Mackenzie Chown B Block

Mackenzie Chown Complex in the background and the path running next to it.

C Block ceiling

View of the ceiling and skylights found in C Block.

A Block Corridor

Main corridor in Mackenzie Chown A Block.

H Block Roof

The interesting ventilation system on the roof of the Science Complex.

Microfacies analysis of the lower paleocene beda formation in Western Concession 59 and Block 59F, Sirte Basin, Libya /

The rock sequence of the Tertiary Beda Formation of S. W. concession 59 and 59F block in Sirte Basin of Libya has been subdivided into twelve platformal carbonate microfacies. These microfacies are dominated by muddy carbonates, such as skeletal mudstones, wackestones, and packstones with dolomites and anhydrite. Rock textures, faunal assemblages and sedimentary structures suggest shallow, clear, warm waters and low to moderate energy conditions within the depositional shelf environment. The Beda Formation represents a shallowing-upward sequence typical of lagoonal and tidal flat environments marked at the top by sabkha and brackish-water sediments. Microfossils include benthonic foraminifera, such as miliolids, Nummulites, - oerculina and other smaller benthonics, in addition to dasycladacean algae, ostracods, molluscs, echinoderms, bryozoans and charophytes. Fecal pellets and pelloids, along with the biotic allochems, contributed greatly to the composition of the various microfacies. Dolomite, where present, is finely crystalline and an early replacement product. Anhydrite occurs as nodular, chickenwire and massive textures indicating supratidal sabkha deposition. Compaction, micr it i zat ion , dolomit izat ion , recrystallization, cementation, and dissolution resulted in alteration and obliteration of primary sedimentary structures of the Beda Formation microfacies. The study area is located in the Gerad Trough which developed as a NE-SW trending extensional graben. The Gerad trough was characterized by deep-shallow water conditions throughout the deposition of the Beda Formation sediments. The study area is marked by several horsts and grabens; as a result of extent ional tectonism. The area was tectonically active throughout the Tertiary period. Primary porosity is intergranular and intragranular, and secondary processes are characterized by dissolution, intercrystalline, fracture and fenestral features. Diagenesis, through solution leaching and dolomitization, contributed greatly to porosity development. Reservoir traps of the Beda Formation are characterized by normal fault blocks and the general reservoir characteristics/properties appear to be facies controlled.

Armourstone revetments : will standard design criteria prevent failure? /

Bank stabilization structures are used to prevent the loss of valuable land within the urban environment and the decision for the type of structure used depends on the properties of the stream. In the urban areas of Southern Ontario there is a preference for the use of armourstone blocks as bank stabilization. The armourstone revetment is a free standing stone structure with large blocks of stone layered vertically and offset from one another. During fieldwork at Forty Mile Creek in Grimsby, Ontario armourstone failure was identified by the removal of two stones within one column from the wall. Since the footer stones were still in place, toe scour was eliminated as a cause of failure. Through theoretical, field, and experimental work the process of suction has been identified as a mode of failure for the armourstone wall and the process of suction works similarly to quarrying large blocks of rock off bedrock streambeds. The theory of lateral suction has previously not been taken into consideration for the design of these walls. The physical and hydraulic evidence found in the field and studied during experimental work indicate that the armourstone wall is vulnerable to the process of suction. The forces exerted by the flow and the resistance of the block determine the stability of the armourstone block within the wall. The design of the armourstone wall, high surface velocities, and short pulses of faster flowing water within the profile could contribute to armourstone failure by providing the forces needed for suction to occur, therefore adjustments to the design of the wall should be made in order to limit the effect.