Tektites

The initial intent of this paper was dedicated to the task of presenting very simple methods to determine meteorites as well as tektites that could be easily performed by anyone. As this paper developed, it now also describes a new method in the form of a very simple device that has been developed and can be performed for the measurement of magnetic susceptibilities of minerals and rocks. Simple, straightforward and versatile, the main features of the apparatus are economical utilising equipment at everyone's disposal. The paper also introduces a proposed new approach to a Magnetic susceptibility Logχ ordinal scale that distinctly shows ordered qualitative characteristics such as, mineral diversity, groupings of visible optical properties attributed to their magnetic nature and is possibly the easiest method for determining the differentiation between the tektite-strewn fields, other impactite glasses and obsidian. These results have led to interesting conclusions that not only complement the current body of knowledge with new theories but also lead to new potential directions of research that could be investigated. Such as how magnetism could play a role in accretion, the final clumping and unification of small matter, as it is believed that all matter attracts other matter to it through gravity as all atoms are magnetic i.e. they have charges moving around within them and that a relation between gravity and electromagnetism exists. This is based on a formula that show that it is the cross-sectional surface area between two magnetic rocks that lead to an interaction of two masses dipped into a surrounding space, where it is clearly seen that a lower pressure " shading force " exists between them based on their masses and cross-sectional areas, which has two main known physical properties currently attributed to it, permeability and Permittivity and could be a description of the property of gravity as defined by Maxwell's equations.

In this paper we explore Aboriginal oral traditions that relate to Australian meteorite craters. Using the literature, first-hand ethnographic records and fieldtrip data, we identify oral traditions and artworks associated with four impact sites: Gosses Bluff, Henbury, Liverpool and Wolfe Creek. Oral traditions describe impact origins for Gosses Bluff, Henbury and Wolfe Creek Craters, and non-impact origins for Liverpool Crater, with Henbury and Wolfe Creek stories having both impact and non-impact origins. Three impact sites that are believed to have been formed during human habitation of Australia. Dalgaranga, Veevers, and Boxhole do not have associated oral traditions that are reported in the literature.

В книге рассмотрены вопросы исследования земных
кратеров и происхождения тектитов на нашей планете.
Новые данные, связанные с необычными регистрациями на Тасмании в период Тунгусского феномена в 1908 г., с большой вероятностью позволяют решить его проблему.

В различных регионах Земли известны т.н. криптовзрывные структуры — линейные цепочки кратеров и полей диатрем, включая кимберлитовые. Долгое время их относили к эндогенным, но появилась и до сих пор доминирует метеоритно-ударная версия. Борьба доктрин длилась десятилетия, касаясь, в основном, известных структур: 1) кратеров Рис и Штайнхайм и соседнего с ними поля диатрем Урах, Германия; 2) кратеров и кимберлитовых полей структур Бушвельд—Вредефорт—Тромсбург, ЮАР; 3) кратеров Уэллс Крик и Хикс и диатрем поля Эйвон, США.
Поскольку кратер Рис связывают с удаленными от него молдавитами, решение проблемы криптовзрывных структур касается и тектитов.

Для астро- и геофизиков, а также широкого круга читателей, интересующихся метеоритами и планетологией.

Australasian tektites (AAT) occur across Southeast Asia, Australia, the Indian Ocean, and southwest Pacific Ocean. AAT form the youngest and most extensive major tektite strewn field, yet they have no known source crater. Review of the literature established that a single c. 40 km post-impact diameter crater exists, probably significantly enlarged by slumping. The oblique impact would be less pervasive in depth but would have resulted in greater downrange shock effects and melt ejection. Multiple lines of evidence, historically viewed in isolation, were examined, concatenated, contextualised, and discussed. Tektite morphology and distribution; ejecta ray regressions; microtektite regressions; geochemical considerations and iso-concentration regressions; lithology, characteristics, and age of source rock; and regional geological considerations were reviewed. The source material was predicted to be an abnormally thick sequence of poorly compacted, deltaic to shallow marine, clay-rich siltstones of early Pleistocene to late Miocene age. Fifty maps of positive and negative parameters were produced and overlain, indicating the AAT source crater probably lies in the central to northwestern Song Hong-Yinggehai Basin / Gulf of Tonkin. This geochemically optimal setting is characterised by exceptionally high sedimentation rates that explain the 10 Be and Rb-Sr age discrepancy and apparent absence of a crater by rapid burial.

