Computer Science
Scientific paper
Sep 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998ep%26s...50..733y&link_type=abstract
Earth, Planets and Space, Volume 50, p. 733-744.
Computer Science
1
Scientific paper
Chamosite-hematite type oolitic ironstone is distributed in the Cretaceous-Tertiary (K-T) boundary zone of the Hazara area, Lesser Himalayan thrust zone, in the northwestern margin of the Indo-Pakistani subcontinent. A total of 52 oriented samples were collected from 6 beds in two open pit mines, Nathia Gali and Bagnotar. Ferromagnetic properties of the oolitic ironstone are dominated by fine-grained hematite that possesses a characteristic remanent magnetization (ChRM). The ChRM is a chemical remanent magnetization (CRM) acquired by the hematite which formed from Fe-rich initial materials (iron hydroxides) during early diagenesis of the ironstone bed. The direction of the remanent magnetization indicates that the magnetization was acquired in an equatorial region (average inclination = 2°, paleolatitude = 1°N), which is consistent with the paleoposition of the Indian subcontinent during early Paleocene time, as estimated by previous data. The initial Fe-rich sediments were deposited under anoxic conditions, probably in a non-marine or brackish environment. During early diagenesis, after development of oolitic textures, the paleoenvironment became arid, where the CRM was acquired through the conversion of amorphous hydroxides or goethite to fine-grained hematite. The paleomagnetic results reveal complicated local rotational movements of oolitic ironstone blocks about vertical axes, which might be a result of intense thrusting within the terrane after early Tertiary collision between India and Asia.
Ahmad M. N.
Khan I. H.
Yoshida Makiko
No associations
LandOfFree
Remanent magnetization of oolitic ironstone beds, Hazara area, Lesser Himalayan thrust zone, Northern Pakistan: Its acquisition, timing, and paleoenvironmental implications does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Remanent magnetization of oolitic ironstone beds, Hazara area, Lesser Himalayan thrust zone, Northern Pakistan: Its acquisition, timing, and paleoenvironmental implications, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Remanent magnetization of oolitic ironstone beds, Hazara area, Lesser Himalayan thrust zone, Northern Pakistan: Its acquisition, timing, and paleoenvironmental implications will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-816344