dissenting.
Pennsylvania law does not favor joint tenancies, and I dissent from the determination of the Majority that the execution of an oil and gas lease did not sever a joint tenancy with *496right of survivorship (JTWROS). In arriving at its position, the Majority has overlooked the four unities that are required to create a joint tenancy and has reached a decision that is inconsistent with our case and statutory law.
“As a first principle, we must recognize that joint tenancies are not favored by the law and that a statute of the Commonwealth eliminates the survivorship feature from joint tenancies unless it is created by express words or by necessary implication.” Pennsylvania Bank and Trust Co. v. Thompson, 432 Pa. 262, 247 A.2d 771, 771 (1968); see also 68 P.S. § 110;1 In re Estate of Michael, 421 Pa. 207, 218 A.2d 338, 342 (1966) (observing that “[b]oth the [statute] and our ease law clearly indicate that joint tenancies with the incident right of survivor-ship are not deemed favorites of the law”).
Thus, in Pennsylvania, the vitality of the joint tenancy rests on the existence of the four unities of interest, title, time, and possession. In addition, there must be a specific intent to create the right of survivorship; otherwise the interest created is presumed to be a mere tenancy in common. See Sheridan v. Lucey, 395 Pa. 306, 149 A.2d 444, 445 (1959) (“[i]t is basic to the relationship of a joint tenancy that the four unities of time, title, interest and possession co-exist with the right of survivorship [and that this right is] clearly manifested by the conveyance”); see also Estate of Kotz, 486 Pa. 444, 406 A.2d 524, 532 (1979) (“joint tenants have one and the same interest, accruing by one and the same conveyance, commencing at one and the same time, and held by one and the same possession”); In re Parkhurst, 402 Pa. 527, 167 A.2d 476, 478 (1961) (“[t]he essence of title as joint tenants with the'right of *497survivorship and not as tenants in common is to vest in two or more persons joint ownerships during lifetime, with sole ownership and control passing to the survivor at the death of the other joint tenant”); In re Cochrane’s Estate, 342 Pa. 108, 20 A.2d 305, 307 (1941) (explaining that “[t]he interests of the joint tenants are equal. They own the half or part and the whole, per my et per tout. There is a unity of interest, title, time and possession”).
A joint tenancy is severed whenever one or more of the four unities are destroyed. Kotz, 406 A.2d at 531-32; Gen. Credit Co. v. Cleck, 415 Pa.Super. 338, 609 A.2d 553, 556 (1992), appeal discontinued, 531 Pa. 655, 613 A.2d 560 (1992); Riccelli v. Forcinito, 407 Pa.Super. 629, 595 A.2d 1322 (1991), appeal denied, 529 Pa. 651, 602 A.2d 861 (1992). This may be achieved “by the action, voluntary or involuntary, of either of the parties [resulting in] the parties [becoming] tenants in common.” Stanger v. Epler, 382 Pa. 411, 115 A.2d 197, 200 (1955); see also In re Larendon’s Estate, 439 Pa. 535, 266 A.2d 763, 766 (1970). “[Although a voluntary act on the part of one of the joint tenants is adequate to work a severance, that act must be of sufficient manifestation that the actor is unable to retreat from his position of creating a severance of the joint tenancy.” Sheridan, 149 A.2d at 446.
Prior to the matter sub judice, this Court had not addressed whether the execution of a lease by fewer than all of the joint tenants is sufficient to terminate the joint tenancy and to convert the interest into a tenancy in common. Pursuant to the old rule followed in England, when one of the joint tenants with a right of survivorship leased his interest to a stranger, the tenancy was severed. See W.W. Allen, “What Acts by One or More of Joint Tenants Will Sever or Terminate the Tenancy,” 64 A.L.R.2d 918 § 11 (1959), and cases cited therein. The courts in this country, however, have reached divergent opinions on this issue. The two leading authorities emerged from Maryland and California.
