GEOLOGICAL FIELD TRIP / STARGAZING SESSION IN BUSO-BUSO
March 27-28, 2004
by James Kevin Ty
The ALP held its March stargazing again in TGPM at Buso-Buso, Antipolo on March 27. To add some spice aside from the event, Edmund Rosales was kind enough to lead the ALPers to get to know a bit more on our own planet history by touring them to the geo sites that are near Antipolo area.
Meeting place was at McDonald's in Katipunan and the group departed there around 3pm. Members who joined the spec trip were James Kevin Ty, Allen Yu, Edmund Rosales, Joel Munoz, Atty Rosemarie Gonzales, Jonathan Ty, Melisa Bata, Angie Tan, Cherry Cheng as well as 2 new ALP members Jhun Embuido and Dante Cruz.
Their first stop was in Oro Vista Royal Subdivision wherein Alluvial Deposits from Laguna Formation were first visited by the group. From the Tres Hermanas Quarry site, Edmund give me good site lecture by teaching the group on how the structures were formed long time ago. Horizontal to nearly horizontal rock layers composed of alluvial sediments can be observed at the site. Some layers show sedimentary structures such as cross bedding, graded bedding, ripple marks, channel structures, etc. Edmund then showed the group some sample of rocks taken at the site that show the remains of ancient flora and fauna (fossils) that were mostly preserved in the rock units. He also told the group that it is also in this quarry that the fossil tusk and other remains of the Stegodon, an ancient elephant smaller than the famous Mammoth, were found. Sedimentary rocks found in this area consist mostly of conglomerates, sandstone and shale. Edmund told the group also that the age of therocks and fossils at the quarry site were estimated to be around 1.5-2 million years ago.
Afterwards, they proceed to Cogeo area where he again pointed to the group pillow lava formations at the Nangka River. Although the lavas flows were already turn into black rocks and boulders, the formation of the pillow flows looks like toothpaste flowing out of the toothpaste tube. Lava flows which have been extruded under the aqueous conditions are characterized by pillow structures. They show elongated bodies which in cross section resemble pillows stacked one on top of the other. He also pointed out to the group, the presence of amygdules (which show parallel orientation, denoting flow) filling the cavities left behind by gas bubbles as the lava solidified. To determine whether the pillow lavas found in the area erupted from a submarine or terrestrial volcano, some evidences which could be used include the wide aereal extent of the lava flows and the associated pelagic (deep sea) sediments. Estimated age of the lava formations were said to be around 136-138 million years ago.
Last stop before going to the stargazing site at Buso was the Puting Bato Quarry. At this site, Edmund explained to the group that limestone containing abundant foraminifera, corals and algal fossils can be found. The limestones here were being excavated to manufacture cement and also into the construction of architectural marbles. Estimated age of the limestone were said to be around 26-27 million years.
After some rest, the group went to TGPM around 5pm to get some rest and refreshments after an enjoyable field trip courtesy of fellow ALP founder Edmund Rosales. The group wind up for a while and use that time to chat with each other before they set up their equipment at around 6pm.
During that time, fellow ALPer Henry and Ice arrived and also setup their equipment together with the rest of the ALPers. James again brought his TV-101 refractor on GP-DX mount ; Allen brought his 6" f / 8 truss tube dobsonian reflector ; Joel brought his fashionable 8" f/6 truss type dobsonian as well; Angie and Melisa brought a 3" f/ 10 reflector which was given to Angie as a present from his friend (Melisa is already anxious of her upcoming 6" reflector which Dob expert Allen Yu will help her built her own scope probably next month ) ; new member Jhun Embuido on the other hand brought his Celestron Nexstar 114 GT; Henry brought along his trusty Orion 5"Apex Mak on EQ-3 mount.
As they were setting up, Edmund shows the other members the planetary formations that can be seen at the western horizon. Down low was the planet Mercury then a bit higher was the brilliant Venus then Mars. At the top of Mars was the quarter Moon follow by the ring planet Saturn. Jupiter on the other hand was rising up as well in the eastern horizon at around 30 deg already.
After they set up their scopes, they observe the Moon to the delight of the new members as looking at the terminator region of the Moon was virtually stunning and the members were able to look at it from the different scopes that were set up there.After viewing the Moon, they went downhill to join Rich Pijuan who just arrived that time to have dinner before continuing the session.
At around 7:30pm, members went up again to the hilltop, and start observing the ring planet Saturn as well as Jupiter, one can hear the sweet sound of fascination from some members who were taking their time to observe the 2 planets. Meanwhile, Joel and Allen were starting to hunt down one Messier to another but they were also a but frustrated by the thin haze hovering the sky that time.
James, on the other hand, forgo his plans to image that night bec transparency was bad so he mostly just observe and share his scope views to fellow members on the planets as well as some bright DSOs.
When Edmund was lecturing specially the new members on how to navigate the sky with the Philippine based planisphere brought along by James, they suddenly saw a very bright mag -3 yellow bolide which brought out cheers from the group. It passed along the constellation Canis Major.
At around 10pm, new member Kenneth Uygongco and his wife join the group and he brought along his new Celestron Nexstar 8i and was also able to observe the planet Jupiter as well as some deep sky objects like Omega Centauri, M65, M66, M58, etc. Joel on the other hand observe old favorites like M42, M43, M36, M37, M38. Pleiades star cluster as well as M3 and Jupiter. Both Allen and Joel as well as James were a bit frustrated over the condition of the sky but James told them that he is planning to coordinate with fellow founder Alice for either a 2 separate stargazing sessions or a straight 2 night / 3 days session in Buso in April.
Overall, the group were happy with the field trip courtesy of Edmund Rosales being the group guide to the geo sites and for the stargazing sessions. All though the sky was bad for DSOs, the group was able to extract the most out of the session. The group called it a night at around 1:30am when the haze and sky condition worsened. They took a group picture before packing up and leave the site at around 2am.
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©2003, 2004 Astronomical League of the Philippines Inc.