Geological Map of the Yemen Arab Republic / Sheet Sa’dah 1:250 000. (1979). Sheet: 91 x 63 cm; map area: 72.5 x 56.5 cm. (Very Good condition, as are the other sheets).
Geological Map of the Yemen Arab Republic / Sheet Al Hazm 1:250 000. (1980). Sheet: 101 x 71.5 cm; map area: 71.5 x 64 cm.
Geological map of the Yemen Arab Republic / Sheet San’a’ 1:250 000. (1983). Sheet: 95.5 x 80 cm; map area: 77 x 65 cm.
Geological map of the Yemen Arab Republic / Sheet Al Hudaydah 1:250 000. (1984). Sheet: 96 x 69 cm; map area: 77 x 62 cm.
Hannover: Germany: Bundesanstalt für Geowissenschaften und Rohstoffe, 1979 – 1984.
The Yemen Arab Republic, popularly known as North Yemen (centred on its capital Sana’a), was an Arab nationalist state that occupied the north-western part of Yemen, and which existed from 1967 to 1990, until the two parts of Yemen were unified. Due to its very rugged topography and political instability, until the 1970s North Yemen had never been geological surveyed, at least not in a scientific or comprehensive fashion. This was despite the fact that its territory was known to be rich in oil and natural gas, as well as coal, gold, lead, nickel, copper, rock salt and marble.
A period of relative stability and economic prosperity in the 1970s and ‘80s encouraged capital investment and resource exploration in North Yemen. The Yemen Minerals and Petroleum Authority, which oversaw drilling and mining in the country, cooperated with the U.S. Geological Survey in making satellite reconnaissance, resulting in the Preliminary Geologic Map of North Yemen (Reston, Va., 1976), published in various regional sheets. While a skeletal work, and not a proper, complete, scientific map, it importantly served as the basis for further, more intensive mapping.
The Yemen Minerals and Petroleum Authority decided to commission West Germany’s Bundesanstalt für Geowissenschaften und Rohstoffe (West Germany’s Federal Institute of Geosciences and Natural Resources) to create the first proper, scientific geological map of North Yemen. Such an arrangement was common practice in the Middle East, as many Western countries had far more developed institutional capabilities for leading surveys, analysing data and producing sophisticated maps and reports. That being said, the local countries, including North Yemen, were home to first rate geologists, who played vital roles in allowing the Western entities to fulfil these projects. In any event, the Bundesanstalt was one of the most technically proficient geology mapping institutes in the world.
The Bundesanstalt placed their senior geologist Wolfgang Kruck in charge of the project, who was at times assisted by the Yemeni geologists, Monsieurs Al Anissi and Saif.
As revealed by the present map, the geology of North Yemen is extremely complex. The country rises from the Red Sea coastal plain (the tihama) to a high plateau that reaches its apex at the Jabal An-Nabī Shuʿayb at 3,666 metres (12,028 ft), a massif created by the violent convergence of the Arabian and African tectonic plates. Much of the country was extremely difficult to access and creating a scientifically accurate geological map of the terrain was considered to an immensely difficult undertaking. Consequently, the country would have be mapped in sections, focusing upon the most ‘commercially promising’ sectors, in the centre and the west.
Kruck and his team compiled the maps from information from recent field surveys, as well as composites of very sophisticated sources, as noted on the map, including aerial reconnaissance by the British Royal Air Force, topographical maps made by the U.K. Defence Ministry and Landsat images from NASA and other U.S. governmental agencies.
The first map sheet, Sa’dah, done to a scale of 1:250,000 was published in Hanover in 1979, followed by the sheets Al Hazm (1980), Sana’a (1983) and Al Hudaydah (1984), all executed to the same scale. As shown by the key on each work, the mapped areas of the four sheets fit together seamlessly, even if the sheet borders are of different sizes.
To be clear, the first edition map sheets did not cover the entire territory of North Yemen, but rather about two-thirds of the country, embracing most of its oil and mineral-rich areas. As such, for some years the project rested at this stage.
Each map sheet, titled in both English and Arabic, with the map text entirely in English, is an arresting pageant of colour and scientific mastery. The legend in the margin identifies the dozens of coloured and patterned geological zones, divided into ‘Cainozoic’, ‘Mesozoic’, Paleozoic’ and ‘Precambrian’ classifications. Additionally, the ‘Geological Symbols’ identify boundaries, faults, circle zones and critical features. The ‘Geographical Symbols’, explains the details of the underlying topographical map, such as cities, towns, roads, wells, wadis, elevation contours, as well as the names of local tribes, etc. Each sheet also includes a ‘Columnar Section’, being a vertical view of the different geological layers, as well as a ‘Cross Section’, a horizonal view of the layers.
The present four-sheet set was considered vitally useful to oil and mining companies, as many new and commercially successful resource ventures came online during the 1980s.
As Yemen was unified in 1990, the Bundesanstalt was commissioned to make a second (and first complete) edition of the Geological Map of the Yemen Arab Republic, in anticipation of perhaps integrating it into the geological mapping of South Yemen (which had been undertaken separately). Wolfgang Kruck, with his colleague Uwe Schäfer, led the project that resulted in the geological mapping of the entire country, releasing an 8-sheets set (plus an explanatory booklet), done to same scale as the first edition sheets, similarly titled as the Geological Map of the Yemen Arab Republic (Hannover: Bundesanstalt für Geowissenschaften und Rohstoffe, 1991). A third edition, quite similar to the previous issue, was published in 1996.
The present first edition of the North Yemen geological map is rare. While examples are cited in at least a dozen libraries, the map seldom appears on the market, as the map sheets have a low survival rate due to heavy field use.
References: Oxford University – Bodleian Library: D64 (110); University of California – Berkeley Library: G7541.C5 s250 .Y4; OCLC: 21608923 / 17913054 / 180498861 / 720387719 / 236416129