Get The Spatial And Temporal Evolution Of The Portland ...

The Isle of Portland, southern England, is composed of gently folded Upper Jurassic Beds ranging from the Kimmeridge Clay through the Portland Group to the Lower Purbeck Group which are gently folded to form part of the northern end of the Shambles Syncline.

The hills date from the late Cenozoic era, and range up to over 1,000 feet (300 m). Composed mainly of basalt, the mountains were formed by several flows of the Grande Ronde basalt flows that were part of the larger Columbia River basalts.

Portland is approximately 100 miles (160 km) upriver from the Pacific Ocean on the Columbia. Though much of downtown Portland is relatively flat, the foothills of the Tualatin Mountains, more commonly referred to locally as the "West Hills", pierce through the northwest and southwest reaches of the city.

The Troutdale Formation consists of quartzite-bearing conglomerate and vitric sandstone that generally overlie the Sandy River Mudstone (Trimble, 1963).

The term Hillsboro Formation is used to disassociate these sediments, in contrast to past prac- tice, from those of the Troutdale Formation or Sandy River Mudstone in the Portland basin. The HBD-1 core is the type section for the Hillsboro Formation. From it, correlations are made to other parts of the basin.

The Troutdale series consists of moderately deep, well drained soils that formed in mixed material weathered from schist, gneiss, and interbedded granitic rocks. Troutdale soils are on mountain slopes and ridge crests, and have slopes of 2 to 50 percent.

Portland is located in the Portland Basin, a forearc basin that lies between the Coast Rang- es and the active volcanic arc of the Cascade Range. The Coast Ranges are composed of Eocene to Miocene marine sedimentary rocks and Eocene intru- sive and extrusive basalt deposited on the accreted Siletz terrane.

Portland is located in the Portland Basin, a forearc basin that lies between the Coast Rang- es and the active volcanic arc of the Cascade Range. The Coast Ranges are composed of Eocene to Miocene marine sedimentary rocks and Eocene intru- sive and extrusive basalt deposited on the accreted Siletz terrane.

Bisected by the lowermost reaches of the Columbia River—one of the few major world rivers cutting through an active volcanic arc—and located within a monogenetic volcanic field, the Portland Basin records not only local tectonic and volcanic activity, but also major North American geologic events, including emplacement ...

The Isle of Portland, southern England, is composed of gently folded Upper Jurassic Beds ranging from the Kimmeridge Clay through the Portland Group to the Lower Purbeck Group which are gently folded to form part of the northern end of the Shambles Syncline.

The hills date from the late Cenozoic era, and range up to over 1,000 feet (300 m). Composed mainly of basalt, the mountains were formed by several flows of the Grande Ronde basalt flows that were part of the larger Columbia River basalts.

Portland is approximately 100 miles (160 km) upriver from the Pacific Ocean on the Columbia. Though much of downtown Portland is relatively flat, the foothills of the Tualatin Mountains, more commonly referred to locally as the "West Hills", pierce through the northwest and southwest reaches of the city.

The Troutdale Formation consists of quartzite-bearing conglomerate and vitric sandstone that generally overlie the Sandy River Mudstone (Trimble, 1963).

The term Hillsboro Formation is used to disassociate these sediments, in contrast to past prac- tice, from those of the Troutdale Formation or Sandy River Mudstone in the Portland basin. The HBD-1 core is the type section for the Hillsboro Formation. From it, correlations are made to other parts of the basin.

The Troutdale series consists of moderately deep, well drained soils that formed in mixed material weathered from schist, gneiss, and interbedded granitic rocks. Troutdale soils are on mountain slopes and ridge crests, and have slopes of 2 to 50 percent.

Portland is located in the Portland Basin, a forearc basin that lies between the Coast Rang- es and the active volcanic arc of the Cascade Range. The Coast Ranges are composed of Eocene to Miocene marine sedimentary rocks and Eocene intru- sive and extrusive basalt deposited on the accreted Siletz terrane.

Portland is located in the Portland Basin, a forearc basin that lies between the Coast Rang- es and the active volcanic arc of the Cascade Range. The Coast Ranges are composed of Eocene to Miocene marine sedimentary rocks and Eocene intru- sive and extrusive basalt deposited on the accreted Siletz terrane.

Bisected by the lowermost reaches of the Columbia River—one of the few major world rivers cutting through an active volcanic arc—and located within a monogenetic volcanic field, the Portland Basin records not only local tectonic and volcanic activity, but also major North American geologic events, including emplacement ...

Bisected by the lowermost reaches of the Columbia River—one of the few major world rivers cutting through an active volcanic arc—and located within a monogenetic volcanic field, the Portland Basin records not only local tectonic and volcanic activity, but also major North American geologic events, including emplacement ...