Arguing from a critical reading of the text, and scientific evidence on the ground, the authors show that the myth of Phaethon – the delinquent celestial charioteer – remembers the impact of a massive meteorite that hit the Chiemgau region in Bavaria between 2000 and 428 BC.

Sangad Bunopas published extensively on the geology of Thailand and left a legacy of maps, reports, stratigraphic nomenclature and insightful papers covering most of the kingdom. His 1981 PhD thesis published in 1982 laid the foundation of modern Thai stratigraphy. His highly cited papers on the tectonics of South East Asia, often with Professor Paul Vella, were based on Sangad's extraordinary first-hand knowledge of Thai geology which allowed him to draw the first reliable tectonic subdivisions of the whole country. Although controversial at the time, these tectonic subdivisions and hypotheses have since been accepted as generally correct in that the Shan-Thai Terrane (as part of Sibumasu) rifted from Australian crust in the early Permian, drifted and warmed as it crossed the Palaeotethyan Ocean and collided with the Indochina Terrane in the late Triassic. His stimulating palaeomagnetically constrained, combined palinspastic-palaeogeographic maps for the Permian to Cenozoic were well in advance at the time and have not been attempted again in the subsequent 40 years. His controversial later work, which attempted to explain the widespread, anomalous loess in northeast Thailand, the Australasian tektite strewn field, the fluvial deposits in Nakhon Ratchasima (Khorat) Province and their middle Pleistocene faunas and flora as the result of a cometary impact at 788 ka has received some support and some criticism but has nevertheless stimulated a considerable research and a lot of discussion. Over more than 50 years, Sangad made many major contributions to Thai geology, South East Asian tectonics and meteoritic research. His wit, wisdom and iconoclastic approach to earth and planetary science will be sorely missed by his numerous friends and colleagues.

Sangad Bunopas published extensively on the geology of Thailand and left a legacy of maps, reports, stratigraphic nomenclature and insightful papers covering most of the kingdom. His 1981 PhD thesis published in 1982 laid the foundation of modern Thai stratigraphy. His highly cited papers on the tectonics of South East Asia, often with Professor Paul Vella, were based on Sangad's extraordinary first-hand knowledge of Thai geology which allowed him to draw the first reliable tectonic subdivisions of the whole country. Although controversial at the time, these tectonic subdivisions and hypotheses have since been accepted as generally correct in that the Shan-Thai Terrane (as part of Sibumasu) rifted from Australian crust in the early Permian, drifted and warmed as it crossed the Palaeotethyan Ocean and collided with the Indochina Terrane in the late Triassic. His stimulating palaeomagnetically constrained, combined palinspastic-palaeogeographic maps for the Permian to Cenozoic were well in advance at the time and have not been attempted again in the subsequent 40 years. His controversial later work, which attempted to explain the widespread, anomalous loess in northeast Thailand, the Australasian tektite strewn field, the fluvial deposits in Nakhon Ratchasima (Khorat) Province and their middle Pleistocene faunas and flora as the result of a cometary impact at 788 ka has received some support and some criticism but has nevertheless stimulated a considerable research and a lot of discussion. Over more than 50 years, Sangad made many major contributions to Thai geology, South East Asian tectonics and meteoritic research. His wit, wisdom and iconoclastic approach to earth and planetary science will be sorely missed by his numerous friends and colleagues.

