Dari catatan sejarah erupsinya, G Lamongan tidak akan meletus terutama dalam
waktu dekat ini.
Aktifitas magma yang diawali oleh erupsi G Lamongan ini sekarang sudah
berpindah ke G Bromo (Tengger) dan Semeru.
Tetapi sekali lagi, kawasan gunungapi aktip seperti P Jawa ini dapat saja
setiap saat melahirkan gunungapi baru kapan saja dan di mana saja (sepanjang
jalurnya) asal kondisi geologisnya vafourable.
Gununapi tipe strato sering menunjukkan struktur "composite", artinya bisa
tumpang tindih, aktifitas baru bisa saja menindih pusat erupsi lama yang
sudah lama padam.
Salam,
Yatno
----- Original Message -----
From: "Rovicky Dwi Putrohari" <[EMAIL PROTECTED]>
To: <iagi-net@iagi.or.id>; "HAGI-Net" <[EMAIL PROTECTED]>
Sent: Saturday, September 09, 2006 10:42 PM
Subject: [iagi-net-l] Lamongan Volcanic ?
Ada pertanyaan seorang netter mengenai Lamongan Volcanic.
Ada yg tahu detilnya ?
Aku juga baru denger sih
RDP
===
Pak Rovicky, apa dari artikel dibawah ini, bermakna Gunung Lamongan
mungkin
akan meletus kapan saja?
http://petrology.oxfordjournals.org/cgi/content/abstract/42/9/1643
Petrology and Geochemistry of the Lamongan Volcanic Field,East Java,
Indonesia: Primitive Sunda Arc Magmas in an Extensional Tectonic Setting?
S. A. CARN,* and D. M. PYLE
DEPARTMENT OF EARTH SCIENCES, CAMBRIDGE UNIVERSITY, DOWNING STREET,
CAMBRIDGE CB2 3EQ, UK
New geochemical data are presented from prehistoric and historical
eruptive
products of the Lamongan volcanic field (LVF), East Java; a region of the
Sunda arc covering ~260 km2 and containing ~90 eruptive vents plus the
historically active Lamongan volcano. LVF lavas include medium-K basalts
and
basaltic andesites from historical eruptions of Lamongan and prehistoric
eruptions in the eastern LVF, along with a high-K suite represented by
prehistoric deposits in the western LVF. Although lacking some of the
characteristics of truly primary basalts, the least evolved lavas
identified
in the LVF have some of the lowest SiO2 contents (~43 wt % SiO2) yet
reported in Sunda arc volcanic rocks. Mass balance considerations indicate
that two chemically distinct LVF magmas may be parental to suites
currently
being erupted from the neighbouring volcanoes, Semeru and Bromo.
Lamongan's
historical lavas can be related to the medium-K andesitic products of
Semeru
by fractional crystallization, despite the former's location at the same
distance from the trench as Bromo, a high-K volcano. Extensional
tectonics,
possibly related to arc segmentation in the region of the LVF, creating
conditions that promote the rapid ascent of parental magmas, is probably
responsible for this and several other features of the complex.
--
http://rovicky.wordpress.com/
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