The Largest and Heaviest Australasian Splash-form Tektites: Description and Discussion

Introduction: Splash-form tektites are wholly melted bodies in which the molten primary morphology was principally controlled by cohesive forces, most importantly by surface tension and variably opposed by centrifugal forces from non-uniaxisymmetric rotation. Ultimately the majority of splash-form tektites are plastically deformed by atmospheric interaction during the ejection phase and variably heated / ablated then cooled / spalled during re-entry. Muong Nong-type layered tektites can be larger [1] [2]; however, these were not fully molten tektite droplets controlled by surface tension. Up to 2011, the heaviest splash-form tektite in the Australasian tektite strewn field, and in the world, was from Paracale-Labo, Bicol Region, Philippines and recovered by Prof. Henry Otley Beyer in April 1937 [3]. This tektite was donated to the Corning Museum of Glass in 2000 by Darryl S. Futrell [4]. It is catalogued as ‘2000.7.4’, measures 984 mm maximum diameter, 905 mm minimum diameter [5] and accurately weighed as 1,070.54 grams [4]. The slightly off-spherical tektite is generally smooth with one side slightly more pitted. It has not been X-rayed. Previously, the same specimen has been reported as 1,065 g [6], 1,069 g [7], 1,069.6 g (4ʺ diameter) [3] and 1,070 g (a little over 4ʺ diameter) [8] and probably erroneously at 1,080 g [9]. In 2011, remarkably, this record was broken twice with two large tektites found within kilometers of the Beyer tektite: These new tektites are described and discussed. New Finds: On 5th February 2011 a 1,194.80 gram (± 0.02 g) tektite was found in Talusan Barangay (within ~1 km of 14°14'52"N, 122°46'4"E), Paracale Municipality, Camarines Norte Province, Bicol Region, Philippines. Attempts to acquire this tektite failed and it was exported to Munich, Germany, on 9th February 2011. It was then exchanged for mineral specimens with a dealer in Melbourne, Australia, before reappearing on 16th May 2011. The specimen was purchased by the author and brought back to the Philippines. The 1,194.80 g tektite has a smooth, locally lightly pitted, surface and is slightly off-spherical with dimensions 111 x 107 x 103 mm. It has a volume of approximately 643 ml and so should weigh 1,575 g. It was therefore concluded that the specimen contained a 66.7 mm diameter bubble. An X-ray taken on 19 September 2011 indicated a bubble of 72 x 71 mm (likely slightly exaggerated due to the X-ray projection onto the film). Reportedly on 23rd August 2011 a new tektite weighing 1,281.89 g (± 0.02 g) was found. At the time of purchase (24th August 2014) the author was told the specimen was found by a gold panner called Ronnel Canaria who comes from Malatap Barangay (within ~3 km of 14°9'16"N, 122°36'37"E), Labo Municipality, Camarines Norte Province, Bicol Region, Philippines. Later, the author was told by his middle man that the specimen itself came from Magsimalo (often cited as 14°17'0"N, 122°45'0"E, but also the name of a river / stream, probably with 3 km of these coordinates, more likely to the east in the author’s opinion), Paracale Municipality, Camarines Norte Province, Bicol Region, Philippines. The 1,281.89 g tektite has a smooth, locally lightly pitted, surface and is slightly off-spherical with dimensions 105 x 102 x 101 mm. It has a volume of approximately 601 ml and so should weigh 1,472.3 g. It was therefore concluded that the specimen contained a 53 mm diameter bubble. An X-ray taken on 19 September 2011 indicated a bubble of 61 x 60 mm (likely slightly exaggerated due to the X-ray projection onto the film).