Although a crater is not yet identified, the Australasian tektite strewn field provides evidence that a major impact cratering event took place in the Southeast Asian region at f 0.8 Ma, just prior to the Brunhes/Matuyama geomagnetic polarity reversal. Paleomagnetic evidence including reversed polarity in mud lens closely associated with in situ tektites suggests that tektitebearing flood deposits near Ban Ta Chang and Chum Phuang in northeast Thailand are penecontemporaneous with the impact event. The deposits include abundant organic debris, including whole tree trunks and mammal bones, that preserved due to reducing conditions, which are also responsible for the presence of abundant iron sulphides. Sedimentological observations suggest a series of major flood events that are out of character with the modern meandering river system to which they are related. The deposits are consistent with the effects of regional deforestation, increased run off and erosion, and other environmental disruptions expected in the aftermath of a major impact event. D

Tektites are formed from silica-rich terrestrial deposits that are melted and ejected by cosmic impacts. The tektites re-enter the atmosphere minutes later. It takes special circumstances to form tektites. The target rock must be siliceous, which is the main reason tektites are not expected on most planetary bodies; the impact must be of sufficient size; an oblique impact of around 30 degrees (Artemieva and Pierazzo 2003) optimizes tektite production and a high velocity impact will likely aid tektite production and ejection. The Australasian strewnfield, being the youngest and freshest, affords us a unique insight into tektite formation and the aftermath of cosmic impacts. Tektites are usually reworked into porous and permeable gravel and then etched to non-existence. The remaining tektites will devitrify and turn to clay minerals, obliterating the geological record; hence the absence of true tektites older than the Tertiary period. When an asteroid or comet impacts the planetary surface, the kinetic energy melts the terrestrial rock. Sedimentary sands and shales, which are high in silica, are ideal for tektite production. Some of the momentum of the impactor is conserved and passed on to the melted rock. The lower the impact angle, the more effectively the momentum can be transferred to the melted rock. The melted rock must, however, traverse the dense atmosphere. An impact/ ejection angle that is too oblique prevents the melted rock effectively leaving the atmosphere (Artemieva and Pierazzo 2003). The melted rock is not ejected as individual tektites, which would be rapidly stopped by the dense atmosphere of the Earth. Instead, as with a splash of water, the melted rock is ejected as a sheet (Fig 1.). This sheet is eventually disrupted and breaks into isolated tektite droplets. By this stage, though, the melt sheet has passed through the densest layers of the atmosphere and there is little in the way of atmospheric impedance to stop these tektites. For roughly every 5.5 km ascended, the atmospheric pressure halves. So, roughly 50°/o of the atmosphere lies below 5.5 km; 7 5°/o below 11 km; 87 .5°/o below 16.5km; 93.8°/o below 22 km; 96.9°/o below 27.5 km; 98.4°/o below 33 km; and 99 .2°/o below 38.5 km. It is clear that by the time the melt sheet is disrupted and the small isolated tektite bodies start their journey, the dense atmosphere below is no longer an issue until they return to Earth. .:-· .,.

Tektites exhibit many different surface sculptures. A distinction is made between primary and secondary surface sculptures (although differentiation may sometimes be difficult). One common secondary surface feature is pitting caused by chemical corrosion, most commonly associated with acidic waters. There is a similar sculpture, but one which is considered to be a primary surface feature, herein described as ‘snake-skin’ surface sculpture due to its scale-like appearance (Fig. 1).

Introduction: Tektites exhibit many different surface sculptures. A distinction is made between primary and secondary surface sculptures (although differentiation may sometimes be difficult). One common secondary surface feature is pitting caused by chemical corrosion, most commonly associated with acidic waters. There is a similar sculpture, but one which is considered to be a primary surface feature, herein described as ‘snake-skin’ surface sculpture due to its scale-like appearance (Fig. 1).

Carbonados are aggregate polycrystalline diamonds and are found in placer deposits of the Central African Republic (CAR) and the Bahia Province of Brazil. Their origin is uncertain, but several mutually exclusive hypotheses have been proposed ranging from extraterrestrial to crustal, and mantle provenance. In an endeavor to further our understanding of these diamonds, we performed a series of magnetic characterization studies on 20 samples from the CAR. Our results reveal that the carbonados contain material with contrasting magnetic hysteresis behavior and magnetization, Acid leaching permitted us to monitor the distribution of magnetic carriers within the samples. An absence of sample size dependence on magnetization loss indicates that the magnetic carriers are distributed at the vitreous surface; including open pores and that the carbonade interior is essentially devoid of the magnetic carriers. The diamond's isolated nonmagnetic interior of carbonados suggests that the initial formation environment was deficient in magnetic particles. The formation of the magnetic carriers is thus closely linked with the origin of the smooth surface, perhaps during the hypervelocity ejection of carbonados into the Earth's atmosphere. Partial ablation in the Earth's primordial, oxygen-poor atmosphere resulted in a fusion of the originally porous material and a decrease in the original pore density at the surface. Secondary mineralization of the impact-generated melt and/or the products of later diagenetic processes, containing the majority of the magnetic carriers, filled the remainder of the open pores

