Origin of calcite by magma mixing in mingled rocks of the Ghansura Rhyolite Dome, Bathani volcano-sedimentary sequence, eastern India

Gogoi, Bibhuti; Basumatary, Pallabi

Origin of calcite by magma mixing in mingled rocks of the Ghansura Rhyolite Dome, Bathani volcano-sedimentary sequence, eastern India

Mineralogia

Volume 55 (2024): Issue 1 (January 2024)

By:

Bibhuti Gogoi

and Pallabi Basumatary

Open Access

|Jul 2024

Figures & Tables

A simplified map featuring geological and tectonic features of India and its neighbouring region (modified after Gogoi & Borah, 2023). The study area is marked by the black box. ADMB, Aravalli Delhi Mobile Belt; BC, Bastar Craton; BuC, Bundelkhand craton; BVSs, Bathani volcano-sedimentary sequence; CGGC, Chotanagpur Granite Gneiss Complex; CITZ, Central India Tectonic Zone; DC, Dharwar Craton; DV, Deccan Volcanics; EGB, Eastern Ghats Belt; KL, Kopili Lineament; MBT, Main Boundary Thrust; MCT, Main Central Thrust; MMB, Mahakoshal Mobile Belt; NSMB, North Singhbhum Mobile Belt; SB, Satpura Belt; SC, Singhbhum Craton; SONA, Son-Narmada graben; STD, South Tibetan Detachment.

(A) Regional geological map of the BVSs illustrating different litho-units (modified after Ahmad & Paul, 2013). The GRD is marked as ‘G’ and (B) Geological map of the GRD. BVSs, Bathani volcano-sedimentary sequence; GRD, Ghansura Rhyolite Dome.

Field photographs displaying (A) vesicular basalt; (B) rhyolite outcrop; and (C,D) mingled rocks with distinct mafic and felsic zones.

Photomicrographs displaying (A) augite phenocryst in the basaltic rocks; (B) plagioclase engulfed within augite representing ophitic texture; (C) a vesicle filled with secondary minerals chlorite and calcite in the basaltic rocks, with augite and plagioclase in the groundmass; and (D) fine-grained groundmass in the rhyolitic rocks. aug, augite; pl, plagioclase.

Pyroxene classification diagram (after Morimoto et al., 1988). The analytical data points have been taken from already published works (Gogoi & Chauhan, 2021; Gogoi & Saikia, 2018).

Photomicrographs displaying (A) contact between amphibole-rich mafic zone and fine-grained felsic zone. The interior amphiboles are pale green, while those occurring in contact with the felsic zone are dark green; (B) actinolite and hornblende-rich zones within an ARM. Unlike the actinolite-rich zone, the hornblende-rich zone consists of minerals like biotite, calcite, and ilmenite; (C) a magnified view of the actinolite and hornblende-rich zones shown in the previous image; and (D) CPL view of the previous image. act, actinolite; ARM, amphibole-rich microzones; bt, biotite; cal, calcite; CPL, crossed polarized light; hbl, hornblende; ilm, ilmenite.

Photomicrographs displaying (A,C,E) occurrence of calcite along with biotite and hornblende; and (B,D,F) CPL view of the previous image. CPL, crossed polarized light.

Amphibole classification diagram (Leake et al., 1997). Symbols: green plus = ARM interior amphibole, red plus = ARM exterior amphibole. ARM, amphibole-rich microzones.

Biotite classification diagram (Tischendorf et al., 1997).

A BSE image from the mingled rocks showing the point analyses for calcite. BSE, back-scattered electron.

