diff --git a/src/LaMEM_ModelGeneration/ModelSetup.jl b/src/LaMEM_ModelGeneration/ModelSetup.jl
index 5ba538a9..da631b87 100644
--- a/src/LaMEM_ModelGeneration/ModelSetup.jl
+++ b/src/LaMEM_ModelGeneration/ModelSetup.jl
@@ -1,6 +1,8 @@
 # Model Setup
 
-export ModelSetup, Write_LaMEM_InputFile, geom_Sphere, set_geom!
+export ModelSetup, Write_LaMEM_InputFile, 
+        geom_Sphere, geom_Ellipsoid, geom_Box, geom_RidgeSeg, geom_Hex, geom_Layer, geom_Cylinder,
+        set_geom!
 
 """
     Structure that contains the LaMEM Model Setup and Advection options
@@ -98,6 +100,8 @@ end
 
 
 # Geometric primitives======
+
+# -------
 """
     LaMEM geometric primitive `sphere` object 
     
@@ -144,6 +148,328 @@ function Write_LaMEM_InputFile(io, d::geom_Sphere)
     println(io, "    <SphereEnd>")
     return nothing
 end
+# -------
+
+# -------
+"""
+    LaMEM geometric primitive `Ellipsoid` object 
+    
+    $(TYPEDFIELDS)
+"""
+Base.@kwdef struct geom_Ellipsoid
+    "phase"
+    phase::Int64          = 1          
+     
+    "semi-axes of ellipsoid in `x`, `y` and `z` "
+    axes::Vector{Float64}      = [2.0, 1.5, 1.0]
+      
+    "center of sphere"
+    center::Vector{Float64} = [1.0, 2.0, 3.0]
+        
+    "optional: Temperature of the sphere. possibilities: [constant, or nothing]"
+    Temperature::Union{String,Nothing} = nothing
+        
+    "required in case of [constant]: temperature value [in Celcius in case of GEO units]"
+    cstTemp::Union{Float64,Nothing}     = nothing   
+end
+
+
+function show(io::IO, d::geom_Ellipsoid)
+    println(io, "Ellipsoid(ph=$(d.phase), axes=$(d.axes), cen=$(d.center), T=$(d.Temperature)=$(d.cstTemp))")
+    return nothing
+end
+
+"""
+    Write_LaMEM_InputFile(io, d::geom_Ellipsoid)
+"""
+function Write_LaMEM_InputFile(io, d::geom_Ellipsoid)
+    fields    = fieldnames(typeof(d))
+    println(io, "    <EllipsoidStart>")
+    for f in fields
+        if !isnothing(getfield(d,f))
+            name = rpad(String(f),15)
+            comment = get_doc(geom_Ellipsoid, f)
+            data = getfield(d,f) 
+            println(io,"        $name  = $(write_vec(data))     # $(comment)")
+        end
+    end
+    println(io, "    <EllipsoidEnd>")
+    return nothing
+end
+# -------
+
+# -------
+"""
+    LaMEM geometric primitive `Box` object 
+    
+    $(TYPEDFIELDS)
+"""
+Base.@kwdef struct geom_Box
+    "phase"
+    phase::Int64          = 1          
+     
+    "box bound coordinates: `left`, `right`, `front`, `back`, `bottom`, `top` "
+    bounds::Vector{Float64}      = [1.0 2.0 1.0 2.0 1.0 2.0]
+        
+    "optional: Temperature structure. possibilities: [constant, linear, halfspace]"
+    Temperature::Union{String,Nothing} = nothing
+        
+    "required in case of [`constant`]: temperature value [in Celcius in case of GEO units]"
+    cstTemp::Union{Float64,Nothing}     = nothing   
+
+    "required in case of [`linear,halfspace`]: temperature @ top [in Celcius in case of GEO units]"
+    topTemp::Union{Float64,Nothing}     = nothing   
+    
+    "required in case of [`linear,halfspace`]: temperature @ top [in Celcius in case of GEO units]"
+    botTemp::Union{Float64,Nothing}     = nothing   
+    
+    "required in case of [`halfspace`]: thermal age of lithosphere [in Myrs if GEO units are used]"
+    thermalAge::Union{Float64,Nothing}     = nothing   
+end
+
+function show(io::IO, d::geom_Box)
+    println(io, "Box(ph=$(d.phase), bounds=$(d.bounds), T=$(d.Temperature)=$(d.cstTemp), [top,box]=[$(d.topTemp), $(d.botTemp)], thermalAge=$(d.thermalAge))")
+    return nothing
+end
+
+"""
+    Write_LaMEM_InputFile(io, d::geom_Box)
+"""
+function Write_LaMEM_InputFile(io, d::geom_Box)
+    fields    = fieldnames(typeof(d))
+    println(io, "    <BoxStart>")
+    for f in fields
+        if !isnothing(getfield(d,f))
+            name = rpad(String(f),15)
