TITLE:
Magnetostratigraphy of the Middle Jurassic Sediments from Kachchh Basin, Western India
AUTHORS:
Venkateshwarlu Mamilla, Bindhyachal Pandey, Deo Brat Pathak, Papanna Guguloth, Jai Krishna
KEYWORDS:
Magnetostratigraphy, Jurassic, Kachchh, India
JOURNAL NAME:
International Journal of Geosciences,
Vol.7 No.3,
March
22,
2016
ABSTRACT: The palaeoposition of
India after its breakup from Gondwana and its subsequent northward journey
during the Mesozoic poses many tectonic riddles. A magnetostratigraphy pattern
has been constructed for the Ammonoid rich Middle Jurassic Bathonian succession
of Jumara Dome, Kachchh, western India. We present the first
magnetostratigraphic results from the Ammonoid bearing exposed Bathonian
sediments in Kachchh. The Jumara Dome comprised of mixed carbonate-siliciclastic
succession is represented by the Jhurio and Patcham formations and
siliciclastic-dominating Chari Formation in the Kachchh Mainland. The Jumara
Dome sediments were deposited during sea-level fluctuating, and were
interruptedby storms in the shallow marine environment. This study is
based on collection of 60 oriented samples from 13 successive levels. Both
thermal and AF demagnetization investigations were carried out to isolate the
Characteristic Remanent Magnetization (ChRM) directions. Palaeolatitudes were
computed using the ChRM directions. Magnetostratigraphic column is prepared and
correlated with Geological Time Scale (GTS) of [1] [2], and this column readily matched with
GTS at M41 to below and exhibits the dominance of normal polarity in Jumara.