EPMA analyses of biotite from ARM in the mingled rocks of the GRD

SiO₂	36.19	35.56	35.91	35.93	36.16	35.54	36.60	35.51
TiO₂	1.63	1.70	1.69	1.69	1.70	1.64	1.60	1.75
Al₂O₃	17.75	16.30	17.06	16.91	16.83	17.58	16.91	16.45
FeO	21.16	21.27	20.92	20.95	20.92	21.25	20.54	21.44
MnO	0.26	0.30	0.16	0.13	0.17	0.20	0.19	0.17
MgO	9.20	9.21	9.33	9.15	9.26	8.81	9.35	9.12
CaO	0.11	0.02	0.08	0.10	0.10	0.09	0.08	0.03
Na₂O	0.15	0.12	0.06	0.14	0.15	0.14	0.09	0.13
K₂O	8.42	9.06	8.59	8.84	8.88	8.67	8.67	8.67
Cl	0.07	0.09	0.08	0.06	0.08	0.07	0.07	0.04
F	0.00	0.01	0.00	0.01	0.00	0.00	0.00	0.00
Total	94.94	93.64	93.88	93.91	94.25	93.99	94.1	93.31
Calculation based on 22 O
Si	5.55	5.58	5.57	5.59	5.60	5.52	5.65	5.58
Al^iv	2.45	2.42	2.43	2.41	2.40	2.48	2.35	2.42
Sum T	8.00	8.00	8.00	8.00	8.00	8.00	8.00	8.00
Al^vi	0.75	0.59	0.69	0.68	0.67	0.75	0.72	0.62
Ti	0.19	0.20	0.20	0.20	0.20	0.19	0.19	0.21
Fe	2.71	2.79	2.72	2.72	2.71	2.76	2.65	2.81
Mn	0.03	0.04	0.02	0.02	0.02	0.03	0.02	0.02
Mg	2.10	2.15	2.16	2.12	2.14	2.04	2.15	2.13
Sum Y	5.79	5.78	5.79	5.74	5.74	5.77	5.74	5.80
Ca	0.02	0.00	0.01	0.02	0.02	0.01	0.01	0.01
Na	0.04	0.04	0.02	0.04	0.05	0.04	0.03	0.04
K	1.65	1.81	1.70	1.75	1.75	1.72	1.71	1.74
Sum X	1.71	1.85	1.73	1.81	1.82	1.78	1.75	1.78
Cl	0.02	0.02	0.02	0.02	0.02	0.02	0.02	0.01
F	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
Fe + Mg	4.81	4.94	4.87	4.84	4.85	4.80	4.80	4.95
Fe/Fe + Mg	0.56	0.56	0.56	0.56	0.56	0.57	0.55	0.57
Fe + Mn + Ti-Al^vi	2.18	2.44	2.24	2.25	2.26	2.23	2.14	2.42