+            comment = get_doc(geom_Box, f)
+            data = getfield(d,f) 
+            println(io,"        $name  = $(write_vec(data))     # $(comment)")
+        end
+    end
+    println(io, "    <BoxEnd>")
+    return nothing
+end
+# -------
+
+# -------
+"""
+    LaMEM geometric primitive `RidgeSeg` object 
+    
+    $(TYPEDFIELDS)
+"""
+Base.@kwdef struct geom_RidgeSeg
+    "phase"
+    phase::Int64          = 1          
+     
+    "box bound coordinates: `left`, `right`, `front`, `back`, `bottom`, `top` "
+    bounds::Vector{Float64}      = [1.0, 2.0, 1.0, 2.0, 1.0, 2.0]
+        
+    "coordinate order: left, right [can be different for oblique ridge]"
+    ridgeseg_x::Vector{Float64}      = [1.5, 1.5]
+    
+    "coordinate order: front, back [can be different for oblique ridge]"
+    ridgeseg_y::Vector{Float64}      = [1.0, 2.0]
+    
+    "initial temperature structure [ridge must be set to `halfspace_age` --> setTemp=4]"
+    Temperature::String = "halfspace_age"
+
+    "required in case of [`linear,halfspace`]: temperature @ top [in Celcius in case of GEO units]"
+    topTemp::Float64     = 0.0   
+    
+    "required in case of [`linear,halfspace`]: temperature @ top [in Celcius in case of GEO units]"
+    botTemp::Float64    = 1300.0   
+    
+    "minimum age of seafloor at ridge [in `Myr` in case of GEO units]"
+    age0::Float64     = 0.001   
+
+    "[optional] parameter that indicates the maximum thermal age of a plate "
+    maxAge::Union{Float64,Nothing}      = nothing
+
+    "[optional] parameter that indicates the spreading velocity of the plate; if not defined it uses bvel_velin specified elsewhere"
+    v_spread::Union{Float64,Nothing}    = nothing
+end
+
+function show(io::IO, d::geom_RidgeSeg)
+    println(io, "RidgeSeg(ph=$(d.phase), bounds=$(d.bounds), ridgeseg_x=$(d.ridgeseg_x),ridgeseg_y=$(d.ridgeseg_y),  T=$(d.Temperature) = [top,box]=[$(d.topTemp), $(d.botTemp)], age0=$(d.age0)), maxAge=$(d.maxAge), v_spread=$(d.v_spread))")
+    return nothing
+end
+
+"""
+    Write_LaMEM_InputFile(io, d::geom_RidgeSeg)
+"""
+function Write_LaMEM_InputFile(io, d::geom_RidgeSeg)
+    fields    = fieldnames(typeof(d))
+    println(io, "    <RidgeSegStart>")
+    for f in fields
+        if !isnothing(getfield(d,f))
+            name = rpad(String(f),15)
+            comment = get_doc(geom_RidgeSeg, f)
+            data = getfield(d,f) 
+            println(io,"        $name  = $(write_vec(data))     # $(comment)")
+        end
+    end
+    println(io, "    <RidgeSegEnd>")
+    return nothing
+end
+# -------
+
+# -------
+"""
+    LaMEM geometric primitive `Hex` object to define hexahedral elements
+    
+    $(TYPEDFIELDS)
+"""
+Base.@kwdef struct geom_Hex
+    "phase"
+    phase::Int64          = 1          
+     
+    """
+    `x`-`y`-`z` coordinates for each of 8 nodes (24 parameters)
+    (counter)-clockwise for an arbitrary face, followed by the opposite face
+    """
+    coord::Vector{Float64}      = [0.25, 0.25, 0.25,   0.5, 0.2, 0.2,   0.6, 0.7, 0.25,   0.3, 0.5, 0.3,   0.2, 0.3, 0.75,   0.6, 0.15, 0.75,   0.5, 0.6, 0.80,   0.2, 0.4, 0.75]
+end
+
+function show(io::IO, d::geom_Hex)
+    println(io, "Hex(ph=$(d.phase), coord=$(d.coord))")
+    return nothing
+end
+
+"""
+    Write_LaMEM_InputFile(io, d::geom_Hex)
+"""
+function Write_LaMEM_InputFile(io, d::geom_Hex)
+    fields    = fieldnames(typeof(d))
+    println(io, "    <HexStart>")
+    for f in fields
+        if !isnothing(getfield(d,f))
+            name = rpad(String(f),15)
+            comment = get_doc(geom_Hex, f)
+            data = getfield(d,f) 
+            println(io,"        $name  = $(write_vec(data))     # $(comment)")
+        end
+    end
+    println(io, "    <HexEnd>")
+    return nothing
+end
+# -------
+
+# -------
+"""
+    LaMEM geometric primitive `Layer` object 
+    
+    $(TYPEDFIELDS)
+"""
