Final answer:
To find the spring from which the oil gushes on the map, one would analyze geologic maps and seismic data to identify geological structures associated with oil deposits. Tools like Figure 9.13, a geologic map, and seismic cross-sections can reveal subsurface geology indicating the presence of potential oil-bearing areas.
Step-by-step explanation:
The passage and accompanying map descriptions suggest that you need to identify a spring or a location related to oil extraction, which would likely include oil wells, drilling sites, or geological structures associated with petroleum deposits. When looking for a spring from which oil gushes, you would typically search for an oil well or a natural oil seep. Based on historical data, like the illustration from the 1909 book depicting oil wells in Baku, Azerbaijan, springs or seeps would be likely placed where oil wells historically existed. In a modern context, finding such a spring would involve analyzing geologic maps and seismic data to pinpoint structures that could contain oil deposits.
For example, Figure 9.13 and 9.15 provided in the question mention geologic maps and a seismic cross-section, which are fundamental tools in the search for oil. These figures likely contain important details that might indicate the presence of an oil-bearing structure, such as salt diapirs, anticlines, or rift basins. In particular, the seismic cross-section can reveal the subsurface geology, showing different layers and structures that might hold oil.
Moreover, the mention of 'fracking' leads to tight oil deposits, indicating that modern drilling techniques can access oil in places where it wouldn't have been considered feasible in the past. Thus, a contemporary map with geologic and seismic information would be paramount in locating a spring of oil today. This data would point to formations with the potential for oil, which might be indicated by specific geological features such as salt beds or the presence of certain sedimentary rock indicative of oil reserves.