Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsThe Rock H. Currier Digital LibraryGeologic Time
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral Quiz
Photo SearchPhoto GalleriesSearch by ColorNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Madhavan, V., Leelanandam, C. (1988) Petrology of the Elchuru Alkaline Pluton, Prakasam District, Andhra Pradesh, India. Journal Geological Society of India, 31 (6). 515-537 doi:10.17491/jgsi/1988/310601

Advanced
   -   Only viewable:
Reference TypeJournal (article/letter/editorial)
TitlePetrology of the Elchuru Alkaline Pluton, Prakasam District, Andhra Pradesh, India
JournalJournal Geological Society of India
AuthorsMadhavan, V.Author
Leelanandam, C.Author
Year1988 (June 1)Volume31
Page(s)515-537Issue6
PublisherGeological Society of IndiaPlaceBangaluru, India
URL
DOIdoi:10.17491/jgsi/1988/310601Search in ResearchGate
Generate Citation Formats
Classification
Not set		LoC
Not set
Mindat Ref. ID17914274Long-form Identifiermindat:1:5:17914274:1
GUID0
Full ReferenceMadhavan, V., Leelanandam, C. (1988) Petrology of the Elchuru Alkaline Pluton, Prakasam District, Andhra Pradesh, India. Journal Geological Society of India, 31 (6). 515-537 doi:10.17491/jgsi/1988/310601
Plain TextMadhavan, V., Leelanandam, C. (1988) Petrology of the Elchuru Alkaline Pluton, Prakasam District, Andhra Pradesh, India. Journal Geological Society of India, 31 (6). 515-537 doi:10.17491/jgsi/1988/310601
In(1988, June) Journal of the Geological Society of India Vol. 31 (6). Geological Society of India
Abstract/NotesAbstract
The oblong alkaline pluton at Elchuru is constituted of shonkinite, malignite, nepheline syenite (foyaite and pulaskitic foyaite) and nepheline gneiss (including litchfieldite and mariupolite); the bulk of the pluton is, however, made up of nepheline syenite and nepheline gneiss. These alkaline rocks are emplaced conformably and permissively by a simple mechanism of dilation of the surrounding country rocks under tensional stress. During emplacement, the pluton deformed its own nearly solid periphery producing an outer ring of nepheline gneiss with subsolvus assemblage which surrounds the central core of nepheline syenite with hypersolvus assemblage.
The field, petrographic and geochemical studies, when viewed together, suggest that all the rocks of the pluron arc comagmatic and that nepheline syenites (and nepheline gneisses) are the differentiated products of a basic alkaline magma. The present study has shown that the alkaline magma remained strongly undersaturated throughout the differentia tion process.
The agpaitic coefficient of these rocks is very near to, but invariably less than unity. In tune with their miaskitic chemistry, these rocks show low Na2O/K2O and Fe2O3/FeO ratios and a generally lower content of MgO, TiO2 and MnO. The contents of Sr and Ba are very high and with differentiation the ratios Ba/Sr and Sr/Ca fall whereas K/Ba ratio rises. The uniformly higher KJRb ratios of these rocks suggest a deep seated source for the magma.

Map of Localities

Locality Pages

LocalityCitation Details
Elchuru Complex, Prakasam District, Andhra Pradesh, India

