Several significant events of a geological nature occurred approximately 800 ka before the present: (1) Australasian tektite fall (AA), (2) Brunhes-Matuyama geomagnetic reversal (BMR), (3) mid-Pleistocene changes in i...Several significant events of a geological nature occurred approximately 800 ka before the present: (1) Australasian tektite fall (AA), (2) Brunhes-Matuyama geomagnetic reversal (BMR), (3) mid-Pleistocene changes in ice age cycles. Add to these the undated fault system (4) in the South-West (SW) of the South China Sea (SCS). Here we offer a unified cause for all four of these in (5), an impact in the SCS of a large, massive cosmic object, likely a comet, obliquely coming from the SW at an extremely shallow angle, striking the Sunda shelf yet unexploded with the shock of its compressed air bow wave, and causing the continual shelf and slope to collapse, resulting in the fault system (4), then traveling almost tangentially to the surface, exploding at impact with the sea surface, ejecting the tektites (1), creating the formation underlying the later atolls of Spratlies Archipelago (6), Nansha Islands in Chinese, & causing the BMR (2). An explanation of event (3) was Richard Muller’s hypothesis of planet Earth passing through an interplanetary dust cloud periodically due to ecliptic precession. Here we hypothesize this cloud actually is a belt of Australasian tektites ejected into space at super-orbital velocities that Earth encounters about every 100 ka.展开更多
In the present age,the potential threat to space projects coming from some intense meteor storms has been noticed.Especially,the increasing activities of mankind in space for scientific,commercial and military purpose...In the present age,the potential threat to space projects coming from some intense meteor storms has been noticed.Especially,the increasing activities of mankind in space for scientific,commercial and military purposes have led to an increase in safety-related problems about the satellites,space stations and astronauts.Several new techniques for observing meteors and meteor showers have been developed.However,how to estimate even predict the effect of an intense meteor shower should be further studied.The initial definition about a meteor storm based on visual observations with a Zenithal Hourly Rate of over one thousand seems insufficient,since it only means a storm or burst of meteors in numbers.In 2006 the author suggested a synthetical index of the potential threats about intense activities of meteors;however,it is too complex to determine several parameters.In this paper,the author suggests a Special True Number Flux Density(STNFD).Set a certain energy-limit,or a certain electric-charge-limit,and then calculate the number flux density.Through the comparison between two of the 10 strong meteor showers in recent years it is found that the important factor affecting the space flight security is not only the number of meteoroids,but also their velocities,their average energy and the population index r.Calculations show that Giacobinids,even June Bootids,should be one of the most hazardous meteor showers.展开更多
This paper reports the recent discovery of 176 stone artifacts, including two handaxes (bifacial large cutting tools), which are preserved in the laterized sediments of terrace 4 of the Youjiang River at the Nanbansha...This paper reports the recent discovery of 176 stone artifacts, including two handaxes (bifacial large cutting tools), which are preserved in the laterized sediments of terrace 4 of the Youjiang River at the Nanbanshan locality of the Damei site in the Bose basin, south China. Their characteristics are similar to Paleolithic stone artifacts discovered from other sites in this basin. The handaxes, picks and other stone artifacts are associated with 155 tektite pieces found in the same horizontal layer. These fresh, unabraded and sharp-edged tektites were buried immediately after the airfall event. This provides fur- ther evidence that the Bose stone artifacts and the tektites were deposited simultaneously around 0.8 Ma. More stone artifacts were also unearthed above the tektite layer, indicating that early humans in the area survived the event.展开更多