The Maryland courts have followed the traditional English rule. In Alexander v. Boyer, 253 Md. 511, 253 A.2d 359 (1969), the Court of Appeals of Maryland held that, where one *498joint tenant leased her interest in real property to the husband of another joint tenant, who subsequently sub-leased the property to a third party, the joint tenancy was terminated. The court reasoned that by executing a lease for a certain term, the joint tenant conveyed her rights in the land to the lessee, “thereby changing the nature of her ‘interest’ in the land from a present interest to a reversionary interest.” Id. at 365 (emphasis in original). Noting that the property was sub-leased after the initial transaction, the court also found that the joint tenant “had parted with all of her possessory rights for the term of the lease.” Id. In accordance with this analysis, the Alexander court determined that the transaction destroyed the unities of interest and possession in the joint tenancy. Id.
The state of California, however, reaches a different result. As the late Justice Stanley Mosk articulated, in writing for the Supreme Court of California in Tenhet v. Boswell, 18 Cal.3d 150, 133 Cal.Rptr. 10, 554 P.2d 330 (1976), when a joint tenant leases his interest to a third person for a term of years, and dies during that term, the lease does not sever the joint tenancy, but expires upon the death of the lessor.
The Tenhet court recognized the view expressed in Alexander. Tenhet, 133 Cal.Rptr. 10, 554 P.2d at 334 (acknowledging that “[i]t could be argued that a lease destroys the unities of interest and possession because the leasing joint tenant transfers to the lessee his present possessory interest and retains a mere reversion”). The California Supreme Court also acknowledged that it is difficult to reconcile the absolute right of survivorship — the essential element of joint tenancy — with “the possibility that the term of the lease may continue beyond the lifetime of the lessor.” Id. Conversely, Mr. Justice Mosk noted that “if the lease entered into ... by [the joint tenant] and [the lessee] is valid only during [the joint tenant’s] life, then the conveyance is more a variety of life estate pur autre vie than a term of years [which is] inconsistent with [the joint tenant’s] freedom to alienate his interest during his lifetime.” Id.
*499It appears that the disfavored treatment of joint tenancy, embodied in the statutory language of the California Civil Code, which requires express declaration of this interest “in the creating instrument,” formed the crux of the legal analysis in Tenhet. Id. at 335. The opinion reasoned that:
Inasmuch as the estate arises only upon express intent, and in many cases such intent will be the intent of the joint tenants themselves, we decline to find a severance in circumstances which do not clearly and unambiguously establish that either of the joint tenants desired to terminate the estate.
Id. at 335-36. This, in turn, led the Tenhet court to conclude that “[bjecause a joint tenancy may be created'only by express intent, and because there are alternative añd unambiguous means in altering the nature of that estate, we hold that the lease here in issue did not operate to sever the joint tenancy.” Id. at 336.
In this case, the Majority labels the leases “identical, except the Bean lease contains a type-written addition that states: ‘Should any question of property ownership or royalty dispursements [sic] arise, the Lessor has agreed to accept full responsibility.’ ” Majority Opinion at 489, 905 A.2d at 479. I believe that the term “identical except” is an oxymoron, serving as a red flag to warn that what is purported to be “identical” is actually different. The situation before us is a good example.
In finding the lease identical, the Majority was constrained to overlook, or rationalize away, the reality that the leases are not the same. The Majority acknowledges that unlike the document executed by Robert Quick, the agreement signed by Robert Bean contained a typewritten addition encumbering him with full liability for any dispute relating to property ownership or royalty payments. Further, the leases were not signed on the same day; instead, they were signed three months apart. This leads me to conclude that the leases were separate from each other and, as a result, failed to meet the essence of a JTWROS, which is four unities: interest, title, time, and possession. Gen. Credit Co. v. Cleck, 415 Pa.Super. 338, 609 A.2d 553, 556 (1992).
*500The Majority is dismissive of these differences, to the detriment of the required unities of interest and possession. Although it recognizes that the Bean lease contained an additional clause not found in the Quick lease, the Majority concludes that what that clause means “is anyone’s guess, but there is no reason to guess that it had anything to do with the way Bean wanted to hold title. The extra clause is so vague and ambiguous as to be meaningless, and is no basis for finding the leases are really different at all....” Majority Opinion at 494, 905 A.2d at 476 (emphasis added). I find the reasoning of the Majority to be internally inconsistent and curious, at best. First, the Majority states that it is impossible to discern what the clause means; nevertheless, despite this impossibility of interpretation, the Majority concludes that the clause cannot have “anything to do with the way Bean wanted to hold title.” Id. Next, the Majority finds that the additional clause, which could mean anything or nothing, is “so vague and ambiguous as to be meaningless.” Finally, the Majority posits that the impossibility of interpreting the clause means that the two leases are not “really different.”
