Australian impact cratering record: Updates and recent discoveries

2021 ◽  
Author(s):  
Raiza R. Quintero ◽  
Aaron J. Cavosie ◽  
Morgan A. Cox ◽  
Katarina Miljković ◽  
Allison Dugdale
Keyword(s):  
First Generation ◽  
Ore Deposits ◽  
Impact Cratering ◽  
Accessory Minerals ◽  
Asteroid Impact ◽  
Shock Deformation ◽  
Structure Recognition ◽  
Deformation Phase ◽  
Oblique Impacts

ABSTRACT There are currently 31 confirmed structures of impact origin in Australia. More than 49 additional structures have been proposed to have formed due to asteroid impact but await confirmation. Many discoveries have been made in Australia in the time since the last comprehensive review of the Australian impact cratering record was published in a peer-reviewed journal in 2005. These include further expanding the record of confirmed craters, and providing new insights into a variety of impact-related processes, such as shock deformation, phase transitions in accessory minerals, new impact age determinations, studies of oblique impacts, and more. This update is a review that focuses principally on summarizing discoveries made since 2005. Highlights since then include confirmation of five new Australian impact structures, identification of Earth’s oldest recognized impact structure, recognition of shock deformation in accessory minerals, discovery of the high-pressure phase reidite in Australia, determination of the links between impact craters and some ore deposits, and publication of the first generation of numerical hydrocode models for some Australian craters.

scholarly journals A structural model of the Fábrica Nova region, Santa Rita syncline, Quadrilátero Ferrífero: flanking folds as a folding mechanism

2015 ◽  
Vol 68 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Daniel Quinaud Rossi ◽  
Issamu Endo
Keyword(s):  
Structural Model ◽  
Axial Direction ◽  
Ore Deposits ◽  
Tectonic Deformation ◽  
Folding Mechanism ◽  
Structural Framework ◽  
Deformation Phase ◽  
Proposed Model ◽  
Quadrilátero Ferrífero ◽  
Iron Ore Deposits

AbstractThis study focuses on the eastern flank of the Santa Rita syncline (Dorr 1969), with specific emphasis on the region known as Fábrica Nova. Important iron ore deposits are located on the flanks of this structure, such as Timbopeba, Alegria, São Luiz, Tamanduá, Almas and Fábrica Nova. The Santa Rita syncline is a fold with N-S axial direction and of subregional scale, with roots in the adjacent basement of the Santa Bárbara Complex and sectioned by the Água Quente thrust fault. The hypothesis of this study is that the structural framework of the region resulted from the superposition of at least three deformation phases on the Ouro Preto nappe. The Fábrica Nova mine, located in the central portion of the study area, is embedded in a synformal structure with a 100/20 trending axis named Fábrica Nova synform. The proposed model to explain the particular structural geometry of this region is based on the flanking folding mechanism (Passchier 2001). This mechanism may have been developed by E-W crustal shortening during the F4 tectonic deformation phase.

scholarly journals Conditions of ore formation of the Aunikskoye F-Be deposit (Western Transbaikal)

2019 ◽  
Vol 61 (1) ◽  
pp. 18-38
Author(s):  
L. B. Damdinova ◽  
B. B. Damdinov ◽  
M. O. Rampilov ◽  
S. V. Kanakin
Keyword(s):  
Pressure Range ◽  
Deposition Process ◽  
Isotopic Signature ◽  
Ore Deposits ◽  
Ore Formation ◽  
Ore Deposit ◽  
Temperature Range ◽  
Main Factors ◽  
Low Solubility

This study examines the compositions of the ore and the ore formation solutions, conditions of formation, and sources of Be mineralization using the Aunikskoye F-Be deposit, which is an integral part of the Western Transbaikal beryllium-bearing provinces, as a representative example. Further, the main factors responsible for the formation of beryllium mineralization were evaluated. The ore deposits are presented by the feldsparic–fluorspar–phenacite–bertrandite metasomatites formed in the carboniferous limestones during their metasomatic alternation with hydrothermal solutions by introducing F, Be, and other associated elements. The formation of early phenacite–fluorspar association occurred in high-fluorite СО2-containing solutions of elevated alkalinity with a salinity of ~10.5%–12% wt eq. NaCl in a temperature range of ~ 370–260 °С at pressures ranging from 1873 to 1248 bar. More recent fluorite and bertrandite deposits were formed by solutions with a salinity of 6.4%–7.7% wt eq. NaCl in a temperature range of ~156 °C–110 °C and a pressure range of 639–427 bar. The examination of the isotopic signature of the ore association minerals confirmed the apocarbonate nature of the main ore deposit and allowed the determination of the magmatogene nature of the ore-forming paleothermal springs, which are the source of subalkaline leucogranites. The primary factors that influenced the formation of the F-Be ore included the reduction of the F activity in solutions because of the binding of Ca and F in fluorite as well as because of the decrease in temperature during the ore deposition process. The elevated alkalinity of the ore-formation solutions resulted in the low solubility of the Be complexes, which caused a relatively low Be content in the ore and a relatively small amount of mineralization in the deposit.

