Mount Sidley is the highest dormant volcano in Antarctica, a member of the Volcanic Seven Summits, with a summit elevation of 4,181–4,285 metres (13,717–14,058 ft). It is a massive, mainly snow-covered shield volcano which is the highest of the five volcanic mountains that comprise the Executive Committee Range of Marie Byrd Land. The feature is marked by a 5 km wide caldera on the southern side and stands NE of Mount Waesche in the southern part of the range.

The mountain was discovered by Rear Admiral Richard E. Byrd on an airplane flight, November 18, 1934, and named by him for Mabelle E. Sidley, the daughter of William Horlick who was a contributor to the 1933–35 Byrd Antarctic Expedition. Despite its height, the volcano's extremely remote location means that it is little known even in the mountaineering world compared to the much more accessible Mount Erebus, the second-highest Antarctic volcano which is located near the U.S. and New Zealand bases on Ross Island.

The first recorded ascent of Mount Sidley was by New Zealander Bill Atkinson on January 11, 1990, whilst working in support of a United States Antarctic Program scientific field party. [Wikipedia]

Lower crustal pyroxenite xenoliths in a phonolite.

The xenoliths have suffered localized breakdown reactions during their residence in a shallow magmatic chamber below the volcano.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List

12 valid minerals.

Rock Types Recorded

Note: data is currently VERY limited. Please bear with us while we work towards adding this information!

Select Rock List Type

Alphabetical List Tree Diagram

ⓘ Tephritic-phonolite

ⓘ Trachyte

Detailed Mineral List:

ⓘ Aegirine

Formula: NaFe³⁺Si₂O₆

References:

Woolley, Alan R. (2019) Alkaline Rocks and Carbonatites of the World. Part 4: Antarctica, Asia and Europe (excluding the former USSR), Australasia and Oceanic Islands. The Geological Society of London. doi:10.1144/mpar4

ⓘ Aenigmatite

Formula: Na₄[Fe²⁺₁₀Ti₂]O₄[Si₁₂O₃₆]

References:

ⓘ Albite var. Anorthoclase

Formula: (Na,K)AlSi₃O₈

References:

ⓘ 'Alkali Feldspar'

References:

ⓘ 'Apatite'

Formula: Ca₅(PO₄)₃(Cl/F/OH)

References:

ⓘ Arfvedsonite

Formula: [Na][Na₂][Fe²⁺₄Fe³⁺]Si₈O₂₂(OH)₂

References:

ⓘ Augite

Formula: (Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆

References:

ⓘ Augite var. Titanium-bearing Augite

Formula: (Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆

References:

ⓘ 'Clinopyroxene Subgroup'

References:

Grapes, R. H., Wysoczanski, R. J., Hoskin, P. W. O. (2003) Rhönite paragenesis in pyroxenite xenoliths, Mount Sidley volcano, Marie Byrd Land, West Antarctica. Mineralogical Magazine, 67 (4) 639-651 doi:10.1180/0026461036740123

ⓘ Diopside

Formula: CaMgSi₂O₆

References:

ⓘ Fayalite

Formula: Fe²⁺₂SiO₄

References:

ⓘ 'Fayalite-Forsterite Series'

References:

ⓘ Forsterite

Formula: Mg₂SiO₄

References:

ⓘ 'Glass'

References:

ⓘ Kaersutite

Formula: NaCa₂(Mg₃AlTi⁴⁺)(Si₆Al₂)O₂₂O₂

References:

ⓘ Magnetite

Formula: Fe²⁺Fe³⁺₂O₄

References:

ⓘ Magnetite var. Titanium-bearing Magnetite

Formula: Fe²⁺(Fe³⁺,Ti)₂O₄

References:

ⓘ Nepheline

Formula: Na₃K(Al₄Si₄O₁₆)

References:

ⓘ Phlogopite

Formula: KMg₃(AlSi₃O₁₀)(OH)₂

References:

ⓘ 'Plagioclase'

Formula: (Na,Ca)[(Si,Al)AlSi₂]O₈

References:

ⓘ Rhönite

Formula: Ca₄[Mg₈Fe³⁺₂Ti₂]O₄[Si₆Al₆O₃₆]

Description: Destabilization of kaersutite.

References:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘ	Magnetite	4.BB.05	Fe²⁺Fe³⁺₂O₄
ⓘ	var. Titanium-bearing Magnetite	4.BB.05	Fe²⁺(Fe³⁺,Ti)₂O₄
Group 9 - Silicates
ⓘ	Fayalite	9.AC.05	Fe²⁺₂SiO₄
ⓘ	Forsterite	9.AC.05	Mg₂SiO₄
ⓘ	Augite	9.DA.15	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
ⓘ	Diopside	9.DA.15	CaMgSi₂O₆
ⓘ	Augite var. Titanium-bearing Augite	9.DA.15	(Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆
ⓘ	Aegirine	9.DA.25	NaFe³⁺Si₂O₆
ⓘ	Kaersutite	9.DE.15	NaCa₂(Mg₃AlTi⁴⁺)(Si₆Al₂)O₂₂O₂
ⓘ	Arfvedsonite	9.DE.25	[Na][Na₂][Fe²⁺₄Fe³⁺]Si₈O₂₂(OH)₂
ⓘ	Aenigmatite	9.DH.40	Na₄[Fe²⁺₁₀Ti₂]O₄[Si₁₂O₃₆]
ⓘ	Rhönite	9.DH.40	Ca₄[Mg₈Fe³⁺₂Ti₂]O₄[Si₆Al₆O₃₆]
ⓘ	Phlogopite	9.EC.20	KMg₃(AlSi₃O₁₀)(OH)₂
ⓘ	Nepheline	9.FA.05	Na₃K(Al₄Si₄O₁₆)
ⓘ	Albite var. Anorthoclase	9.FA.35	(Na,K)AlSi₃O₈
Unclassified
ⓘ	'Alkali Feldspar'	-
ⓘ	'Clinopyroxene Subgroup'	-
ⓘ	'Fayalite-Forsterite Series'	-
ⓘ	'Plagioclase'	-	(Na,Ca)[(Si,Al)AlSi₂]O₈
ⓘ	'Glass'	-
ⓘ	'Apatite'	-	Ca₅(PO₄)₃(Cl/F/OH)