Australasian tektites (AAT) occur across Southeast Asia, Australia, the Indian Ocean, and southwest Pacific Ocean. AAT form the youngest and most extensive major tektite strewn field. Unlike other tektite strewn fields, AAT have no known source crater. Review of the literature establishes that a single ~ 43 km post-impact diameter crater exists, possibly significantly enlarged by slumping. The obliquity of the impact that formed the AAT would result in a crater that is less pervasive in depth but with greater downrange shock effects and melt ejection. Multiple lines of evidence, historically viewed in isolation, were examined, concatenated, contextualized, and discussed. Tektite morphology and distribution; microtektite regressions; geochemical considerations, comparisons, and iso-concentration regressions; lithological characteristics; age of source rock; and regional geological considerations are reviewed. The source material is predicted to be an abnormally thick sequence of rapidly deposited, poorly compacted, deltaic to shallow marine, shales to clay-rich siltstones of early Pleistocene to Pliocene age. The impact likely occurred in a shallow marine environment. Fortytwo maps of positive and negative parameters are presented and overlain. These indicate the AAT source crater probably lies in the central to northwestern Yinggehai-Song Hong Basin / Gulf of Tonkin. This geochemically optimal setting is characterized by exceptionally high sedimentation rates that explain the 10 Be and Rb-Sr age discrepancy, the seawater signature, and apparent absence of a crater by rapid burial.

The Australasian tektite strewn field is the youngest of the major strewn fields. Tektites fell over 16-18 percent of the Earth's surface. The distal ejecta has a strongly down-range distribution pattern, indicative of an oblique impact from the north-northwest. The estimated size of the source crater is ~40 km diameter, based on a calculated ejecta layer thickness from microtektite concentrations [1]. Evidence is reviewed, a general source crater location suggested and a strong candidate structure identified.

The circa 14 km diameter Pantasma circular structure in Oligocene volcanic rocks in Nicaragua is here studied for the first time to understand its origin. Geomorphology, field mapping, petrographic and geochemical investigations all are consistent with an impact origin for the Pantasma structure. Observations supporting an impact origin include outward-dipping volcanic flows, the presence of former melt-bearing polymict breccia, impact glass (with lechatelierite and low H 2 O, < 300 ppm), and also a possible ejecta layer containing Paleozoic rocks which originated from hundreds of meters below the surface. Diagnostic evidence for impact is provided by detection in impact glass of the former presence of reidite in granular zircon as well as coesite, and extra-terrestrial  54 Cr value in polymict breccia. Two 40 Ar/ 39 Ar plateau ages with a combined weighted mean age of 815 ± 11 ka (2 σ; P=0.17) were obtained on impact glass. This age is consistent with geomorphological data and erosion modeling, which all suggest a rather young crater. Pantasma is only the fourth exposed crater > 10 km found in the Americas

In 2010 the primary author (1) purchased an unusual tektite (Fig. 1) from an online seller in China. The specimen is reportedly from Guangdong Province, China. Precise locality details are not known. The tektite is the only indisputably agglutinated macrotektite known to the authors. Suspected, but questionable, agglutinated macrotektites have previously been reported in indochinites (some also noted as coming from Guangdong Province) [1] [2] [3].

