Preliminary Research: Feature of Cross Section, Hardness, and Specific Gravity Some Petrified Wood from Loa Janan, Kutai Kertanegara, East Kalimantan

Abstract

The aim of this research is to identify some petrified wood discovered in Loa Janan district of Kutai Kertanegara East Borneo, for anatomical feature in the cross section, the hardness and the specific gravity as well. It was hypothesized that the petrified woods which were discovered would be endemic hardwood species from East Borneo. Six specimens with different size were taken and grinded with different grit (16 to 60). A binocular microscope was used to observe pattern of pores, rays, including resin ducts. Digital balance and measuring glass was used to determine the specific gravity, while selector diamond was used to determine hardness. Reference identifying was used to identify the wood species or genus. Result showed that all specimens were macroscopically identified as Fossil of hardwood, they were characterized by the existence of growth ring, pores, and rays. Most solitary pores grouping filled with mineral deposits were apparent in all of fossil woods. The diversity of color line was probably based on its formed minerals. The hardness of specimens were between 3 to 6 mosh, and were based on the color. The specific gravity of specimens were between 1,715 g/ml to 6,050 g/ml. The Important thing, that based on identification result, the biggest petrified wood which discovered in Loa Janan district of Kutai Kertanegara is most likely species of cf.Leptospermum family Myrsinaceae.

Characteristics of Wood Fossils From Bengkinang Village Kutai Kartanegara Regency

“…The wood fossils' hardness is determined through the utilization of a hardness testing instrument known as the Diamond Selector II (Husien et al, 2016). The procedure is as follows: Affix the tip of the Diamond Selector II (equipped with an iron tip) onto the wood fossil specimen, then exert pressure on the iron surface against the Diamond Selector using a fingertip.…”

“…The presence of black color in wood fossils is likely attributed to carbon content, while the red color can be attributed to iron content [7]. Additionally, wood fossils have been discovered in the Kutai Kartanegara region and were documented in a prior study that investigated the macroscopic properties of several wood fossils unearthed in the Loa Janan area of Kutai Kartanegara [8]. Furthermore, wood fossils have been uncovered in the village of Bengkinang, Kutai Kertanegara, yet their characteristics have not been documented.…”

Ciri Makroskopis, Kekerasan dan Berat Jenis Fosil Kayu Asal Desa Purwajaya Kutai Kartanegara

“…Hal ini kemungkinan pembuluh terisi oleh zat mineral selama proses fosilisasi dalam jangka waktu yang lama dan adanya tekanan, sehingga bentuk dari sel pembuluh menjadi tidak beraturan (bulat gepeng). Pada bidang yang sama tampak sel jari-jari yang sempit dan agak lebar mengarah tidak lurus ke arah radial dan terlihat melengkung, hal ini sejalan dengan penelitan makroskopis fosil kayu oleh Husien, et. al (2016) yang menyatakan bahwa arah jari-jari fosil kayu tidak lurus melainkan melengkung.…”