scholarly journals Petrological Characteristics of the Peddavura Schist Belt and Adjacent Rocks in Eastern Dharwar Craton in Parts of Nalgonda District, Telangana State

2018 ◽  
Vol 08 (02) ◽  
pp. 124-134
Author(s):  
Lakshmi Pagidoju ◽  
Naresh Bandari ◽  
Narsing Rao Alwal
Keyword(s):  
Dharwar Craton ◽  
Schist Belt ◽  
Eastern Dharwar Craton ◽  
Telangana State ◽  
Nalgonda District

Mineralogy of the Vattikod lamproite dykes, Ramadugu lamproite field, Nalgonda District, Telangana: A possible expression of ancient subduction-related alkaline magmatism along Eastern Ghats Mobile Belt, India

2018 ◽  
Vol 82 (1) ◽  
pp. 35-58 ◽  
Author(s):  
Gurmeet Kaur ◽  
Roger H. Mitchell ◽  
Suhel Ahmed
Keyword(s):  
Dharwar Craton ◽  
Eastern Ghats ◽  
Mobile Belt ◽  
Alkaline Magmatism ◽  
Eastern Dharwar Craton ◽  
Secondary Phases ◽  
Bona Fide ◽  
Telangana State ◽  
Eastern Ghats Mobile Belt ◽  
Nalgonda District

ABSTRACTThe mineralogy of nine recently discovered dykes (VL1:VL8 and VL10) in the vicinity of Vattikod village, Nalgonda district in Telangana State is described. The mineral assemblage present and their compositions are comparable to those of bona fide lamproites in terms of the presence of phlogopite (Ti-rich, Al-poor phlogopite and tetraferriphlogopite); amphiboles (potassic-arfvedsonite, potassic-richterite, potassic-ferro-richterite, potassic-katophorite, Ti-rich potassic-katophorite, Ti-rich potassic-magnesio-katophorite); Al-poor clinopyroxenes; feldspars (K-feldspar, Ba-K-feldspar and Na-feldspar) and spinels (chromite-magnetite and qandilite-ulvöspinel-franklinite). These dykes have undergone diverse and significant degrees of deuteric alteration as shown by the formation of secondary phases such as: titanite, allanite, hydro-zircon, calcite, chlorite, quartz and cryptocrystalline SiO2. On the basis of their respective mineralogy: the VL4 and VL5 dykes are classified as pseudoleucite-phlogopite lamproite; VL2 and VL3 dykes as pseudoleucite-amphibole-lamproite; and VL6, VL7 and VL8 as pseudoleucite-phlogopite-amphibole-lamproite. VL10 is extensively altered but contains fresh euhedral apatite microphenocrysts together with pseudomorphs after leucite and is classified as a pseudoleucite-apatite-(phlogopite?) lamproite. The mineralogy of the Vattikod lamproite dykes is compared with that of the Ramadugu, Somavarigudem and Yacharam lamproite dykes which also occur in the Ramadugu lamproite field. The lamproites from the Eastern Dharwar Craton are considered as being possible expressions of ancient subduction-related alkaline magmatism along the Eastern Ghats mobile belt.

Sign in / Sign up

Export Citation Format

Share Document