The foreground surface looks like matted soil that has been highly eroded by water. Ideally depicted, it would have been dull with a grainy texture. There could be scratches and other imperfections on its surface. A network of shallow erosional patterns radiates from a main drainage channel running between the two figures and toward the tomb. The drainage patterns are believable geologically. The pebbles which are not well rendered are randomly placed on the front of the painting, yet the edges of the rock along the perimeter of the crag are not believable. They are irregularly jagged like a jig-saw puzzle piece. The edges are too sharp. They should have been weathered by water resulting in softer edges and a grainier texture.
The other objection to the foreground is the lack of sfumato, or shading on the ground surface. It is slightly darker in the front and lighter in the back giving the appearance that the foreground surface is moving up vertically, rather than moving horizontally toward the background.
To the right of St. Leonardo (at lower left), between his foot and his knee, a section of eroded soil looks as if it is being lifted vertically, off the ground. This is because of inadequate shading. The rounded edges of this piece of soil capture the spirit of erosion but miss the point because shadow is used incorrectly and there are too many irregular edges. The soil surface around the foot of St. Lucia is depicted much more believably, although there could be more texture to the ground surface.
To the left of St. Leonardo’s back, a ledge project out. Again, there is no texture to the rock. The rock ledge also gives the indication of a precipice, which seems dangerously close to the rear foot of St. Leonardo and appears to be very deep. What is the boundary of this drop-off? Is St. Leonardo in danger of falling?
The width of the foreground is sufficiently wide to allow figures room on which to kneel. This is in contrast to the Virgin of the Rocks, National Gallery, London (Fig. 3) whose foreground rock ledge is too narrow, making the figures look as if they might fall into an abyss.
These impressions are due to the lack of technique by the painters. Leonardo always placed figures on different rocks, varying the elevations. He worked hard as assuring that the placement of the figures was correct so that the viewer feels no tension that one of the figures is going to fall off a precipice.
To the left of the tomb, the shadowing of the ground surface is believable, giving it a sense of depth. This is in contrast to the ground surface in front of the tomb which is too light. The tomb, also light, gives the appearance that it is almost one-dimensional, rising from the ground. Interestingly, the tomb looks like it is made of fine marble. The sophisticated marbleized effect is well done, indicating Leonardo’s influence. There appears to be a rock or rock formation behind the lid of the tomb. Perhaps this was the rock that “sealed” the tomb. Unfortunately, the rock lacks texture, a key feature needed to enable the viewer to identify it. Although the tomb is set on solid ground, a dark area behind implies that there is an abyss. Theoretically, the lid of the tomb should have slid down the abyss, yet because the lid is still visible, the abyss cannot be too deep. Further, if the formation behind the lid is the boulder used to block the tomb, it too should have fallen into the dark, deep abyss. The area, therefore, should not have been depicted with colors which are so dark that they indicate extreme depth.
Behind St. Lucia are billowy rocks. These are certainly reminiscent of the spheroidally weathered sandstone in Leonardo’s Virgin of the Rocks, Louvre (Fig. 2), but they lack the correct texture. They seem to be light, almost like brown clouds ready to float away. Although the rocks are not accurately depicted, there is enough detail in the rendering and placement to support the inference that these rocks were chunks of the rock at the top of the formation which, due to erosion, had broken off, fallen to the ground, and had been further weathered. This is entirely plausible geologically.
Above St. Lucia’s head, the rocks appear harder and their edges sharper. These rocks are very indicative of Leonardo’s influence. They have an angular characteristic to them with vertical relief. This rock is called diabase, a rock of igneous origin that was formed by the cooling of a molten liquid. When it cooled, it hardened and a preponderance of vertical cracks or joints, with a lesser amount of horizontal ones were formed. These are depicted quite well at the extreme right of the painting. Although these are represented very well, they lack the sophistication of Leonardo’s shading. A look at the diabase (found above the Virgin’s head) in the Virgin of the Rocks, Louvre (Fig. 2) provides the viewer with an idea of the ideal portrayal of these rocks; angularity and subtle shading at the edges. The lack of shading and the extreme angularity as portrayed is not realistic from a geological perspective because extensive weathering should have caused a softening of the edges and a dirtying effect on these rocks.
Extending to the right, from Christ’s robe, is a horizontal crack between the section of rock with vertical relief and that with horizontal layers. This is called a contact-surface, or the plane where two different types of rocks meet. The layered or bedded sandstone above this formation is quite recognizable and accurate geologically. It could be made more believable, however, by a softening of the blunt edges of rock. Once again, the Virgin of the Rocks, Louvre (fig. 2) offers a fine depiction of this type of rock in the foreground.
Hidden behind St. Lucia, would be a similar horizontal plane, the basal (or bottom) contact where the diabase comes in contact with the sandstone found in the foreground. Although this feature is hidden, it is implicit in the painting as we can see the change in the type of rock. This is a sophisticated geologic concept and the subtlety in which the accuracy is portrayed is admirable (Fig. 6).
