woodworth: geological expeditiox to brazil and chile. 33 



We entered Coneepcion Bay on December 8th, and on the 9th I 

 went ashore at Talcahuano. I spent several days in the vicinity of 

 Coneepcion examining evidences of cliange of level. As the results 

 of my observations are given in a subsequent chapter I make mention 

 here only of some unrelated geological details. 



On December 11th, while yet in bed, at about ten minutes past 

 seven, I felt a slight quivering followed by a sharp lurch of the hotel. 

 The wooden framework of the ceiling cracked and creaked. The 

 daily press stated that at 7.10 a short but violent shock was felt. 

 Again on the 13th of December while in Coneepcion, the daily press 

 reported during various hours of the night subterranean noises ac- 

 companied by a shock at 12.40 a. m., which caused some alarm. I 

 was awakened at about 1.35 a. m. by what at the time I thought was 

 the fall of an object in the room below; meanwhile I heard a rumbling 

 noise sounding like that made by street cars. The destruction of 

 Valparaiso by the earthquake of August, 1906, has made the inhabi- 

 tants fearful of a repetition of such violent earthquakes, particularly 

 at Coneepcion whose ancient site at Penco on the shores of the Bay 

 has been the seat of the most famous earthquakes in the annals of 

 Chile. The practice of the Spanish in South America of leaving a 

 site more than once damaged by earthquakes has much to recommend 

 it. In the case of Old Coneepcion or Penco, twice destroyed by 

 earthquakes and inundations from the sea, the site was mainly on a 

 marsh behind a barrier beach filling out an indentation of the coastal 

 hills, a location, owing to the soft nature of the recent alluvial deposits, 

 likely to be severely shaken by earthquakes. The new cit}' of Con- 

 eepcion stands on a plain of Pleistocene alluvium mxantling much 

 disturbed sandstones which here and there rise as low hills through 

 the plain. That this city has escaped destruction so far from earth- 

 quakes is seemingly due rather to the failure of local violent shocks 

 than to its location. 



On December 13th, I \dsited Penco, the site of ancient Coneepcion. 

 Since Darwin's time the construction of a railway along the shore of 

 the bay has led to the partial demolition of the old Spanish Fort, the 

 seaward portion of the walls onh^ remaining. (Plate 4). Of what 

 I presume to be this building, Lyell states: "It has, however, been 

 ascertained that the foundation of the Castle of Penco was so low in 

 1835, or at so inconsiderable an elevation above the highest spring 

 tides, as to discountenance the idea of any permanent upheaval in 

 modern times, on the site of that ancient port; but no exact measure- 

 ments or levellings appear as j^et to have been made to determine this 



