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Proceedings of the second symposium integrated geological survey of Northern Sumatra

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The serpentinised ultramafic rocks of Northern Sumatra occur in linear zones along the main faults of the Sumatra Fault system within the Barisan Mountains
They are considered to be alpine type and are discussed within a framework of a general review of the nature
and origin of serpentinite belts. The greatest development of ultramafics occur at the northern end of Suma tra, bodies reaching 27 km by 3 km. Serpentinite clasts have not been found in the coarse Neogene sediments derived from the Barisan Mountain zone but stream sediment samples derived from the Neogene show a concentration of high chromite values. The Paleogene rocks are barren of detrital ultramafic influence. Serpentinite is produced by hydration of ultramafic protolith and the field evidence suggests the constant composition, with
high expansion, reaction as more likely than the constant volume transformation. Isotope studies of similar
rocks in other areas (Wenner & Taylor 1973) indicate meteoric water to be the cause of hydration. Diapiric rise of serpentinite along faults is thus restricted to upper crustal levels with protolith, now considered to
be oceanic crust, inserted tectonically by transcurrent movement. The opening of the Andaman sea is 10.8 my
(Curray et al 1977). The date of serpentinite emplacement and the initiation of the Sumatran Fault system
is considered to be structurally connected with this opening and is therefore put as mid-Miocene

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Ketersediaan

Informasi Detail

Judul Seri

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No. Panggil

PK No. 3

Penerbit

Bandung : Direktorat Sumber Daya Mineral., 1981

Deskripsi Fisik

33p.,ill. 14 x 21 cm

Bahasa

English

ISBN/ISSN

0216 - 0811

Klasifikasi

NONE

Tipe Isi

text

Tipe Media

unmediated

Tipe Pembawa

other (unmediated)

Edisi

-

Subjek

Chromite
ultramafic rocks
the Barisan Mountains

Info Detail Spesifik

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Pernyataan Tanggungjawab

Direktorat Sumber Daya Mineral

Informasi Lainnya

Kode Wilayah

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Pulau Dan Lembar Peta

Lainnya

Provinsi

Sumatera Utara

Koordinat - Latitude

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Koordinat - Longitude

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Versi lain/terkait

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