May 8 1896.] 



SCIENCE. 



693 



or inner pores, those on the opposite sides 

 being placed at right angles, thus producing 

 a kind of maltese cross within each circle. 

 This is very characteristic of the Palseozoic 

 genus Dadoxylon, and your material can- 

 not by any means have come from the Ter- 

 tiary unless it has been redeposited. The 

 specimen itself is Palaeozoic, and the ques- 

 tion of its possible removal from its original 

 position is, of course, one of stratigraphy." 

 Geo. E. Ladd. 

 Atlanta, Ga. 



NOTE ON A BREATHING GAS WELL. 



A VERY remarkable gas well recently 

 came under the writer's observation while 

 engaged in studying the geology of the 

 Santa Lucia Eange. It is situated on the 

 Eagle Ranch, on the eastern side of the 

 Eange in San Luis Obispo county, Cali- 

 fornia. 



The well is interesting on account of two 

 things: (1), the presence of gas in the 

 Oolden Gate series, it being encountered 

 while boring for water ; and (2), the inter- 

 mittent flow of gas, the periods of flow al- 

 ternating with those of drawing in air. 



The geology of this portion of the range 

 is quite complicated. In the vicinity of the 

 Eagle Ranch there are four different forma- 

 tions; the oldest, the Golden Gate series, 

 consisting of shale, sandstone and jasper, 

 with numerous ancient eruptives, the whole 

 being probably of Upper Jurassic age. The 

 rocks of this series are extensively devel- 

 oped through the Coast Ranges of Cali- 

 fornia, but have never before been found 

 to contain gas, nor have any indications of 

 coal or oil been met with. 



The well was bored on the point of a hill 

 rising perhaps seventy-feet above a little 

 flat on which the ranch buildings are sit- 

 uated; this flat is underlaid by Lower Creta- 

 ceous shales which surround the hUl on 

 three sides. The Chico sandstone occurs, 

 overlying the shales in various places; 



while to the east, some distance away, the 

 Bituminous Slate series (Miocene) is met 

 with filling the Salinas Valley. The Mio- 

 cene is preeminently the oil and gas bear- 

 ing formation of California. The writer 

 does not know of any locality in the State 

 where gas is obtained in quantities sufli- 

 cient for use from beds of Cretaceous age, 

 although such may be the case. 



The well under consideration has a bore 

 of six inches and was put down to a depth 

 of three hundred and fifty- six feet. The 

 strata passed through consists of shale and 

 sandstone having a very steep dip. They 

 are exposed on the south side of the hill at 

 a distance of a little more than a hundred 

 feet from the well, and exhibit the intense 

 distortion of and shearing so characteristic 

 of the Golden Gate series. When first 

 bored, the water rose to within about eighty- 

 five feet of the surface. A small amount of 

 gas was encountered at a depth of ninety 

 feet. Comparatively little gas came from 

 the well at first, but during a stormy spell 

 the well was pumped continuously for some 

 time, and as the water grew lower a notice- 

 able amount of gas began to issue. This in- 

 creased until it was estimated to amount 

 to twenty thousand feet per day. This 

 state of things lasted for about six weeks, 

 when the volume began to decrease, finally 

 becoming intermittent. The well has now 

 been opened for four years, the gas continu- 

 ing to average about 250 feet per day. 

 During settled weather the intermittent ac- 

 tion is fairly regular, the gas issuing for 

 about three hours, when an equilibrium be- 

 ing reached, the current changes and air is 

 sucked in for the same length of time. If 

 the air is not allowed to enter the gas will 

 not fiow ; consequently an automatic valve 

 has been placed at the surface of the well, 

 permitting the ingress of the air. The suc- 

 tion is frequently so strong that, if only a 

 small opening is left a roaring sound is pro- 

 duced, which is audible at the ranch house. 



