94 PK0CEEDING8 OF THE PHILADELPHIA MEETING 



Discussion 



Dr. C. N. Fenner inquired as to tlie character of tlie contacts in those ex- 

 posures where the basalt sheets rest directly on older rocks not belonging to 

 the Triassic, especially as to whether the basement I'ocks were absolutely bare 

 or wliether tliere was some small amount of detrital material between the 

 basalt and the floor on wliich it rests. 



Prof. J. VoLNEY Lewis : Some of the basalt sheets in the Newark formation 

 of New Jersey are undoubtetlly composite, but the evidence on \\-hich successive 

 flows are distinguished is not in every case clear cut and decisive. In some 

 places a platy jointing or bedlike parting is very deceptive. I sliould like to 

 ask Mr. Powers on what basis he was able to separate the members of the 

 multiple basalt which lie has described and shown to us from the Bay of 

 Fundy. 



Dr. John M. Clarke stated that he believeil the term Caledonian should l>e 

 used in preference to Shiclishock and Brunswickian as a name for the mid- 

 Devonic disturbance. 



GEOLUGICAL UltiTOlxy OF THE BAl' OF FUXDY 



{Abstract) 



The Bay of Fundy lies along orographic axes which appear to liave existed 

 since the beginning of the Cambrian period. Transgressions of the seas in 

 Cambrian, Ordovician, Silurian, and Lower Devonian times are recorded in 

 small remnants of sedimentary rock, but there is a lack of evidence to sliow 

 that tlie sea at any of these times occupied the entire Fundy region. 



A disturl)ance of Middle Devonian age folded the Lower Paleozoic rocks 

 with a trend similar to that of the pre-Cambrian axes. Minas Basin was 

 formed as a structural unit at this time by the folding of the Cobequid Moun- 

 tains. The Nova Scotian granites, and probably the igneous rocks of the 

 Cobequids. were intruded at tliis time 



LHiring a portion of the Mississippian perio<l. sedimentation continued in the 

 northern part of the Fundy region. In the I'eunsylvanian period, the I'nion- 

 Riversdale and Mispec-Little River formations were deposited along the axes 

 of Minas Basin and a portion of the Bay of Fundy. After the Millstone grit 

 and the Coal Measures had l)een deposited nortli of the Cobequid I\I(nnitains, 

 another disturbance folded these Lower Pennsylvanian sediments. 



The period of deformation in mid-Pennsylvanian (ConemaughV) time is 

 correlated with the Armorican-Variscan disturbance of lOurope. as the Middle 

 Devonian disturbance is correlated with the Caledonian of Europe. In the 

 Armorican-Variscan disturljance tlie Union Riversdale and Mispec-Little River 

 sediments were greatly folded, wliile the Coal Measures, north of the Cobe- 

 quids, were not greatly disturbed. The main axis of folding was east-west 

 from Saint John through Truro. 



Following the mid-Pennsylvaiiiaii disturliiiiiic came activ(> erosion and the 

 deposition of the ITj^per Pennsylvanian-Permian New tilasgow conglomerate 



1 Introduced by R. A. Daly. 



