『Abstract
A total of 54 samples from thirteen different profiles of interflow
sediment units occurring in the Deccan Volcanic Province (DVP,
India) are studied using an integrated mineral magnetic and field
documentation approach. The occurrence and distribution of ferri-
and antiferromagnetic oxides associated with these sediments infer
depositional conditions dominated by various detrital modes and
recycling of baked sediments under limited authigenic environments.
The baking of underlying sediments is conditioned by aqueous or
dry nature of the substrate via-a（頭に｀）-vis
the viscosity of the overlying lava flow that can be identified
by a combination of brown/red boles and compact/pahoehoe type
flows. The presence of antiferromagnetic superparamagnetic (SP)
fraction in the ‘red bole capped brown boles’ indicates the depth
of baking to 〜20 cm; while the SP fraction also marks infilling,
recycling and pigmentation in other occurrences of the red boles
studied here.
Overall, the mixed magnetic mineralogy and sediment characters
depict frequent recycling and re-deposition by surface run-off,
infiltration and ponding as the most common processes of bole
bed formation in DVP governed by shallow basalts is frequently
shown by the red and brown boles, while infilling into the interstices
and cavities is common with green boles. The red boles are also
characteristic of detrital mixing of oxidized/partially oxidized
ferrimagnets, many times coated with pigmentary hematites. The
present results envisage a great scope for the routine mineral
magnetic studies (integrated with field observations) for rapid
characterization of the extensively occurring bole bed horizons
in the DVP and their study as analogs of Martian soils and sediments.
Keywords: Deccan Volcanic Province; Bole beds; Mineral magnetism;
Paleoweathering』
1. Introduction
2. Study area and methods
2.1. Experimental methods
3. Field description of individual bole bed profiles
3.1. ZW profile
3.2. DG-2
3.3. DG-3
3.4. DG-4
3.5. Sus-1
3.6. PG-1
3.7. PG-2
3.8. RH-1
3.9. KJO-1
3.10. RGB
3.11. DGB/3
3.12. KRB-1a
3.13. AMT/GB
3.14. Summary of the field characteristics
4. Mineral magnetic results
5. Profile wise interpretations
5.1. Zindewadi profile (ZW)
5.2. Dive Ghat (DG/2)
5.3. Dive Ghat (DG/3)
5.4. Dive Ghat (DG/4)
5.5. SUS-1
5.6. Pirangut (PG-1)
5.7. Pirangut (PG-2)
5.8. RH-1
5.9. KJO-1
5.10. RGB
5.11. DGB/3
5.12. KRB-1a
5.13. AMT/GB
6. Genesis and distribution of magnetic minerals in the bole beds
7. Paleoweathering and depositional conditions of the bole beds
formation
8. Conclusion
Acknowledgments
References