+Base.@kwdef struct geom_Layer
+    "phase"
+    phase::Int64          = 1          
+     
+    "top of layer"
+    top::Float64         = 5.0
+    
+    "bottom of layer"
+    bottom::Float64      = 3.0
+    
+    "optional: add a cosine perturbation on top of the interface (if 1)"
+    cosine::Union{Int64,Nothing} = nothing
+    
+    "required if cosine: wavelength in x-direction"
+    wavelength::Union{Float64,Nothing} = nothing
+
+    "required if cosine: amplitude of perturbation"
+    amplitude::Union{Float64,Nothing} = nothing
+
+    "optional: Temperature structure. possibilities: [constant, linear, halfspace]"
+    Temperature::Union{String,Nothing} = nothing
+
+    "required in case of [`constant`]: temperature value [in Celcius in case of GEO units]"
+    cstTemp::Union{Float64,Nothing}     = nothing   
+
+    "required in case of [`linear,halfspace`]: temperature @ top [in Celcius in case of GEO units]"
+    topTemp::Union{Float64,Nothing}     = nothing   
+    
+    "required in case of [`linear,halfspace`]: temperature @ top [in Celcius in case of GEO units]"
+    botTemp::Union{Float64,Nothing}     = nothing   
+    
+    "required in case of [`halfspace`]: thermal age of lithosphere [in Myrs if GEO units are used]"
+    thermalAge::Union{Float64,Nothing}  = nothing   
+end
+
+function show(io::IO, d::geom_Layer)
+    println(io, "Layer(ph=$(d.phase), bot/top=[$(d.bot),$(d.top)], T=$(d.Temperature)=$(d.cstTemp), [Ttop,Tbot]=[$(d.topTemp), $(d.botTemp)], thermalAge=$(d.thermalAge), cosine perturbation=$(d.cosine), wavelength=$(d.wavelength), amplitude=$(d.amplitude))")
+    return nothing
+end
+
+"""
+    Write_LaMEM_InputFile(io, d::geom_Layer)
+"""
+function Write_LaMEM_InputFile(io, d::geom_Layer)
+    fields    = fieldnames(typeof(d))
+    println(io, "    <LayerStart>")
+    for f in fields
+        if !isnothing(getfield(d,f))
+            name = rpad(String(f),15)
+            comment = get_doc(geom_Layer, f)
+            data = getfield(d,f) 
+            println(io,"        $name  = $(write_vec(data))     # $(comment)")
+        end
+    end
+    println(io, "    <LayerStart>")
+    return nothing
+end
+# -------
+
+# -------
+"""
+    LaMEM geometric primitive `Cylinder` object 
+    
+    $(TYPEDFIELDS)
+"""
+Base.@kwdef struct geom_Cylinder
+    "phase"
+    phase::Int64          = 1          
+     
+    "radius of cylinder "
+    radius::Float64      = 1.5
+    
+    "center of base of cylinder"
+    base::Vector{Float64}      = [1.0, 2.0, 3.0]
+    
+    "center of cap of cylinder"
+    cap::Vector{Float64}      = [3.0, 5.0, 7.0]
+    
+    "optional: Temperature structure. possibilities: [constant]"
+    Temperature::Union{String,Nothing} = nothing
+        
+    "required in case of [`constant`]: temperature value [in Celcius in case of GEO units]"
+    cstTemp::Union{Float64,Nothing}     = nothing   
+
+end
+
+function show(io::IO, d::geom_Cylinder)
+    println(io, "Cylinder(ph=$(d.phase), radius=$(d.radius) base=$(d.base), cap=$(d.cap), T=$(d.Temperature)=$(d.cstTemp) )")
+    return nothing
+end
+
+"""
+    Write_LaMEM_InputFile(io, d::geom_Cylinder)
+"""
+function Write_LaMEM_InputFile(io, d::geom_Cylinder)
+    fields    = fieldnames(typeof(d))
+    println(io, "    <CylinderStart>")
+    for f in fields
+        if !isnothing(getfield(d,f))
+            name = rpad(String(f),15)
+            comment = get_doc(geom_Cylinder, f)
+            data = getfield(d,f) 
+            println(io,"        $name  = $(write_vec(data))     # $(comment)")
+        end
+    end
+    println(io, "    <CylinderEnd>")
+    return nothing
+end
+# -------
+
 # ==========================
 
 
@@ -193,7 +519,6 @@ function Write_LaMEM_InputFile(io, d::ModelSetup)
             Write_LaMEM_InputFile(io, object)
         end
 
-        println("WARNING! Still need to implement geometric primitives!!")
     end