In the terrestrial planet zone, Comets start outgassing due to solar radiation. This can make comet composition fragile enough to break under the gravitational gradient. Examples like those of Comet Shoemaker-Levy 9 [...In the terrestrial planet zone, Comets start outgassing due to solar radiation. This can make comet composition fragile enough to break under the gravitational gradient. Examples like those of Comet Shoemaker-Levy 9 [1] show that it is not unusual for comets to disintegrate due to gravitational gradients. In the event of an impact of such a disintegrated comet on earth, multiple coherent impact craters will be distributed over a large area. The low-density porous composition of the comet will result in the formation of “large flat-floored craters” spread over a large area with a network of faults and fractures as described by Roddy and co-workers (Roddy, 1976;Roddy et al., 1977) [2] [3]. Due to its unusual appearance these impacts patterns are different than rock/metal asteroid impact craters. As a result, these sites are difficult to identify. There are multiple such sites on the planet earth which are under study for impact but due to complex nature of comet impact craters, they have been a conundrum for some time. One such possible site matching the comet impact features can be observed in the southern Tibet between the latitudes of 82°30'E and 90°30'E and 29°N and 33°N. This study indicates that the lakes in this region were formed by the impact of a single disintegrating comet that hit the region. Observation indicates that the lakes are unusually closely aligned and have a steep slope facing circular feature on the eastern side. Fractures and faults connecting these lakes can be observed over entire subject site hinting towards the multiple impact craters. These craters are large flat-floored and spread over a large area. Gravitational anomaly in the lake region along with the presence of Ultra High Pressure (UHP) minerals like cubic Born Nitride, micro-diamond with the inclusion of Platinum Group Elements (PGE), coesite, Stishovite, osbornite and other complex finds in the region support the possibility of impact.展开更多
In southern Tibet, there is a series of lakes in the region (82°30'E, 29°N and 90°30'E, 33°N). This study indicates that these lakes were formed by the impact of a single disint...In southern Tibet, there is a series of lakes in the region (82°30'E, 29°N and 90°30'E, 33°N). This study indicates that these lakes were formed by the impact of a single disintegrating comet that hit the region. Observation indicates that the lakes are unusually closely aligned and have a steep slope facing circular feature on the eastern side. Fractures and faults connecting these lakes can be observed over entire subject site hinting towards the multiple impact craters. The terrain is uneven and lakes are partially filled hence in some cases do not look like circular or elliptical. These lakes vary from 1 Km to 65 Km in diameter and are linearly aligned around a single line. Studies of deuterium by Yuan et al. (2011) [1] indicate an abrupt 4‰ increase in δ18O in middle Holocene period around 6000 years ago. The study indicates that the region is rich in diamond, Coesite, Platinum Group Elements (PGE), Stishovite, tektites, and other complex alloys, as would be expected from a high energy impact of an extraterrestrial object. The possibility of the impact as one of the reasons for the diamond in this region was also suggested by Wen-Ji Bai and Qing-Song Fang (2007) [2]. However in absence of definitive evidence they favoured mantle origin. Two possible reasons of absence of impact signature are source of sample and impact pattern. First is the source of the sample which is collected from the river beds of Yarlung-Zangbo Suture Zone of Tibet which is believed to be the origin of this diamond, however it ignores the fact that these rivers get water from lakes which are in the proposed impact zone and the second reason is the impact-pattern spread over close to 800 km which is not expected from the asteroid impact. It will therefore be prudent to test samples from the lake region to understand surface distortion features to confirm the impact. Based on satellite imagery major industrial development supported by road infrastructure in the subject region near lakes and rivers originating from thes展开更多
