system

2019 ◽  
Vol 15 (3) ◽  
pp. 155014771983283
Author(s):  
Qiuping Wang ◽  
Weihua Yang ◽  
Lie Li ◽  
Guokai Yan ◽  
Huihui Wang ◽  
...  
Keyword(s):  
Late Stage ◽  
Stress Test ◽  
Fetal Monitoring ◽  
Late Pregnancy ◽  
Cardiac Monitoring ◽  
Control Group ◽  
Research Subjects ◽  
Neonatal Asphyxia ◽  
The Difference ◽  
Experimental Group

With the adoption of the two-child policy, there has been a large increase in women of older maternal and high-risk pregnant women. So, it is necessary to analyze the health status of women in the late pregnancy on time. To analyze the effect on using remote fetal monitoring on women in the late pregnancy, we selected women in the late stage of pregnancy in our hospital as research subjects. They were randomly divided into two groups: the experimental group, which engaged in remote fetal monitoring, and the control group, which adopted traditional cardiac monitoring. In order to get more effective data, we used the Kalman filter and audio repair algorithms to preprocess the collected data. During follow-up observation, we compared the two groups using neonatal cardiac monitoring by employing the non-stress test and observed the occurrence of neonatal asphyxia. The incidence of neonatal abnormal non-stress test in the experimental group and the control group was 33.6% and 17.3%, respectively; the difference was statistically significant ( p < 0.05). The incidence of neonatal asphyxia in the experimental group was 12.5%, which was significantly lower than in the control group (30%; p < 0.05). We have found that women in the late stage of pregnancy who adopted remote fetal monitoring could detect abnormal non-stress test earlier and thus increase in the detection of rate of neonatal asphyxia.

Measurement of total energy and material balance in rats by means of doubly labeled water

1960 ◽  
Vol 199 (2) ◽  
pp. 238-242 ◽  
Author(s):  
J. S. Lee ◽  
Nathan Lifson
Keyword(s):  
Body Weight ◽  
Water Intake ◽  
Material Balance ◽  
Body Water ◽  
Doubly Labeled Water ◽  
Final Body Weight ◽  
Water Output ◽  
Isotopic Analyses ◽  
The Difference ◽  
Metabolism Chamber

A test has been carried out in rats of the possibility of measuring with the aid of doubly labeled water (D2O18) the following components of the material balance of an animal: output of CO2 and water; intake of oxygen, food and water. The items of information used for the measurement were a) isotopic analyses of initial and final blood samples, b) composition of the diet with respect to percentage protein, carbohydrate and fat, c) initial and final body weight, d) final percentage body water. Initial percentage body water obtained from a by the volume of dilution principle could substitute for d. CO2 and water output were estimated isotopically; O2 consumption, from the CO2 output and dietary R. Q.; food intake, from CO2 output and dietary composition; water intake, from the difference between water output and dietary metabolic water. A rough correction for storage of materials was made from the change in body weight. The average difference between observed values for each of the above components of the material balance and values calculated by the isotope procedure was less than 10%. The fact that dry air was supplied to the animal in the metabolism chamber used to obtain the observed values probably favored better agreement between calculated and observed values for water intake and output than would prevail in ordinary moist air.

Recent geological advances in the understanding of the Torres Basin

2013 ◽  
Vol 53 (2) ◽  
pp. 459
Author(s):  
Michael Swift
Keyword(s):  
Cross Sections ◽  
Large Scale ◽  
Regional Scale ◽  
Coastal Region ◽  
Petroleum Potential ◽  
Structural Style ◽  
Time Space ◽  
Australian Plate ◽  
History Of ◽  
Geological Section

The Torres Basin is a recently discovered Mesozoic basin in the Papuan Plateau, southeast Papua New Guinea. Newly acquired deepwater offshore seismic data and older regional data have been (re)interpreted with the view of defining structural regimes in line with the onshore geological maps and conceptual cross sections. A regional time-space plot has been developed to elucidate the breakup of the northeastern Australian Plate with a focus on the geological history of the Papuan Plateau, which holds the Torres Basin geological section. This in turn has led to a re-evaluation of the structural style and history of the southern coastal region incorporating the East Australian Early Cretaceous Island Arc; it highlights that a significant horizontal structural grain needs to be considered when evaluating the petroleum potential of the region. The southern margin is characterised as a frontal thrust system, similar to the nearby Papuan Basin. A series of regional strike lines in conjunction with the dip lines is used to divide the region into prospective and non-prospective exploration play fairways. The role of transfer faults, basement-detachments faults, regional-scale thrust faults, and recent normal faulting is discussed in the compartmentalisation of the geological section. There is basement-involved anticlinal development on a large scale and a complementary smaller-scale thin-skinned anticlinal trend. These trends are characterised as having significant strike length and breadth. Anticlinal trap fairways have been defined and have similar size and distribution as that of the Papuan Basin.

scholarly journals A Spatio-Temporal Bayesian Model for Estimating the Effects of Land Use Change on Urban Heat Island

2019 ◽  
Vol 8 (12) ◽  
pp. 522 ◽  
Author(s):  
Xin Liu ◽  
Zuolin Xiao ◽  
Rui Liu
Keyword(s):  
Land Use ◽  
Urban Heat Island ◽  
Southwest China ◽  
Regional Scale ◽  
Heat Island ◽  
Bayesian Hierarchical ◽  
Temporal Autocorrelation ◽  
Urban Heat ◽  
Spatio Temporal ◽  
The Difference

The urban heat island (UHI) phenomenon has been identified and studied for over two centuries. As one of the most important factors, land use, in terms of both composition and configuration, strongly influences the UHI. As a result of the availability of detailed data, the modeling of the residual spatio-temporal autocorrelation of UHI, which remains after the land use effects have been removed, becomes possible. In this study, this key statistical problem is tackled by a spatio-temporal Bayesian hierarchical model (BHM). As one of the hottest areas in China, southwest China is chosen as our study area. Results from this study show that the difference of UHI levels between different cities in southwest China becomes large from 2000 to 2015. The variation of the UHI level is dominantly driven by temporal autocorrelation, rather than spatial autocorrelation. Compared with the composition of land use, the configuration has relatively minor influence upon UHI, due to the terrain in the study area. Furthermore, among all land use types, the water body is the most important UHI mitigation factor at the regional scale.

Sign in / Sign up

Export Citation Format

Share Document