UA PTYS 554 - Lecture Notes (37 pages)

Previewing pages 1, 2, 17, 18, 19, 36, 37 of 37 page document View the full content.
View Full Document

Lecture Notes



Previewing pages 1, 2, 17, 18, 19, 36, 37 of actual document.

View the full content.
View Full Document
View Full Document

Lecture Notes

23 views

Lecture Notes


Pages:
37
School:
University of Arizona
Course:
Ptys 554 - Evolution of Planetary Surfaces

Unformatted text preview:

PTYS 554 Evolution of Planetary Surfaces Weathering Weathering and and Fate Fate of of Sediments Sediments PYTS 554 Weathering and Fate of Sediments Production of sediments on terrestrial planets Transport and deposition of sediments Source rocks Physical and chemical weathering Production of clays and oxides Landscape evolution and sedimentary basins Size sorting and Desert pavement Stratigraphy of sediments ripple laminae cross bedding etc Burial and metamorphism of sediments Diagenesis Kinds of metamorphism The following 5 lectures 2 PYTS 554 Weathering and Fate of Sediments Most sediment comes from weathering initially solid rocks Ultimately almost all terrestrial planet sediments were volcanically produced Intrusive volcanism Surface flows Ash flows falls 1 Rocks need to be broken up 2 Sediment needs to be transported and lithified 3 Buried sediment can be metamorphosed 3 PYTS 554 Weathering and Fate of Sediments Tephra pyroclastic deposits Escaping volatiles drive eruptions of different strengths Bombs blocks 64mm Cinders Lapilli 2 64mm Ash 2mm Measured by fragments 1mm in size Measured by area covered by tephra High silica magmas drive the most explosive eruptions Schmincke 2004 4 PYTS 554 Weathering and Fate of Sediments Volcanic ash can be unconsolidated or easily remobilized 5 PYTS 554 Weathering and Fate of Sediments Growth of Regolith Crust of airless bodies suffers many impacts Repeated impacts create a layer of pulverized rock Old craters get filled in by ejecta blankets of new ones Regolith grows when crater breccia lenses coalesce Assume breccia regolith thickness of D 4 Maximum thickness of regolith is Deq 4 but not in all locations Smaller craters are more numerous and have interlocking breccia lenses D eq 4 Shoemaker et al 1969 6 PYTS 554 Weathering and Fate of Sediments Minimum regolith thickness Figure out the fractional area f c covered by craters D Deq where D Deq Choose some Dmin where you re sure that every point on the surface has been hit



View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view Lecture Notes and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Lecture Notes and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?