scholarly journals Granular impact cratering by liquid drops: Understanding raindrop imprints through an analogy to asteroid strikes

2014 ◽  
Vol 112 (2) ◽  
pp. 342-347 ◽  
Author(s):  
Runchen Zhao ◽  
Qianyun Zhang ◽  
Hendro Tjugito ◽  
Xiang Cheng
Keyword(s):  
High Speed ◽  
Granular Media ◽  
Liquid Drop ◽  
Impact Craters ◽  
High Speed Photography ◽  
Impact Cratering ◽  
Liquid Drops ◽  
Asteroid Impact ◽  
Liquid Marble ◽  
Crater Morphology

When a granular material is impacted by a sphere, its surface deforms like a liquid yet it preserves a circular crater like a solid. Although the mechanism of granular impact cratering by solid spheres is well explored, our knowledge on granular impact cratering by liquid drops is still very limited. Here, by combining high-speed photography with high-precision laser profilometry, we investigate liquid-drop impact dynamics on granular surface and monitor the morphology of resulting impact craters. Surprisingly, we find that despite the enormous energy and length difference, granular impact cratering by liquid drops follows the same energy scaling and reproduces the same crater morphology as that of asteroid impact craters. Inspired by this similarity, we integrate the physical insight from planetary sciences, the liquid marble model from fluid mechanics, and the concept of jamming transition from granular physics into a simple theoretical framework that quantitatively describes all of the main features of liquid-drop imprints in granular media. Our study sheds light on the mechanisms governing raindrop impacts on granular surfaces and reveals a remarkable analogy between familiar phenomena of raining and catastrophic asteroid strikes.

Chelyabinsk Meteorite

2021 ◽  
Author(s):  
Olga Popova
Keyword(s):  
Energy Deposition ◽  
Seismic Waves ◽  
The Body ◽  
Structure And Properties ◽  
Ural Mountains ◽  
Asteroid Impact ◽  
Unusual Event ◽  
The Earth ◽  
First Time

The asteroid impact near the Russian city of Chelyabinsk on February 15, 2013, was the largest airburst on Earth since the 1908 Tunguska event, causing a natural disaster in an area with a population exceeding 1 million. On clear morning at 9:20 a.m. local time, an asteroid about 19 m in size entered the Earth atmosphere near southern Ural Mountains (Russia) and, with its bright illumination, attracted the attention of hundreds of thousands of people. Dust trail in the atmosphere after the bolide was tens of kilometers long and was visible for several hours. Thousands of different size meteorites were found in the areas south-southwest of Chelyabinsk. A powerful airburst, which was formed due to meteoroid energy deposition, shattered thousands of windows and doors in Chelyabinsk and wide surroundings, with flying glass injuring many residents. The entrance and destruction of the 500-kt Chelyabinsk asteroid produced a number of observable effects, including light and thermal radiation; acoustic, infrasound, blast, and seismic waves; and release of interplanetary substance. This unexpected and unusual event is the most well-documented bolide airburst, and it attracted worldwide attention. The airburst was observed globally by multiple instruments. Analyses of the observational data allowed determination of the size of the body that caused the superbolide, its velocity, its trajectory, its behavior in the atmosphere, the strength of the blast wave, and other characteristics. The entry of the 19-m-diameter Chelyabinsk asteroid provides a unique opportunity to calibrate the different approaches used to model meteoroid entry and to calculate the damaging effects. The recovered meteorite material was characterized as brecciated LL5 ordinary chondrite, in which three different lithologies can be distinguished (light-colored, dark-colored, and impact-melt). The structure and properties of meteorites demonstrate that before encountering Earth, the Chelyabinsk asteroid had experienced a very complex history involving at least a few impacts with other bodies and thermal metamorphism. The Chelyabinsk airburst of February 15, 2013, was exceptional because of the large kinetic energy of the impacting body and the damaging airburst that was generated. Before the event, decameter-sized objects were considered to be safe. With the Chelyabinsk event, it is possible, for the first time, to link the damage from an impact event to a well-determined impact energy in order to assess the future hazards of asteroids to lives and property.