Six tektites from Guilin of Guangxi, Hainan, and Guangdong were analyzed for the abundances of major elements and 27 trace elements. All samples are splash-form tektites and have SiO2 contents ranging from 73.1wt% to ...Six tektites from Guilin of Guangxi, Hainan, and Guangdong were analyzed for the abundances of major elements and 27 trace elements. All samples are splash-form tektites and have SiO2 contents ranging from 73.1wt% to 76.0wt% (74.6wt% on average). The chemical compositions, except Cr and Ni, of tektites from different areas, are similar. Guangdong tektite shows enrichments of Ni and Cr contents by a factor of 3, and has slightly higher MgO and FeO than Hainan and Guilin tektites. It indicates that the tektites were formed by mixing several target rocks. The major and trace element concentrations of southern China tektites closely resemble previously reported data for average splash-form and Muong Nong-type indochinites, indicating that they have the same source. (La/Lu)CI (7.99), Zr/Hf (35.45 on average), Ba/Rb (3.59 on average), and the rare earth element (REE) contents of tektites are similar to those of typical post Archean upper crustal rocks. This study suggests that the best fit for the target source of southern China tektites could be a combination of 41% shale, 2% sandstone, 20% greywacke, and 37% quartzite.展开更多
文摘Several significant events of a geological nature occurred approximately 800 ka before the present: (1) Australasian tektite fall (AA), (2) Brunhes-Matuyama geomagnetic reversal (BMR), (3) mid-Pleistocene changes in ice age cycles. Add to these the undated fault system (4) in the South-West (SW) of the South China Sea (SCS). Here we offer a unified cause for all four of these in (5), an impact in the SCS of a large, massive cosmic object, likely a comet, obliquely coming from the SW at an extremely shallow angle, striking the Sunda shelf yet unexploded with the shock of its compressed air bow wave, and causing the continual shelf and slope to collapse, resulting in the fault system (4), then traveling almost tangentially to the surface, exploding at impact with the sea surface, ejecting the tektites (1), creating the formation underlying the later atolls of Spratlies Archipelago (6), Nansha Islands in Chinese, & causing the BMR (2). An explanation of event (3) was Richard Muller’s hypothesis of planet Earth passing through an interplanetary dust cloud periodically due to ecliptic precession. Here we hypothesize this cloud actually is a belt of Australasian tektites ejected into space at super-orbital velocities that Earth encounters about every 100 ka.
文摘In the present age,the potential threat to space projects coming from some intense meteor storms has been noticed.Especially,the increasing activities of mankind in space for scientific,commercial and military purposes have led to an increase in safety-related problems about the satellites,space stations and astronauts.Several new techniques for observing meteors and meteor showers have been developed.However,how to estimate even predict the effect of an intense meteor shower should be further studied.The initial definition about a meteor storm based on visual observations with a Zenithal Hourly Rate of over one thousand seems insufficient,since it only means a storm or burst of meteors in numbers.In 2006 the author suggested a synthetical index of the potential threats about intense activities of meteors;however,it is too complex to determine several parameters.In this paper,the author suggests a Special True Number Flux Density(STNFD).Set a certain energy-limit,or a certain electric-charge-limit,and then calculate the number flux density.Through the comparison between two of the 10 strong meteor showers in recent years it is found that the important factor affecting the space flight security is not only the number of meteoroids,but also their velocities,their average energy and the population index r.Calculations show that Giacobinids,even June Bootids,should be one of the most hazardous meteor showers.
基金the National Natural Science Foundation of China (Grant No. 40163001)
文摘This paper reports the recent discovery of 176 stone artifacts, including two handaxes (bifacial large cutting tools), which are preserved in the laterized sediments of terrace 4 of the Youjiang River at the Nanbanshan locality of the Damei site in the Bose basin, south China. Their characteristics are similar to Paleolithic stone artifacts discovered from other sites in this basin. The handaxes, picks and other stone artifacts are associated with 155 tektite pieces found in the same horizontal layer. These fresh, unabraded and sharp-edged tektites were buried immediately after the airfall event. This provides fur- ther evidence that the Bose stone artifacts and the tektites were deposited simultaneously around 0.8 Ma. More stone artifacts were also unearthed above the tektite layer, indicating that early humans in the area survived the event.
