Disintegrated Comet Trail in Southern Tibet

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 δ 18 O 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 these lakes can be observed hinting towards placer mining activity associated with lakes (craters). Our study suggests that the diamonds, Platinum Group Elements, Stishovite and other alloys harvested from the region should be considered as comet impact diamonds rather than those created in the interior of the earth.

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 these lakes can be observed hinting towards placer mining activity associated with lakes (craters). Our study suggests that the diamonds, Platinum Group Elements, Stishovite and other alloys harvested from the region should be considered as comet impact diamonds rather than those created in the interior of the earth.

Introduction
Tibet has several types of lakes some of them are freshwater whereas others are saline or saltwater lakes. For formation of these lakes multiple theories like the plate tectonics and glacial activity are proposed. However it's a complex network and cannot be justified under a single mechanism. In this study, we propose that most of the lakes between the latitudes of 82˚30'E and 90˚30'E longitudes 29˚N Meteorites, asteroids and comets have collided with the earth in the past, many leaving their imprint in the form of craters. Comet impact craters are different from asteroids because of their size, velocity, strength and density. Comet Nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small rocky particles, The Comets are distinguished from asteroids by the presence of an "extended, gravitationally unbound atmosphere" surrounding their central nucleus as a result comet has different entry and impact pattern. On one hand its composition makes it very fragile body which will break easily under influence of gravitational and frictional force, however since it has its own atmosphere it will act as cushion while making entry into the earth's atmosphere and will substantially reduce the friction, avoiding vaporization in the path allowing most of the material to fall on the earth. Hence comet impact will scatter over a large area. On the surface of the The impact of small bodies is controlled by our atmosphere which acts as a shield and vaporizes them before they can touch the ground. For larger bodies, the crater depends on their composition and fragmentation in the atmosphere.

Comet and Impact Patterns
Examples like those of Comet Shoemaker Levy 9 [5] show that it is not unusual for comets to break up into multiple pieces due to gravitational gradients around a large planet. Earth, because it's a small planet, such gravitational gradients are small, probably not enough to break comet, like shoemaker broke in to 21 pieces but due to radiation effects in terrestrial planet region comet will become fragile enough to break under Earth's gravitational gradient hence collision of such nature would, therefore, create a series of impressions on the ground. Then there are tektites, small, glassy aerodynamical dusty earth material, which is thrown outward from the earth as ejecta by an impact and re arrive on earth after travelling through the atmosphere on their ballistic trajectory. The study of comet impact of Sahara desert show desert glass spread over 6000 sq.km. is possible because of similar entry and impact pattern. The study indicates that the series of lakes seen in southern Tibet were caused by the impact of one such disintegrating comet. This Impact pattern to be known as Shoemaker-Vyas Pattern (SVP) in the respect of visionary personalities ( Figure 1).
Based on the SVP impact patterns and other findings like tektites, micro diamonds, series of lakes/dry lakes in sites like Egypt, South Australia Glikson A.
(2013) [6] and few other possible comet impact sites can be studied.

Other Possible Comet Impact Site under Study and Features as per Proposed Pattern
Sahara comet collision and Diamond-Andrew Fazeka (Oct 2013)-National Geographic [7]. The Sahara Desert, Comet Impact is under study as per current theory comet busted in mid-air over this region, however, features on the ground are similar to proposed impact pattern (SVP) and can be observed over approximately 900 km of the proposed impact zone. Each of the proposed circular features is approximately 25 km in diameter ( Figure 2). Since it's a desert area many such features will be covered by sand.
Unique Chemistry Of Diamond Bearing Pebble From The Libyan Desert Glass Strewnfield, SW Egypt: Evidence For Shocked Comet Fragment, this glass is spread over a large area of Sahara close to 6000 sq.km., Chemical Analysis confirm the origin from the comet nucleus, It was created as a result of heated sand at 2000˚C.

Factor
Comet Asteroid Gravity Radiation will make comet fragile enough so gravitational gradient may break the comet before it enters the atmosphere, hence each fragment enter over a period of time Most of the time It remains un affected hence enter as one unit

Friction with Earths Atmosphere
Comet has its own atmosphere with inert gases as a result its nuclei does not come in direct friction hence may not burn but will disintegrate Asteroid Starts burning due to friction

Lakes Features
We identify a region between 82˚30'E and 90˚30'E and 29˚N and 33˚N in southern Tibet (Figure 3). The top panel shows the region of Tibet studied here. The second panel shows the lake region marked in Figure 3A. The third panel shows the marking of each lake in the region. As can be seen from the figure, the craters seem to be roughly aligned. In Table 1 below we give the property of the lakes.

