8342937104

EDGARDO A. AUXTERO.J. SHAMSHUDDIN AND S.PARAMANANTHAN

Platę l: TKM micrographs showing kaolin i te (hexagonal), hallovsite (tubiilar) and ja rosi te (cubie).

act ivit ies olk\

and SC)“' .

9

Platę 2: SFAI mierographs shnwing hiorelics in ac id snllau

smls ol Pnlan l.ninnt.

(Mermut c/<j/1985).

Platcs 2 A and B show ilu* presence o! hiorelics ot variousshapes and sizesin thesoils.Theseare the remnantsoforganismsliving in the depositsot tłu* sea bcd. The presence <>t such hiorelics provide evidence for the marinę origin of the underlying deposits.

A torf) ho logi cal Properties

Texturally, the soils varyfrom sili loam toclay, with silty clay loain the dominant textural class (Table 2). Ap horizonsof the soils in the reclaimedareas have weak to moderate, subangular blocky structures, while those in the newly drained have strong subangular blocky. (.olour ofCg horizon of Parit BotakSeriesislightbrownish gray (2.5Y6/2), while that of Sodu. Jawa and Tongkang Series art greenishgra\ (5G5/1) .The( ghoi izonof thesoih in the newl\ drainedarea iseitherdarkgray (5Y4 1) or bluish gray (AB 5/ 1) , rełlecting the marinę influence of the substratum.

Drainageon the island isgenerallypoor. In tłu rainy mon tli of \ovember. the soils are flooded These conditions influence the oxido-rediiction processin the soils, contributing to the\ariation in the depth at which jarosite occurs. In Parit Botak SeduandSedu (silty) Series soils,jarosite mottle occur within 50 cm depth. while in the Tongkang and Jawa Series, these occur at 50- 100 cm deptl (Fig. 4). The variable morphological propertiesatt the results of various processes being subjecteć on to the soils upon drainage. These differencesir morphological properties can be used to classift thesoils.

Classification

Based on morphological featuresobserved in tłu field ( labie 2, Fig. 4) and Chemical propenie (Table 1) the soils at Pulau Lumut were classified according to Soil Taxonom\ (Soil Survey Stal*

48 PKRTANIKA VOL. 14 NO.I. 1991