Avalanches and debris flows caused by catastrophic events such as volcanic eruptions can be seen as huge granular flows. Due to the impossibility ofprediction and danger of such events, given the high temperatures and the moving masses involved, their study is limited to remote observation and measurement of the deposits generated. The observation of these phenomena from the beginning is almost impossible because the start and development are extremely short and impossible to predict accurately; furthermore, it has to be done from a considerable distance. The study of deposited material provides important information, but it is still an indirect method to infer the dynamics of a debris flow. This article describes the characteristics of the device GRANFLOW-SIM (Granular Flows Simulator), its sensors, and the type of studies that it is able to do. GRANFLOW-SIM is the first experimental unit of its kind designed and built in Mexico to study and simulate different types of granular flo...

The witness and cultural impact of meteorite falls and cosmic impacts has been studied extensively in some world cultures, including cultures of Europe, China, and the Middle East. However, ethnographic records and oral traditions of meteorite falls in Aboriginal culture remain relatively unknown to the scientific community. Various Aboriginal stories from across Australia describe meteorite falls with seemingly accurate detail, frequently citing a specific location, including Wilcannia, NSW; Meteor Island, WA; Hermannsburg, NT; McGrath Flat, SA; and Bodena, NSW among others. Most of these falls and impact sites are unknown to Western science. In addition, some confirmed impact structures are described in Aboriginal lore as having cosmic origins, including the Gosse's Bluff and Wolfe Creek craters. This paper attempts to analyse and synthesize the plethora of fragmented historic, archaeological, and ethnographic data that describe meteorite falls and cosmic impacts in the mythologies and oral traditions spanning the 300+ distinct Aboriginal groups of Australia. Where applicable, coordinates of the reputed falls and impacts are cited in order for future inspections of these sights for evidence of meteoritic masterial or impact cratering.

There is increasing evidence that confirms the existence of the Acheulean or Acheulean-like technology at sites in Southeast and East Asia, especially for its earliest appearance at ~0.8 Ma, and two competing hypotheses have been proposed to interpret its origins. Regardless of whether this technology is due to Acheulean population movements or to independent invention, however, one clear feature of these earlier sites is the significantly low lithic densities and infrequent numbers of Large Cutting Tools (LCTs) (e.g., for sites in the Bose Basin). Various hypotheses have been proposed to account for these low artefact densities. In this paper, we consider the in- terplay between cataclysmic events in the environment and population dynamics during the Acheulean in the Bose Basin, which has received little attention with regard to ecology. We focus on two sudden pene- contemporaneous geological events at ~0.8 Ma: the Australasian tektite fall and the oldest Toba super-eruption, both of which have been well documented in Southeast Asia and the southern part of South China and have been confirmed as causing severe environmental change (e.g., deforestation). We propose that this destruction of the original habitat created a population bottleneck effect for the toolmakers, who very likely occupied the land- scape at approximately the same time as the cataclysms. This study broadens our understanding of the regional character of the Acheulean sites in Southeast and East Asia, and it provides an interesting case study that highlights the potential relationship between Acheulean population dynamics and sudden environmental change.

Impact craters on geologically inactive worlds such as the Moon or Mercury, clearly exhibit crater ray systems. The pattern of the rays is principally determined by the obliquity of the impact. The Earth has an atmosphere which, to some degree, will repress ray formation. It is inferred, however, that medial and distal tektites (e.g. Philippinites & Australites) were still molten and forming above 99% of the atmosphere. As early as 1912 [1] rays of tektite material were recognized in Australia. Uneven tektite distribution patterns, suggestive of rays, have also been noted in SE Asia. A distinct ray in the Philippines passes through the north of Metro Manila, through the northern Bikol region and into the Pacific Ocean. Tektite rays are defined by higher concentrations of material and larger than average sized tektites for the region.

Primary tektite morphologies are de-rived through rotation. This was recognized as early as 1934 [1]. Historically, primary forms are spheres, variably prolate spheroids, spheroidal dumbbells and spheroidal apioids. Almost all tektites demonstrate a 'flattening' of spheroidal morphologies to ellipsoidal. In the proximal setting, e.g. indochinites, the trend continues to biconvex, plano-convex, concavo-convex and bi-concave discs to tori (as fragments). It is suggested by [2] & [3] that centrifugal forces in a rolling motion trend a sphere to an oblate (discoidal) form. As the rolling becomes a tumbling motion, discs irreversibly evolve to prolate forms (including dumbbells). No atmospheric interaction is implied and therefore all morphologies are considered primary.