EPMA analyses of ilmenite from ARM in mingled rocks of the GRD

SiO₂	0.10	0.05	0.75	0.02	0.33	0.49	0.64	0.06
TiO₂	53.53	53.00	52.33	52.75	51.46	51.34	53.03	52.24
Al₂O₃	0.00	0.00	0.43	0.02	0.03	0.14	0.22	0.00
FeO	43.13	42.64	40.71	42.42	42.42	41.53	41.01	42.01
MnO	3.61	3.24	3.58	3.70	3.42	3.40	3.93	3.37
MgO	0.04	0.07	0.10	0.06	0.13	0.17	0.19	0.14
CaO	0.15	0.11	0.92	0.11	0.98	0.85	0.21	0.86
Na₂O	0.02	0.04	0.02	0.02	0.03	0.02	0.01	0.00
K₂O	0.04	0.08	0.00	0.20	0.08	0.03	0.24	0.02
Cr₂O₃	0.01	0.04	0.00	0.00	0.04	0.01	0.00	0.00
Total	100.63	99.27	98.84	99.30	98.93	97.97	99.48	98.69
The recalculated chemical composition based on an inverse spinel formula
SiO₂	0.10	0.05	0.75	0.02	0.33	0.49	0.64	0.06
TiO₂	53.53	53.00	52.33	52.75	51.46	51.34	53.03	52.24
Al₂O₃	0.00	0.00	0.43	0.02	0.03	0.14	0.22	0.00
Fe₂O₃	0.00	0.00	0.00	0.00	0.77	0.00	0.00	0.00
FeO	44.36	44.17	42.99	43.49	41.72	41.92	43.88	42.30
MnO	3.61	3.24	3.58	3.70	3.42	3.40	3.93	3.37
MgO	0.04	0.07	0.10	0.06	0.13	0.17	0.19	0.14
CaO	0.15	0.11	0.92	0.11	0.98	0.85	0.21	0.86
Na₂O	0.02	0.04	0.02	0.02	0.03	0.02	0.01	0.00
K₂O	0.04	0.08	0.00	0.20	0.08	0.03	0.24	0.02
Cr₂O₃	0.01	0.04	0.00	0.00	0.04	0.01	0.00	0.00
Total	101.85	100.81	101.11	100.36	99.00	98.36	102.35	98.98
Calculation based on 3 O
Si	0.00	0.00	0.02	0.00	0.01	0.01	0.02	0.00
Ti	1.01	1.01	1.00	1.01	0.98	0.99	1.01	1.00
Al	0.00	0.00	0.01	0.00	0.00	0.00	0.01	0.00
Fe⁺³	0.00	0.00	0.00	0.00	0.01	0.00	0.00	0.00
Fe⁺²	0.93	0.94	0.91	0.92	0.89	0.90	0.93	0.90
Mn	0.08	0.07	0.08	0.08	0.07	0.07	0.08	0.07
Mg	0.00	0.00	0.00	0.00	0.01	0.01	0.01	0.01
Ca	0.00	0.00	0.02	0.00	0.03	0.02	0.01	0.02
Na	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
K	0.00	0.00	0.00	0.01	0.00	0.00	0.01	0.00
Cr	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
Total	2.03	2.04	2.05	2.03	2.00	2.01	2.07	2.01