Mineral Occurrences

LocalityMineral(s)
Elchuru Complex, Prakasam District, Andhra Pradesh, Indiaβ“˜ Aegirine-augite, β“˜ Alkali Feldspar, β“˜ Amphibole Supergroup, β“˜ Apatite, β“˜ Augite, β“˜ Biotite, β“˜ Calcite, β“˜ Calcrete, β“˜ Camptonite, β“˜ Cancrinite, β“˜ Carbonatite, β“˜ Charnockitic granite, β“˜ Chloromelanite, β“˜ Clinopyroxene Subgroup, β“˜ Diopside, β“˜ Fassaite, β“˜ Feldspar Group, β“˜ Ferro-kaersutite, β“˜ Ferro-pargasite, β“˜ Gabbro, β“˜ Garnet Group, β“˜ Gneiss, β“˜ Granite, β“˜ Hedenbergite, β“˜ Ijolite, β“˜ Jadeite, β“˜ Lamprophyre, β“˜ Magnetite, β“˜ Malignite, β“˜ Melanocratic nephelinolite, β“˜ Microcline, β“˜ Minette, β“˜ Muscovite, β“˜ Nepheline, β“˜ Nepheline-syenite, β“˜ Omphacite, β“˜ Orthoclase, β“˜ Perthite, β“˜ Plagioclase, β“˜ Sannaite, β“˜ Scapolite, β“˜ Shonkinite, β“˜ Titanite, β“˜ Zircon

See Also

These are possibly similar items as determined by title/reference text matching only.

Madhavan, V., Leelanandam, C. (1978) Some Observations on the Rocks of the Elchuru Alkaline Pluton, Prakasam District, Andhra Pradesh. Journal of the Geological Society of India, 19 (11). 522-526
Madhavan, V., Mallikharjuna Rao, J., SUBRAHMANYAM K, K. S., & LEELANANDAM, C. (1989). Bedrock geology of the Elchuru alkaline pluton, Prakasam district, Andhra Pradesh. Geol. Soc. India Memoir, 15, 189-205.
Leelanandam, C., Reddy, K. Krishna (1981) The Uppalapadu Alkaline Pluton, Prakasam District Andhra Pradesh. Journal of the Geological Society of India, 22 (1). 39-45
Leelanandam, C. (1989) The Prakasam Alkaline Province in Andbra Pradesh, India. Journal Geological Society of India, 34 (1). 25-45 doi:10.17491/jgsi/1989/340102
Leelanandam, C. (1993) Almandine-Rich Garnets from Payalite-Perrosilite- Quartz-Bearing Ferrosyenites in the Prakasam District of Andhra Pradesh, India. Journal Geological Society of India, 41 (5). 437-443 doi:10.17491/jgsi/1993/410504
Madhavan, V., Mallikarjuna Rao, J. (1990) Petrology of Olivine Basalt Dyke of Lamprophyre Affinity at Uppalapadu, Prakasam District, Andhra Pradesh. Journal Geological Society of India, 36 (5). 493-501 doi:10.17491/jgsi/1990/360505
Madhavan, V., Mallikharjuna Rao, J., Balaram, V., Kumar, Ramesh (1992) Geochemistry and Petrogenesis of Lamprophyres and Associated Dykes from Elchuru, Andhra Pradesh, India. Journal Geological Society of India, 40 (2). 135-149 doi:10.17491/jgsi/1992/400205
Leelanandam, C., & Ratnakar, J. (1980). Ocellar lamprophyres from the Purimetla alkaline pluton, Prakasam district, Andhra Pradesh. QJ Geol. Ming. Metall. Soc. India, 52(2), 77-79.
Ratnakar, J., & Leelanandam, C. (1986). A PETROCHEMICAL STUDY OF THE PURIMETLA ALKALINE PLUTON, PRAKASAM DISTRICT, ANDHRA-PRADESH, INDIA. NEUES JAHRBUCH FUR MINERALOGIE-ABHANDLUNGEN, 156(1), 99-119.
Leelanandam, C., & Ratnakar, J. (1983). The Purimetla alkaline pluton. Prakasam District, Andhra Pradesh. Quart. Jour. Geol. Min. Met. Soc. India (presently Indian Jour. Geol.), 55, 14-30.
Leelanandam, C. (1989). The Prakasam alkaline province in Andhra Pradesh, India. Jour. Geol. Soc. India, 34, 25-45.
 
and/or  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2025, except where stated. Most political location boundaries are Β© OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: August 13, 2025 14:39:38
Go to top of page