Avalanches and debris flows caused by catastrophic events such as volcanic eruptions can be seen as huge granular flows. Due to the impossibility ofprediction and danger of such events, given the high temperatures and the moving masses involved, their study is limited to remote observation and measurement of the deposits generated. The observation of these phenomena from the beginning is almost impossible because the start and development are extremely short and impossible to predict accurately; furthermore, it has to be done from a considerable distance. The study of deposited material provides important information, but it is still an indirect method to infer the dynamics of a debris flow. This article describes the characteristics of the device GRANFLOW-SIM (Granular Flows Simulator), its sensors, and the type of studies that it is able to do. GRANFLOW-SIM is the first experimental unit of its kind designed and built in Mexico to study and simulate different types of granular flo...

The australite fall sites in S. Australia at 10 km/s require loft times of 7.5 hrs from Indochina and 112.5 deg Earth spin, inconsistent with a launch from that same hemisphere. Alternative AA source regions must explain these imprint elements.

Introduction: In the early phase of investigations in the northern part of the proposed Chiemgau meteorite impact strewn field in southeast Germany [1] the strong magnetic signature of smaller crater-like structures [2, 3] raised attention as did extens- ive soil magnetic susceptibility measurements in forests that re- vealed significantly enhanced values at some decimeter depth [4]. The authors exclude industrial and geologic delivery but avoid to discuss a third possibility. Such a possibility was later introduced when similar horizons with peak magnetic susceptibilities where found also in the southern part of the strewn field where they were associated with various peculiar components such as frac- tured pebbles, cindery glass and carbonaceous spherules [1]. Here we report on one of these locations at Eglsee near Lake Chiemsee where we have studied the content of the anomalous soil horizon of enhanced susceptibility with a focus on the glass and glass-like particles. We treated the soil samples with nearly the same procedures described in [5] for unconsolidated samples, and used optical microscopy for the investigations.
Observations: The dark, clayey to sandy soil horizon under discussion is inserted in a loamy layer over glacial gravels at 0.5- 1 m depth. The sandy fraction consists dominantly of angular quartz and quartz-rich rock fragments along with rounded com- ponents. A small part of the grains of millimeter and submilli- meter size show very unusual features: - brownish to yellow translucent glass with irregular and fragile shapes,  glass cementing mineral and rock grains, - black humpy spheroids exhibiting beginning melting, - components of bottle or teardrop shape.
Discussion: The unusual composition and mixture excludes a common natural soil, farming and other human activities, and the depth points to a preindustrial age. Not any artifacts were ob- served. Melted soil material from wildfires is unlikely because of lacking charcoal. Glassy material from Holocene explosive vol- canism would require a transport over more than 750 km (Mount Vesuvius, Italy). Reworked material from former events can be excluded because of the presence of very fragile particles and the distance to pre-ice age sediments of more than 10 km. From the obvious similarity of the horizon with layers of comparable facies containing microtektites [5, 6] we suggest the Eglsee layer to be also of impact origin possibly as a distal ejecta layer having ori- ginated from one or more of the proposed craters in the Chiemgau impact event. Another confirmed impact event of spa- tio-temporal relationship is unknown [7].
References:
[1] K. Ernstson et al. 2010. Journal of Siberian Federal Uni- versity Engineering & Technologies 1, (2010 3):72-103. [2] Rösler, W. et al. (2006). ESA First International Conference on Impact Cratering in the Solar System, ESTEC, Noordwijk, Neth- erland. [3] Hoffmann, V. et al. 2005. Meteoritics & Planetary Science 40:A129. [4] Hoffmann, V. et al. (2004). Paneth-Kolloquium Nördlingen, Germany. [5] Glass, B. P. and Si- monson, B. M. 2013. Distal Impact Ejecta Layers. [6] Glass, B. P. and Simonson, B. M. 2012. Elements 8:43-48. [7] Earth Im- pact Database http://www.passc.net/EarthImpactDatabase/