Above the horizontally bedded layers of rock is spheriodally weathered sandstone. This actually is the same type of rock, sandstone, as the horizontally bedded rock seen just below it. This section, however, has been subjected to the weathering forces of wind, rain and water and thus, has been eroded so much as to eliminate all traces of the original bedding features. Although this rock formation is recognizable and accurate from a geological perspective, it should be depicted as grainy, dull and more highly textured because it has been so highly weathered. The well-formed smooth mound to the right of and below the flag should have a more irregular shape at its perimeter and the texture itself should be grainier. To the right of the flag, the layer of bedded sandstone with the plant growing, would be more believable if the bedded sandstone were underneath and, thereby protected from erosion. Because the rock is exposed, one wonders why it hasn’t been more highly eroded.
The rock formation as a whole is interesting as the location of the cave for the tomb of Christ. Because the formation is made of highly weathered sandstone, it is a feasible location for the excavation of a tomb. This point would not have been lost on Leonardo whose vast knowledge of mechanical tools and excavation techniques would have encouraged the painters to portray an excavation of any sort properly, both from a technical and geological perspective.
In the background is a meandering (winding) river. The artists would have been familiar with this concept from Leonardo, who wrote about it. The meandering river winds its way around pinnacles made of a massive rock such as granite. These pinnacles were formed when the overlying softer rock was eroded away by the forces of wind and water. The pinnacles remained because they consist of granite, or another hard rock which is resistant to weathering. Te pinnacles are portrayed well enough when compared to other artists, indicating Leonardo’s influence. They are also painted with the characteristic blue-gray color used by Leonardo for background details. The pinnacles are painted in a way which demonstrates their inherent hardness, varying heights and saw-toothed nature. The detailing could have been more precise to more closely mimic Leonardo, however the fact that they are recognizable indicates the influence of the teacher.
The geology of the city is implausible. The city is built on a flat fluvial point bar (flat sediments deposited by the river). However, there are several granite pinnacles coming out of the water around the city. Either these should be eliminated, making the entire area flat, or more should be added, showing the city built on a rugged landscape. The color of the city is also peculiar. According to Leonardo, it should be bluer, reflecting its position in the distance.
As it winds, the meandering river leaves sediments on the insides of the curves of the bends of the river called point bars. These sediments are normally deposited so they lie flat. In the painting, the point bars show small peaks. This is geologically inaccurate. The area scoured out by the river is called a cut bank. It, however, is accurately portrayed.
Another interesting point is that although the background of the painting is quite plausible and identifiable geologically, the geologic features are not Alpine. That is, geological formations and land-mass formations resulting from the presence and movement of glaciers. Leonardo normally depicted Alpine geology in his paintings. Perhaps Boltraffio and d’Oggiono wished to depict another type of landscape, which of course is acceptable, as the location of the Resurrection would not have been in an Alpine environment. They also might not have been the intrepid explorers of the Alps that Leonardo was. If they had stayed close to Milan, they would have seen the type of geology portrayed in the Resurrection. The fact that the scene is plausible and identifiable is, however, the most important aspect to be considered.
To the left of Christ’s knee, the nature of the land formation is ambiguous. Perhaps there are trees present, it is not clear. The confusion of the area, combined with natural features which are unidentifiable and such a dark blackish green color is not a Leonardian portrayal. In his Treatise on Painting, Leonardo is very clear as to how the backgrounds and mountains should be portrayed. Behind this dark area are several high mounds which have no texture. These do not seem plausible. They should be either high, like the other granite pinnacles or they should be lower indicating flatter, sedimentary deposits.
The atmosphere in the background is flat and not exciting. There is no sense of dimension or atmospheric conditions that are dramatic. The clouds are well defined but the one on the left has a fat bottom which makes it have the panel-like effect of a stage set. The mountains in the greater distance should be better defined, even through the haze.
These observations are useful to the art historian as a diagnostic tool to identify painters of various works. Using Leonardo’s trademark of geological accuracy as an indicator, we now know that he instilled in his students an appreciation of geology which they emulate very well in the geologic formations portrayed in the Resurrection.
We can take this analysis to a logical conclusion by using geology as a diagnostic tool for analyzing those artists who painted the three paintings referenced (all painted in Milan); Virgin of the Rocks, Louvre (fig. 2), Virgin of the Rocks, National Gallery, London (fig. 3) and the Resurrection (fig. 5). In the first instance the Virgin of the Rocks, Louvre (fig. 2) was painted by Leonardo as confirmed by the accurate geology portrayed in the picture. The Resurrection (fig. 5) was painted by Leonardo’s students as seen by the fact that the depiction of the geology is credible, the formations are identifiable and the painting techniques, although certainly not of Leonardo’s caliber, pay attention to geologic detail to such an extent as to allow the rocks to be identified. The National Gallery (fig. 3) painting exhibits no fidelity to geologic representation. The rocks are caricatures that cannot be identified. The painting exhibits no geological accuracy at all which thereby eliminates it as a work of wither Leonardo or his students, Boltraffio and d’Oggiono.
Using geology as a diagnostic tool acts as an objective indicator of Leonardo’s work. Now we can use it to identify those works of his students as well.
Glossary of geologic terms
