Davao Region, Mindanao, Southern-most Philippines
Map indicates known tektite localities in the Philippines, from Beyer, H. O. 1962. We have been told that the locality for these tektites is 'Davao North Barangay Diwalwal Mati Capital'. This obviously isn't a very good address and will be followed up further. I think that most likely these tektites are coming from the gold rush area of Mount Diwata, which is more popularly known as Diwalwal (Latitude 7°50' N, Longitude 126°11' E). The Diwata Barangay (District) is in the Municipality of Monkayo, Compostela Valley (which used to be part of Davao del Norte up until 1998), Davao Region. Mati Capital is to the south in Davao Oriental, so where it fits in here I have no idea, but other gold areas also lie closer to Mati. As you can see, this means that this is a new tektite locality. The closest known Beyer locality is the Goodall Site, which is Port Lamon, Surigao and is around 105 kilometres away.
The specimens were bought from a lady in Manila, who acquired the specimens from a brother located in Cebu, who in turn got them from the Davao Region. This makes good sense as, according to Wikipedia, the majority of the inhabitants in Compostela Valley are migrants from Cebu and other Visayan provinces (Cebu being the biggest city). Cebu is also a tektite locality, but we are confident these specimens are from Davao - there is simply no benefit to the seller in lying about the locality. We have requested further locality information and how the tektites are found.
It is currently not recommended that foreigners visit the island of Mindanao due to terrorist activity. I, however, have been to the north of the island (Cagayan de Oro) and found it to be safe. Basically, if you stay in the city of Davao it is safe, although travelling into the coutryside is not as wise. Personally I would avoid Diwalwal as there is a peace and order problem - according to Bulatlat, Diwalwal is '.... the murder capital of the Philippines, with bodies turning up dead practically every day. People also would go missing and nobody seemed to care. (Criminals and strangers would come to Diwalwal and use aliases.) But Tito puts a positive spin to it by saying that the opportunities Diwalwal presented to people, particularly those with shady pasts and those who are too illiterate to even dream about having a "normal" job, was real. "If an ex-convict wanted to turn a new leaf," says Tito in Visayan, "Diwalwal was the place." It also appears to be a place for tektites - so you make your choice!
ABOVE: The lady selling the Davao tektites. Des Leong on the left and me (Aubrey Whymark) on the right.
Now the interesting stuff: these tektites differed in many ways from other Philippinites I've seen, the vast majority of which have come from the Paracale region in Bicol. Second interesting point - these tektites are practically the same distance from the source area as tektites from Belitung Island, Indonesia. Tektites in Belitung, however, look like regular grooved Philippinites.
I initially acquired 50 specimens, with a total weight of 1,422g (I have since acquired more). Specimens in the first batch ranged in size from 2g to 101g. All the typical morphologies - spherical, dumbbell and teardrop were found. Some specimens had deep U-grooves like typical Philippinites, many however, had much finer and less prominent grooving. Around 15% displayed a pre-Anda to slight, poorly developed Anda sculpture. Around 15% showed unusual dimples in the centre of navels, which I had previously only observed very rarely from the Bicol region. Finally a few specimens seem to start resembling australite cores! Take a look at the photos.
ABOVE: Typical finer grooved specimens. As with all Philippinites the grooved side is the anterior and the smoother side is the posterior.
ABOVE: Some pre-Anda to start of Anda-type sculpture, or V-grooves, on the posterior of the specimens. These specimens remind me of the Australites found at Hampton Hill Station, Western Australia and figured in Cleverly, W. H. 1986 - a paper I recommend. This sculpture develops due to the chemical attack of residual strains present in the tektite.
ABOVE: A posterior view and side view of a 16g specimen.
ABOVE: An anterior (left) and posterior (right) surface of a 36g specimen.
ABOVE: An anterior (left) and posterior (right) surface of a 51g specimen.
ABOVE: A 46g specimen (left) and a 27g specimen (right). Note the shiney surface on the 27g specimen - this is what I term pre-anda surface. Some good V-grooves have then developed on this surface.
ABOVE: These shiney specimens show what I term 'pre-anda' sculpture. Often the starts of V-grooving are found on specimens with surfaces like these.
ABOVE: Some of the interesting specimens with fine navels and protruding elements from the centre of the navels.
ABOVE: Close-up on protruding elements from navels.
ABOVE: Close-up on two protruding elements from navels.
ABOVE: A 14g core (posterior on left, anterior in middle and side view on right - on the side view the posterior iis at the top).
ABOVE: A 16g core (posterior on left, anterior in middle and side view on right - on the side view the posterior is at the top).
ABOVE: An interesting form of weathering. I have previously seen 2 specimens from the Philippines looking like the one on the top left. I thought they were some kind of impact feature - similar to radial rays on Indochinites. This is, however, not the case. It is some kind of etching - but what causes the lines of weakness / pattern? I wonder if it is some form of conchoidal fracture from a central point - material seems to have flaked off around the outer circular parts.
ABOVE: Some Davao specimens did have deep U-grooves, more typical of Philippinites.
I hope you enjoyed seeing these specimens from Davao!