Raising the West: Mid-Cenozoic Colorado-plano related to subvolcanic batholith assembly in the Southern Rocky Mountains (USA)?

Geology ◽  
2021 ◽  
Author(s):  
Peter W. Lipman
Keyword(s):  
United States ◽  
Rocky Mountains ◽  
Rocky Mountain ◽  
The United States ◽  
Crustal Thickness ◽  
Crustal Thickening ◽  
High Plains ◽  
High Potassium ◽  
Southern Rocky Mountains ◽  
Moho Depths

The Southern Rocky Mountains of Colorado, United States, have the highest regional elevation in North America, but present-day crustal thickness (~42–47 km) is no greater than for the adjacent, topographically lower High Plains and Colorado Plateau. The chemistry of continental-arc rocks of the mid-Cenozoic Southern Rocky Mountain volcanic field, calibrated to compositions and Moho depths at young arcs, suggests that paleocrustal thickness may have been 20%–35% greater than at present and elevations accordingly higher. Thick mid-Cenozoic Rocky Mountain crust and high paleo-elevations, comparable to those inferred for the Nevadaplano farther west in the United States from analogous volcanic chemistry, could be consistent with otherwise-perplexing evidence for widespread rapid erosion during volcanism. Variable mid-Cenozoic crustal thickening and uplift could have resulted from composite batholith growth during volcanism, superimposed on prior crustal thickening during early Cenozoic (Laramide) compression. Alternatively, the arc–crustal thickness calibration may be inappropriate for high-potassium continental arcs, in which case other published interpretations using similar methods may also be unreliable.

scholarly journals The Distribution of Glaciers in the Rocky Mountains of the United States

1977 ◽  
Vol 18 (79) ◽  
pp. 325-328 ◽  
Author(s):  
W. L. Graf
Keyword(s):  
United States ◽  
Rocky Mountains ◽  
The United States ◽  
Aerial Photographs ◽  
Northern Rocky Mountains ◽  
Southern Rocky Mountains

AbstractEvidence from aerial photographs, maps, and field checks indicates that 319 glaciers lie in cirques of the Rocky Mountains, south of the United States-Canadian border. On a subcontinental scale, the distribution of glaciers is highly clustered, with larger and denser clusters located in the northern Rocky Mountains. Lesser concentrations of small glaciers occur in the southern Rocky Mountains. The total area of glaciers in the Rocky Mountains of the U.S.A. is 78.9 km2.

scholarly journals Recession of Grasshopper Glacier, Montana, Since 1898

1986 ◽  
Vol 8 ◽  
pp. 65-68 ◽  
Author(s):  
Jane G. Ferrigno
Keyword(s):  
United States ◽  
Rocky Mountains ◽  
Little Ice Age ◽  
Rocky Mountain ◽  
The United States ◽  
Ice Age ◽  
Positive Mass ◽  
Mountain Glaciers ◽  
If Current ◽  
Central Rocky Mountains

Grasshopper Glacier is a cirque glacier in the central Rocky Mountains of the United States. It is a remnant of the “Little Ice Age”, rather than the more widespread and older Pinedale Glaciation. The glacier has not been monitored on a regular basis and very few maps have been published of the area, but it has been studied, photographed, occasionally mapped, and described by scientific and non-scientific groups, at different times since 1898. These photographic, cartographic, and written records make it possible to trace the fluctuations of this glacier since 1898. Grasshopper Glacier has had periods of positive mass balance, but the overall trend has been negative, with accelerated melting in recent years. It is estimated that Grasshopper Glacier has lost about 50% of its area and as much as 90% of its volume, since 1898. Other Rocky Mountain glaciers are experiencing similar wastage and, if current conditions continue, these glaciers will disappear by the middle of the next century.

scholarly journals Recession of Grasshopper Glacier, Montana, Since 1898

1986 ◽  
Vol 8 ◽  
pp. 65-68 ◽  
Author(s):  
Jane G. Ferrigno
Keyword(s):  
United States ◽  
Rocky Mountains ◽  
Little Ice Age ◽  
Rocky Mountain ◽  
The United States ◽  
Ice Age ◽  
Positive Mass ◽  
Mountain Glaciers ◽  
If Current ◽  
Central Rocky Mountains

Grasshopper Glacier is a cirque glacier in the central Rocky Mountains of the United States. It is a remnant of the “Little Ice Age”, rather than the more widespread and older Pinedale Glaciation. The glacier has not been monitored on a regular basis and very few maps have been published of the area, but it has been studied, photographed, occasionally mapped, and described by scientific and non-scientific groups, at different times since 1898. These photographic, cartographic, and written records make it possible to trace the fluctuations of this glacier since 1898. Grasshopper Glacier has had periods of positive mass balance, but the overall trend has been negative, with accelerated melting in recent years. It is estimated that Grasshopper Glacier has lost about 50% of its area and as much as 90% of its volume, since 1898. Other Rocky Mountain glaciers are experiencing similar wastage and, if current conditions continue, these glaciers will disappear by the middle of the next century.