文摘In the terrestrial planet zone, Comets start outgassing due to solar radiation. This can make comet composition fragile enough to break under the gravitational gradient. Examples like those of Comet Shoemaker-Levy 9 [1] show that it is not unusual for comets to disintegrate due to gravitational gradients. In the event of an impact of such a disintegrated comet on earth, multiple coherent impact craters will be distributed over a large area. The low-density porous composition of the comet will result in the formation of “large flat-floored craters” spread over a large area with a network of faults and fractures as described by Roddy and co-workers (Roddy, 1976;Roddy et al., 1977) [2] [3]. Due to its unusual appearance these impacts patterns are different than rock/metal asteroid impact craters. As a result, these sites are difficult to identify. There are multiple such sites on the planet earth which are under study for impact but due to complex nature of comet impact craters, they have been a conundrum for some time. One such possible site matching the comet impact features can be observed in the southern Tibet between the latitudes of 82°30'E and 90°30'E and 29°N and 33°N. This study indicates that the lakes in this region were formed by the impact of a single disintegrating comet that hit the region. Observation indicates that the lakes are unusually closely aligned and have a steep slope facing circular feature on the eastern side. Fractures and faults connecting these lakes can be observed over entire subject site hinting towards the multiple impact craters. These craters are large flat-floored and spread over a large area. Gravitational anomaly in the lake region along with the presence of Ultra High Pressure (UHP) minerals like cubic Born Nitride, micro-diamond with the inclusion of Platinum Group Elements (PGE), coesite, Stishovite, osbornite and other complex finds in the region support the possibility of impact.
文摘In southern Tibet, there is a series of lakes in the region (82°30'E, 29°N and 90°30'E, 33°N). This study indicates that these lakes were formed by the impact of a single disintegrating comet that hit the region. Observation indicates that the lakes are unusually closely aligned and have a steep slope facing circular feature on the eastern side. Fractures and faults connecting these lakes can be observed over entire subject site hinting towards the multiple impact craters. The terrain is uneven and lakes are partially filled hence in some cases do not look like circular or elliptical. These lakes vary from 1 Km to 65 Km in diameter and are linearly aligned around a single line. Studies of deuterium by Yuan et al. (2011) [1] indicate an abrupt 4‰ increase in δ18O in middle Holocene period around 6000 years ago. The study indicates that the region is rich in diamond, Coesite, Platinum Group Elements (PGE), Stishovite, tektites, and other complex alloys, as would be expected from a high energy impact of an extraterrestrial object. The possibility of the impact as one of the reasons for the diamond in this region was also suggested by Wen-Ji Bai and Qing-Song Fang (2007) [2]. However in absence of definitive evidence they favoured mantle origin. Two possible reasons of absence of impact signature are source of sample and impact pattern. First is the source of the sample which is collected from the river beds of Yarlung-Zangbo Suture Zone of Tibet which is believed to be the origin of this diamond, however it ignores the fact that these rivers get water from lakes which are in the proposed impact zone and the second reason is the impact-pattern spread over close to 800 km which is not expected from the asteroid impact. It will therefore be prudent to test samples from the lake region to understand surface distortion features to confirm the impact. Based on satellite imagery major industrial development supported by road infrastructure in the subject region near lakes and rivers originating from thes
基金supported by National Natural Science Foundation of China (Grant Nos. 40773046 and 10621303)Minor Planet Foundation of China
文摘Six tektites from Guilin of Guangxi, Hainan, and Guangdong were analyzed for the abundances of major elements and 27 trace elements. All samples are splash-form tektites and have SiO2 contents ranging from 73.1wt% to 76.0wt% (74.6wt% on average). The chemical compositions, except Cr and Ni, of tektites from different areas, are similar. Guangdong tektite shows enrichments of Ni and Cr contents by a factor of 3, and has slightly higher MgO and FeO than Hainan and Guilin tektites. It indicates that the tektites were formed by mixing several target rocks. The major and trace element concentrations of southern China tektites closely resemble previously reported data for average splash-form and Muong Nong-type indochinites, indicating that they have the same source. (La/Lu)CI (7.99), Zr/Hf (35.45 on average), Ba/Rb (3.59 on average), and the rare earth element (REE) contents of tektites are similar to those of typical post Archean upper crustal rocks. This study suggests that the best fit for the target source of southern China tektites could be a combination of 41% shale, 2% sandstone, 20% greywacke, and 37% quartzite.