Lake Characteristics (Based on Google Map Images)
1) Most of them have a circular/oval shape on one side.

Circumstantial Evidence in the Subject Site (Based on Google Map Images)
Industrial units near the origin of rivers starting from these lakes indicate alluvial/Placer mining activity (Figure 4) Fang (2007) [2] discusses diamonds and ultrahigh pressure minerals found in Tibet are incorporated in the chromitites in the deep upper mantle or they are result of impact but since there is "absence of evidence" of impact, study is indicating its origin from earth's mantle this is in sharp contrast with Sahara Diamond case since even in Sahara no impact crater has been identified for Comet impact but detailed investigation of Diamond is carried out to prove its origin.

1) Association of Diamond and Coesite is surprise find, it occurs mainly in
UHP metamorphic rock in meteorite impact craters. 2) These diamonds UHP minerals in Luobusa chromitites can originate either from deep earth source or meteorite impact. However, these minerals have a shallow origin. Only in absence of evidence of meteorite impact study is concluding that it has the origin in deep upper mantle. This need to be reviewed.
3) Presence of PGE is again characteristic of impact.
4) The Unique case of kyanite along with Ti and Osbornite (TiN) must be seen in co-relation with NASA study of comet dust "Comet 81p/Wild2" [8] which confirms the presence of Ti in comet.

Raman Peak
Kyanite: Study of Dr. Fang [2] the apparently amorphous phase with variable composition yielded no Raman peaks in the entire spectrum from 140 to 4000 cm -1 . Its composition does not match any known mineral or natural melt. Hence Kyanite association with Ti must be reviewed from the impact perspective.

2) Osbornite (TiN): Laser-Raman spectroscopic and XPS Study conducted by
Prof. G. Parthasarthy [9] also strongly recommend extraterrestrial origin. Mr. Xu-Feng [10] Study also Indicate the Presence of Following Alloys  In Cr-c alloy Cr is not native.  Fractured shiny grains of Fe-Si alloy are found which he is trying to co-relate with findings in other parts of the world which are formed by the impact of lightning (but to our knowledge Tibet is not known for such heavy lightning) so the source of impact need review.  Many complex alloys and minerals that are detected are similar to minerals found near impact sites e.g. Zircon, Garnet.
 Formation of so many alloys itself create doubt about the formation process.

Tektites
Tektites have been reported from placer deposits and dry lake beds (unconfirmed sources) are a strong evidence of impact.
Neighborhood Occurrence: Vietnam, Laos, Cambodia and in some cases found in Thailand and China (Indochinites).
As on date, it is believed that Indochinites are of Australian Strewn field, however, no impact crater has been identified. Australian Tektites are concentrated in southern Australia hence neither plate tectonics, nor ocean current can explain their presence in mainland of places like Laos, Vietnam. The main source of this spread is the Mekong which originates from Tibet. Hence these Tektites are from Independent strewn possibly from Tibet ( Figure 6).

Sample Collection and Its Limitations to Impact Theory
Mr. Xu-Feng [10] has reported sample from 2913.86N, 9211.32E and Prof. Fang Qing-Song in his report also mentioned sample collection from Yarlung-Zangbo Suture Zone of Tibet.
This location is 200 -300 Km away from proposed impact zone and is on the river bank (the river is originating from the proposed zone) Hence diamonds can be found in the river bed but finding impact evidence at such distances is difficult. To get the correct perspective on the origin of diamond it is prudent to test sample from the origin of the river rather than searching it in sediments of the river. Samples should be collected from lakes like Dagze co to obtain complete clarity about its origin.

Conclusions
On the basis of Diamonds, PGE and other alloys found in Tibet with ambiguity about its origin, Ti-rich Kyanite, Tektites, proximity of lakes and their shapes with crater-like features, D level data and Oxygen 18 study data indicating origin/fluctuation at close to 6000 years, we would like to propose that disintegrated comet has collided in the Tibetan region between the latitudes of 82˚30'E and 90˚30'E and 29˚N and 33˚N approximately 6000 years back forming series of large impact craters. A fresh study of the sample from the proposed region will help to obtain better clarity.
This study has taken reference and inspiration from story of ancient literature which talks about similar event in the region.