List of minerals for each chemical element

H	Hydrogen
H	ⓘ Arfvedsonite	[Na][Na₂][Fe₄²⁺Fe³⁺]Si₈O₂₂(OH)₂
H	ⓘ Phlogopite	KMg₃(AlSi₃O₁₀)(OH)₂
H	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
O	Oxygen
O	ⓘ Aegirine	NaFe³⁺Si₂O₆
O	ⓘ Aenigmatite	Na₄[Fe₁₀²⁺Ti₂]O₄[Si₁₂O₃₆]
O	ⓘ Albite var. Anorthoclase	(Na,K)AlSi₃O₈
O	ⓘ Arfvedsonite	[Na][Na₂][Fe₄²⁺Fe³⁺]Si₈O₂₂(OH)₂
O	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
O	ⓘ Diopside	CaMgSi₂O₆
O	ⓘ Fayalite	Fe₂²⁺SiO₄
O	ⓘ Forsterite	Mg₂SiO₄
O	ⓘ Kaersutite	NaCa₂(Mg₃AlTi⁴⁺)(Si₆Al₂)O₂₂O₂
O	ⓘ Magnetite	Fe²⁺Fe₂³⁺O₄
O	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
O	ⓘ Phlogopite	KMg₃(AlSi₃O₁₀)(OH)₂
O	ⓘ Rhönite	Ca₄[Mg₈Fe₂³⁺Ti₂]O₄[Si₆Al₆O₃₆]
O	ⓘ Magnetite var. Titanium-bearing Magnetite	Fe²⁺(Fe³⁺,Ti)₂O₄
O	ⓘ Fayalite-Forsterite Series
O	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
O	ⓘ Augite var. Titanium-bearing Augite	(Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆
O	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
F	Fluorine
F	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
Na	Sodium
Na	ⓘ Aegirine	NaFe³⁺Si₂O₆
Na	ⓘ Aenigmatite	Na₄[Fe₁₀²⁺Ti₂]O₄[Si₁₂O₃₆]
Na	ⓘ Albite var. Anorthoclase	(Na,K)AlSi₃O₈
Na	ⓘ Arfvedsonite	[Na][Na₂][Fe₄²⁺Fe³⁺]Si₈O₂₂(OH)₂
Na	ⓘ Kaersutite	NaCa₂(Mg₃AlTi⁴⁺)(Si₆Al₂)O₂₂O₂
Na	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
Na	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Na	ⓘ Augite var. Titanium-bearing Augite	(Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆
Mg	Magnesium
Mg	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
Mg	ⓘ Diopside	CaMgSi₂O₆
Mg	ⓘ Forsterite	Mg₂SiO₄
Mg	ⓘ Kaersutite	NaCa₂(Mg₃AlTi⁴⁺)(Si₆Al₂)O₂₂O₂
Mg	ⓘ Phlogopite	KMg₃(AlSi₃O₁₀)(OH)₂
Mg	ⓘ Rhönite	Ca₄[Mg₈Fe₂³⁺Ti₂]O₄[Si₆Al₆O₃₆]
Mg	ⓘ Fayalite-Forsterite Series
Mg	ⓘ Augite var. Titanium-bearing Augite	(Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆
Al	Aluminium
Al	ⓘ Albite var. Anorthoclase	(Na,K)AlSi₃O₈
Al	ⓘ Kaersutite	NaCa₂(Mg₃AlTi⁴⁺)(Si₆Al₂)O₂₂O₂
Al	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
Al	ⓘ Phlogopite	KMg₃(AlSi₃O₁₀)(OH)₂
Al	ⓘ Rhönite	Ca₄[Mg₈Fe₂³⁺Ti₂]O₄[Si₆Al₆O₃₆]
Al	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Al	ⓘ Augite var. Titanium-bearing Augite	(Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆
Si	Silicon
Si	ⓘ Aegirine	NaFe³⁺Si₂O₆
Si	ⓘ Aenigmatite	Na₄[Fe₁₀²⁺Ti₂]O₄[Si₁₂O₃₆]
Si	ⓘ Albite var. Anorthoclase	(Na,K)AlSi₃O₈
Si	ⓘ Arfvedsonite	[Na][Na₂][Fe₄²⁺Fe³⁺]Si₈O₂₂(OH)₂
Si	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
Si	ⓘ Diopside	CaMgSi₂O₆
Si	ⓘ Fayalite	Fe₂²⁺SiO₄
Si	ⓘ Forsterite	Mg₂SiO₄
Si	ⓘ Kaersutite	NaCa₂(Mg₃AlTi⁴⁺)(Si₆Al₂)O₂₂O₂
Si	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
Si	ⓘ Phlogopite	KMg₃(AlSi₃O₁₀)(OH)₂
Si	ⓘ Rhönite	Ca₄[Mg₈Fe₂³⁺Ti₂]O₄[Si₆Al₆O₃₆]
Si	ⓘ Fayalite-Forsterite Series
Si	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Si	ⓘ Augite var. Titanium-bearing Augite	(Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆
P	Phosphorus
P	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
Cl	Chlorine
Cl	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
K	Potassium
K	ⓘ Albite var. Anorthoclase	(Na,K)AlSi₃O₈
K	ⓘ Nepheline	Na₃K(Al₄Si₄O₁₆)
K	ⓘ Phlogopite	KMg₃(AlSi₃O₁₀)(OH)₂
Ca	Calcium
Ca	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
Ca	ⓘ Diopside	CaMgSi₂O₆
Ca	ⓘ Kaersutite	NaCa₂(Mg₃AlTi⁴⁺)(Si₆Al₂)O₂₂O₂
Ca	ⓘ Rhönite	Ca₄[Mg₈Fe₂³⁺Ti₂]O₄[Si₆Al₆O₃₆]
Ca	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Ca	ⓘ Augite var. Titanium-bearing Augite	(Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆
Ca	ⓘ Apatite	Ca₅(PO₄)₃(Cl/F/OH)
Ti	Titanium
Ti	ⓘ Aenigmatite	Na₄[Fe₁₀²⁺Ti₂]O₄[Si₁₂O₃₆]
Ti	ⓘ Kaersutite	NaCa₂(Mg₃AlTi⁴⁺)(Si₆Al₂)O₂₂O₂
Ti	ⓘ Rhönite	Ca₄[Mg₈Fe₂³⁺Ti₂]O₄[Si₆Al₆O₃₆]
Ti	ⓘ Magnetite var. Titanium-bearing Magnetite	Fe²⁺(Fe³⁺,Ti)₂O₄
Ti	ⓘ Augite var. Titanium-bearing Augite	(Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆
Fe	Iron
Fe	ⓘ Aegirine	NaFe³⁺Si₂O₆
Fe	ⓘ Aenigmatite	Na₄[Fe₁₀²⁺Ti₂]O₄[Si₁₂O₃₆]
Fe	ⓘ Arfvedsonite	[Na][Na₂][Fe₄²⁺Fe³⁺]Si₈O₂₂(OH)₂
Fe	ⓘ Augite	(Ca_xMg_yFe_z)(Mg_y1Fe_z1)Si₂O₆
Fe	ⓘ Fayalite	Fe₂²⁺SiO₄
Fe	ⓘ Magnetite	Fe²⁺Fe₂³⁺O₄
Fe	ⓘ Rhönite	Ca₄[Mg₈Fe₂³⁺Ti₂]O₄[Si₆Al₆O₃₆]
Fe	ⓘ Magnetite var. Titanium-bearing Magnetite	Fe²⁺(Fe³⁺,Ti)₂O₄
Fe	ⓘ Fayalite-Forsterite Series
Fe	ⓘ Augite var. Titanium-bearing Augite	(Ca,Na)(Mg,Ti, Fe,Al,)(Si,Al)₂O₆

Geochronology

Mineralization age: Neogene : 5.68 ± 0.06 Ma to 4.18 ± 0.04 Ma

Important note: This table is based only on rock and mineral ages recorded on mindat.org for this locality and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.

Geologic Time

Rocks, Minerals and Events

ⓘ Basanite (youngest age)

4.18 ± 0.04 Ma

Miocene

ⓘ Basanite (oldest age)

5.68 ± 0.06 Ma

Other Databases

Wikipedia:	https://en.wikipedia.org/wiki/Mount_Sidley
Wikidata ID:	Q924312

Other Regions, Features and Areas containing this locality

Antarctic MeteoritesGroup of Meteorite Fall Locations

Antarctic PlateTectonic Plate

Marie Byrd LandMagmatic Province

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Geologic Map of Antarctica, 1:5,000,000 scale.

Panter, K.S., Kyle, P.R., Smellie, J.L. (1997) Petrogenesis of a phonolite–trachyte succession at Mount Sidley, Marie Byrd Land, Antarctica. Journal of Petrology, 38, 1225–1253.

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