Sydney Mary Thompson (also known as Madame Christen; 1847 – 16 July 1923) was an Irish

geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, alt ...

, botanist and artist.

Background and family life

Thompson was born in Whitehouse,

County Antrim County Antrim (named after the town of Antrim, ) is one of six counties of Northern Ireland and one of the thirty-two counties of Ireland. Adjoined to the north-east shore of Lough Neagh, the county covers an area of and has a population o ...

, the daughter of James Thompson, a

Belfast Belfast ( , ; from ga, Béal Feirste , meaning 'mouth of the sand-bank ford') is the capital and largest city of Northern Ireland, standing on the banks of the River Lagan on the east coast. It is the 12th-largest city in the United Kingd ...

linen merchant. Her uncle was the naturalist William Thompson. She described her childhood as "amphibious"; her family home was at Macedon Point and she frequently explored the coastline with her brother in a small boat. She spent three years in

Dresden Dresden (, ; Upper Saxon: ''Dräsdn''; wen, label=Upper Sorbian, Drježdźany) is the capital city of the German state of Saxony and its second most populous city, after Leipzig. It is the 12th most populous city of Germany, the fourth ...

, Germany, then studied art at the Belfast Government School of Art, beginning in 1870, and later in London. In 1900, she married Swiss artist Rodolphe Christen. The couple later moved to Scotland.

Geology

An active member of the Belfast Naturalists' Club, Thompson organised lectures and practicals, showing a particular interest in

stratigraphy Stratigraphy is a branch of geology concerned with the study of rock layers ( strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

and

petrography Petrography is a branch of petrology that focuses on detailed descriptions of rocks. Someone who studies petrography is called a petrographer. The mineral content and the textural relationships within the rock are described in detail. The classi ...

. Her original fieldwork mostly concerned sources of material in the glacial deposits of northern Ireland. She was a friend and collaborator of northern Irish geologist Mary Andrews, and together they worked on

glacial erratics A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

, collecting samples, mapping and naming erratics with the aim of finding out the direction of ice flow in Ulster. As the secretary of the Belfast Field Club, her reports were published in the club's ''Proceedings''. In 1894, Thompson was elected to the Glacialists' Association. Some time between 1907 and 1910, Thompson discovered a piece of

Ailsa Craig Ailsa Craig (; sco, Ailsae Craig; gd, Creag Ealasaid) is an island of in the outer Firth of Clyde, west of mainland Scotland, upon which microgranite has long been quarried to make curling stones. The now-uninhabited island comprises the ...

microgranite at Moys, near

Limavady Limavady (; ) is a market town in County Londonderry, Northern Ireland, with Binevenagh as a backdrop. Lying east of Derry and southwest of Coleraine, Limavady had a population of 12,032 people at the 2011 Census. In the 40 years between ...

, County Londonderry. The granite erratic showed the westernmost extent of the

Irish Sea Glacier The Irish Sea Glacier was a huge glacier during the Pleistocene Ice Age that, probably on more than one occasion, flowed southwards from its source areas in Scotland and Ireland and across the Isle of Man, Anglesey and Pembrokeshire. It proba ...

, as it had been carried south by the glacier from Scotland and its incorporation into glacial sediments allowed the route of the glacier to be mapped. Thompson's discovery placed the western limit of the glacier further west than its previous designation.

Art

Thompson won many prizes for her art, and was a member of the Belfast Ramblers' Sketching Club and the Belfast Art Society, of which she became patron in 1921.

Death

Madame Christen passed of heart failure at Llandudno in July, 1923.

Bibliography

;SM Thompson: *"A Plea for Irish Glaciology", ''Irish Naturalist'', vol. iii, 1894, p 30. *"The Belfast Field Club Donegal", ''Irish Naturalist'', vol iii, 1894, p 226. *"Geology (of Co. Galway)", ''Irish Naturalist'', vol iv, 1895, p 225. *"Glacial Geology of Kerry" (note on): ''Irish Naturalist'', vol viii, 1899, p 61. *"The Supposed Occurrence of White Lias at Macedon Pt.", ''Irish Naturalist'', vol ix, 1900, p 154. ;Madame Christen: *"Investigations into the Glacial Drifts of the Northeast of Ireland", ''Irish Naturalist'', vol xi, 1902, p 275. *"A summary of the NFClub's recent Glacial Work", ''Irish Naturalist'', vol xv, 1906, p 80.

References

{{DEFAULTSORT:Thompson, Sydney Mary 1847 births 1923 deaths 19th-century Irish painters 20th-century Irish painters 19th-century Irish botanists Irish women geologists Scientists from Belfast 20th-century Irish botanists 19th-century Irish geologists