In lieu of an abstract, here is a brief excerpt of the content:

32.0. Nicaragua 545 Extensive excavations, carried out with the cordial support of President Somoza, revealed most interesting conditions, best summarized by quoting the preliminary report of Dr. Howel Williams, of the University of California, who, on being appealed to by the Division, generously sacrificed his Easter vacation to fly to Nicaragua and examine the deposits. Before the footprints were made, there had probably been millions of years of volcanic activity, as they are underlain by hundreds of feet of ash. It may be, however, that about the time the prints were formed the craters, a short distance south of Managua, burst into unusually violent eruption. I hope that microscopic study of the deposits will throw light on this point. Just before the prints were produced, volcanic “mud flows” (technically known as lahars) swept across the plains around Managua and emptied into the lake. It may be that these were formed by temporary damming of the rivers that drain from the highlands to the T H E C A R N E G I E M A Y A 32.1. FRANCIS B. RICHARDSON Nicaragua YB 40:300–302, 1941 As was stated in the introduction to this report, Mr. Richardson, who went to Nicaragua to study relatively recent stone sculpture, was diverted from that end by the necessity of investigating a series of ancient human footprints found in deeply buried volcanic deposits near Managua. A similar discovery had been made in the seventies by Earl Flint, who was working for the Peabody Museum of Harvard University. Flint’s attribution of great age to the footprints was received with considerable skepticism, no attempt was made to follow up the discovery, and the whole occurrence was soon practically forgotten. Mr. Richardson, however, who had read Flint’s reports and his correspondence filed at the Peabody Museum, felt that the matter should be investigated further. On arrival at Managua, he accordingly made inquiries and learned that footprints were still from time to time encountered in a quarry in El Cauce, a short distance west of the city. He, at once visited the site, where by great good fortune the workmen were just bringing some of the tracks to light. 546 NICARAGUA south, at a time when the cones and craters of Asososca, Nejapa, Tiscapa, etc. were particularly active. Whatever the cause of the lahars, and other possible causes are easy to imagine, they inundated a wide area. Soon after they came to rest, the prints were impressed. I say “soon” because the deposits left by lahars tend to harden rapidly. Somewhat similar deposits were laid down on the slopes of Lassen Peak in California in 1915 and within a few hours it was difficult to stamp an impression on them with the feet. Lahars which sweep down from the volcano of Java are known to behave in the same way. Incidentally, the laharic deposits of Managua are remarkably like those which buried Herculaneum in AD 79. Shortly after the making of the prints possibly even while they were being made they were covered by a thin veneer of black cinders. Then followed another lahar, another eruption of black cinders, and then a rapid succession of thick lahars. These last are now represented by the thick stratum quarried and used as a building stone in Managua. An interval of quiescence ensued. In the region of El Cauce, rivers excavated a channel some 20 m wide and at least 3 m deep. They cut not only through the layers of volcanic mud but far into the underlying ashes. Slowly the channel was filled with sand and gravel. Subsequently, a distant volcano, perhaps in the vicinity of Masaya, erupted showers of white pumice. About El Cauce the pumice accumulated to a depth of approximately 50 cm. Once more quiet followed. Rivers cut new channels through the pumice; elsewhere a soil up to 1 m thick was developed. Renewed eruptions covered the soil with ash; another soil, up to 30 cm thick, was formed; more ash fell, and finally the topmost layer of soil on the present surface was laid down to a depth of 1.25 to 1.5 m. The record of events since the prints were impressed is thus a long one, as four layers of soil were formed and a deep river channel was cut. The tracks were made by a number of barefooted adults. All those uncovered by Mr. Richardson were going in the direction of a point which at present...

Share