Continental-scale salt tectonics on Mars and the origin of Valles Marineris and associated outflow channels

2006 ◽  
Vol preprint (2008) ◽  
pp. 1 ◽  
Author(s):  
David R. Montgomery ◽  
Sanjoy M. Som ◽  
Martin P.A. Jackson ◽  
B. Charlotte Schreiber ◽  
Alan R. Gillespie ◽  
...  
Keyword(s):  
Salt Tectonics ◽  
Valles Marineris ◽  
Continental Scale ◽  
Outflow Channels

scholarly journals Martian outflow channels: How did their source aquifers form and why did they drain so rapidly?

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
J. Alexis P. Rodriguez ◽  
Jeffrey S. Kargel ◽  
Victor R. Baker ◽  
Virginia C. Gulick ◽  
Daniel C. Berman ◽  
...  
Keyword(s):  
Geographic Location ◽  
Glacial Sediments ◽  
Fluvial Erosion ◽  
Valles Marineris ◽  
Geologic Materials ◽  
Outflow Channels ◽  
Basal Melting ◽  
Outflow Channel ◽  
South Polar ◽  
Viking Orbiter

Abstract Catastrophic floods generated ~3.2 Ga by rapid groundwater evacuation scoured the Solar System’s most voluminous channels, the southern circum-Chryse outflow channels. Based on Viking Orbiter data analysis, it was hypothesized that these outflows emanated from a global Hesperian cryosphere-confined aquifer that was infused by south polar meltwater infiltration into the planet’s upper crust. In this model, the outflow channels formed along zones of superlithostatic pressure generated by pronounced elevation differences around the Highland-Lowland Dichotomy Boundary. However, the restricted geographic location of the channels indicates that these conditions were not uniform. Furthermore, some outflow channel sources are too high to have been fed by south polar basal melting. Using more recent mission data, we argue that during the Late Noachian fluvial and glacial sediments were deposited into a clastic wedge within a paleo-basin located in the southern circum-Chryse region, which at the time was completely submerged under a primordial northern plains ocean. Subsequent Late Hesperian outflow channels were sourced from within these geologic materials and formed by gigantic groundwater outbursts driven by an elevated hydraulic head from the Valles Marineris region. Thus, our findings link the formation of the southern circum-Chryse outflow channels to ancient marine, glacial and fluvial erosion and sedimentation.

Salt tectonics and collapse of Hebes Chasma, Valles Marineris, Mars

Geology ◽  
2009 ◽  
Vol 37 (8) ◽  
pp. 691-694 ◽  
Author(s):  
J.B. Adams ◽  
A.R. Gillespie ◽  
M.P.A. Jackson ◽  
D.R. Montgomery ◽  
T.P. Dooley ◽  
...  
Keyword(s):  
Salt Tectonics ◽  
Valles Marineris

Formation of Martian outflow channels by catastrophic dewatering of evaporite deposits

Geology ◽  
2005 ◽  
Vol 33 (8) ◽  
pp. 625-628 ◽  
Author(s):  
David R. Montgomery ◽  
Alan Gillespie
Keyword(s):  
Geothermal Gradient ◽  
Geological Mapping ◽  
Lava Flows ◽  
Laser Altimeter ◽  
Topographic Analysis ◽  
Valles Marineris ◽  
Volumetric Expansion ◽  
Outflow Channels ◽  
Tharsis Rise ◽  
New Hypothesis

Abstract Geological mapping based on topographic analysis of Mars Orbiter Laser Altimeter (MOLA) data, together with photointerpretation of Mars Orbiter Camera (MOC) images and thermodynamic and heat-flow considerations, frame a new hypothesis for the formation of Martian outflow channels through catastrophic dewatering of evaporite deposits. MOLA transects across Valles Marineris show that the valley is located at the crest of a 3-km-high topographic bulge on the flank of the much larger Tharsis Rise. Interpretation of MOC images showing layered deposits within Valles Marineris as unconformably underlying Hesperian-age lava flows means that these thick deposits, thought to contain hydrous sulfates, were heated by an increased geothermal gradient due to development of Tharis. Increased temperatures adequate to dehydrate hydrous evaporites would trigger significant volumetric expansion and catastrophically release tremendous amounts of overpressured water.

The Determinants of Entrepreneurship Development in Spatial Systems

2017 ◽  
Vol 13 ◽  
pp. 8-24
Author(s):  
Zbigniew Zioło
Keyword(s):  
Spatial Scales ◽  
Institutional Barriers ◽  
Entrepreneurship Development ◽  
Continental Scale ◽  
Spatial Systems ◽  
Business Conditions ◽  
Mutual Relations ◽  
Growth Shape ◽  
Strategic Goal

The processes of technological  progress create new opportunities for economic, social and cultural growth, shape new relations between economic  entities and their environment,  and influence changes in the determinants  of entrepreneurship development.  These processes vary significantly in certain geographic locations, characterised by an enormous  diversity of natural, social, economic and cultural structures. As a consequence, this creates different opportunities  and different conditions for the development of entrepreneurship in certain spatial scales, from the continental scale, through national and regional to local scales. The article presents complex conditions  for the development of entrepreneurship, highlights its limitations resulting from institutional  barriers, and the importance of knowing the mechanisms of mutual relations between spatial systems and the influence of control instruments. The quality of central and local government authorities is of particular significance here, which do not always properly use the mechanisms of rational business support. A serious barrier to the development of entrepreneurship is the low quality of social capital, manifested in a lack of trust in institutional authorities and reluctance to engage in entrepreneurship and business development. The conclusions point out that further research should be developed that will take into account changing business conditions, with a defined strategic goal of raising the quality and standard of living, international competitiveness of the country and products in different market categories.

Sign in / Sign up

Export Citation Format

Share Document