EPMA analyses of amphiboles from ARM in the mingled rocks of the GRD

	ARM interior amphibole								ARM exterior amphibole
SiO₂	51.53	54.90	53.57	54.41	52.83	53.31	54.67	53.8	43.19	49.02	49.29	50.38	46.78	47.71	48.89	0.45
TiO₂	0.17	0.00	0.08	0.05	0.07	0.05	0.05	0.02	0.27	0.36	0.33	0.34	0.28	0.36	0.21	0.45
Al₂O₃	3.72	0.50	1.73	0.60	1.56	2.13	0.24	1.54	12.41	6.16	5.97	4.67	8.62	7.68	7.26	11.86
Cr₂O₃	0.00	0.00	0.00	0.00	0.01	0.00	0.00	0.05	0.00	0.07	0.04	0.06	0.08	0.03	0.07	0.00
FeO	16.56	15.86	15.05	14.11	16.32	15.76	15.47	14.86	19.09	17.70	17.33	17.5	17.91	18.3	17.94	18.37
MnO	0.40	0.51	0.41	0.42	0.40	0.43	0.53	0.36	0.38	0.52	0.41	0.49	0.33	0.45	0.49	0.29
MgO	11.93	13.84	13.27	14.05	12.75	12.95	14.04	13.70	7.19	10.48	10.69	11.19	9.23	9.54	9.95	7.62
CaO	11.70	10.94	11.90	11.96	11.95	11.65	11.30	12.01	11.50	11.61	11.52	11.24	11.53	11.24	11.14	11.53
Na₂O	0.32	0.06	0.15	0.09	0.13	0.21	0.04	0.11	0.91	0.57	0.46	0.43	0.69	0.69	0.46	0.87
K₂O	0.09	0.00	0.07	0.03	0.05	0.11	0.02	0.05	0.57	0.15	0.18	0.04	0.25	0.20	0.20	0.34
Total	96.42	96.61	96.23	95.72	96.07	96.60	96.36	96.50	95.51	96.64	96.22	96.34	95.70	96.20	96.61	96.33
Calculation based on 23 O
Si	7.65	8.03	7.90	8.01	7.86	7.86	8.02	7.90	6.63	7.32	7.37	7.52	7.08	7.17	7.30	6.79
Al^iv	0.35	0.00	0.10	0.00	0.14	0.14	0.00	0.10	1.37	0.68	0.63	0.48	0.92	0.83	0.70	1.21
Sum T	8.00	8.03	8.00	8.01	8.00	8.00	8.02	8.00	8.00	8.00	8.00	8.00	8.00	8.00	8.00	8.00
Al^vi	0.30	0.09	0.20	0.10	0.14	0.23	0.04	0.17	0.87	0.40	0.42	0.34	0.61	0.53	0.57	0.90
Ti	0.02	0.00	0.01	0.01	0.01	0.01	0.01	0.00	0.03	0.04	0.04	0.04	0.03	0.04	0.02	0.05
Fe³⁺	0.05	0.15	0.00	0.07	0.01	0.00	0.13	0.00	0.17	0.19	0.14	0.11	0.16	0.23	0.10	0.10
Cr	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.01	0.00	0.01	0.01	0.01	0.01	0.01	0.01	0.00
Mg	2.64	3.02	2.92	3.08	2.83	2.85	3.07	3.00	1.65	2.33	2.38	2.49	2.08	2.14	2.21	1.72
Fe²⁺	1.99	1.74	1.86	1.67	2.02	1.92	1.76	1.82	2.28	2.02	2.01	2.02	2.10	2.06	2.07	2.22
Mn³⁺	0.00	0.00	0.02	0.05	0.00	0.00	0.00	0.00	0.00	0.01	0.00	0.00	0.00	0.00	0.00	0.01
Sum C	5.00	5.00	5.00	4.98	5.00	5.00	5.00	5.00	5.00	5.00	5.00	5.00	5.00	5.00	5.00	5.00
Mg	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
Fe²⁺	0.01	0.04	0.00	0.00	0.01	0.02	0.02	0.01	0.00	0.00	0.02	0.06	0.01	0.01	0.06	0.00
Mn²⁺	0.05	0.06	0.03	0.00	0.05	0.05	0.07	0.04	0.05	0.06	0.05	0.06	0.04	0.06	0.06	0.03
Ca	1.86	1.71	1.88	1.89	1.91	1.84	1.78	1.89	1.89	1.86	1.85	1.80	1.87	1.81	1.78	1.86
Na	0.07	0.02	0.04	0.03	0.04	0.06	0.01	0.03	0.06	0.09	0.09	0.08	0.08	0.12	0.10	0.11
Sum B	2.00	1.84	1.96	1.91	2.00	1.97	1.87	1.97	2.00	2.00	2.00	2.00	2.00	2.00	2.00	2.00
Na	0.02	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.21	0.08	0.05	0.04	0.12	0.08	0.04	0.15
K	0.02	0.00	0.01	0.01	0.01	0.02	0.00	0.01	0.11	0.03	0.03	0.01	0.05	0.04	0.04	0.07
Sum A	0.03	0.00	0.01	0.01	0.01	0.02	0.00	0.01	0.32	0.11	0.08	0.05	0.17	0.12	0.08	0.21
Total	15.03	14.86	14.97	14.91	15.01	14.99	14.90	14.98	15.32	15.11	15.08	15.05	15.17	15.12	15.08	15.21
(Mg + Fe²⁺ + Mn²⁺)	4.69	4.87	4.82	4.81	4.91	4.84	4.91	4.87	3.97	4.42	4.46	4.62	4.23	4.26	4.41	3.98
Mg/Mg + Fe²⁺	0.57	0.63	0.61	0.65	0.58	0.59	0.63	0.62	0.42	0.54	0.54	0.55	0.50	0.51	0.51	0.44
(Ca + Na)_B	1.94	1.73	1.92	1.91	1.94	1.90	1.79	1.92	1.95	1.94	1.93	1.88	1.95	1.93	1.88	1.97
(Na + K)_A	0.03	0.00	0.01	0.01	0.01	0.02	0.00	0.01	0.32	0.11	0.08	0.05	0.17	0.12	0.08	0.21

