REPORT OF TEE CHIEF ASTRONOMER XV 



SESSIONAL PAPER No. 25a 



Page. 



Tertiary (?) rocks at Osoyoos lake 433 



Petrography of the composite batholith 433 



Richter Mountain hornblendite 433 



Chopaka basic intrusives 433 



Ashnola gabbro 435 



Basic Complex 436 



Nodule-bearing peridotite dike 437 



- Vesicular andesite dikes • . . . . 439 



Osoyoos batholith 439 



Original granodioritic type 439 



Dynamic and hydrothermal metamorphism of the granodiorite 441 



Eemmel batholith 443 



Western phase 443 



Eastern phase 445 



Interpretations of the two phases 447 



Kruger alkaline body 448 



General description 448 



Augite-biotite malignite 459 



Femic nephelite syenite 451 



> Nephelite syenite 452 



Summary 454 



Metamorphism 455 



Similkameen batholith 455 



General character 455 



Basic phase at contact 457 



Comparison with Kruger alkaline body 458 



Dikes cutting the Similkameen batholith 459 



Cathedral batholith 459 



Older phase 459 



Younger phase 461 



Relation to Similkameen batholith 461 



Dikes cutting the Cathedral batholith 464 



Park granite stock 464 



Geological relations and general structure 466 



Resume of the geological history 470 



Sequence of the eruptive rocks 471 



Method of intrusion 476 



General summary 477 



CHAPTER XVII. 



Formations of the Hozomeen range 479 



General description 479 



Pasayten series 479 



Introduction 479 



Stratigraphy 480 



Eossils collected 486 



8364— BB^ 