scholarly journals Procedure for risk assessment of initiation and progression of oxidation processes during development of pyrite ore deposits

2020 ◽  
Vol 192 ◽  
pp. 03005
Author(s):  
Gennady Einbinder ◽  
Natalia Mitishova ◽  
Dmitry Radchenko ◽  
Egor Knyazkin
Keyword(s):  
Risk Assessment ◽  
Hazard Analysis ◽  
Ore Deposits ◽  
Industrial Safety ◽  
Accident Risk ◽  
Hazard Degree ◽  
Increased Risk ◽  
Sulfide Ore ◽  
Hazardous Production

In the modern conditions, the scale of subsoil transformation in the process of mineral extraction is characterized by an increased risk of accidents, often accompanied by man-made disasters. In this regard, hazard analysis and accident risk assessment is the most important scientific and technical task, the solution of which is based on methods for identification of hazards, study of development trends and assessment of consequences of theoretically possible accidents. In relation to development conditions of sulfide ore deposits, only an accident risk assessment with determination of the possible accident hazard degree, as well as preparation and timely correction of measures aimed at reduction of accident risks can ensure an acceptable level of industrial safety at the hazardous production facility.

scholarly journals PET Radiopharmaceuticals for Imaging Integrin Expression: Tracers in Clinical Studies and Recent Developments

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Roland Haubner ◽  
Simone Maschauer ◽  
Olaf Prante
Keyword(s):  
Nuclear Medicine ◽  
First Generation ◽  
Integrin Expression ◽  
Rgd Peptides ◽  
Recent Developments ◽  
Interesting Approach ◽  
Complex Chemistry ◽  
Pet Radiopharmaceuticals

Noninvasive determination of integrin expression has become an interesting approach in nuclear medicine. Since the discovery of the first18F-labeled cyclic RGD peptide as radiotracer for imaging integrinαvβ3expression in vivo, there have been carried out enormous efforts to develop RGD peptides for PET imaging. Moreover, in recent years, additional integrins, includingα5β1andαvβ6, came into the focus of pharmaceutical radiochemistry. This review will discuss the tracers already evaluated in clinical trials and summarize the preliminary outcome. It will also give an overview on recent developments to further optimize the first-generation compounds such as [18F]Galacto-RGD. This includes recently developed18F-labeling strategies and also new approaches in68Ga-complex chemistry. Furthermore, the approaches to develop radiopharmaceuticals targeting integrinα5β1andαvβ6will be summarized and discussed.

Modeling and Simulation for One Leg of Quadruped Robot Trajectory

2016 ◽  
Vol 826 ◽  
pp. 140-145
Author(s):  
Hasrul Che Shamsudin ◽  
Mohammad Afif Ayob ◽  
Wan Nurshazwani Wan Zakaria ◽  
Mohamad Fauzi Zakaria
Keyword(s):  
First Generation ◽  
Open Loop ◽  
Quadruped Robot ◽  
Movement Planning ◽  
Android Apps ◽  
Robot Trajectory ◽  
Real Model ◽  
Zero Position ◽  
Forward Kinematic

In legged robot movement planning, the leg must be carefully design before trajectory analysis can be done. The objective of this paper is to develop a 3 DOF leg which will be used in quadruped robot. In addition, forward kinematic and comparison between real and simulation of the leg is presented. To achieve the objective, SolidWorks 2013 x64 Edition is used to develop the 3D modeling of the leg while SimMechanics with First Generation Format was applied to export the models to Simulink. For the comparison purposes, real model of 3 DOF leg with Arduino Pro Mini 328 - 5V/16MHz as a microcontroller to control the rotation of three servomotors was constructed. With MIT AI2 Companion software, android apps is developed to send signal to rotate each servomotor wirelessly. The zero position of the leg robot has been determined and the maximum rotation range of each servomotor. This is very important in determination of D-H Parameters which allow the resolving of kinematics problems. It is found that specific rotations of each servomotor provide the trajectory pattern of the leg which is compared through Simulink and real model. Nevertheless, there are errors between simulation and real position of the robot leg due to the open loop system.

Sign in / Sign up

Export Citation Format

Share Document