EPMA analyses of calcite from ARM in mingled rocks of the GRD

Point analysis	1/1.	1/2.	1/3.	1/4.	1/5.	1/6.	1/7.	1/8.	1/9.	1/10.	1/11.	1/12.
SiO₂	0.00	0.01	0.00	0.03	0.04	3.67	0.04	0.05	0.02	0.02	0.03	0.00
TiO₂	0.03	0.01	0.00	0.00	0.00	0.00	0.00	0.00	0.06	0.00	0.00	0.00
Al₂O₃	0.01	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.09	0.01	0.01
Cr₂O₃	0.00	0.00	0.05	0.00	0.00	0.00	0.00	0.02	0.00	0.03	0.00	0.00
FeO	0.71	0.81	0.75	0.71	0.69	0.46	0.59	0.74	0.58	0.88	0.67	0.61
MnO	0.61	0.81	0.55	0.71	0.63	0.40	0.67	0.65	0.53	0.73	0.52	0.64
MgO	0.22	0.25	0.27	0.18	0.20	0.17	0.19	0.21	0.20	0.20	0.18	0.21
CaO	62.85	63.89	63.09	58.71	59.24	54.71	57.73	58.41	58.06	52.38	56.2	59.45
Na₂O	0.03	0.00	0.03	0.03	0.01	0.00	0.05	0.05	0.00	0.06	0.00	0.00
K₂O	0.02	0.01	0.01	0.04	0.04	0.01	0.03	0.07	0.02	0.04	0.01	0.04
P₂O₅	0.00	0.01	0.05	0.00	0.03	0.05	0.06	0.05	0.00	0.08	0.03	0.00
BaO	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
F	0.03	0.01	0.00	0.00	0.00	0.00	0.01	0.00	0.01	0.02	0.00	0.01
Cl	0.00	0.01	0.00	0.00	0.00	0.00	0.00	0.02	0.01	0.00	0.02	0.02
Total	64.52	65.84	64.79	60.41	60.90	59.49	59.37	60.27	59.47	54.55	57.66	0. 61
(Fe + Mn)CO₃	2.05	2.46	2.01	2.35	2.17	1.54	2.13	2.32	1.87	2.97	2.07	2.05
CaCO₃	97.61	97.16	97.57	97.35	97.50	98.15	97.55	97.33	97.79	96.66	97.62	97.60
MgCO₃	0.34	0.38	0.42	0.30	0.33	0.30	0.32	0.35	0.34	0.37	0.31	0.34

DOI: https://doi.org/10.2478/mipo-2024-0002 | Journal eISSN: 1899-8526 | Journal ISSN: 1899-8291

Journal RSS Feed

Language: English

Page range: 15 - 29

Submitted on: Feb 28, 2024

Accepted on: Jun 19, 2024

Published on: Jul 22, 2024

Published by: Mineralogical Society of Poland

In partnership with: Paradigm Publishing Services

Publication frequency: 1 times per year

Keywords:

Calcite,

Ilmenite,

Magma mixing,

Diffusion,

Bathani volcano-sedimentary sequence,

Chotanagpur Granite Gneiss Complex

Related subjects:

Geosciences,

Geophysics,

Geosciences, other

© 2024 Bibhuti Gogoi, Pallabi Basumatary, published by Mineralogical Society of Poland
This work is licensed under the Creative Commons Attribution 4.0 License.

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Origin of calcite by magma mixing in mingled rocks of the Ghansura Rhyolite Dome, Bathani volcano-sedimentary sequence, eastern India

Figures & Tables

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Figure 11.

Figure 12.

EPMA analyses of biotite from ARM in the mingled rocks of the GRD

EPMA analyses of ilmenite from ARM in mingled rocks of the GRD

EPMA analyses of amphiboles from ARM in the mingled rocks of the GRD

EPMA analyses of calcite from ARM in mingled rocks of the GRD

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