Instantiate() Argument error

Hey,

I want to use the Instansiate function to clone a prefab. I have a empty parent object that should emit those prefabs. But when I want to Instantiate the object, the function wants me to enter a Transform and not a Vector3. I don't understand this error because in the Documentation it says that it should work with a position and a object assigned.

 GameObject logPrefab;
 GameObject spawnObject;
 string logPath;
 Vector3 spawnPosition;


 // Use this for initialization
 void Start()
 {

     spawnObject = GameObject.Find("obstacleSpawn");

     logPath = "models/log";

     logPrefab = (GameObject)Resources.Load(logPath);
     Debug.Log(logPrefab);

     createWoodLog();

     spawnPosition = new Vector3(14, 27, 12);
     
 }

 // Update is called once per frames
 void Update()
 {

 }

 void createWoodLog()
 {
     Instantiate(logPrefab, spawnPosition);

 }

And the error

 Assets/Resources/script/SpawningScript.cs(39,9): error CS1503: Argument `#2' cannot convert `UnityEngine.Vector3' expression to type `UnityEngine.Transform'