scholarly journals Carbon storage potential of windbreaks in the United States

2019 ◽  
Vol 36 (E) ◽  
pp. 108-123
Author(s):  
William Ballesteros Possú ◽  
James R. Brandle ◽  
Héctor Ramiro Ordóñez
Keyword(s):  
United States ◽  
Carbon Storage ◽  
Rocky Mountains ◽  
Tree Species ◽  
Rocky Mountain ◽  
The United States ◽  
Southern Plains ◽  
North East ◽  
Storage Potential ◽  
Field Windbreak

In the United States of America, agriculture is performed on large farms of monocultures, affecting ecosystems and making a great contribution to climate change. The carbon storage potential for twelve field windbreak designs containing one-, two- and three-rows and nine farmstead windbreaks encompassing three- to ten-rows of mixed tree species were analyzed in nine regions: Northern Lake States (NLS), Corn Belt (CB), Southern Plains (SP), Delta States (DS), Appalachia (AP), Rocky Mountains North (RMN), Rocky Mountains South (RMS), North East (NE), y Northern Plains (NP), using the US Forest Inventory and Analysis database and allometric equations.  Carbon storage potentials for different field windbreak designs across regions ranged from 0.3 Mg C km-1 yr-1 for a single-row small-conifer windbreak in the Northeast region to 5.8 Mg C km-1 yr-1 for a three-row tall-deciduous windbreak in the Appalachia region.  Carbon storage potentials for farmstead windbreaks ranged from 0.8 Mg C 300 m-1 yr-1 for a three-row of mixed tree species windbreak in the Rocky Mountain North to 12.7 Mg C 300-1 yr-1 for a ten-row of mixed tree species windbreak in Delta States region.

scholarly journals The Distribution of Glaciers in the Rocky Mountains of the United States

1977 ◽  
Vol 18 (79) ◽  
pp. 325-328 ◽  
Author(s):  
W. L. Graf
Keyword(s):  
United States ◽  
Rocky Mountains ◽  
The United States ◽  
Aerial Photographs ◽  
Northern Rocky Mountains ◽  
Southern Rocky Mountains

Abstract Evidence from aerial photographs, maps, and field checks indicates that 319 glaciers lie in cirques of the Rocky Mountains, south of the United States-Canadian border. On a subcontinental scale, the distribution of glaciers is highly clustered, with larger and denser clusters located in the northern Rocky Mountains. Lesser concentrations of small glaciers occur in the southern Rocky Mountains. The total area of glaciers in the Rocky Mountains of the U.S.A. is 78.9 km2.

scholarly journals GOES Climatology and Analysis of Thunderstorms with Enhanced 3.9-μm Reflectivity

2006 ◽  
Vol 134 (9) ◽  
pp. 2342-2353 ◽  
Author(s):  
Daniel T. Lindsey ◽  
Donald W. Hillger ◽  
Louie Grasso ◽  
John A. Knaff ◽  
John F. Dostalek
Keyword(s):  
United States ◽  
Rocky Mountain ◽  
The United States ◽  
Vertical Shear ◽  
High Plains ◽  
Eastern United States ◽  
Ice Crystal ◽  
Reanalysis Dataset ◽  
The North ◽  
Ice Crystal Size

Abstract By combining observations from the Geostationary Operational Environmental Satellite (GOES) 3.9- and 10.7-μm channels, the reflected component of the 3.9-μm radiance can be isolated. In this paper, these 3.9-μm reflectivity measurements of thunderstorm tops are studied in terms of their climatological values and their utility in diagnosing cloud-top microphysical structure. These measurements provide information about internal thunderstorm processes, including updraft strength, and may be useful for severe weather nowcasting. Three years of summertime thunderstorm-top 3.9-μm reflectivity values are analyzed to produce maps of climatological means across the United States. Maxima occur in the high plains and Rocky Mountain regions, while lower values are observed over much of the eastern United States. A simple model is used to establish a relationship between 3.9-μm reflectivity and ice crystal size at cloud top. As the mean diameter of a cloud-top ice crystal distribution decreases, more solar radiation near 3.9 μm is reflected. Using the North American Regional Reanalysis dataset, the thermodynamic environment that favors thunderstorms with large 3.9-μm reflectivity values is identified. In the high plains and mountains, environments with relatively dry boundary layers, steep lapse rates, and large vertical shear values favor thunderstorms with enhanced 3.9-μm reflectivity. Thunderstorm processes that lead to small ice crystals at cloud top are discussed, and a possible relationship between updraft strength and 3.9-μm reflectivity is presented.

Sign in / Sign up

Export Citation Format

Share Document