In my opinion, the clause imposes a substantive obligation on Bean that is neither meaningless nor vague. Although the language could have been crafted more artfully, the fact is that the Bean lease includes a: substantive obligation that the Quick lease does not. The lease is different because of the additional clause, and the Majority merely speculates that it is “meaningless” in order to reach its preordained conclusion that the difference is of no import. The terms of the obligation contained in the clause encumbered Bean with full liability for any dispute relating to property ownership or royalty payments. This disparity, rather than being meaningless, plainly involves important legal obligations.
Likewise, I can not reconcile the fact that the leases were signed three months apart with the Majority’s view that the separate signings were “not legally significant.” Majority Opinion at 493, 905 A.2d at 476. Again, the Majority seeks to minimize this difference by surveying the changes in technology that have occurred since 1979, when fax machines, over*501night mail delivery, and teleconferencing were not used as they are today. While I recognize that it may have been more difficult to effectuate simultaneous signings by parties in the 1970s, it was not impossible. The fact is that the leases were signed on different dates, violating the unity in time requirement for a JTWROS.
The Majority correctly notes that “[i]ntent is equally as significant when addressing a severance of a JTWROS as it is when considering whether a JTWROS was created.” Majority Opinion at 492, 905 A.2d at 475. It further acknowledges that “[a] joint tenancy is severed when one of more of the four unities is destroyed.” Id. (citation omitted). The Majority then proceeds to analyze the intent of the parties in executing the leases and notes that the record does not contain evidence demonstrating that the parties intended to destroy the joint tenancy. While the record was silent with respect to evidence indicating the parties’ intent to sever the tenancy, the Majority fills in the gap by surmising that “the parties may very well have intended to execute the leases contemporaneously.” Id. at 6, 609 A.2d 553.
I find this reasoning flawed, given that the Majority has merely speculated that the parties did not intend to sever the JTWROS, a supposition that is contradicted by fact that the leases were not executed contemporaneously and that one lease contained a substantive term encompassing an obligation that the other one did not. Conjecture by the Majority that the parties did not intend to sever the tenancy does not trump the fact that the parties signed leases that were not identical three months apart.
Essentially, I find that it is necessary to make the same determination as the Tenhet court — both solutions to the question that we are facing are reasonable. Although the obvious flexibility of the Tenhet approach is appealing, this area of the law, with its multiple nuances and factual scenarios, as vividly demonstrated by this case, requires a plain directive and guidance understandable by all citizens of this Commonwealth, who will be affected by our decision, and by our courts that will ultimately be tasked with applying it. *502Therefore, in my opinion, the bright-line rule espoused by Alexander that the signing of a lease for a number of years by one of the joint tenants to a third party severs the joint tenancy is the better option.2
The rule that I would adopt today is consistent with the way this Court has previously addressed execution of mortgages by joint tenants with right of survivorship. In Kotz, supra, we determined that, where all joint tenants execute a mortgage for the purchase price of the jointly held property, the unities have not been disturbed and, accordingly, the possessory interest of the joint tenants remains intact. Kotz, 406 A.2d at 531-32. On the other hand, this Court has also found that the execution of a mortgage on the joint tenancy property by fewer than all of the joint tenants severs the joint tenancy. Simpson v. Ammons, 1 Binn. 175 (Pa.1806). Just as with the mortgage in Simpson, in our case, the lease was executed by fewer than all of the joint tenants who held the property. Therefore, finding that such a transaction severs joint tenancy promotes harmony with our earlier pronouncement in Simpson.
Having concluded that a lease executed by fewer than all of the joint tenants in fact severs a joint tenancy with right of survivorship, it is necessary to consider whether the same rule would apply to the execution of an “oil and gas” lease. In other words, is there something so atypical about an “oil and gas” lease that would require a different result given the present circumstances? I conclude that there is no material difference in this respect.
