Collections of Henry Clifford Potter
 
 
 
 
1.) Collection of thin sections, partly to Potter (1974a and 1974b):
Collection of thin sections, partly mentioned in Potter, H.C. (1974 a). The Geology of the western part of the Northern Range of Trinidad. PhD thesis, University of Durham, 168 p.,
 
and in
 
Potter, H.C. (1974 b). Type sections of the Maraval, Maracas, and Chancellor formations in the Caribbean Group of the Northern Range of Trinidad. VIIème Conférence Géologique des Caraibes, Antilles, Françaises, 30 Juin-12 Juillet 1974. 25 p., 15 figs.
 
Collection consisting of 46 trays with thin-sections (most of them bearing the label P from Potter, and labelled from P 1301 through P 7555). The majority of trays is arranged by the stratigraphic formations. Formations cover the Pre-Upper Jurassic through Upper Cretaceous Maracas Formation, Maraval Beds, Rio Seco Formation, Chancellor Beds, Grande Rivière Formation, Toco Formation, Sans Souci Volcanics, Laventille Formation, and Galera Formation (in stratigraphic order), and Morvant Grits and Paramin Limestone. No sample list was with these slides. However, most of the slides bear the stratigraphic and locality information directly on their labels. To some slides no information except the sample number was found. In Potter (1974a and b) labels run from P 5083 through P 6569.
 
 
 
Curator's remarks:
This is not a reference collection to a particular publication but rather a study collection. By now (18 July 2019) no particular publication or other documentation was found to the majority of these slides with the exception of few preparations, that are mentioned in Potter (1974 a and b). However, these slides were probably consulted by John Saunders for his Northern Range studies published in Saunders (1972), in Frey et al. (1988), and especially for the stratigraphic revision to publicise the Explanatory Notes for 1997 Geological Map of Trinidad (Saunders and Potter, 1998), and from the NW Trinidad Islands. In addition, there is a correspondence file (manuscript version to Potter, 1974 b) of H.C. Potter with H.G. Kugler between 1962-1972 in the Kugler archive, Box No. 64.
 
Thin-sections in drawer 2 of this collection were received from friends of J.B. Saunders by shipment from 23 November 2019.
 
See also the extended collection of photographic prints in the archive of John B. Saunders showing outcrop localities and sedimentary structures and structural geology from Northern Range, particularly from Blanchisseuse Road, and elsewhere in Trinidad.
 
For further information on Northern Range geology see also
Weber, J. and Arkle, J. (2015). Trinidad's Northern Range: "Reversal of fortune": bedrock structure and metamorphic geology, and tectonic geomorphology. 20th Caribbean Geological Conference 2015. Conference Field Trip Guide. http://cbth.uh.edu/outreach/fieldtripguides/CGC_Northern-Range_FieldGuide.pdf.
 
Also important with relation to the geology of the northwestern Trinidad islands is the reference collection to Kugler, H.G. (1974). The geology of Patos Island (East Venezuela). Eclogae Geologicae Helvetiae, vol. 67, No. 3, pp. 469-478.
 
 
 
Along to the above materials reprints of the following publications are deposited:
Note:
There exists also an upublished draft of Cliff Potter (dated 1965 or later). A preliminary geological map of the eastern part of the southern Range, Trinidad. Type-written text, deposited in folder "Rio Seco", Archive H.G. Kugler Box No. 65: Reports Trinidad & Venezuela 1920-1958 (see also enclosed folders "Tompire Formation" and "Grande Rivière Formation".
 
Standort
 
 
 
 
 
 
 
 
 
 
 
2.) Collection of stained acetate peels from Upper Jurassic (Tithonian) to Lower Cretaceous formations and rocks from Northern Range, North Trinidad:
 
Peels were stained using alizarin-red S and potassium ferricanide staining for recognition of various carbonate phases. Alizarine-red S stained slides are red and labelled with "alizarine", those stained with potassium ferricyanide are blue and labelled with "pot ferri".
 
Because nowadays the peel-technique is no longer widely used some references are given below. A recipe about these staining methods can be found at the homepage of the Department of Earth Sciences of the University of Cambridge under https://www.esc.cam.ac.uk/resources/facilities/laboratories/carbonate-staining (a printout is accompanying the collection).
 
 
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