Magento – Magento Custom Header

I create custom header in cart page like this

<checkout_cart_index> 
    <reference name="root"> 
        <block type="page/html_header" name="header" as="header">
            <action method="setTemplate"><template>page/html/cartheader.phtml</template></action> 
        </block>          
    </reference>

    <reference name="footer">
        <block type="cms/block" name="Shopping Cart" before="footer_links">
            <action method="setBlockId"><block_id>shoppingcart</block_id></action>
        </block>        
    </reference>

</checkout_cart_index>

then i see my log files it shows below error what is problem on it's

2016-05-06T05:35:51+00:00 ERR (3):
exception 'Mage_Core_Exception' with message 'Invalid block type: Mage_Page_Block_Header' in /var/www/html/domain/app/Mage.php:595
Stack trace:
#0 /var/www/html/domain/app/code/core/Mage/Core/Model/Layout.php(495):
Mage::throwException('Invalid block t…')
#1 /var/www/html/domain/app/code/core/Mage/Core/Model/Layout.php(437):
Mage_Core_Model_Layout->_getBlockInstance('page/header', Array)
#2 /var/www/html/domain/app/code/core/Mage/Core/Model/Layout.php(472):
Mage_Core_Model_Layout->createBlock('page/header', 'header')
#3 /var/www/html/domain/app/code/core/Mage/Core/Model/Layout.php(239):
Mage_Core_Model_Layout->addBlock('page/header', 'header')
#4 /var/www/html/domain/app/code/core/Mage/Core/Model/Layout.php(205):
Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element),
Object(Mage_Core_Model_Layout_Element))
#5 /var/www/html/domain/app/code/core/Mage/Core/Model/Layout.php(210):
Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /var/www/html/domain/app/code/core/Mage/Core/Controller/Varien/Action.php(344):
Mage_Core_Model_Layout->generateBlocks()
#7 /var/www/html/domain/app/code/core/Mage/Core/Controller/Varien/Action.php(269):
Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /var/www/html/domain/app/code/core/Mage/Checkout/controllers/OnepageController.php(212):
Mage_Core_Controller_Varien_Action->loadLayout()
#9 /var/www/html/domain/app/code/core/Mage/Core/Controller/Varien/Action.php(418):
Mage_Checkout_OnepageController->indexAction()
#10 /var/www/html/domain/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254):
Mage_Core_Controller_Varien_Action->dispatch('index')
#11 /var/www/html/domain/app/code/core/Mage/Core/Controller/Varien/Front.php(172):
Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#12 /var/www/html/domain/app/code/core/Mage/Core/Model/App.php(365):
Mage_Core_Controller_Varien_Front->dispatch()
#13 /var/www/html/domain/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#14 /var/www/html/domain/index.php(83): Mage::run('', 'store')
#15 {main}