Admittedly, this Court has recognized the peculiar nature of the “oil and gas” leaseholds. “Owing to the marked differences in the nature of oil and gas and solid minerals such as coal, the rights of lessees in the respective minerals are not the same.... They bear scarcely any resemblance to a house *503or farm lease and they resemble only in part leases for solid minerals such as coal.” Appeal of Baird, 334 Pa. 410, 6 A.2d 306, 311 (1939) (per curiam); see also Kleppner v. Lemon, 176 Pa. 502, 35 A. 109, 109 (1896) (“[t]he nature of oil and gas, the pressure of the superincumbent rocks, and the vagrant habit of both fluids under the influence of this pressure, enter into the contemplation of both parties to such an agreement”).
Gas, it is true, is a mineral; but it is a mineral with peculiar attributes, which require the application of precedents arising out of ordinary mineral rights, with much more careful consideration of the principles involved than of the mere decisions.... Water and oil, and still more strongly gas, may be classed by themselves, if the analogy be not too fanciful, as minerals feroe nature. In common with animals, and unlike other minerals, they have the power and the tendency to escape without the volition of the owner.... They belong to the owner of the land, and are part of it, so long as they are on or in it, and are subject to his control; but when then escape, and go into other land, or come under another’s control, the title of the former owner is gone. Possession of the land, therefore, is not necessarily possession of the gas. If an adjoining, or even a distant, owner, drills his own land, and taps your gas, so that it comes into his well and under his control, it is no longer yours, but his.
Westmoreland & Cambria Nat. Gas Co. v. DeWitt, 130 Pa. 235, 18 A. 724, 725 (1889); see also Hague v. Wheeler, 157 Pa. 324, 27 A. 714, 719 (1893) (“it is said that the oil and gas are unlike the solid minerals, since they may move through the interstitial spaces or crevices in the sand rocks in search of an opening through which they may escape from the pressure to which they are subject”).
Nonetheless, despite the unique, fugacious nature of oil and gas, “oil and gas” leases are treated in the same manner as other documents purporting to convey property interests:
It is, of course, true that there is a distinction, upon questions of interpretation, between an oil and gas lease and an agricultural and even a coal lease ... the reason being *504that leases, like all other instruments relating to a particular business, must always be construed with due regard to the known characteristics of the business ... but there is no difference between them as respects the interest or estate conveyed ... and ... as to the owner in fee and his grantees, their dominion is, upon general principles, as absolute over the fluid as over the solid minerals. It is exercised in the same manner and with the same results.
Hamilton et al. v. Foster, 272 Pa. 95, 116 A. 50, 52 (1922) (internal citations and quotations omitted); see also Prager’s Estate, 74 Pa.Super. 592, 595 (1920) (“[wjhile owing to the migratory or fugacious character of oil and gas there are certain distinctions existing between them and fixed minerals, there is no difference as respects the interest or estate conveyed by [a will]”).
In the case before us, I see no difference between an “oil and gas” lease and a “run-of-the-mill” leasehold. In both instances, the lessee obtains the right to present enjoyment and utilization of the property for a predetermined period of time. Ultimately, applying the rule I propose today to the facts of this case, I find that by executing a lease in favor of Gerrie, Robert Bean irrevocably altered the nature of his interest in the land, changing from a present interest to a reversionary interest, thus destroying the unities of interest and possession and terminating the joint tenancy. The unity of time was destroyed by the three-month gap between the parties’ signing of the leases. Thus, after Robert Bean leased his interest to Gerrie, both Robert Bean and Robert Quick owned undivided one-half interests in the property as tenants in common. Following his death in 1981, the interest of Robert Quick did not revert to Robert Bean, but remained an asset in his estate.
Conclusion
• Accordingly, for all of the above reasons, I would reverse the Opinion and Order of the Superior Court.
. In relevant part, this statute provides as follows:
If partition be not made between joint tenants, whether they be such as might have been compelled to make partition or not, or of whatever kind the estates or thing holden or possessed be, the parts of those who die first shall not accrue to the survivors, but shall descend or pass by devise, and shall be subject to debts, charges, curtesy or dower, or transmissible to executors or administrators, and be considered to every other intent and purpose in the same manner as if such deceased joint tenants had been tenants in common ....
68 P.S. §110.
. We recognize that this rule may prevent the fairest results in specific cases. However, it will also provide the needed predictability in the way future disputes would be resolved, which will ultimately serve to ensure justice by forestalling the contextual, intent-oriented decision-making that the analysis of this issue could become should we adopt the other approach.