Magnetostratigraphy of the Middle Jurassic Sediments from Kachchh Basin, Western India  

作　　者：Venkateshwarlu Mamilla Bindhyachal Pandey Deo Brat Pathak Papanna Guguloth Jai Krishna Venkateshwarlu Mamilla;Bindhyachal Pandey;Deo Brat Pathak;Papanna Guguloth;Jai Krishna(Paleomagnetism Division, CSIR-National Geophysical Research Institute, Hyderabad, India;Department of Geology, Banaras Hindu University, Varanasi, India)

机构地区：[1]Paleomagnetism Division, CSIR-National Geophysical Research Institute, Hyderabad, India [2]Department of Geology, Banaras Hindu University, Varanasi, India

出　　处：《International Journal of Geosciences》2016年第3期301-310,共10页地球科学国际期刊（英文）

摘　　要：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 interrupted by 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.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 interrupted by 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.

关 键 词：MAGNETOSTRATIGRAPHY JURASSIC KACHCHH INDIA 

分 类 号：P53[天文地球—古生物学与地层学]