You need to learn the Planar Summons (Earth Elemental) Spell
Prerequisites
And
Or
You also need $500 of Magically/Alchemically Enhanced Insenses and Oils associated with Purity of Earth.
You also should use a Magic Circle or Medicine Lodge to ensure you don't get outside influences disrupting your summoning
Lesser Earth Elemental
This is a basic Earth Elemental with minimal Attributes, Total 50 points (Cost 5)
Attributes: ST 12 [+20], DX 9 [-20], IQ 8 [-40], HT 8 [-20]
Secondary Characteristics: Hit Points +5 [+10], Speed 4.25, Move 4, Dodge 7 Base Melee Damage = Thr:1d+1, SW: 2d+1
Advantages: Immunity to Metabolic Hazards [+30], Injury Tolerance (Diffuse) [+100], Inate Attack {(Crushing):{Melee (C,1), Armour Divisor (2)} L2(1d6) [+5/Level]. Payload L10 (BL in lb) [+10], Striking ST +5ST [+25]
Disadvantages: Vulnerability (Air Based Attacks; x2) [-20], Fragile (Unnatural) [-50]
Larger Earth Elemental
This is a more powerful, and more costly Air Elemental, Total 80 points (Cost 8)
Attributes: ST 12 [+20], DX 10 [-0], IQ 8 [-40], HT 8 [-20]
Secondary Characteristics: Hit Points +10 [+20], Speed 4.5, Move 4, Dodge 7, Base Melee Damage = Thr: 1d+2, SW: 3d-1
Advantages: Immunity to Metabolic Hazards [+30], Injury Tolerance (Diffuse) [+100], Inate Attack {(Crushing):{Melee (C,1), Armour Divisor (2)} L2(1d6) [+5/Level]. Payload L10 (BL in lb) [+10], Striking ST +5ST [+25]
Disadvantages: Vulnerability (Air Based Attacks; x2) [-20], Fragile (Unnatural) [-50]
The above 2 are just examples, the costs can be tweaked within reason. Attributes have no limits except for Power Levels, same with the attack and Striker ST, adding HP, Speed, Move and Enhanced Dodge are viable within limits.
The Crushing Innate Attack is resolved as a Grappling Attack followed by the Crush, the Earth Elemental projects some of its form and surrounds a body part and crushes it until the effected body part is destroyed, Earth Elementals of SM+2 or higher can crush whole human sized creatures
Note on SM: ST 10 to 13 = SM -1, ST 14 to 17 = SM 0, ST 18 to 21 = SM +1, ST 22+ = SM +2