Name_____KEY___________________ NOTES for Plate Boundaries, Stresses and Faults The Lithosphere is made of the __crust__ and the UPPER rigid __mantle________. Plates may be called by different names, like __Tectonic_______Plates, Lithosheperic Plates and __Crustal______ Plates. ( Remember! Plates around Earth move in different directions & cause different geologic events, which are things that happen on Earth). Remember! What makes the plates move? >>>Answer: _Convection___ Currents in the mantle move the plates as the core heats the slowly-flowing asthenosphere (the elastic/plastic-like part of the mantle). PLATE BOUNDARIES: There are 3 types of Plate Boundaries. Each one has a type of _stress____ on the rock & a way that it breaks, called a _fault____. The three types of BOUNDARIES are divergent boundaries, _convergent_______ boundaries and transform boundaries. What is this kind of boundary? (define it) Divergent Boundary Place where 2 plates pull away from each other (like dissecting or dividing) What does this kind of boundary look like? (draw it) Convergent Boundary Place where 2 plates crash (or crunch) or subduct (one sink under) each other (like connecting or coming together) Transform Boundary Place where 2 plates slide past each other (like cars side swiping each other) DIVERGENT BOUNDARIES – plates Divide Question: How is the rock pulled at Divergent Boundaries? Answer: Rock gets __thin____ in the middle as it is __pulled___ apart. This stress is called ___tension_______. Question: What happens when the rock SNAPS from the Stress of Tension? Answer: A Normal __fault_____ (fault is a break in Earth’s crust). Rock __drops_____ down as it breaks. Question: What happens next @ Divergent Boundaries? Answer:__Rift valleys___ may form on continents & ___________Seafloor______SPREADING in the ocean . NORMAL FAULT STRIKE-SLIP FAULT REVERSE FAULT CONVERGENT BOUNDARIES – plates crash together Question: How is the rock pushed at convergent boundaries? Answer: Rock is _pressed_ or squeezed together. Question: What happens when the rock is squeezed from the Stress of Compression? Answer: A REVERSE _fault___________. Rock is forced __upward____as it is squeezed. Question: What happens next @ Convergent Boundaries? Answer: They may form ___mountain______ ranges like the Himalayas or the Rockies. TRANSFORM BOUNDARIES - Rocks are PUSHED AWAY in opposite directions. Question: What happens when the rock is sheared (or “cut”) from the Stress of Shearing? Answer: A ____strike-slip_________FAULT, which is when rocks on each side of the fault slip past each other as they break. Question: What happens next at Transform Boundaries? Answer: This may cause__earthquakes_____ when the rock snaps from the pressure. (A famous fault at a Transform Boundary is the San Andreas Fault in California.) • HELPFUL HINTS: Shearing means cutting (“Shears” are like scissors) • Transform boundaries run like trains going past each other in different directions & they shake the ground!