The amount of water loss was determined by drying at 110°C

Deep-sea deposits, which resemble in nearly every respect the deep-sea oozes have been observed in many islands of the East-Indian Archipelago, notably the islands of Borneo, Rotti and Timor. Manganese nodules are found in equivalents of deeep-sea red clays on Timor and Rotti island. In this paper, those relative to red clay deposits dating from a Cretaceous ocean are analysed in detail in the vicinity of the town of Niki Niki in Western Timor.

Geochemistry on manganese nodules from Timor

Fossil Mn nodules of Cretaceous age from western Timor exhibit chemical, structural and radioisotope compositions consistent with their being of deep-sea origin. These nodules show characteristics similar to nodules now found at depths of 3,500-5,000 m in the Pacific and Indian Oceans. Slight differences in the fine structure and chemistry of these nodules and modern deep-sea nodules are attributed to diagenetic alteration after uplift of enclosing sediments.

(Table 5, page 626), Tin and main metal elements composition of ferromanganese concretions (acid-soluble fractions)

Concentrations of tin in sea water decreased from estuarine and shelf (0.02-0.04 µg/kg) to surface Atlantic waters (0.009 µg/kg). Mean contents (ppm) in other materials included: ultramafic rocks, 0.8; basalts, 1.7; silicic rocks, 2.5; red clays, 3.4; amphibolites, 1.2. Oceanic ferromanganese deposits contained from 0.2 to 5.8 ppm; tin and cobalt contents were correlated.

(Table 3, page 264), Composition of a manganese micronodule found in a fossil red clay bed from Western Timor

Chemical analyses are presented for two Cretaceous clays from Noil Tobee, Timor. Mineralogical examination has shown that they consist principally of quartz, feldspar, illite and chlorite, together with minor amounts of montmorillonite. Both chemically and mineralogically the clays are very similar to the recent argillaceous deep-sea sediments of the Pacific and Indian Oceans, which confirms Molengraaff's theory (1921) that they are of deep-sea origin. Further confirmation of this theory is provided by comparison of the composition of micromanganese nodules, separated from one of these clays, with that of manganese nodules from the Pacific Ocean.